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The Philosophy Book Big Ideas Simply Expl - Will Buckingham

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Matheus Puppe

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Here is a summary of the key ideas in the extracts:

  • According to Socrates and Plato, the unexamined life is not worth living and truth resides in the world around us.

  • Philosophers such as Laozi, Siddhartha Gautama and Confucius emphasized living in harmony with nature, overcoming the ego and holding sincerity as a first principle.

  • Thales believed everything is made of water. Pythagoras proposed that number rules forms and ideas.

  • Epicurus argued that death is nothing to us. Diogenes advocated contentment with little. Zeno encouraged living in agreement with nature.

  • Key medieval ideas include: the soul is distinct from the body (Avicenna); God foresees our actions (Boethius); we can know God through reason (Anselm); philosophy and religion are compatible (Averroes).

  • Aquinas said the universe has not always existed. Cusanus said God is the not-other.

  • In the Renaissance, Montaigne said fame and tranquillity cannot coexist. Bacon promoted knowledge as power.

  • The Enlightenment saw key ideas from Voltaire (doubt), Hume (custom as guide), Rousseau (man born free), Smith (man as bargaining animal).

  • Revolution-era ideas include: man as machine (Hobbes); I think therefore I am (Descartes); imagination decides all (Pascal); God as cause of all (Spinoza); knowledge limited to experience (Locke).

  • 19th-century thinkers explored: two kinds of truth (Leibniz); mind has no gender (Wollstonecraft); happiness for most (Bentham); theology as anthropology (Feuerbach); individual sovereignty (Mill); anxiety as freedom (Kierkegaard); class struggle (Marx).

  • Key modern ideas include: will to power (Nietzsche); what we do matters (James); life as series of collisions (Ortega y Gasset); limits of language are thought’s limits (Wittgenstein).

In summary, the extracts point to key ideas that have shaped Western philosophy regarding metaphysics, ethics, society, politics, knowledge, and the human condition. A major theme is humanity’s relationship with existence, knowledge and meaning.

that allows us to determine whether

perfectly logical arguments. Other

but because they realized that

  • Philosophy seeks to explore fundamental questions about existence, knowledge, reason, and ethics through logical argument and discussion.

an argument is valid or not by

philosophers developed reasoning

beneath these concepts lay issues

  • Early philosophers were driven by wonder about the natural world and sought rational rather than mythical explanations. They asked questions such as “What is the universe made of?” and “How do we acquire knowledge?”

applying certain principles. The

to solve specific problems; Aristotle,

deserving of philosophical analysis.

  • Philosophical thinking relies on logical reasoning and debates ideas and arguments. Logic provides the tools for constructing valid arguments and ensuring beliefs have justification.

most influential system of logic was

for example, invented his syllogistic

Inevitably, these speculative ideas

  • Metaphysics considers profound questions about existence, consciousness, free will, morality, and aesthetics. Epistemology examines what we can know and how we can know it.

devised by Aristotle. The principles

reasoning to determine the validity

led to reflections on human conduct

  • Language and concepts shape how we think and understand the world. Analyzing language and conceptual frameworks is key to philosophy.

he established were refined over

of logical propositions.

and purpose. Questions arose such

  • Ethics explores how we should live and what constitutes right and wrong. Different ethical theories provide frameworks for moral reasoning.

many centuries into the system that

Language itself has long been

as “How should we live?”; “What

  • There are many branches of philosophy, including political philosophy, philosophy of science, philosophy of mind, and aesthetics.

today forms the basis for logical and

a philosophical subject of study.

makes for a just or virtuous life?”;

  • Philosophy is an ongoing, open-ended enterprise. New ideas emerge through discussion and debate, challenging and building on what came before.

mathematical reasoning. However,

Philosophers recognize that

and “What are our moral duties to

some arguments that seemed

language shapes thought, and that

others?” This led to the branch of

logically sound were found to lead to

in analyzing the way we use and

philosophy called ethics, which is

false conclusions or contradictions.

understand various concepts and

concerned with right and wrong

expressions, we gain insight into

behavior and moral reasoning.

Language is the

assumptions and preconceptions

foundation of reason.

that would otherwise remain

Reason branches out

unexamined. Debates around the

From these initial preoccupations

meanings and proper usages of

with existence, knowledge,

words provoke philosophical

reasoning, and ethics, philosophy

analysis. Philosophers ask questions

has branched out into many other

such as “What is truth?” not simply

areas. As human knowledge and

to find a definition, but to uncover

society have become more complex,

the deeper issues that the concept

philosophers have turned their

embodies. The ideas we express

attention to more specific areas of

through language shape how we

study. Fields such as the philosophy

understand the world.

of science, philosophy of mind,

Johann Gottlieb Fichte

These paradoxes showed that logic is a tool that needs to be wielded with care and understanding.

The origins of ethics The discussions around metaphysics and epistemology inevitably led to questions about concepts that were fundamental to human thinking and purpose. Philosophers asked “What is

political philosophy, philosophy of art (aesthetics), and philosophy of religion have emerged. Yet all remain connected through


their reliance on the kinds of

is informed by and depends upon

not just on recognizing and

Questions arise that the existing

fundamental reasoning that gave

what came before. New ideas are

contemplating great ideas—it

system hasn’t answered adequately.

rise to philosophy in the first place.

put forward and assessed, accepted

depends on participation. We all

What we accept as knowledge

or rejected, built upon or replaced,

have a part to play in exploring

can be challenged. Moral views

An ongoing enterprise

but always in reference to the

life’s mysteries and seeking to

that seemed unassailable prove

Philosophy is not a subject that

existing body of work that forms

expand human understanding.

to have counterarguments. For

progresses in a linear fashion,

the ongoing discourse of ideas

with each new theory replacing

that is philosophy.

Philosophy is collaborative rather

So philosophy continues as an

than competitive, cumulative

open-ended discussion that is as

the old. Although science builds

Philosophy belongs to

rather than striving to prevail over

much about exploring new lines of

on previous findings and aims

everyone. It is not the preserve

opposing arguments. Like science,

thought as it is about finding fixed

at a steady accumulation of

of academics in ivory towers;

its progress depends on each new

and final answers. There is always

knowledge, philosophy does not

generation assessing ideas

work toward definitive answers

afresh, questioning assumptions,

or an ultimate conclusion. Each

raising new objections or

philosopher’s vision is his own,

developing new perspectives.

although it is always in relation

Progress occurs through this

to the ideas of others. The subject

open and critical engagement

is open-ended and self-renewing.

with ideas, not by adhering

Each thinker’s contribution builds

rigidly to any particular system

on that of previous philosophers,

of thought. Philosophy depends

rather than aiming to replace it

And since no society can stand still, since all societies are involved in an endless process of change, philosophical systems cannot remain static. They must develop and grow or else philosophic thought will die.

Morris R. Cohen

with something entirely new.

Philosophy is about exploring the ideas and beliefs that shape our thought. Although there are perennial questions, philosophy progresses through successive generations engaging critically yet openly with these questions. Understanding the major branches of philosophy—metaphysics, epistemology, ethics, logic, and aesthetics—provides insight into humanity’s deepest concerns and a framework for thinking about life’s most profound mysteries. This book provides an overview of how philosophical thought has developed and the most influential thinkers and schools of philosophy. My hope is that it will inspire readers to contribute their own thinking to philosophy’s ongoing and open-ended discussion. Philosophy belongs to all of us.

Yet science also owes philosophy

their lines of reasoning, but also

a debt for ideas that shaped the

learn from how they construct

  • Philosophy began as a way to analyze arguments and explore concepts, but developed into a field of study exploring how to live well, knowledge, beauty, society, and religion.

scientific theories of such figures as

these arguments. Reading the

Darwin, Newton, and Einstein. Many

originals does take time and effort

  • Philosophy is closely connected to science and math. While logic seems precise, philosophy deals with ambiguous language. Philosophers clarify language and meanings.

philosophers have applied logical

though, so this guide is designed to

reasoning to scientific knowledge,

provide a quick introduction to the

  • Philosophy examines individual lives (ethics), society (political philosophy), and religion. Eastern and Western philosophy differ in their relationships to religion and starting points.

and this philosophical analysis of

key ideas of the greatest thinkers.

science in turn feeds back into the

It gives you an insight into the roots

  • Philosophical ideas form systems of thought with interconnections. Ideas come from analyzing others’ work. Philosophers’ views on knowledge lead to views on reality, ethics, society, and ideal lives.

development of scientific theory

of their philosophies and an

and methods.

understanding of how profoundly

  • Philosophical ideas spread influence and some spawned scientific, political or artistic movements. Philosophy and science inform each other. Philosophers analyze science, influencing science.

Of course, philosophers can

their ideas have shaped the world.

  • Philosophical ideas seem simple but end paradoxically. They call into question assumptions and make us think in new ways. Some were first of their kind. They still matter, though conclusions differ or were disproven.

Here is a summary of Thales’ reasoning and conclusions:

This Milesian philosopher was probably influenced by ancient Egyptian monism and Eastern mystical ideas, but he broke from traditional theocratic and mythological explanations of natural phenomena. Instead, Thales sought rational and naturalistic explanations based on observation and reasoning.

Thales proposed that the underlying substance of the world was water—all things arise from and return to water. He observed that water can transform into a solid (ice), a liquid (the sea), and a gas (vapor), so it seemed the logical choice as the primal substance. His hypothesis was an early example of the attempt to find unity in diversity.

Thales was also practically-minded. He is said to

Greece, who became increasingly interested in natural explanations of the world, directed their questions away from the gods and toward the workings of nature itself. Thales studied nature intensively and rationally explained many things, such as the flooding of the Nile River, without resorting to mythology. His proposed underlying substance, water, though an oversimplification, was a seminal example of early scientific reasoning.

Here is a summary of the key ideas associated with Pythagoras:

• Pythagoras believed that number is the underlying principle of the cosmos. The relationships between numbers are the basis of harmony and order in the universe.

• Pythagoras saw the cosmos as governed by harmonious pairs of opposites, such as light-dark, male-female, and odd-even. The union of opposites produces harmony.

• The Pythagoreans explored the relationships between numbers and geometry. They saw nature as shaped by archetypal geometric forms and proportions.

• Pythagoras believed in the transmigration of souls and in reincarnation until the soul reaches a state of purity. He taught strict moral and bodily discipline to facilitate this purification.

• The Pythagoreans were a religious brotherhood who followed a mystical way of life. They studied mathematics, music, astronomy, and philosophy as a path to wisdom and union with the divine.

• Key Pythagorean contributions include discoveries in mathematics, music, and astronomy. Their insights influenced later philosophers such as Plato. However, little is known about Pythagoras himself and many of the ideas attributed to him likely came from his followers.

• The Pythagorean belief in number as the essence of all things and in the harmony of the cosmos influenced Western thought for centuries. But their mystical approach was critiqued by rational philosophers such as Heraclitus.

• Key Pythagorean concepts include the harmony of the spheres, the tetractys (a triangular symbol), and the idea that “all is number.” But Pythagoras left no writings, so his teachings are hard to determine with certainty.

Does this help summarize the key ideas associated with Pythagoras and the Pythagoreans? Let me know if you would like me to explain anything in more detail.

• Pythagoras lived in ancient Greece in the 6th century BCE. Little is known about his life, but he founded a religious cult and philosophical school in Croton, southern Italy.

• Pythagoras was influenced by earlier Greek philosophers known as the Milesian School, who sought rational explanations for natural phenomena. Like them, Pythagoras approached philosophy and mathematics scientifically. However, he also held mystical and religious beliefs.

• Pythagoras believed that mathematics, especially geometry and the relationships between numbers, revealed the structure of the universe. He saw the cosmos as fundamentally mathematical and harmonious. His famous theorem showed that in a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the other two sides.

• Pythagoras proposed that the same harmonic ratios that govern musical intervals also govern the stars, planets and chemical elements. This “music of the spheres” demonstrated the harmony in the cosmos. His ideas influenced later astronomy, mathematics and chemistry.

• Pythagoras advocated deductive reasoning, starting from axioms to reach new conclusions. This approach was refined by Euclid and influenced later philosophy. Pythagoras also believed that abstract thinking and reason were superior to sensory evidence, an idea developed by Plato.

• Pythagoras and his followers attributed mystical significance to numbers and geometric shapes. They saw numbers as the essence of all things, giving rise to the dimensions of the physical world. Though bizarre by today’s standards, these ideas demonstrated the Pythagoreans’ belief in the power of mathematics.

• Pythagoras’s ideas have had a profound and lasting influence on Western thought, though his life remains largely shrouded in mystery. His thought represents an early attempt to combine rationalism and mysticism.

Here is a summary of Siddhartha Gautama and Buddhism:

  • Siddhartha Gautama, later known as the Buddha, lived in India in the 6th century BCE. He was born into a life of luxury but was dissatisfied and left his privileged life to find spiritual enlightenment.

  • After trying extremes of sensual indulgence and asceticism, Gautama found the “middle way” - a balanced path that led to enlightenment. He gained enlightenment while meditating under a bodhi tree.

  • Gautama taught that suffering is universal and caused by desire and attachment. One can end suffering by freeing oneself from desire and ego. The “not-self” refers to the idea that there is no permanent self or soul. All things are impermanent and interdependent.

  • Gautama’s teachings are summarized in the Four Noble Truths: 1) Suffering exists; 2) Suffering is caused by desire; 3) Suffering can end; 4) The Eightfold Path can end suffering. The Eightfold Path is a practical guide to enlightenment and an ethical way of living.

  • The ultimate goal in Buddhism is Nirvana - release from suffering and the cycle of rebirth. Nirvana is a state of enlightenment and oneness with the eternal “not-self”.

  • Gautama’s teachings spread throughout India and Asia, eventually being written down 400 years after his death. Different schools of Buddhism evolved in different regions. Buddhism had little influence on Western philosophy until the 20th century.

  • Gautama’s philosophy emphasizes reasoning and experience. He taught that one can achieve enlightenment through one’s own efforts, not through divine grace. However, Gautama is revered as the Buddha - the enlightened one.

That covers the basic ideas in Siddhartha Gautama’s life, teachings, and the development of Buddhism. Let me know if you would like me to explain anything in the summary in more detail.

Confucius taught an ethical system based on traditional Chinese values such as loyalty, filial piety, ritual propriety, and reciprocity. He believed virtue and moral authority were achieved through merit and cultivated behavior, not inherited or god-given. The main source of Confucius’ teachings is the Analects, a collection of his sayings compiled by disciples. In it, he argues that leaders should rule with benevolence and by virtuous example. Individuals should know their place in a hierarchy of relationships - as ruler-subject, parent-child, husband-wife, elder-younger - and observe the proper ritual proprieties. Sincerity is key. By performing rituals with sincerity, virtue becomes visible to others. Individuals are transformed, and society improved.

afford a fee. His most famous

dictatorship of relativism.”

pickings to be made. The law courts

doctrine is that “man is the

were busy, but anyone who was

measure of all things”, meaning

Protagoras came to Athens from Thrace. He was one of the first professional philosophers (known as “Sophists”) who taught rhetoric and practical subjects for money.

Protagoras argued for relativism - the idea that knowledge and truth depend on perspective. He believed that contradictory perspectives could both be true depending on the viewpoints of those holding them.

His most famous statement is “Man is the measure of all things” - meaning that humanity is the source of all value judgments about what is true or good. Truth and morality are relative and depend on individual and cultural beliefs.

Protagoras challenged the notion of absolute and universal truths. His relativism and subjectivism were opposed to the absolutism of philosophers like Parmenides. Protagoras emphasized practical “skills” like rhetoric over abstract reasoning. He reflected the secularism and individualism that were emerging in Athenian democracy.

Here is a summary of key points about Socrates:

• Socrates wrote nothing himself, but his method of questioning and reasoning, known as the dialectical method, influenced subsequent Western philosophy.

• He persistently asked questions about ethics and morality in order to examine commonly held beliefs and determine the truth.

• He believed that “the unexamined life is not worth living” and that we must reason for ourselves to gain knowledge and wisdom.

• He believed in absolute moral truths that could be determined through reasoning. He rejected moral relativism.

• He was convicted for corrupting the youth of Athens and sentenced to death. His student Plato portrays him as a martyr for philosophy in his Apology.

• Although Socrates proposed no theories himself, his method of questioning and reasoning, and his belief in absolute moral truths, influenced subsequent philosophers like Plato and Aristotle.

• He believed that the only life worth living is a good and virtuous life, achieved through reasoning and knowledge. Virtue is the highest aim of human existence.

• He saw philosophy as a means to gain self-knowledge and become a better person. The quest for truth and virtue was his guiding motivation.

• He believed the soul or psyche is the true self, not the physical body. The soul can be purified through philosophy.

• He believed we can come to objective moral knowledge through a process of questioning commonly held beliefs and opinions. True knowledge comes from within, not from the senses.

Does this summary accurately reflect Socrates and his philosophical views? Let me know if you would like me to clarify or expand on any part of the summary.

Here is a summary of Plato’s theory of knowledge:

• Plato believed that knowledge is not gained through the senses, but through reason. True knowledge comes from innate ideas that exist in the mind.

• There is an immaterial realm of Ideas, or Forms, that represent perfect archetypes of the objects and concepts in the material world. These Ideas provide the patterns for the imperfect objects we perceive with our senses.

• We are born with a basic knowledge of the Ideas, which allows us to recognize the material world. When we see an object, like a dog, we recognize it because we have a concept of the archetypal “Idea of Dog” in our mind.

• The material world is an imperfect shadow of the world of Ideas. Objects are in a constant state of change, but the Ideas are eternal and unchanging. True knowledge comes from understanding the Ideas, not the material world.

• Reason allows us to recollect our knowledge of the Ideas. Dialectic, the process of philosophical debate and logical argument, helps in recollecting the Ideas.

• Plato believed the world of Ideas provides the only true reality, while the material world is illusory and deceiving. True philosophers aim to understand the world of Ideas, not the shadows of the material world.

• Plato founded his Academy to teach philosophy and enable others to discover the nature of the Ideas through dialogue and reason. His works, including The Republic and Symposium, explore his theory of knowledge and other philosophical concepts.

That covers the essence of Plato’s theory of knowledge, including his concepts of the Forms, innate ideas, the difference between the world of Ideas and the material world, and the methods for gaining true knowledge. Let me know if you would like me to explain anything in the summary in more detail.

• Primarily, Plato’s concerns were similar to those of his mentor, Socrates: to search for definitions of abstract moral values and refute relativism.

• In the Republic, Plato described his vision of an ideal just society and explored virtue. But he also discussed knowledge, reality, and politics.

• Plato argued that to understand virtue or any concept, we must first grasp its essence or “Form”. There are ideal Forms of everything, like perfect triangles, that exist in a transcendent realm of Ideas.

• We can only access this realm through reason, not our senses. The material world is an imperfect reflection of the world of Ideas.

• Plato argued that we innately know the Forms, though we may not realize it. Our immortal souls perceived the Forms before birth. Learning is recollection.

• Philosophers, who comprehend the Forms, should rule in Plato’s ideal society. But most people focus on the material world, like prisoners seeing only shadows in Plato’s allegory of the cave.

• Plato profoundly influenced Western thought. His theory of Forms and focus on reason and knowledge shaped rationalism and idealism. Though Aristotle disagreed with him, Plato inspired generations of thinkers.

• Aristotle studied under Plato at the Academy in Athens, but disagreed with Plato’s theory of Forms.

• Unlike Plato, Aristotle believed that universal truths could be found in the natural world, not in an abstract realm. He thought we gain knowledge through experience and observing the world around us.

• Aristotle studied the natural sciences, especially biology. He collected and classified specimens, creating the first comprehensive system of biological taxonomy.

• Aristotle’s classification system was hierarchical, dividing the natural world into living vs. nonliving things, then plants vs. animals. He believed we recognize these differences through the shared characteristics of each category.

• Aristotle applied the same approach to abstract concepts like virtue, justice, and goodness. He thought we have no innate ideas and gain knowledge of universals through experience.

• Aristotle’s empiricist epistemology influenced later philosophers like Locke, Berkeley, and Hume. His approach differed from the rationalism of philosophers like Descartes, Leibniz, and Kant.

• Aristotle made significant contributions to many fields of knowledge, including physics, logic, metaphysics, ethics, politics, and poetics, in addition to biology. His works shaped the development of these disciplines.

Nicomachus, the court physician

philosophical school in a

to the Macedonian royal family.

gymnasium. According to legend

  • Aristotle’s approach was empirical and logical. He observed the world, classified natural

Aristotle was a student of Plato at

he lectured while walking with

phenomena, and used reasoning and logical syllogisms.

Plato’s Academy, remaining there

his students—“Peripatetics”

  • He rejected Plato’s theory of Forms, instead focusing on the characteristics and purposes of

for 20 years. In 341 BCE he left

meaning “walkers about”).

existing things. He believed we can understand universal concepts like justice by observing

Athens to tutor Alexander, son of

Their range of subjects was

King Philip II of Macedon. After

encyclopaedic—physics, biology,

  • Aristotle pioneered the study of biology and classified animals based on their characteristics.

Philip’s death he returned to

ethics, politics, rhetoric,

He proposed four causes to explain change in nature: material, formal, efficient, and final.

Athens and founded his own school.

metaphysics, logic, and more.

how they manifest in the world.

  • Aristotle’s logic and model of deductive reasoning with syllogisms was influential for centuries.

Aristotle died in 322 BCE, aged 62.

  • His philosophy and science dominated Western thought for centuries but declined after his death. His works were preserved and spread through the Islamic world, influencing scholars like Avicenna. In Europe, his works were reintroduced in the Middle Ages and influenced thinkers like Thomas Aquinas. His thought shaped fields from logic to biology to ethics.

and Seneca the Younger writes

• Zeno of Citium founded the philosophical school of Stoicism.

benefits whenever they appear, he

about Stoic ethics.

• He was influenced by the Cynic Diogenes, who advocated an ascetic life lived

must accept whatever it brings. As a

in accord with nature. • Zeno believed that the cosmos was governed by the laws of a “supreme

consequence, the goal of life is to

lawgiver” and that humans have no power to change this.

live in harmony with nature by being completely rational, maintain self-

• According to Zeno, a good life meant living in harmony with nature by being rational, self-controlled, and indifferent to pleasure or pain, poverty or riches. • Stoicism appealed widely in ancient Greece and Rome, influencing ethics and politics.

Key works

Posts (a collection of short

sayings), now lost but recorded by later Stoic writers.







EPICTETUS (C.50/55–C.135 CE)



Stoicism, established


by Zeno of Citium in the

• Desire and aversion are the main causes of unhappiness; both are the result of “false judgments” that lead us to want what is not

3rd century BCE, endured


for nearly 500 years. It found


strong, lasting expression in the

c.300 BCE Zeno of Citium

within our control and dislike what is inevitable.

work of Epictetus. Though he

founds Stoicism, advocating

wrote no books, his teachings

indifference to pleasure and

were preserved by his pupil

pain, and life in accord with

• The only things that are within our control are our opinions, judgments, choices, and actions. All else lies outside of our control in what Epictetus

Arrian in The Discourses and the

nature and reason.

calls the “external sphere”—our bodies, property, reputation, and relationships.

Enchiridion (Handbook).

• The key to happiness is recognizing what is and is not within our control, and accepting what is out of our hands. Desire and aversion should be

Epictetus was born a slave, but

c.40–45 CE The Roman

attained his freedom in Rome,

statesman Seneca expounds

limited only to what is under our control—our choices and judgments. Everything else should be met with indifference.

possibly thanks to his Stoic

Stoic principles.

education. He was sent into exile

• Our actions should be guided by virtue—courage, justice, temperance, and wisdom. Virtue is the only true good; all else is indifferent.

in 93 CE and lived in Nicopolis in


northwestern Greece, where he

c.160 CE The Stoic

founded his own school.

philosopher Marcus

• Freedom and happiness lie in understanding what we can control, and not worrying about what we cannot. We should aim not for what pleases us, but

Aurelius’s Meditations

for what benefits us and accords with nature and reason. This is achieved through wisdom, judgment, self-discipline, and virtuous action.

Epictetus taught that through

expresses key Stoic ideas.

philosophy, individuals could attain inner peace by living

Key works

according to Stoic principles. His

The Discourses,

main ideas include:

Enchiridion (The Handbook)

Augustine believes that God did not create evil, because evil is simply the absence of good. God created the world and everything in it, including rational beings such as humans.

earthquakes, and other disasters

To be rational, humans must have free will, which means the ability to choose good or evil.

As for moral evils, Augustine argues

“natural evils” assumes that they

God gave humans free will, so they can act well or badly. This is why God left open the possibility of

that they occur because of the

are unavoidable and parts of the

Adam choosing evil in the Garden of Eden.

abuse of free will. God created the

natural order, like evil arising from

first humans with a capacity for

human choices. But God as creator

Augustine argued that God allows evil to exist so that the good can be better appreciated, just

goodness, but they chose evil

of that order is still responsible

as shadows or dark patches can enhance a painting or harmony in music. Augustine believed

instead. Although God foresaw that

for allowing them. Again, there

this was the best of all possible worlds that included free, rational beings. His explanation is

they would make this choice, he

are answers, but none wholly

meant to solve the problem of how an all-powerful, all-good God can exist when there is evil

still created them, because even

satisfactory. Augustine’s approach

a world with moral evil in it,

remains the starting point for

in the world.

allowing rational creatures the

most Christian philosophers, but

So, in summary, Augustine argued:

freedom to choose evil, was better

the problems it addresses remain

than a world with no moral evil but

deep and complex. ■

• Evil is the absence of good, not a thing in itself. God did not create evil.

also no free, rational creatures.

• God gave humans free will, which allows for the possibility of evil. This is better than a world with no free, rational beings. • God allows evil to exist so that good can be better appreciated. This is the best possible world that includes free, rational beings. • Augustine’s explanation aims to solve the problem of evil for Christians who believe in an all-powerful, all-good God.

Augustine also suggests that a world containing a mixture of good and evil is a more perfect creation than one containing only good. The good, he argues, is enhanced and made more lovely by contrast with its opposite. A world with some evil in it may be the best that

Here is a summary of key points from the passage:

  • Avicenna was a Persian philosopher who lived from 980 to 1037 CE.

  • He was heavily influenced by Aristotle and saw himself as an Aristotelian philosopher. However, he adapted and synthesized Aristotle’s ideas in his own philosophy.

  • Avicenna argued for mind-body dualism, the view that the mind and the body are separate substances. He gave several arguments for this view, including that we would still be aware of our self even if we were sense-deprived and unaware of our body.

  • Avicenna’s dualism was a departure from Aristotle, who saw the mind as the “form” of the body. Avicenna believed the soul could survive after the death of the body, unlike Aristotle.

  • Avicenna was a polymath who also made significant contributions to medicine. He lived his life in service of various rulers, working as both a physician and political advisor.

  • Avicenna helped establish the canon of Greek-inspired philosophy in the Islamic world that would influence later philosophers in Europe. He is considered one of the most important philosophers in the Arabic tradition and in the history of philosophy in general.

Here is a summary of Anselm’s Ontological Argument:

  1. Even a fool understands the definition of “God” as the greatest being that can be conceived.

  2. God exists in the mind (as an idea).

  3. If God exists only in the mind but not in reality, then we can conceive of a greater being (one that exists in the mind and in reality).

  4. But we cannot conceive of a being greater than the greatest being that can be conceived (God).

  5. Therefore, God must exist in reality as well as in the mind. God’s existence is necessary by definition.

  6. If God exists only in the mind, then God would not be the greatest conceivable being. But God, by definition, is the greatest conceivable being.

  7. Therefore, God must exist in reality. God’s existence is logically necessary.

The key premises of the argument are: 1) We have an idea of the greatest conceivable being (God); and 2) Existence is greater than non-existence. Therefore, the idea of God must necessarily include his existence, otherwise God would not be the greatest conceivable being. God’s essence implies his existence.

The argument is ingenious but controversial. Objections include: 1) Existence is not a predicate (or property) in the way required for the argument. 2) We cannot define things into existence. 3) The argument seems to depend on a subjective standard of greatness. 4) The argument seems to conflate imagination and reality.

Nonetheless, the Ontological Argument remains a topic of serious discussion in philosophy and theology. At the very least, it shows that the question of God’s existence can be approached rationally and philosophically.

  • Averroes was an Islamic scholar who tried to reconcile philosophy and religion. He believed the Qur’an contained poetic truths that required interpretation by the educated elite.

  • Averroes accepted many of Aristotle’s teachings and wrote commentaries on Aristotle’s works. Averroes believed humankind was immortal through a shared intellect, though individual humans perished with their bodies.

  • Averroes’s work influenced later Jewish and Christian scholars known as Averroists, who accepted contradicting philosophic and religious truths.

  • Moses Maimonides was a Jewish philosopher who wrote about Jewish law and Aristotle. He tried to avoid anthropomorphizing God.

  • Maimonides developed a strand of negative theology, claiming God has no attributes. We cannot describe God as “good” or “powerful.” God transcends such descriptions.

• The question of whether the universe has always existed or began at some point has long divided opinion.

• In the medieval period, Aquinas argued for a middle path. He accepted Aristotle’s view that the universe could not have begun from nothing. However, he believed that God created the universe, so it must have had a beginning.

• To resolve this, Aquinas said that God created the universe with an “eternal law of becoming.” The universe is constantly changing and being created by God at every moment. In this way, it has no beginning but is not eternal either.

• Aquinas’ view allowed him to reconcile Christian belief in God as creator with Aristotelian philosophy. It proposed a model of continuous creation that avoided the seeming contradiction of the universe having a beginning yet always existing.

• Aquinas’ approach illustrates how medieval thinkers sought to integrate faith and reason through philosophical argument. His views influenced much subsequent Christian theology.

That covers the key elements around Aquinas’ argument, his influences, his reconciliation of philosophy and theology, and his lasting impact. Please let me know if you would like me to explain anything in the summary in more detail.

this is a gift of the Holy Spirit and

gain knowledge in two ways:

Aquinas also believes we possess

Christian doctrine represents divine

through the senses, and through

“intuitive knowledge”, which comes

truth. Aquinas insists that there

the intellect. The senses give us

to us directly from God and does not

can be no ultimate contradiction

direct knowledge of particular,

depend on reasoning. In Aquinas’s

between faith and reason.

individual things, such as sights,

view, the knowledge that God exists,

It is easy to see how difficult a

sounds, smells, tastes, and textures.

and that we have an immortal soul,

position this was to sustain. It

But through the intellect, we are

comes to us through this intuitive

involved accepting doctrines such

able to grasp the general nature

knowledge—although once we have

as the belief in life after death and

of things, such as the different

it, we can also reason about these

the immortality of the human


truths and show that they are not

reason cannot exist without a body.

of the soul in a living body, then it

logically incoherent. Nevertheless,

The human mind is the “form”

cannot exist without a body at all: it

our knowledge of them depends

of the matter that makes up the

will perish when the body perishes.

in the first place on this direct

physical body. The mind is what

Aquinas thinks this is a mistake.

intuitive insight, which comes from

gives shape and order to the lump

He claims that although the

God. Science and philosophy can

of matter that is a human body,

mind is indeed the form of the

never prove or disprove truths that

and allows it to function as a living,

body, this only means that for

come to us through intuitive faith.

conscious being. Without the mind,

a human being to be alive, mind

the matter that makes up the body

and body must be united. It does

would just be a jumble of elements.

not mean that the mind cannot

Body and mind

The other crucial aspect of

exist without the body. The mind

Aquinas’s thought is his view of the

Aquinas thinks that mind and body

is immaterial and spiritual; it is not

relation between mind and body.

are united in a living human being,

made up of physical elements itself.

He rejects the dualism proposed

but that the mind can exist without

It needs to be united to a physical

by Platonists, who say that mind

the body. Some philosophers, says

body in order for a person to live

and body are separate substances.

Aquinas, make the mistake of

and think and act—just as form

He also rejects the materialism

assuming that if the mind cannot

needs to be united to matter for

proposed by some Aristotelians, who

perform its functions in the absence

anything to exist in the physical

say that mind is simply part of the

world. But the mind itself remains

physical structure of the body, and

immaterial, even when separated

that there can be no mind without

from the body, as happens at death.

a body. Aquinas holds an

Thus for Aquinas, the belief in an

intermediate position.

afterlife and the immortality of

He agrees with the Aristotelians

the soul can be reconciled with

that the human mind functions only

the fact that in this life, mind and

when united with a body; without

body are intimately united. The

bodily senses and the brain, the

mind is the immaterial form of the

mind would have nothing to work

body, not part of its physical make-

on and could not operate. However,

up; but the body provides the mind

he disagrees that this means the

with the matter it requires in order

mind cannot exist without a body.

to function and to express itself in

His view has sometimes been called “moderate realism”. He

Averroes and some other Aristotelians

claims that universal concepts,

believed that humans share a single

such as “humanity”, have some

collective mind. Aquinas disagreed,

kind of reality beyond the mind.

arguing that every individual human

But they are not independent

possesses their own immaterial mind

substances, as Platonists claim.

or soul. Our minds give shape and order

Rather, they exist as the shared

to our physical bodies, allowing us to live

essence of individual things—the

and think, but the mind itself survives

underlying nature that makes a thing

death, according to Aquinas.

the kind of thing it is. The concepts

are in the mind, but refer to

something real in the world. The philosophers who say that the

the living human being.


Here is a summary of Nikolaus von Kues’ view of God:

  • Von Kues believes we can gain knowledge about God through reason. By defining the nature of all things, we can deduce what God must be like.

  • God cannot be comprehended by the human mind. Whatever we know or can conceive is not God. God is “beyond apprehension.”

  • God is before all things—not in time, but ontologically. All things exist through God, not after God.

  • God is not a “thing” and has no substance. God is what comes before even the possibility of anything existing.

  • For this reason, von Kues describes God as “Not-other”—beyond being and non-being. God transcends all concepts and definitions.

  • Although incomprehensible, God is the source of all reason, knowledge, and existence. Like Plato’s “Good” or “One,” God is the ultimate first principle.

  • Von Kues builds on ideas from Plato, Dionysius the Areopagite, and other Christian Platonists in developing his view of God as “Not-other.” His thinking points toward later apophatic theology.

  • Apophatic theology is the attempt to describe God by negation—by saying what God is not—rather than by positive assertions. For von Kues, God transcends even being and non-being.

So in summary, von Kues portrays God as ineffable, incomprehensible, and transcendent—yet the source of all that exists. By stripping away all limitations and conceptualizations, he points to the mysterious ground of being itself.

Here is a summary —then annexed Florence in 1406, and writing, which he hoped would

of Machiavelli’s key ideas:

some historical context about

Florence did not regain independence impress the new Medici rule.

Machiavelli and Florence.

until 1434. The Medici family took

The Republic explored different

control as unofficial rulers in 1434. In types of government in Florence’s

• The success and security of the state is the highest priority.

Machiavelli was born in Florence, 1512, the Medici were overthrown,

history, concluding that a republic

Italy, during a time of political

and Florence became a republic.

was the best option. However,

upheaval. Florence had been ruled

Machiavelli served as a civil servant

by the Medici family, but in 1494

under the new republic.

• Leaders should aim for the glory and success of the state above all

in The Prince (published

else, not their own glory.

posthumously in 1532),

they were overthrown, and the

Machiavelli set out his views on

republic of Florence was established. In 1512 the Medici regained controlhow an ideal leader—a “prince”

of Florence and had Machiavelli

in the broadest sense—should

means, even those that violate

While Florence was a republic, Machiavelli was a senior official. When imprisoned and tortured for conspiring act to acquire and maintain

moral rules, to achieve their ends.

the Medici regained control, Machiavelli against the Medici. Released in

1513, he retired to his estate,

was accused of conspiracy, imprisoned, where he wrote The Prince.

power. He took a bluntly pragmatic and amoral stance, arguing that “the ends justify the means”. Rulers, he

• Leaders should use whatever

• The health and security of the state depends on a strong leader.

said, should let necessity, not morality,

we know Machiavelli was educated,

but not published until after his

Machiavelli lived during a turbulent time in Florentine politics. In 1494, King Charles II of France invaded

well-read in Latin classics, and

death. Machiavelli died in 1527.

Italy and overthrew the Medici family rule of Florence. The city became a republic for 18 years. During this

fascinated by politics.

Niccolò Machiavelli is best

time, Machiavelli worked as a diplomat and gained experience in political affairs.

After the fall of the Medicis,

known for his political treatise

Machiavelli worked for the republic

The Prince, published in 1532.

In 1512, the Medicis regained control of Florence. Machiavelli lost his position and was exiled. To try and

for 18 years in a series of official

Though its cynical and ruthless

regain favour, he wrote The Prince in 1513, dedicating it to Lorenzo de Medici. The book advised rulers

posts, including Secretary of the

advice shocked many of his

how to gain and maintain power. It advocated that the ends justify the means, that it is better for a ruler to be feared than loved, and that ruthlessness is necessary.

Second Chancery, the body

contemporaries, it has endured

responsible for Florence’s internal

as a classic study of power

and external diplomatic affairs.

politics. Machiavelli is seen as

Machiavelli believed republics were the ideal form of government, as seen in his work Discourses on Livy.

After the Medici return, his life

a pivotal figure who helped move

However, he recognized that princedoms were sometimes necessary. The Prince may represent his views

descended into relative poverty,

political philosophy away from

on how princes should rule in such cases. However, its contents should be treated cautiously, as Machiavelli

relieved only occasionally by such

the idealism of Plato and Aristotle

may have written what he thought the Medici rulers wanted to hear in order to regain their favour.

activities as playwriting, as well

toward political realism.

After Francis Bacon inherited his estate in 1596, he devoted himself to philosophy and the advancement of learning. In 1620,

and rebellion. Imprisoned

and religion deal with completely

Bacon proposes that scientists

and fined, he was banished

separate spheres: science aims

should put aside received wisdom

from public life, though later

to understand the operations of

and prejudices, and instead collect

pardoned by King James I.

nature in this world, while religion

data through observation and

is concerned with spiritual matters

controlled experiments. The data

Key works

and life after death. To gain true

is then analyzed inductively to

1605 The Advancement

knowledge, Bacon argues, we must

form hypotheses and theories.

of Learning

free our minds from prejudices

These theories then suggest new

1620 Novum Organum

and preconceived ideas, which

experiments that can test them,

1623 The New Atlantis

he calls “idols”. He identifies four

ultimately leading to scientific laws.

such “idols”: the “idols of the tribe”,

This inductive and experimental

1627 New Experiments

our natural human tendency to see

approach, argues Bacon, will enable

what we expect to see; the “idols

scientific knowledge to advance

of the cave”, which arise from our

steadily and cumulatively. ■

Bacon published his main philosophical work, the Novum Organum. This proposed a new system of logic based on experimental science and induction, rather than deduction. Bacon believed that scientific knowledge builds upon itself, enabling new discoveries and inventions. He saw knowledge as power, giving humanity mastery over nature.

‘e retreated from public life after

1621 accused of bribery





THOMAS HOBBES (1588–1679)

IN CONTEXT BRANCH Political philosophy

Consequentialism is the moral philosophy that judges actions by their outcomes or consequences rather than by the acts themselves. It is sometimes summarized in the phrase “the end justifies the means”.

Thomas Hobbes’ political philosophy proposes a system that aims


for an end—namely, civil peace—even if the means adopted seem


harsh. In a time of violent political and religious conflicts, Hobbes


argued for an absolute sovereign to keep the peace.

5th century BCE Sophists argue

Hobbes was born shortly before the outbreak of the English Civil

that the rightness of actions depends on circumstances

War in 1642. He studied at Oxford University but left without

and cultural conventions.

graduating. In the 1640s, as the civil war raged, he went into self-

4th century BCE Plato, in

imposed exile in France, where he wrote his best-known work,

The Republic, argues that justice Leviathan, published in 1651. is defined by the harmonious


working of society.

Hobbes starts from the proposition that humans are essentially

The end justifies the means

18th century Jeremy Bentham

self-interested. In a hypothetical “state of nature” without government,

advocates utilitarianism:

life is “solitary, poor, nasty, brutish, and short” because people will

actions that produce the

the most good for the most

always put their own interests first. To escape this miserable condition,

people are morally right.

individuals come together in a social contract, establishing a sovereign—

1987 In A Theory of Justice,

an absolute ruler or ruling body—to govern them and keep the peace.

philosopher John Rawls

proposes a theory of justice

Hobbes argues that the sovereign has to have absolute power to fulfill

based on principles people

this role. While some of the sovereign’s acts may seem harsh, the

would choose behind a “veil

ends—peace and order—justify the means. Individuals give up their

of ignorance”.

rights to the sovereign, who then has the authority to do whatever is necessary to maintain civil order and security.


See also: Plato 68–73 ■ Jeremy Bentham 134–37 ■ John Rawls 258–61

Hobbes claims that in a state of nature, life is “solitary, poor, nasty, brutish, and short”. His Leviathan proposes an absolute sovereign to impose order.

The “state of nature” is a

The Leviathan answered

hypothetical condition of humanity

supporters of parliament who had

Arguments against

before the formation of civil society.

just executed Charles I, arguing that

For Hobbes, it represents a state of

even the tyranny of a king is preferable

• Hobbes’ social contract depends on hypothetical individuals

perpetual war, where life has no arts,

to the war of all against all. Many saw

in an imagined state of nature, not actual people in society.

letters, or society, and is at constant

Leviathan as a defense of despotism.

• People do not necessarily act only out of self-interest—they

risk of violent death. To escape this

Hobbes contested this view, arguing

can show altruism and work together voluntarily.

state, people join in a social contract,

that his theory aims to make the

• Absolute power can corrupt and be open to abuse, however

surrendering their natural rights to a

ruling power accountable to the people.

sovereign to gain security and order.

• The sovereign may not actually achieve peace and security.

Leviathan proposes that sovereignty

Hobbes’ theory has been very influential

• Individual rights and liberties are valuable in themselves,

should lie either in a single absolute

in Western political thought, though

monarch or in an assembly of the

much disputed. His radical view of

whole people. Whichever is chosen,

human nature has been challenged, but

Hobbes argues that sovereignty must

his argument that government authority

benevolent its aims.

not just as means to an end.

• There are alternative ways to achieve and maintain civil order without an absolute sovereign.

is essential to civil society remains

be absolute to prevent disorder.

powerful. His work laid foundations

Hobbes’ radical theories aroused

for modern social contract theory.

controversy. Royalists objected to his

Thomas Hobbes Born in Wiltshire, England, Thomas Hobbes was educated at Oxford. He became a tutor to the aristocracy and travelled in Europe, meeting major thinkers. In the 1640s, Hobbes went into exile in France during the English Civil War. He returned to England in 1651 after the execution of King Charles I.

view of the sovereign as dependent on the people, while parliamentarians and republicans saw Leviathan as a defense of tyranny.

Key works 1651 Leviathan 1665 De Corpore (On the Body) 1668 De Homine (On Man)

Disputes generally arise from the tendency of humans to compete for power and gain. An absolute sovereign is therefore required to enforce laws and maintain order.




IN CONTEXT BRANCH Epistemology APPROACH Rationalism BEFORE 4th century BCE Plato argues that knowledge comes through reason, not the senses.

13th century Theologian Thomas Aquinas claims that reason and faith (revelation) are compatible.

René Descartes is often called the “father of modern philosophy”. His revolutionary way of thinking emphasized reason and skepticism toward received wisdom. He aimed to establish absolutely certain foundations for knowledge, arguing that “the only thing I cannot doubt is that I doubt”.

Descartes was born to a wealthy family in France. He studied law at university but became interested in mathematics and philosophy. After traveling around Europe, he settled in the Netherlands to devote himself to philosophy and research. Descartes’ most famous argument is found in his Discourse on the Method (1637) and Meditations (1641). He resolves to doubt everything he possibly can, in order to find an irrefutable foundation for knowledge. His methodical doubt leads him to deny his senses, his body, the existence of the material world, even mathematics—all of which could be illusions created by an evil demon.

16th c. Philosopher Giordano Bruno promotes a rationalistic metaphysics.

The one

• Thomas Hobbes was a 17th-century English philosopher best known for his political philosophy.

• Hobbes was a physicalist, believing that everything in the universe is physical. He saw human beings as biological machines.

• In Leviathan, Hobbes stated that “The universe…is corporeal, that is to say, body.” He believed that everything, including God, occupies physical space.

• Hobbes used the concept of “animal spirits” or “physical spirits” to explain human activity and consciousness. These spirits were imperceptible but carried information around the body.

• Hobbes failed to provide a persuasive account of how the mind arises from the body. He did not address the “hard problem of consciousness”—how physical processes produce subjective experience.

• Hobbes’ argument for physicalism depends on his inaccurate assumption that the only kind of substance is body. His belief in imperceptible spirits could also justify belief in nonphysical minds.

• Hobbes’ view conflicted with Descartes’ dualism—the theory that mind and body are distinct substances. Descartes argued that the mind is nonphysical, unlike anything in the physical world.

• Hobbes’ physicalism seems to arise more from prejudice against nonphysical theories than from reasoned argument. His definition of “physical” is unclear and excludes much that we now class as physical.

• In summary, Hobbes’ theory of the human being as a purely physical mechanism is flawed and unconvincing. His assumptions and arguments do not stand up to scrutiny.

Here is a summary of Descartes’ Meditations:

  • Descartes wants to establish firm foundations for knowledge, so he subjects his beliefs to radical doubt.

  • He questions whether an evil demon could be deceiving him, making the world an illusion. If so, he cannot trust his senses.

  • He questions whether he might be dreaming. If so, he cannot rely even on reason and mathematics.

  • This radical doubt leaves him with nothing he can be certain of. He feels helplessly adrift, unable to find a footing.

  • But then he realizes that even if he is being deceived, he must exist in order to be deceived. His existence is indubitable.

  • This forms his “First Certainty”: “I think, therefore I am” or simply “I am, I exist”. His existence is self-evident and grasped intuitively.

  • From this first certainty, he seeks to rebuild knowledge on sure foundations using reason alone. His approach is rationalist and foundationalist.

  • He argues for a real distinction between mind and body. Mind is characterized by consciousness and thought; body is characterized by extension.

  • He believes that God’s existence can be proven rationally, and that God guarantees knowledge and prevents error and deception.

  • In this way, Descartes moves from radical doubt to certainty, providing philosophical grounding for science and knowledge.

René Descartes sought to overcome radical skepticism

Here is a summary of Spinoza’s main arguments:

  1. There can be only one self-explanatory substance. If there were two, we would need to understand one in terms of the other, contradicting the definition of substance.

  2. This one substance is what underlies the world of experience. It provides everything in the universe with its being, process of formation, purpose, shape, and matter. In these four ways, it “causes” everything.

  3. This substance can be conceived under various attributes, of which the human mind can grasp two: extension (physicality) and thought (mentality). These attributes are distinct but parallel.

  4. This unique substance, conceived under its attributes, is what we call “God” or “nature” (Deus sive natura). Everything else that exists is in some sense a part of it.

  5. The one substance is both an extended thing (in so far as it is conceived under the attribute of extension) and a mental thing (in so far as it is conceived under the attribute of thought). In particular instances, it is both a physical event and an idea.

  6. There are not two substances but only two ways of conceiving the one substance. Mind and body are two expressions of the same thing. This position is known as “substance monism.”

In summary, Spinoza argues for a metaphysical monism in which there exists only one substance, “God” or “nature,” of which mind and body are merely two attributes or expressions. This substance is the self-caused cause of all things.

Here is a summary of John Locke’s epistemology:

• Locke rejected the rationalist notion of innate ideas. He argued that there are no universal ideas or truths

that are present in the human mind at birth. If we observe newborn children, we find little evidence that they

have many ideas to begin with.

• According to Locke, the human mind at birth is like a “tabula rasa” or blank slate. All of our knowledge comes

from experience. We gain knowledge through perceiving the world with our senses and reflecting on those

perceptions with our minds.

• Locke proposed that the material world is made up of particles that are too small for us to perceive directly.

Although we cannot have direct knowledge of these corpuscles, we can infer their existence to explain things

we observe. Our knowledge of the physical world, then, goes beyond direct sense experience.

• While Locke believed all knowledge comes from experience, experience includes not just sensory perception

but also reflection - the mental operation of associating ideas, comparing them, and drawing logical conclusions.

So Locke was not strictly an empiricist, but believed experience encompasses both sensation and reasoning.

• Locke thought that we can only ever have knowledge of the observable qualities of things, not of their

underlying essences. We cannot know things as they truly are in themselves. We can only know how they

appear to us and the effects they have on us.

• For Locke, the scope of human knowledge is limited to things that can be experienced either directly or

indirectly. We cannot have knowledge of things that transcend experience, such as spiritual or supernatural entities.

So in summary, Locke held that all knowledge comes from experience, but experience is a broad category that

includes not just sensing the world but also reflecting on and reasoning about our senses. He rejected the notion of

innate ideas, thought the mind begins as a tabula rasa, and believed we can only know the observable qualities of

things, not their underlying essences. The scope of knowledge is limited to what can be experienced in some way.

Gottfried Leibniz distinguished between two kinds of truth:

  1. Truths of reasoning: These are necessary truths that can be known through rational reflection and logical analysis. They relate to concepts and essences, not to particular existing things. In principle, by continuing the process of analysis we can reach a final, fundamental truth.

  2. Truths of fact: These are contingent truths relating to actual things in the world. They can only be known through experience, not through reasoning alone. As the analysis of actual things is infinitely complex, we can never reach a final, complete truth about them through reasoning.

Leibniz believed that every individual thing has a distinct notion which contains all the truth about that thing, including its connections to other things. By analyzing these notions through reason, we can gain knowledge of necessary truths. But the analysis of actual things in the world is infinitely complex, so we need experience to gain knowledge of contingent truths.

In short, Leibniz saw a fundamental distinction between the rational knowledge of essences or concepts, and the empirical knowledge of existing things. Both are required for our understanding of the world.

George Berkeley’s philosophy of idealism can be summarized as follows:

• Berkeley was an empiricist who believed that all knowledge comes from experience.

• However, Berkeley took empiricism further than Locke by denying the existence of material objects independent of perception.

• According to Berkeley, the objects of experience are ideas, not physical things. They exist only in the mind.

• Our perceptions do not represent or resemble material objects in an external world. Rather, to perceive is to have an idea.

• The physical world and physical objects do not exist when they are not being perceived. As Berkeley famously put it, “esse est percipi”—to be is to be perceived.

• Nature is not itself material but consists in the laws that connect ideas, which are perceived by human and divine minds.

• The permanence and coherence of ideas is ensured by God, who perceives all things at all times. God’s constant perception of the world maintains its existence.

• Space, time, corporeality, and causality have no reality apart from the mind. They are constructs of our thinking and perceiving.

• Berkeley’s immaterialism or subjective idealism avoids the philosophical problems brought by matter and the representative theory of perception. However, it raises questions about the status of the real world.

• Berkeley’s idealism was very influential and shaped empiricism, as well as philosophers like Hume, Kant, and others. However, his system is open to objections, and most later philosophers rejected his immaterialism.

So in summary, Berkeley’s idealism denies the existence of matter and claims that the world consists solely of minds and the ideas they contain. Physical objects depend for their existence on being perceived by some mind. This solves problems with the philosophical concept of matter but raises difficult questions about reality and the external world.

The 18th century, known as the Age of Enlightenment or the Age of Reason, saw a flowering of thought across philosophy, politics, science, and economics. This period promoted scientific method, reductionism, and the primacy of human reason.

Philosophers such as Voltaire, Rousseau, Locke, and Montesquieu explored ideas of social reform, constitutional government, and individual liberty that shaped modern democracy. The American and French Revolutions put many of these Enlightenment ideas into practice.

Science advanced rapidly, with groundbreaking work by Lavoisier on chemistry, Laplace on probability and statistics, and Linnæus on biological classification. The Industrial Revolution began in Britain, driven by technological innovation and the move to mechanization, marking the start of the modern factory system.


skepticism and materialism associated been under the control of the Catholic Church.

with the Enlightenment. Key Enlightenment

thinkers like Voltaire and Diderot promoted While feudalism declined, most Europeans

deism, atheism, and anticlericalism. The

still lived difficult lives as peasants. However,

extraordinary success of Diderot and the spread of Enlightenment ideals, new

d’Alembert’s Encyclopédie helped spread scientific knowledge, and a rising middle class

Enlightenment ideas throughout Europe.

would spur calls for political and social reform

that shaped the modern world.


The Enlightenment

The Enlightenment was an intellectual movement that emerged in Western Europe in the 18th century. Centered around reason and scientific method, Enlightenment thinkers promoted intellectual interchange and challenged traditional institutions and beliefs. Key ideas that shaped the Enlightenment included:

• Reason: Enlightenment thinkers argued that rational thought could lead to human progress. They opposed traditional authority and superstition.

• Scientific method: The works of scientists like Isaac Newton demonstrated that observation and experiment could reveal the natural laws governing the universe. This approach was seen as a model for achieving knowledge in many fields.

• Liberalism: Enlightenment thinkers explored individual liberty, constitutional government, and the social contract theory of the state. Key proponents include John Locke and Montesquieu.

• Deism: Some Enlightenment thinkers promoted deism, a rational and naturalistic view of God and the universe. Deists rejected divine revelation and religious superstition. Key proponents include Voltaire and Thomas Paine.

• Secularism: Enlightenment thinkers tended to emphasize reason and scientific knowledge over religious belief. Some promoted concepts of materialism, atheism, and anticlericalism that challenged traditional religious authority.

• Cosmopolitanism: Enlightenment thinkers believed in the unity of humanity and promoted tolerance, reason, and international cooperation. Nationality and ethnic differences were seen as secondary to our shared humanity.

• Progress: Most Enlightenment thinkers believed that human reason and scientific advancement would lead to progress in society: moral, intellectual, and material. There was optimism that reason could improve the human condition.

The Enlightenment shaped revolutionary ideas that led to democratic reforms in government, including key documents such as the Declaration of Independence (1776) and the Declaration of the Rights of Man and of the Citizen (1789). However, the Enlightenment also received criticism for excessive optimism in reason, human progress, science, and individualism. Critics argued that it lacked historical and religious perspectives. Nonetheless, the Enlightenment remains the foundation for modern Western liberal democracy.

The Scientific Revolution The Scientific Revolution of the 17th century saw the emergence of modern science through groundbreaking discoveries and theories in astronomy, physics, chemistry, and more. Key contributors include:

• Nicolaus Copernicus (1473-1543): His heliocentric theory that the Earth revolves around the Sun challenged the established Ptolemaic geocentric model. Copernicus helped spark the Scientific Revolution.

• Johannes Kepler (1571-1630): His laws of planetary motion described the orbits of the planets, with the Sun at the center. Kepler built on Copernicus’s work.

• Galileo Galilei (1564-1642): A key proponent of the heliocentric model, Galileo used observations with the newly invented telescope to provide evidence for Copernicus’s theory. He also studied inertia, acceleration, and astronomy.

• Isaac Newton (1643-1727): Newton’s theories of gravitation and classical mechanics had a profound influence on the Scientific Revolution. In Philosophiæ Naturalis Principia Mathematica (1687), Newton described universal gravitation and the three laws of motion.

• Robert Hooke (1635-1703): Hooke studied microscopy, astronomy, and paleontology. He worked with Robert Boyle and was a founding member of the Royal Society. Hooke proposed a wave theory of light and anticipated the cell theory in biology.

• Antonie van Leeuwenhoek (1632-1723): Using simple microscopes, van Leeuwenhoek was the first to observe bacteria, protozoa, and many microscopic organisms unknown before. He is known as the “father of microbiology.”

• Robert Boyle (1627-1691): Boyle studied chemistry and is known for Boyle’s law relating pressure and volume of gases. He was a founder of the Royal Society, which helped establish the scientific method.

The Scientific Revolution represented a paradigm shift from medieval natural philosophy to modern science based on observation, experiment, and mathematical analysis. It transformed our understanding of the natural world and laid the groundwork for modern science.


The Industrial Revolution

Jean-Jacques Rousseau (1712-1778) was a Genevan philosopher and writer. His political philosophy influenced the French Revolution and the overall development of modern political and educational thought.

Rousseau’s key works include:

• Discourse on the Arts and Sciences (1750): Argued that the arts and sciences had corrupted human morality. Rousseau believed civilization led to inequality and vice.

• The Social Contract (1762): Outlined Rousseau’s political philosophy. He argued for popular sovereignty and a social contract between rulers and people. Rousseau said governments derive their right to rule from the consent of the governed.

• Emile, or On Education (1762): Rousseau’s theory of education and child development. He proposed an educational method tailored to a student’s developmental stages, allowing children to develop naturally without constraints of civilization.

Rousseau’s main ideas include:

• Social contract: Governments derive their authority and legitimacy from the consent and participation of their citizens, not divine right or tradition. Rulers and people enter into a social contract.

• General will: The general will represents the common good of citizens. It is sovereign over the individual wills of rulers or citizens. Rousseau believed the general will would lead to virtuous policies and equality.

• Civil religion: Rousseau proposed a civil religion with principles common to all religions that would strengthen the state. Religious toleration should be extended to all religions that accept the civil religion.

• Natural man: In a state of nature, man is essentially good and innocent. It is society and civilization that corrupt our nature and lead to inequality, selfishness, and vice.

• Popular sovereignty: Governments should express the general will of citizens. Rulers hold power only as delegation from the people, so the people are collectively sovereign.

• Liberty and equality: Rousseau emphasized both liberty and equality. Individual liberty finds meaning in participation in political bodies which make citizens equal partners in the social contract.

• Education: In Emile, Rousseau proposed an educational method where children can develop naturally according to their stage of growth. Education should avoid corrupting influences of society and teach self-reliance and virtue.

Rousseau’s political philosophy inspired both radical and moderate ideas of Enlightenment and democracy. His works inspired leaders of the French Revolution but were also criticized for a lack of practicality. Rousseau remains one of the most influential Enlightenment thinkers, shaping modern concepts of democracy, civil religion, education, and human development.

Key Leaders of the Enlightenment

The 18th century saw an explosion of intellectual activity centered around reason, science, individualism and radical thought. Key leaders of the Enlightenment include:

• Voltaire (1694-1778): The pen name of François-Marie Arouet, a French writer and philosopher known for his wit and defense of civil liberties. He advocated for freedom of religion, expression and the separation of church and state.

• Denis Diderot (1713-1784): A French philosopher, writer and editor of the Encyclopédie, a comprehensive encyclopedia representing Enlightenment thought. The Encyclopédie helped disseminate Enlightenment ideas across Europe.

• David Hume (1711-1776): A Scottish philosopher known for his empiricism and skepticism. Hume advocated for naturalism and secularism in philosophy, and explored liberalism in political thought. He was a key figure in the Scottish Enlightenment.

• Thomas Paine (1737-1809): An English political activist who supported American and French revolutions. His pamphlets Common Sense (1776) and The Rights of Man (1791) advocated Enlightenment ideals of democracy, constitutionalism, and attacks on traditional institutions.

• Mary Wollstonecraft (1759

Here is a summary of the key ideas in the passage:

  • David Hume was an 18th-century Scottish philosopher. He lived during the Enlightenment, a time when traditional authority and beliefs were being questioned through reason and empirical evidence.

  • Hume divided all human mental experiences into impressions (sensations, feelings, emotions) and ideas (thoughts, beliefs, imaginings). He argued that all ideas are derived from impressions, so if there is no corresponding impression, an idea has no meaning. This is known as Hume’s fork.

  • Hume was an empiricist. He believed that all human knowledge comes from experience and that reason alone cannot produce new ideas. He rejected the notion of innate ideas.

  • Hume was a skeptical philosopher. He believed that we can never have absolute certainty about anything except mathematical and logical truths. All factual or “metaphysical” knowledge is based on the fallible evidence of the senses and scientific conclusions are provisional.

  • Hume argued that we have no rational basis for some metaphysical beliefs like the existence of God or the external world. He concluded that such notions arise from psychological causes, not reason. This form of skepticism called all philosophical doctrines into question.

  • Hume believed that morality is based on sentiment, not reason. Moral judgments arise from the feelings and “passions” of human nature. Reason alone cannot determine moral truths. Ethics is therefore subordinate to human psychology.

  • Hume had a great influence on later philosophers like Kant. His radical empiricism and skepticism shaped debates in epistemology, metaphysics, and ethics. He is considered one of the most important Enlightenment thinkers.

That covers the essence of Hume’s philosophy as described in the passage. Please let me know if you would like me to explain anything in the summary in more detail.

David Hume was a Scottish empiricist philosopher who lived in the 18th century. He challenged the notion of rationalism set forth by philosophers like Descartes. Hume argued that knowledge comes from experience or impressions, not innate ideas.

Hume divided all statements into two types: demonstrative and probable. Demonstrative statements were logical or mathematical truths that could not be denied without contradiction, like “2+2=4.” Probable statements were empirical claims that could be verified through evidence and experience.

Hume then applied this framework to the problem of induction. Inductive reasoning involves inferring from the past to the future, as when we assume the sun will rise tomorrow just because it has risen every day in the past. Hume argued this type of inference was not rationally justified. The statement “the sun will rise tomorrow” is neither demonstrative (it could be false without contradiction) nor probable (we can’t experience the future sunrise).

According to Hume, we make inductive inferences out of “custom” or “habit.” We are naturally inclined to assume the future will resemble the past. While not rationally justified, inductive reasoning is useful and guides us in everyday life. We should still apply it cautiously, though, and not automatically infer cause and effect relationships without considerable evidence.

Hume’s arguments dealt a major blow to rationalism and emphasized the role of belief and habit in human knowledge and reasoning. His work influenced later philosophers like Kant, Wittgenstein, and Popper. Hume highlighted the “problem of induction” that continues to be debated by philosophers today.

In summary, Hume argued our knowledge comes from experience, not reason alone. He challenged the rationalist notion of innate ideas and showed how inductive reasoning is based on belief and habit, not logic. Though not rationally justified, inductive inference still guides us in everyday life, but should be applied carefully. Hume’s work dealt a significant challenge to rationalism that continues to influence modern philosophy.

Jean-Jacques Rousseau was an 18th-century Enlightenment philosopher who challenged conventional thinking. In his Discourse on the Sciences and Arts, he controversially argued that the progress of the sciences and arts had corrupted morality. In his Discourse on Inequality, he theorized that humanity in a state of nature was fundamentally good, but that society and civilization had led to inequality, vice, and the loss of freedom.

Rousseau believed that when people began to claim private property, it led to the development of society. Laws were then imposed to protect property, resulting in the loss of natural virtue and empathy. Although humanity was naturally virtuous, society corrupted people. Although people were born free, society’s laws put them “in chains.”

Rousseau proposed a solution in his work The Social Contract. He envisioned an alternative society governed collectively by citizens according to the “general will.” Rousseau’s radical ideas helped inspire the French Revolution. His vision of humanity in a state of nature as virtuous and free shaped the Romantic movement. Although often misunderstood, Rousseau did not see natural humanity as “noble savages” but as naturally compassionate, with reason and society corrupting innate goodness.

In summary, Rousseau believed:

  1. Humanity in a state of nature was good but society corrupted virtue.

  2. Society resulted in inequality, vice, and loss of freedom. Laws favored the rich over the poor.

  3. Although born free, people were “in chains” under the unequal laws of society.

  4. An ideal society would follow the general will of citizens, not the powerful elite.

  5. The progress of arts and sciences led to the decline of morality.

  6. Rousseau’s radical ideas influenced revolution and shaped Romanticism.

Does this summary accurately reflect Rousseau’s key philosophical ideas? Let me know if you would like me to clarify or expand on any part of the summary.

• Adam Smith argues that self-interest is the primary human motivation. However, he says people also show benevolence toward others, especially when they need help to survive.

• Smith says humans are “animals that make bargains.” We exchange goods and services with others in mutually beneficial ways. These bargains arise from self-interest but also allow society to function.

• The division of labor refers to the specialization of work. Rather than each person being self-sufficient, people focus on specific skills and trade with others. This increases productivity.

• Smith illustrates the benefits of the division of labor with the example of pin manufacturing. Many workers each performing a single task can produce far more pins than a single worker doing every task.

• The free market allows people to pursue their self-interest through mutually beneficial exchanges. Smith sees this as the basis for a fair and prosperous society. Money facilitates market exchanges by eliminating the need for bartering.

• Smith argues that civil society depends on cooperation and mutual assistance between many people. Although self-interest motivates individuals, the interdependence of people in the market also binds society together.

• Smith believes the increasing division of labor and specialization of work will continue to improve productivity, as in the Industrial Revolution. The free market and self-interest drive this progress.

That covers the key elements in Smith’s philosophy regarding self-interest, exchange, specialization, and markets according to the information given. Please let me know if you would like me to explain or expand on any part of the summary.

• Immanuel Kant believed philosophy had failed for 2,000 years to prove the existence of an external world outside our consciousness. He was particularly critical of Descartes, who doubted all knowledge other than

previous ages.

Kant’s key insight was that

knowledge requires both sensibility

(the senses) and understanding

our own existence, and Berkeley, who said the only things we can know are our own perceptions.

(the ability to think). Both are

• Kant argued that we can only experience time through things that change in the world, so the existence of

equally necessary for knowledge.

Without sensibility, we would have no

experience through which we could

exercise our understanding; without

something that changes requires there to be an external world. Our certainty about the external world is as

great as our certainty of our own consciousness.

• Kant was impressed by the progress of science but believed empiricism (that all knowledge comes through

experience) could not fully explain this. We require both sensibility (experience) and understanding (reason)

to have knowledge. Space and time are not learned through experience but are intuitions supplied by our mind.

understanding (concepts and

• Things in themselves (noumena) are unknowable. We can only know appearances (phenomena) — the

rules for thinking), we would

way our mind represents the world to us. The world conforms to our knowledge, not the other way round.

not be able to cognize objects

and events even through sensibility.

What is really fundamental to

knowledge, according to Kant, are

the concepts of space and time,

which he calls “pure intuitions.”

These intuitions are supplied

Kant developed a new theory called transcendental idealism that overturned the disagreement between empiricists and rationalists. He aimed to determine the limits of human knowledge and how we should reason

and act. Kant believed philosophy’s goal was to answer three central questions: What can I know? What should

I do? What may I hope? His answers formed the basis of modern philosophy.

by the human mind, rather than

being learned through experience.

They are the framework within

which sensibility and understanding

can operate, and without which

there could be no knowledge

  • According to Kant, knowledge requires both intuitions (direct sensory experience) and concepts (abstract ideas).
  • Some knowledge comes from experience (empirical knowledge) while some is independent of experience (a priori knowledge).
  • Space, time, and concepts like substance are a priori, meaning they are the necessary preconditions of experience.
  • We cannot know things-in-themselves, things independent of our experience. We can only know the phenomenal world, the world as it appears to us.
  • A priori knowledge makes science and a strict demarcation of the limits of knowledge possible. But it also means we cannot have knowledge of things like God, the soul, free will, etc.
  • Kant’s position is called transcendental idealism: Space, time and a priori concepts are features of our experience, not of things-in-themselves.

Here is a summary of Jeremy Bentham’s philosophy:


BEFORE 4th century BCE Aristotle argues that the highest virtue is happiness

(eudaimonia). 1214 CE Peter Abelard proposed the idea that right is determined by intention.

AFTER 1861 John Stuart Mill develops utilitarianism further, arguing for individual liberty and rights. 1958 G. E. Moore argues in Principia Ethica that intrinsic good (and not pleasure alone) is the correct utilitarian standard.

pain and the Pursuit of happiness For Bentham, the goal of ethics

and pleasure. He argued that

was to promote human well-being

these two principles could form

and happiness. He advocated creating

the basis for an ethical philosophy

a system of law and governance that

called “utilitarianism”. Its central aim

would provide “the greatest happiness for the greatest number” of citizens. By focusing on simple, quantifiable measures of pleasure and pain, utility,

1983 Robert Nozick’s book Anarchy, State, and Utopia advances a libertarian theory that challenges utilitarian arguments.

could calculate the costs and benefits of any action to determine whether or not it was morally right. Bentham believed that individuals always act out of self-interest to gain pleasure and avoid pain. So by structuring laws and institutions to align the interests of individuals with the general well-being of society, the greatest overall happiness could

7 0 1 2 3 8 7

be achieved. His vision of a utilitarian society


• An Introduction to the Principles

emphasized individual freedom, equality, and

of Morals and Legislation (1781),in

universal suffrage.

which he laid out his theory of

Bentham has been hugely influential

utilitarianism based on “the greatest happiness principle”.

• Panopticon Writings (1791), describing his idea for an ‘ideal

prison’ enabling total surveillance

in philosophy, political science, economics, and law. His work laid the foundations for

of inmates.

liberal reforms in Britain and inspired early

• Proposals for Judicial Reform

socialists and anarchists. Though controversial,

(1792), arguing for the codification of laws and judicial transparency. Jeremy Bentham’s preservedbody (dressed in his own clothes) is on public display at University College London. He requested that his corpse be dissected as part of a public anatomy lecture.

his radical utilitarian philosophy continues to shape debates over ethics, governance, and social policy today.

Here is a summary of Georg Hegel’s philosophy:

preeminent German

• Hegel believed that reality is not static but is constantly changing as a result of

philosopher of the 19th century.

the dialectical process of history. This process involves the emergence of ideas


He saw the world as fundamentally

(thesis), which then come into conflict with opposing ideas (antithesis), resulting


rational, and believed that reality

in a synthesis of the two which incorporates the truth of both. This synthesis then

itself—including human history,

becomes a new thesis, and the whole process is repeated. For Hegel, history shows

German idealism

politics, and thought—is the

the progressive unfolding of the World Spirit or Absolute Idea as it overcomes


progressive self-realization of Spirit

limitations through conflict and contradiction.

4th century BCE Plato proposes

(Absolute Idea or Reason). According

• Hegel saw the dialectical process of history culminating in the rationalist political

the theory of forms—an ideal,

to his dialectical method, progress

structures of the 19th-century Prussian state. He believed that history had come

unchanging reality behind the

is made through the conflict of

to an end with the advent of the rational state.

changing world of objects and

opposites and the reconciliation of

• Hegel rejected Kant’s notion that we can never have knowledge of things-in-

events. For Plato, ultimate reality

contradictions. He believed this

themselves. Hegel argued that philosophy can attain absolute knowledge of reality

is rational and intelligible.

process culminates in the Prussian

through a dialectical investigation of our conceptual thought. Our thought and reality

state, which he saw as an embodiment

are co-terminous and interpenetrating. Philosophy is able to grasp this totality.

1789 Immanuel Kant argues

of reason in the real world.

that while we cannot have

• Hegel proposed an all-embracing philosophical system that aimed to encompass

knowledge of “things-in-

Hegel’s metaphysical system

all spheres of reality. His system incorporates theories of ethics, aesthetics, politics,

Hegel developed an elaborate

themselves” (the world as it

and logic. For Hegel, philosophy itself is the highest expression of the Spirit’s

really is), we can know the

self-realization in thought.

world as it appears to us,

philosophical system that

interpreted through our mind.

encompassed the whole of reality. His theories of history, politics,

That is the proper object of

ethics, aesthetics, and logic were

philosophical inquiry.

all interconnected. He aimed to achieve total knowledge of the


Absolute—the ultimate reality

1900s Logical positivism rejects

that underlies all appearances.

Hegelian metaphysics as

For Hegel, philosophy was itself

meaningless. Philosophers such

the highest expression of the

as Russell argue that philosophy

Absolute comprehending itself

should aim to analyze language

through human thought.

and solve logical problems, not make grand metaphysical claims.

See also: Plato 50–55 ■ Immanuel Kant 164–71 ■ G.W.F. Hegel 180–85

■ Bertrand Russell 254–55 ■ Karl Popper 258–63



Hegel said, “Freedom is the


fundamental character

of the will.” By this he meant that

Human beings cannot be free if they


freedom defines human will or

act from desire, passion, self-interest,

intentional action. For Hegel,

or any other contingent motivation.


freedom is achieved through

True freedom requires acting from

German idealism

reason and an understanding of

reason in accordance with universal


necessity. Merely following our

moral law. For Hegel, this law is

4th century BCE Aristotle says

passions or desires does not make

embodied in society’s ethical life,

that being virtuous and acting

us free in a deeper sense. True

institutions, customs, and laws.

according to reason is the path

freedom, Hegel argues, comes

As individuals, our task is not

to wellbeing and happiness.

only with understanding the

just to pursue our own happiness

17th century Benedict Spinoza

necessity that governs events

and desires, but to understand

argues that liberating ourselves

and finding our role within that

where true freedom lies within the

from bondage to emotions and

order. Freedom is achieved by

existing social order. Ethical action

passions allows us to understand

willing in accord with universal

involves upholding the laws and

necessity (God or Nature) and

moral law.

customs of one’s community,

act virtuously.

According to Hegel, the

understanding one’s social role and

trajectory of history is the

responsibilities, and so realizing

18th century Immanuel Kant

progressive realization of freedom.

one’s own freedom and rationality. ■

says we achieve freedom by

At each stage, individuals gain

acting according to principles

a wider understanding of necessity

of reason and duty. Happiness

and a correspondingly greater

should not be the motivation

degree of freedom and rational

for moral action.

self-determination. However,


Lacking an ethical life

within the institutions, practices,

20th century Existentialists

in common, men lack the

and customs of society, freedom is

such as Sartre argue that we

element in which they can

abstract and empty. According to

have complete freedom to

recognize and respect one

Hegel, individuals must find their

determine our own essence

freedom in their participation in

through the choices we make.

another as free.

social ethical life, not in isolation

Georg Hegel

from it. Freedom is achieved by understanding necessity, and necessity is embodied in the ethical and social structures of the time.

Society and the state represent ethical freedom realized.

See also: Aristotle 56–63 ■ Benedict Spinoza 126-29 ■ Immanuel Kant 164–71

■ Jean-Paul Sartre 266–71

Georg Hegel




Hegel’s explanation of

self-realization of Spirit. History is


art and beauty formed

the unfolding realization of the

an important part of his huge

Absolute Idea—the ultimate reality


philosophical system. For Hegel,

that underlies all appearances.

“the beautiful” is an expression of

He argued that art plays an

German idealism

“the Absolute” (Spirit or Reason)

important role in this process.


in the realm of art, just as religion,

All art starts from the idea of

4th century BCE Plato argues

philosophy, and the state represent

unity with the Absolute, which

that art imitates the physical

its expression in other spheres. Art,

is then progressively realized

world, which is itself an

he argues, allows the Spirit to

through symbolic, classical, and

imperfect imitation of the real

manifest itself sensuously, for

romantic forms of art. Finally,

world of unchanging forms.

immediate apprehension.

in the romantic stage, art achieves

For Hegel, art, religion,

a unity of meaning and shape that

4th century BCE Aristotle says

philosophy, and other elements

allows the deepest insight into the

the goal of art is to imitate

of culture evolve as part of the

Absolute. At this point, art has

human action in an idealized

fulfilled its purpose and is

form. Art should aim at beauty

superseded by philosophy.

and create universal truths.

According to Hegel, all cultural phenomena—including art—move

1790 Immanuel Kant argues

dialectically through a process of

that our experiences of beauty

thesis, antithesis, and synthesis.

are entirely subjective but also

Different art forms emerge and

share a commonsense basis.

are superse

The single most famous German philosopher during the first half of the 19th century was Georg Wilhelm Friedrich Hegel. His central idea was that all phenomena, from consciousness to political institutions, are aspects of a single Spirit (by which he means “mind” or “idea”) that over the course of time is reintegrating these aspects into itself. This process of reintegration is what Hegel calls the “dialectic”, and it is one that we (who are all aspects of Spirit) understand as “history.”

Hegel believed that Spirit progresses through a dialectical process in which it passes from stage to stage, each new stage (or synthesis) transcending the contradictions inherent in the previous stage. According to Hegel, this progress ultimately leads to the full self-realization of Spirit in the form of the modern democratic state. He was therefore a monist, believing that all things are aspects of a single thing (Spirit), and an idealist, believing that reality is ultimately something non-material (Spirit).

Hegel argued against Kant’s notion of a “world-in-itself” beyond our experience, claiming that there is nothing beyond what comes to manifestation in consciousness. He also criticized Kant for assuming that the categories of thought are fixed and unchanging. For Hegel, the categories themselves develop over time through the progress of Spirit.

Hegel’s thought has been hugely influential. His dialectical method in particular inspired responses by Arthur Schopenhauer, Karl Marx, and Jean-Paul Sartre, among others. Hegel represents the culmination of German Idealism, radically transforming philosophy with his vision of reality as the historical development of Spirit.

Here is a summary of Arthur Schopenhauer’s key ideas:

• The world as we perceive it is a representation of the mind. There is a deeper reality beneath the world of appearances which we call the “thing-in-itself”.

• The thing-in-itself is the Will - a blind, aimless, purposeless striving and urge. The Will expresses itself in the world as the constant striving and desires of all beings.

• The Will is the innermost essence of everything in the universe - including animals, humans, and all of nature. The Will is the driving force behind all actions and natural phenomena.

• The Will constantly generates craving and striving. All desires arise from a deficiency felt by the Will. When one desire is satisfied, another arises to take its place. This is the endless cycle of desire and suffering.

• Aesthetic experience and ethical behavior can lead to a denial of the Will. By contemplating art or behaving compassionately, we can achieve a temporary escape from the endless striving of the Will. This results in a peaceful state of mind.

• Ultimately, denial of the Will is the only way to escape suffering. By rejecting desires and attachments to the world, we can achieve a saintly state of calm and inner peace. This is a quasi-mystical experience of transcending the Will.

• Schopenhauer believed that philosophy should be a means for attaining insight into the human condition and achieving inner peace or tranquility. His metaphysical system was meant to diagnose the root cause of suffering and provide a therapeutic remedy.

That covers the essence of Schopenhauer’s philosophical system and his view of the world. Let me know if you would like me to explain anything in the summary in more detail.

• Ludwig Feuerbach was a 19th-century German philosopher known for his book The Essence of Christianity (1841).

• Feuerbach argued that rather than theology being the study of God, it is really anthropology - the study of humanity.

• He believed that humans have created the idea of God out of our own desires and longings for virtues like love, compassion, and kindness.

• We have imagined a being that embodies these virtues in the highest degree and called it “God.” But these virtues actually exist in humans, not in Gods.

• Feuerbach argued we should focus less on heavenly righteousness and more on human justice in this life on Earth. Humans, not Gods, deserve our attention.

• Feuerbach saw humans as the creators of God, not the creation of God. We have deceived ourselves into thinking a divine being exists.

• Feuerbach believed we have lost sight of what we are ourselves in creating the idea of God. We should rediscover our own virtues and potential, not project them onto deities.

• Feuerbach’s ideas influenced later thinkers like Marx and Freud, who saw religion as a human creation that satisfies psychological needs. But for Feuerbach, the idea of God is really just a reflection of human ideals.

That covers the essence of Feuerbach’s argument that theology is really anthropology, because God is a human creation, not the other way around. Let me know if you would like me to elaborate on any part of the summary.

• Thomas Hobbes believed that without government, people would behave brutishly, so they establish the social contract and a sovereign to maintain order.

• John Locke wrote that people have natural rights and establish government through consent and social contract to protect those rights. His ideas influenced liberalism.

• Jeremy Bentham advocated the principle of utility: the greatest happiness for the greatest number.

• John Stuart Mill built on Bentham’s utilitarianism. He said individuals should be free to pursue happiness but not harm others. He advocated freedom of speech and other civil liberties.

• Mill’s ideas influenced later liberal thinkers like John Maynard Keynes and shaped modern liberalism and economics.

• Mill advocated freedom and reform rather than revolution. He said society and education should foster an association between individual and social good.

• Mill tried to reconcile utilitarianism and empiricism with new romantic ideas. He said higher pleasures like intellectual pursuits contribute more to happiness than physical pleasures.

• Mill argued for women’s suffrage and against slavery. He believed individual freedom and fulfillment benefit society.

• Mill’s ideas influenced thinkers like Bertrand Russell, Karl Popper, William James, and John Rawls.

Here is a summary of Marx’s argument:

• Marx believed that the history of human society was driven by class struggle. In each historical period, there is a dominant class that exploits a subordinate class.

• In Marx’s time, the dominant class was the bourgeoisie - the capitalist class who owned the means of production. The subordinate class was the proletariat - the workers who sold their labor.

• The bourgeoisie had gained power through the rise of industrial capitalism. As markets grew and demand for goods rose, traditional craftspeople could not keep up and were replaced by factories. The factory owners accumulated wealth and power.

• Marx criticized the bourgeoisie for reducing human relationships to economic self-interest and “callous ‘cash payment’“. People were valued only for what they could produce and consume, not for who they were.

• Marx believed the class struggle between the bourgeoisie and proletariat would lead to a revolution by the proletariat, who would seize the means of production. This would lead to a classless and stateless communist society.

• Marx articulated these ideas in The Communist Manifesto, published in 1848. The Manifesto laid out Marx’s vision for an egalitarian communist society and called upon the proletariat to unite and overthrow the bourgeoisie.

So in short, Marx reduced history to class struggle, and believed the struggle between the bourgeoisie and proletariat would lead to a communist revolution that would fundamentally transform human society. His ideas were hugely influential and shaped global politics for generations.

  • Karl Marx was a 19th-century philosopher who analyzed the historical development of human society in terms of class conflict and the means of production.

  • According to Marx, as the means of production change, society progresses through different economic systems or “modes of production,” including tribalism, slavery, feudalism, and capitalism. Each mode of production benefits a different class, leading to class conflict.

  • In capitalism, the bourgeoisie (property owners) exploit the proletariat (workers) by extracting surplus value from their labor. Marx predicted this conflict would ultimately lead to a revolution in which the proletariat seize the means of production, establish a socialist system, and create a classless utopia.

  • Marx believed social institutions like religion, philosophy, and politics are influenced by the economic system and serve to promote the interests of the ruling class. As the economic system changes, so too do these institutions. For Marx, material and economic factors shape society more than ideas.

  • Marx’s theory of historical materialism uses a dialectical view of change as progressing through a cycle of conflict and resolution, not as a spiritual journey. Marx adapted the dialectic from Hegel but gave it a material rather than idealist basis.

  • According to Marx, class interests, not ideas, are the driving force behind historical change and political events. The ruling class gains and maintains power by promoting the illusion it acts in the general interest. But in reality, politics is shaped by underlying class conflicts.

  • Marx drew on influences such as Hegel, Feuerbach, Rousseau, and Smith. His work combines German idealism, French revolutionary thought, and British political economy. Although Marx built on pre-existing ideas, his synthesis was original.

That covers the key highlights of Marx’s theory, including historical materialism, class conflict, dialectical change, the influence of the economic system, and Marx’s intellectual influences and sources. Let me know if you would like me to explain anything in the summary in more detail.

Here is a summary of Charles Sanders Peirce’s pragmatic maxim:


observable effects that follow from it.

1878 With Peirce, William James and others found

Meaning depends on effects: According to Peirce, the meaning of any concept or idea is determined by the sensory


effects we can attribute to it. We cannot know anything purely through abstract reasoning or speculation—there must be some practical consequences to our beliefs and theoretical claims.

1906 Peirce coins the phrase

“pragmatic maxim”.

Reject metaphysics: Peirce was deeply skeptical of abstract metaphysical speculation that could not be tied to practical effects or consequences. He believed many philosophical debates were just “debates about words” if they could

1907 Pragmatism is popularized in William

not specify any differences in sensory experience.

James’s book Pragmatism.

What works is truth: For the pragmatists, the “truth” of an idea or concept is not an abstract representation of reality, but rather what “works” in practice—what is useful and has valuable consequences. So pragmatism evaluates ideas in terms of their practical usefulness and success.

Focus on practice: Pragmatism is concerned with practical consequences and experiential effects, not abstract theory or speculation. It aims to shift philosophy away from mere theorizing toward a focus on practice, experience, and the connection between thought and action.

See also: John Locke 152–57 ■ Immanuel Kant 182–87 ■ William James 272–75

Here is a summary of William James’s pragmatism:

  • Truth is not static or inherent, but is made through experience and events. Truth “happens to” an idea as we act upon it.

  • The truth of an idea depends on its usefulness and practical consequences, not just logical consistency. An idea is true if it accomplishes what is required of it.

  • We have a “right to believe” in ideas that guide our actions, even without conclusive evidence. Our beliefs shape reality by influencing what we do.

  • Reality is constantly changing and “still in the making.” Truth is an ongoing process, not a fixed state. We can’t fully grasp reality through empirical observation alone.

  • Beliefs, especially religious ones, can be pragmatically useful even if not factually true. A belief is true if it leads to positive consequences like a fulfilling life.

  • We must test ideas through action and experience, not just logical reasoning. The pragmatic method focuses on practical effects rather than abstract principles.

  • Truth is shaped by its effects and usefulness, not just logical validity or correspondence to the facts. Pragmatism focuses on the difference ideas can make in life.

  • Our actions create the world around us. We should “act as if what we do makes a difference” because our beliefs and choices actively construct reality.

That covers the essence of James’s pragmatic philosophy, with an emphasis on practical consequences, experiential truth, the role of belief, and reality as an ongoing process of events. Let me know if you would like me to explain anything in the summary in more depth.

Here is a summary of Nietzsche’s central ideas in Thus Spoke Zarathustra:

• Nietzsche attacks three key ideas of Western thought: our concept of “man”, our concept of God, and our moral ideas. He believes these undermine human potential.

• Nietzsche believes the idea of “man” as traditionally understood in Christianity is limiting. He says we must “surpass” this idea by overcoming Christianity’s belief that this world is less important than some next, spiritual world.

• Nietzsche proclaims “God is dead!”. By this he means belief in God can no longer give meaning or purpose to human life in the modern world. We must find our own sources of meaning and value.

• Nietzsche argues against traditional Christian morality, which he believes promotes a “slave morality” that holds people back. He believes we need a new “master morality” that celebrates human vitality, courage, and purpose.

• Nietzsche’s prophet Zarathustra descends from his mountain retreat to share his wisdom with humanity. But he finds people are not yet ready to receive his radical message about overcoming traditional values and embracing a new vision of human possibility.

• Although Nietzsche’s style is often heated and intense, his work articulates a remarkably cohesive vision of human potential and meaning in a world where “God is dead”. His radical ideas went on to have an enormous influence.

That covers the central themes and ideas in Nietzsche’s influential work. Let me know if you would like me to explain anything in the summary in more detail.

Zarathustra, a prophet modeled on the ancient Persian philosopher Zoroaster, has been living alone in the mountains for 10 years. He realizes that “God is dead” and decides to share this revelation with humankind. On his way down the mountain, Zarathustra meets an old hermit who warns him that no one will understand his radical message.

Zarathustra goes to the marketplace and proclaims the coming of the “Superman” who will overcome ordinary humanity. However, the crowd laughs at him, seeing him as merely an entertainer. To understand Nietzsche’s philosophy, we must look beyond the superficial reception of his ideas.

Nietzsche believes we must reevaluate all values inherited from religion and philosophy. Saying “God is dead” means questioning traditional morality and the idea that a transcendent realm of ideals exists. Nietzsche sees belief in a purely “real” world as a myth that prevents us from living fully in this world.

Both Plato and Christianity divided the world into a transcendent, permanent realm of ideals or heaven and an imperfect sensory world. Nietzsche sees this as devaluing life itself in favor of an illusory afterlife. The Superman represents humanity that has overcome reliance on otherworldly hopes and lives powerfully in this world.

In summary, Nietzsche’s Zarathustra comes down from solitary contemplation to proclaim a radical philosophy of affirming life in this world rather than deferring to otherworldly hopes. But his message meets only incomprehension. Nietzsche sees the belief in a transcendent “real world” as rooted in Plato and Christianity, and as denying life’s value. Overcoming this belief through a “revaluation of values” will produce the Superman.

Here is a summary of Ferdinand de Saussure’s theory of language as a system of signs:

  • Saussure saw language as made up of signs, with each sign consisting of two parts:
  1. The signifier: The sound-image or written symbol that represents something. For example, the word “dog”.

  2. The signified: The mental concept associated with the signifier. For example, our idea of what a dog is.

  • The relationship between the signifier and the signified is arbitrary. There is nothing inherent about the word “dog” that connects it to the concept of a dog. It could just as easily be “chien” or “gou” in other languages.

  • For Saussure, language is a system of relationships between signs. The meaning of any one sign depends on its relationship to other signs in the system. So “dog” only means what it does because of how it differs from “cat”, “log”, “dig”, and so on.

  • Saussure’s theory of language as a system of signs became the foundation for modern linguistics and influenced many philosophers and literary theorists. It provides a way to analyze how meaning is created within language and culture.

  • The key ideas are that:

  • Language is a system of signs

  • Each sign consists of a signifier (a symbol) and a signified (a mental concept)

  • The relationship between the signifier and signified is arbitrary

  • Meaning comes from the relationships between signs within the system

That covers the essence of Saussure’s theory of language, according to my understanding. Let me know if you would like me to explain anything in more depth.

• Henri Bergson believes there are two kinds of knowledge: relative knowledge and absolute knowledge.

• Relative knowledge involves knowing objects from a particular perspective. It is gained through our intellect and reason. We remain distant from the thing itself.

• Absolute knowledge involves knowing objects as they actually are. It is acquired through intuition—a very direct form of knowledge.

• Bergson thinks Immanuel Kant underestimated the importance of intuition. Intuition allows us to grasp an object’s uniqueness through direct connection. It is linked to Bergson’s vitalism: his idea of an élan vital or life-force.

• Bergson gives the example of getting to know a city. Compiling images of the city involves relative knowledge—we remain distant from the living city. Walking the streets and focusing the right way can lead to absolute knowledge of the city itself.

• Intuition means seeing the world in terms of our sense of unfolding time. Our inner sense of time overlaps with the times of the objects around us, allowing direct connection.

• For Bergson, “intuition goes in the very direction of life.” It reflects the vital impulse of life itself. Analysis and intellect pull us away from this direct experience of life.

• Bergson believes philosophy should aim to put us in contact with absolute reality through intuitive thinking. His vitalism sees life as creative evolution.

That’s a summary of Bergson’s ideas relating to intuition, knowledge, and vitalism. Let me know if you would like me to clarify or expand on any part of the summary.

John Dewey was an influential American pragmatist philosopher. He believed that philosophy should help us solve practical problems in life, rather than provide a “true” picture of the world.

For Dewey, philosophical problems arise naturally from living in an uncertain, constantly changing world. We have two main strategies for dealing with this uncertainty:

  1. Appeal to higher powers through religion and ritual. This approach sees the world as governed by mysterious forces that we must appease.

  2. Gain knowledge and control over the world through science and technology. This approach aims to understand how the world works so we can modify our environment, though we can never eliminate uncertainty completely.

Dewey argued for the second approach. He believed philosophy should make experience more coherent and help empower us, like science does. To judge a philosophical theory, we should consider how useful it is in addressing life’s problems.

Dewey had an enormous influence on American thought, especially in education. His work focused on using philosophy to solve practical problems, rather than search for absolute truth. Overall, Dewey offered a “luminous” philosophy that could enrich human experience.

Here is a summary of the key ideas:

Du Bois was a pioneering civil rights activist and intellectual. His philosophical approach was influenced by Pragmatism, emphasizing the practical implications and usefulness of ideas.

Du Bois believed that progress toward a better, fuller human life is possible, but only if we maintain faith in that possibility. Without that belief, we suffer a kind of living death, as human beings cease to grow and progress.

• Du Bois argued that racial inequality was a social problem, not a scientific one. It could only be addressed through political and social action.

• He devoted his life to finding solutions to social inequality in all its forms. In his final message, he expressed the hope that the work he had started would be continued by others.

• Du Bois’s thinking was influenced by ideas of human flourishing that go all the way back to Aristotle. But he gave these ideas a modern, politically engaged interpretation.

• Du Bois rejected claims that black people were inherently inferior to whites. He saw racism as a purely social problem.

• Martin Luther King Jr. cited Du Bois as a key influence. Du Bois pioneered the kind of engaged, active approach that King adopted.

• Inequality and lack of opportunity are social problems that lead to further problems like high crime rates. They must be addressed at their roots.

That covers the essence of Du Bois’s thinking and his significance as an activist and political philosopher. Please let me know if you would like me to explain any part of the summary in more depth.

virtue in leisure too. In the modern

no need of it.

der that we view work through

world, where work has become both

Bertrand Russell

a moral lens that is relic of a less

prestigious and obligatory, we may

enlightened age, and that we need

find Russell’s praise of idleness

A profound thinker who struggled throughout his long and

to see the purpose of work in terms

rather subversive—but perhaps

productive life to diminish injustice and increase human happiness,

of genuine human fulfillment

necessary too. Our obsession

Bertrand Russell argued that we should cast off irrational moral

rather than duty or obligation, is a

with work may not be providing

attitudes that see work as virtuous in itself and embrace more leisure.

prescient one. Work, Russell says,

meaning in the way we expect.

He believed that reducing excessive work would make possible a richer

should be “a means to certain

Some leisure, it seems, might be

and more creative life, so long as leisure was used well. While Russell’s

and a richness of imagination,

Russell tells us, would value both

vision may ignore certain economic realities, his reminder that human

leisure and work, but “would not

work should aim at fulfilling human ends rather than serving as an end

see the former as a bit of residual

in itself remains pertinent. With a balanced and thoughtful approach

waste, which could be eliminated

to human activity, both work and leisure can nurture our humanity.

by the efficiency of utter scientific

• José Ortega y Gasset was a 20th-century Spanish philosopher and existentialist.

• For Ortega, philosophy should engage creatively with life, not just analyze the world in a detached way. Reason allows us to understand and improve our circumstances.

• We cannot separate ourselves from our circumstances. We are always immersed in a particular situation, with certain habits of thought and behavior. Philosophers should strive to understand and change these circumstances.

• To transform our lives, we must look at them with fresh eyes—questioning our assumptions and imagining new possibilities. But our circumstances will always limit how much we can change.

• Life involves a constant collision between the circumstances we find ourselves in and the new futures we can imagine. There is a creative tension between the habitual and the possible.

• Ortega influenced philosophers across Spain and Latin America with his call to actively and creatively engage with life. His philosophy explores what it means for us to realize our freedom and shape our existence.

Here is a summary of Wittgenstein’s key ideas in the Tractatus Logico-Philosophicus:

  • The world consists of facts, which are states of affairs that are either true or false.
  • Language consists of propositions, which are pictures or models of possible states of affairs in the world.
  • Meaningful propositions correspond to possibilities in the world and have sense; nonsensical propositions do not correspond to anything in the world and are meaningless.
  • The limits of language are the limits of the world: we cannot meaningfully speak about things beyond the possibilities of the world.
  • Many philosophical problems arise from misunderstandings about the logic of our language. By clarifying the logical structure of propositions, philosophical problems can be resolved or shown to be nonsensical.
  • What can be meaningfully said at all can be said clearly; propositions on ethics, aesthetics, and religion are nonsensical.
  • The purpose of the Tractatus is to set limits to thought by clarifying the logical essence of propositions and language. Within those limits, meaning can then operate.

The key ideas, then, are that the meaningful content of language is limited to propositions that correspond to and picture possibilities in the world. Nonsensical propositions that go beyond language and the world cannot meaningfully be spoken. By explaining this view of language and logic, Wittgenstein believes many philosophical problems can be addressed.

Martin Heidegger was a German philosopher who is considered to be one of the most influential figures of 20th-century philosophy. He developed a phenomenological approach and devoted much of his work to a fundamental ontology exploring “being” (Sein).

Heidegger’s magnum opus, Being and Time (1927), investigates the meaning of being through an analysis of Dasein, or “being there.” For Heidegger, Dasein refers to human existence and consciousness. He argues that humans cannot be understood in abstraction from the world in which they live. We are fundamentally self-interpreting beings embedded in meaningful contexts with others.

Heidegger’s philosophy focuses on phenomenological analysis of human existence and rejects the notion of a disembodied, rational subject favored in philosophy since Descartes. He seeks to explore how things show up for us in our normal, everyday experience and understand the meaning they have for us. For Heidegger, the question of being aims at uncovering the meaning of being that already permeates our existence but usually remains hidden or covered over.

Heidegger sees human existence as articulated through care, concern, and inquiry. We care about things, are concerned with our being, and inquire into the meaning of it all. Our being is essentially being-with and being-in-the-world. We dwell in possibilities, in projects and goals that matter to us. Heidegger calls this “care structure” of human existence “thrown projection.” We are thrown into a world not of our choosing but still must project our own lives by making choices.

Heidegger wants to understand being through an analysis of the kind of being that asks the question of being: human existence. His phenomenology attempts to get beneath theoretical constructs to the meaningful experience we have as beings-in-the-world. He seeks to revitalize philosophical questioning by uncovering the original sense of being that makes all particular beings intelligible. For Heidegger, philosophy is not a matter of theories but of self-understanding and insight into our own finite, historical existence.

Here is a summary of Tetsuro Watsuji’s view:

  • Tetsuro Watsuji was an influential 20th-century Japanese philosopher who studied both Eastern and Western philosophy.

  • He believed that ethics is not about individual action or choice, but about self-sacrifice for the benefit of one’s community. He called this “betweenness” - the interconnected network of relationships within which we exist.

  • For Watsuji, the individual has no true moral choice outside of sacrificing for the community. Our identity and existence are defined by our relationships and community, not as isolated individuals.

  • He argued against Western individualism and believed that individuals only gain meaning through social relationships. We have obligations to our communities that come before our individual interests or desires.

  • Overall, Watsuji saw ethics as a matter of individuals transcending themselves to act for the common good of their communities. The self is not an end in itself and gains purpose through service to others.

That’s a high-level summary of Tetsuro Watsuji’s view that individuals have a moral duty to sacrifice for the good of their communities. He believed we only gain meaning and purpose through our relationships with and obligations to others.

• Hans-Georg Gadamer was a 20th-century German philosopher associated with hermeneutics, the philosophical study of interpretation.

• Gadamer was influenced by Martin Heidegger, who believed that philosophy should interpret human existence. Gadamer applied this view to interpreting texts and history.

• Gadamer argued that we interpret texts by moving in a “hermeneutic circle”—our understanding of individual parts depends on our sense of the whole, and vice versa. Our interpretations are shaped by our preexisting understandings, or “prejudices.”

• For Gadamer, history and tradition shape our prejudices and identities. We do not have an objective view of history from outside; rather, we are embedded within history. “History does not belong to us but we belong to it.”

• To understand a historical text, we fuse its “horizon of meaning” with our own horizon of the present. This gives us a deeper understanding of both the past and our own time.

• Gadamer’s hermeneutics aimed to overcome the subject-object distinction and show how understanding depends on tradition and historical effect. Our prejudices are not obstacles but the basis for any interpretation.

• Key concepts include: hermeneutic circle, prejudice, historical consciousness, horizon of meaning, fusion of horizons.

• Gadamer built on Dilthey’s view that the human sciences depend on understanding and interpretation, not just explanation. But Gadamer gave hermeneutics a more ontological focus.

That covers the essence of Gadamer’s hermeneutical approach and philosophy of history. Let me know if you would like me to explain anything in the summary in more detail.

such arguments into the form:

is nothing in the premises that

If P then Q

really implies that cats are


banana-flavored. So, because one


of the premises (that all cats are

For example:

banana-flavored) is undoubtedly

If it is an apple, then it is a fruit.

(If P then Q)

It is an apple.


Therefore, it is a fruit.


Therefore, while the form of the argument may be valid,

Deductive reasoning moves from general principles to specific conclusions. It is either valid or invalid, depending on whether the conclusion follows logically from the premises. Valid arguments can be sound (true premises) or unsound (false premises). Inductive reasoning moves from specific observations to general conclusions. No inductive argument can be proven conclusively valid, since we can never rule out the possibility of encountering evidence that falsifies our conclusion. At best, inductive arguments are more or less strong, based on the amount of evidence. According to Karl Popper, science should avoid trying to prove theories true (since this is logically impossible) and instead aim to prove them false through observations and experiments. Theories that have withstood many attempts at falsification become well-corroborated, though never proven.

The key idea expressed in the statement “Existence precedes essence” is that humans have no predetermined essence or nature. Rather, we define our essence or nature through the choices we make. This is a central claim of existentialist philosophy.

Before existentialism, Western philosophy had traditionally held that essence comes before existence. This means that things in the world, including human beings, have a predetermined essence that shapes what they fundamentally are. For human beings, this essence was often thought to be a soul, spirit, or mind that made us essentially rational beings.

In contrast, existentialists like Jean-Paul Sartre argue that there is no predetermined essence that defines human nature. We have no essential self, spirit, or mind that determines what we are. Rather, we define our essence or nature through the choices we freely make. As Sartre puts it, “existence precedes essence”. We exist first, and then create our essence through our choices.

This means that we alone are responsible for defining who we are through the choices we make. We have radical freedom to choose our path in life, and we must accept the responsibility and angst that comes with this freedom. There are no predetermined values or guidelines that define who we should be. We must determine our values and purpose through the choices we freely make.

So in short, the statement expresses the existentialist view that we have no predetermined essence, and we define our essence or nature through the choices we make in life. This is in contrast to views that see human nature as essentially or fundamentally defined by a soul, spirit, or mind. For existentialists, existence comes before essence. Choice and freedom define who we are.

• Jean-Paul Sartre was an existential philosopher who believed that existence precedes essence. This means that humans have no predetermined nature or purpose. We define our own essence or nature through the choices we make.

• Sartre argues that we have radical freedom and responsibility. We are “condemned to be free” and responsible for shaping ourselves and the world.

• Sartre rejected the idea of human nature as limiting our freedom. He believed there were no moral absolutes or guidelines to determine how we should act. We must determine that for ourselves.

• Sartre’s ideas influenced generations of thinkers and activists. His call for radical freedom and responsibility inspired young people in 1960s France to challenge traditional social conventions.

• Hannah Arendt applied Sartre’s thinking to her analysis of evil. She argued that evildoers like Adolf Eichmann are not monsters but ordinary people who fail to think critically about their actions and responsibilities. Evil can be banal, arising from thoughtlessness and conformity rather than radical evil intentions.

• Arendt and Sartre emphasized the importance of individuals thinking critically about their moral choices and not just blindly following social conventions or orders. When we fail to do so, we can be complicit in evil without even realizing it.

That’s a high-level summary of the key ideas discussed in this section on Sartre, Arendt, and the banality of evil. Please let me know if you would like me to explain anything in the summary in more detail.

The key ideas in this passage are:

male is by nature superior, and the female inferior.”

humanity with masculinity. Others,

1919 Virginia Woolf argues for

though less explicit, have imposed

The Look

“a room of one’s own” for

a masculine standard in more

De Beauvoir says that woman is

female literary independence.

subtle ways. For example, when

turned into the “Other” as the

philosophers refer to “Man” as the

object of what she calls “the Look”.


measure of humanity, they usually

In the Look, woman is “trapped

From 1960s Second-wave

mean a male standard according to

as an erotic object under the male

feminism develops around the

which everything else human is to

gaze”. This has profound effects

world, promoting women’s

be judged. Women, then, have had

on woman’s sense of self. She is

rights and gender equality.

to define themselves in relation

rewarded only for her sexual and

to this standard and, in the process,

physical qualities, rather than her

1990s The notion of the “male

have become “the second sex”.

intellectual and moral being.

gaze” in visual culture is

It is in this context that de Beauvoir

explored by feminist theorists.

wrote The Second Sex.

The Self and the Other

Woman as Other De Beauvoir believes that

2000s “Intersectional feminism”

highlights how women from

different backgrounds face

When philosophers refer to

patriarchal societies define woman

different and combined forms

“Man” as the measure of human,

as Other from an early age. She

of discrimination.

women have had to define themselves

is taught that her worth lies in

in relation to this and become “the

pleasing men and being an object of

second sex”. De Beauvoir says that

desire. However, de Beauvoir insists

historically the standard measure

that biology does not determine a

of what we take to be fully human

woman’s destiny. She has free will,

has been male. The male Self is the

and the ability to choose her own

active subject of knowledge, whereas

path in life. Woman, says de Beauvoir,

woman is judged as the passive

must reject her conditioning as Other

object—the Other—in relation to

and regain her sovereignty as a

which everything else human

thinking, conscious, human subject.

See also: Aristotle 56–63 ■ Edmund Husserl 224–25 ■ Maurice Merleau-Ponty 274–76 ■ Jean-Paul Sartre 268–71 ■ Luce Irigaray 320

■ Julia Kristeva 323





ROLAND BARTHES (1915–1980)


French philosopher Roland

each individual advertised product

Barthes was interested in the

and how we perceive it as different.


relationship between language

In other words, difference is built in


and culture. In particular, he studied

to the system of consumerism itself.


the ways in which the media and

Without difference, there would be


popular culture represent the world

no motivation to desire new products.

to us, and how these representations


come to seem natural and inevitable.


1900 Ferdinand de Saussure

In Mythologies (1957), Barthes examines

proposes semiotics: the study

popular culture and advertising

of signs and meaning.

in postwar France. He looks at

The power of difference

everything from magazines, cinema,

Barthes says that no two things have

1950s Jacques Derrida develops

and photography to toys, food, and

ever been absolutely identical. Even

“deconstruction” to challenge

fashion. He wants to decode the

products of the same type differ in

dominant ways of thinking.

myths—the messages and meanings—

some way, whether in color, style,

contained within these cultural

year of production, packaging, or


products. Barthes examines how

brand. And it is these differences

1960s Michel Foucault explores

certain representations come to

that are emphasized in order to make

power and knowledge.

be seen as “natural” and universal.

us desire the product. The differences,

He aims to denaturalize these myths

no matter how trivial, appeal to our

1970s Judith Butler develops

and show that they are constructed,

sense that we are individuals with

ideas of “gender performativity”.

human-made rather than inevitable.

unique tastes—that we consume in order to forge our distinctive identities.

1990s Cultural studies explores

popular and media culture. Barthes also looks at advertising.

Theorists apply Barthes’ ideas.

He says that advertising works by

Barthes’ analysis suggests that the

constantly generating perceived

differences between products—and

differences between products and

even between people—are in many

brands that are in reality very similar.

cases constructed through language

Advertising builds desire through

and marketing. What makes us

the representation of products as

think two garments are crucially

somehow special, unique, or different.

different in look or style is often just

By emphasizing difference, it plays

the way they are advertised and

into consumers’ need for individuality.

represented through brand image. ■

The representation of even tiny distinctions between products fuels

See also: Ferdinand de Saussure 242–45 ■ Jacques Derrida 290–91 ■ Michel Foucault 296–99

■ Judith Butler 304–05

the perception that no two are alike.

In advertising, the differences are next to nothing, but are emphasized for their power to generate desire. Barthes says that it is not the products themselves that differ so greatly, but



Every act of communication involves encoding a message, transmitting it, and then decoding it at the other end. The ancient Greeks realized that language is a system of signs that stand for the things they signify, creating inevitable room for misunderstanding. Polish-American philosopher Alfred Korzybski made a related point in the early 20th century when he said, “The map is not the territory.” A map is a simplified model that represents a complex, multifaceted reality. All language is a map that shapes our perception and understanding. But the danger is that we mistake the map for reality itself.

See also: Plato 68–71 ■ Structuralism 242–43 ■ Post-structuralism 290–92 ■ Deconstruction 290–91

Negative liberty means freedom

obstruction, or interference by

from external obstacles like coercion,

others. This corresponds to what

Berlin believed that there are two concepts of liberty:

Berlin calls “negative” liberty.

Positive liberty refers to the possibility of acting in

Positive liberty is the freedom and

such a way as to take control of one’s life and realize

capacity to determine one’s own

one’s fundamental purposes. This is Berlin’s idea of

destiny, to be in control of one’s

“positive” liberty.

life, and choose one’s own goals.

Berlin argued that these two concepts can conflict. Maximizing

This is self-direction and

positive liberty could require restricting negative liberty.


Excessive focus on negative liberty could prevent the possibility

Berlin argued that both concepts

of positive liberty. A balance is needed between the two.

are important, but they can come

For Berlin, the history of ideas illustrates the dangers of privileging

into conflict. An emphasis on

one concept over the other. Promoting only negative liberty could

positive liberty could lead to

justify limiting it in the name of autonomy or self-realization. But

totalitarianism by restricting

promoting only positive liberty could justify coercion in the name of

negative liberty. But too much

someone’s “real interests”.

focus on negative liberty could

Berlin concludes that in the end, “Everything is what it is: liberty is

prevent the possibility of positive

liberty, not equality or justice or culture, or human happiness or a quiet

liberty or self-fulfillment. For

conscience.” But he also argues that “liberty is liberty, not equality or

Berlin, the key was to find the

fairness or justice or culture, or human happiness or a quiet conscience”.

right balance between the two.

In other words, we should not confuse the concept of liberty with other

While emphasizing that “liberty

political ideals. But we must recognize that liberty alone, without these

is liberty”, he argued that some

other ideals, may not lead to a good society.

measure of both positive and negative liberty is needed. ■

Here are the key points:

• Arne Naess’s concept of “thinking like a mountain” encourages us to

identify with the natural world and see ourselves as part of the whole biosphere, rather than as separate from it.

• Naess claims that broadening our sense of self to include other living beings and nature leads to a more meaningful life. He calls this the “ecological self.”

• Naess argues that we must think about the long-term interests of the environment as a whole, not just our own immediate needs. We must recognize our responsibility to all life on Earth.

• Naess believes living well involves living harmoniously as part of nature, not trying to control or manipulate it for our benefit. We must change our perspective to see ourselves as equal with all elements of our environment.

• Naess’s philosophy of “deep ecology” has been very influential in shaping environmental thought and activism. Although thinking like a mountain may seem difficult for city dwellers, it remains an ideal we can work toward.

to non-academics, or simply

confronting the world. An

Japanese philosopher Ryōsuke

• The post-World War II period saw increasing globalization and the spread of popular culture. There

because life in the closing decades

important strand of postwar

Ōhashi, continued to develop

of the 20th century was

thought was African philosophy,

traditional schools of Western

becoming rapidly more complex.

which sought political as well as

philosophical thought, especially

A bewildering world quite possibly

cultural self-determination after

political theory and ethics. Others

demanded answers rather than

the collapse of European colonial

advocated a “return to the real

more questions. Both the academic

empires. Thinkers such as

world”—a practical, problem-

were major social and political upheavals, including dissent and unrest in Western nations.

• Western philosophy followed an elitist path, distancing itself from popular concerns. Structuralism was influential, promoting the “deconstruction” of texts to reveal multiple meanings. Key proponents included Derrida, Althusser, Foucault, and Lacan.

• Postmodern philosophy rejected objective truths and “grand narratives.” It influenced art and literature but was largely incomprehensible to non-academics.

• Some philosophers focused on practical issues like ethics, politics, feminism, and postcolonialism. African philosophy sought self-determination. Environmental philosophy emerged.

• Ordinary language philosophy and analytic philosophy dominated Anglo-American thought. Quine and Kripke were influential. Searle studied consciousness and language.

• Developments in science, like chaos theory, influenced some philosophers. Buddhism and Taoism also became more prominent in the West.

• Globally, philosophers aimed to share non-Western traditions and create cross-cultural dialogue. Oruka studied “sage philosophy” in Africa.


Kwame Appiah, Paulin Hountondji,

solvent approach to real-world

and Achille Mbembe wrote from

issues. Philosophy itself began to

the perspectives of postcolonial

diversify in several directions.

Ghana and Cameroon. Feminism

Environmental philosophy

was revitalized, addressing

emerged as a discipline in its own

women’s experience in the

right. Buddhism and Taoism

Third World. Environmental

gained more adherents in the

philosophy emerged in response

West. And as concepts from

to growing ecological concerns.

chaos theory and complexity

Analytic philosophy also became

science spread into popular

more socially engaged, with

culture, some philosophers were

philosophers such as Peter Singer

inspired to consider their relevance

promoting utilitarianism and animal

to metaphysics and epistemology.

rights, and John Rawls developing

The rapid progress of

his influential theory of justice.

communications technologies fulfilled the prophecies of Marshall

Anglo-American thought

McLuhan. With telephones,

In the Anglo-American philosophical

satellites, and computers

tradition, ordinary language

enabling instant global

philosophy and analytic philosophy

connections, philosophers were

continued to hold sway. The

grappling with ideas that were

American philosopher W. V. O.

influencing thought across

Quine was instrumental in shifting

cultures. Cross-cultural

the focus of analytic philosophy

philosophy and intercultural

away from logical positivism

dialogue were coming to the

toward more holistic theories of

forefront of the discipline.

knowledge and meaning. Saul

Philosophy was poised to

Kripke’s work in modal logic

become more global than ever

and the philosophy of language

before in its history.

was also highly influential. John Searle, known for his work on speech acts and consciousness,

With increasing globalization, philosophy aimed

towards cross-cultural dialogue and becoming

more globally engaged. There was a new focus on

real-world ethical issues and environmental concerns.

explored the relationship between mind and language. While postmodernism never really took hold in mainstream

world was arguably as intellectually

philosophers were determined

Anglo-American philosophy,

self-absorbed as postmodernism

to share non-Western traditions

the interconnected and media-

at its height, and tended to ignore

with a wider audience. The Kenyan

saturated nature of the modern

pressing societal concerns. Some

philosopher Odera Oruka studied

Ethics became a major concern, with philosophers such as

Peter Singer advocating utilitarianism and animal rights. Environmental philosophy also developed as an important field.


This map shows some of the key nationalities, movements, and subject areas in contemporary philosophy from the mid20th century onward.

FRANCE Jean-François Lyotard Jacques Derrida Deconstruction

Helen Cixous Luce Irigaray Postmodern feminism


Theory of mind Philosophy of language



Devendra Satyarthi Navya-Nyāya school Postcolonialism

Ryōsuke Ōhashi Modern Kyoto school Philosophy of nothingness



Kwame Appiah Paulin Hountondji Achille Mbembe Postcolonialism

Thinkers and movements AUSTRALIA

Peter Singer Utilitarianism, animal rights

John Searle

Subject areas Ethics Politics Aesthetics Metaphysics Epistemology

W. V. O. Quine Saul Kripke Ordinary language philosophy Analytic philosophy


Cornelius Castoriadis Social philosophy

Tetsurō Watsuji Cultural phenomenology


Paulo Freire Critical pedagogy

what he called “sage philosophy”

Philosophy for the Future of the globe. There have been some moves towards more globally engaged,

in rural East Africa, recording the

The world’s philosophical traditions have been dominated by Western schools

thoughts of traditional elders and

of thought for centuries. As globalization accelerates and the world becomes

healers. Other non-Western

more interconnected, one of the major challenges for philosophy today is how

philosophers sought to revive

to broaden its perspectives and facilitate meaningful cross-cultural dialogue.

and revitalize indigenous schools

By acknowledging non-Western philosophies and other ways of thinking as

of thought or open them up to

valuable alternatives, rather than as “exotic” adjuncts to Western thought,

new influences, as with modern

philosophy may come to provide the kind of open and inclusive guidance that an

proponents of Navya-Nyāya

increasingly borderless world requires. To serve the global community, philosophy

(“new logic”) in India, and the

needs to become more reflective of the diversity of human thought. It must seek

Kyoto school’s interpretations of

to understand how different philosophical traditions—Eastern and Western, ancient

Buddhism and phenomenology

and modern—can enrich each other, and ultimately provide a shared vision of

in Japan. Meanwhile, Latin

what it means to lead a good and just existence in the 21st century. This is the

American philosophers such as

challenge that lies before philosophy and philosophers today.

Paulo Freire developed critical and

socially useful philosophy centered on ethics, politics, and the environment.

liberationist philosophies suited to the region. And in Africa thinkers explored indigenous belief systems and their relation to modern political and ethical concerns.

See also: Ludwig Wittgenstein 230–37 ■ Jean-Paul Sartre 268–71 ■ Postmodernism 274–77 ■ Deconstruction 296–99 ■ Postcolonialism 310–13 ■ Feminist philosophy 314–17 ■ Environmental philosophy 332–35


Aesthetics & art criticism


Aesthetics, the philosophical study of art and beauty, became

Ethics continued to be a active area of philosophy. In the

more pluralistic. Postmodern thinkers rejected the idea of

analytic tradition, philosophers such as Philippa Foot and Judith

universal standards of artistic value. Art criticism embraced a

Jarvis Thomson developed forms of virtue ethics and explored

wider range of media, including popular art forms, and feminist

topics like abortion.

■ Kuhn argues that science progresses through a cycle of normal science and revolutions.

1637 René Descartes publishes

■ Normal science is puzzle-solving within an accepted theoretical framework or paradigm.

his Discourse on Method,

■ Anomalies arise that the paradigm struggles to accommodate.

aiming to provide a new

■Eventually, a crisis leads to the emergence of a new paradigm.

philosophical paradigm.

■ There is then a scientific revolution as the old paradigm is replaced.

■ The new paradigm becomes accepted and normal science resumes.


■ Kuhn uses the shift from Ptolemaic to Copernican cosmology as an example.

1970s Criticism of Kuhn’s

■ Normal science aims to elaborate and extend the paradigm, not challenge it.

theory leads to modifications in later editions of The Structure of Scientific Revolutions.

See also: Copernicus 102–07

■ Descartes 118–23 ■ Einstein 242–45

■ Paul Feyerabend 294

1992 Physicist David Bohm

proposes a new “holistic” paradigm to replace existing

quantum theory.






PAUL K. FEYERABEND (1924–1994)



Paul Feyerabend was a

science—science as an ideology,

philosopher of science at the

or “scientific imperialism”. On

University of California, Berkeley.

this view, science tries to impose

Philosophy of science

In his 1975 book Against Method,

a single universal method and


Feyerabend presents a radical

worldview, dismissing competing

critique of the idea that there is

forms of knowledge. Feyerabend

Epistemological anarchism

a single scientific method. He

argues that scientific theories


argues that science is a much

are historically and culturally

more anarchic enterprise than

specific, not universally true.

1959 Physicist and philosopher

its supporters suggest. There are

His attitude to science has been

Thomas Kuhn argues in

no fixed rules governing scientific

described as “epistemological

The Structure of Scientific

progress, only those that scientists

anarchism”—the view that there

Revolutions that science

choose to adopt. Science should

are no universal rules of method

progresses through paradigm

not impose constraints on other

or evidence in science. Feyerabend

shifts, not by a single method.

forms of knowledge.

aims to free thought from the

Fact and reason are tied to

tyranny of abstract rules and ideals.

particular scientific theories.

Science as ideology

Normal science aims at preserving


Feyerabend is critical of the

the status quo, not seeking truth.

1990s French philosopher

popular view of science as

His work is a defence of pluralism.

Jean-François Lyotard argues

the epitome of reason and

in The Postmodern Condition

objectivity. He sees another side

that science is a “language

of science—what he calls “folk

game” with no privileged access to truth. 21st century Critical theories

of science continue to question scientific authority and method.

See also: Thomas Kuhn 293 ■ Postmodernism 308–13

Paul K. Feyerabend Feyerabend was born in Vienna, Austria. He studied physics, mathematics, and philosophy, receiving his doctorate from the University of London in 1951. He held academic positions in several countries, eventually settling at the University of California, Berkeley in 1958, where he remained until his retirement in 1989. Feyerabend’s early work was in the philosophy of science and philosophy of religion. His mature philosophy incorporated insights from many disciplines and cultures. He was critical of concepts such as “reason”, “evidence”, and “truth”, arguing that they often serve ideological purposes. His epistemological anarchism holds that there are no universally valid rules governing science or rational thought. Feyerabend aimed to defend intellectual freedom and plurality of thought. He was influenced by philosophers such as Popper, Wittgenstein, and Duhem. His radical relativism and critique of science earned him both fame and notoriety. He died in 1994 at the age of 70. Key works 1970 Conquest of Abundance 1975 Against Method 1987 Farewell to Reason










David Chalmers is an Australian are knowable without needing to conscious experience in the first

philosopher known for his work

consult the external world.

place. He defends a view known

in philosophy of mind. His central

Chalmers is a dualist about mind

as naturalistic dualism, proposing

Philosophy of mind

focus is on the philosophical

and body. He believes that physical

that consciousness arises from


problem of consciousness: how it

and mental phenomena exist in

non-physical, as yet unknown

relates to the physical world.

separate realms. The existence

phenomena in the natural world.

Property dualism

Chalmers’ key position is that

of consciousness cannot be

Known as the “hard problem”,


consciousness is not logically

explained in purely physical terms.

explaining how physical processes

supervenient on the physical:

Even if we had a completed physics,

give rise to consciousness is, for

17th century Philosophers such

it cannot be wholly accounted for

including a theory of quantum

Chalmers, a tough philosophical

as René Descartes propose

in terms of physical properties and

gravity, this would not on its own

challenge. His work highlights

laws. There are psychological truths

explain why we have the inner

this mystery at the heart of existence.

about consciousness that are not

subjective experiences and

wholly reducible to physical facts.

qualitative feel that make up

Unlike Descartes, however,

consciousness. Physical theory

Chalmers does not appeal to a

leaves open the question of why there

nonphysical mind but argues

is something it is like to be conscious,

that science must face the hard

rather than just mechanisms.

problem of understanding how

Independence of consciousness Chalmers argues for the logical independence of consciousness from the physical world. There are truths about consciousness that

dualism to account for mind.

Martial arts and philosophy were my two passions growing up. Both involve cultivating skills for mental discipline and clarity.


2000s Chalmers’ arguments prompt much debate on consciousness and dualism. Some philosophers advocate

physicalism; others defend See also: René Descartes 118–23 ■ Mind–body problem 232 ■ Contemporary theories of mind 320–21

alternative theories.

Chalmers’ early interest in philosophy was sparked by debates over the mind–body problem in an introductory philosophy course. His doctoral work at Indiana University focused on the philosophy of mind under Douglas Hofstadter. After receiving his PhD in 1993, Chalmers held positions at UC Santa Cruz, UC Berkeley, and the Australian National University before becoming Professor of Philosophy and Director of the Centre for Consciousness at the Australian National University. Chalmers defends the idea that consciousness is a fundamental feature of reality that cannot be explained in purely physical terms. He argues for a kind of property dualism, proposing naturalistic principles to account for the emergence of consciousness. Chalmers believes we will need to develop more fundamental theories of consciousness, physics, and the relationship between them. His work has been very influential in shaping modern debates on the philosophy of mind. Key works 1996 The Conscious Mind: In Search of a Fundamental Theory 2002 Philosophy of Mind: Classical and Contemporary Readings (editor) 2010 The Character of Consciousness

David Chalmers






BELL HOOKS (1952–)



bell hooks is the pen name

us to open up and expand our of Kentucky. In her view, love is

of Gloria Jean Watkins, an

capacity for connection. For it is

not a feeling but an act of will—

American author, feminist, and

only when we love without fear

the decision to connect with others

Philosophy of love

social activist. In her

The key ideas in Paul Feyerabend’s philosophy are:

• There is no one correct “scientific method.” The progress of science is not governed by strict rules.

• Traditional philosophies of science are too limiting and rationalist. They fail to capture how science really progresses.

• Scientific revolutions involve radical changes that alter concepts and the meaning of theories. There are no permanent frameworks.

• The only principle that fits the actual history of science is “anything goes.” All methodologies have their limits, so none should be ruled out.

• Strict rules and a rationalist view of science can limit progress. An “anarchistic” and open-minded approach is needed.

• Science is a human activity embedded in a social and political context. It does not provide an “objective” account of the world.

• There are no hard and fast distinctions between science and other areas like religion, mythology, and art. They should be seen as continuous.

• Our knowledge of the world is always limited and fallible. We should remain open-minded and skeptical of truth claims.

• Feyerabend was influenced by Popper but came to differ significantly from Popper’s more rationalist philosophy of science.

That’s a good summary of Feyerabend’s radical and controversial philosophy of science. The key point is his rejection of a strict “scientific method” and rationalist view of how science progresses in favor of a more open-minded, skeptical, and anarchistic approach.

Frantz Fanon was born

1925 on the island of Martinique,

a Caribbean island that was then

thought. He was struck by the

The Wretched of the Earth,

a French colony. He served in the

discrepancy between the ideal

which became a hugely influential

Free French forces during World

of a universal French citizenship

work of anti-colonial theory.

War II, then studied psychiatry and

promised by the Revolution of

Fanon died in 1961 at the age

philosophy in France. His exposure

1789 and the discrimination and

of 35, and was buried in Algeria.

to racism when he first arrived in

lack of opportunity he witnessed.

France profoundly shaped his

In 1952, while practising as a

Key works

thinking. He became interested in

psychiatrist in Algeria, Fanon

how colonized people internalized

1952 Black Skin, White Masks

the values of the colonizer, and

1961 The Wretched of the

how racism caused psychological


harm. While in Algeria, Fanon

1965 On National Culture

See also: Jean-Paul Sartre 268–71 ■ Sigmund Freud 276–81 ■ Edward Said 321



EDWARD SAID (1935–2003)

human sciences. Said argues that


Most of us tend to think of

in many cases our knowledge of

knowledge as something that we

other cultures is distorted by the


discover about the world as it really

prejudices and interests of Western

Philosophy of culture

is. But according to Edward Said’s

scholars. He criticizes the “school

book Orientalism, published in 1978,

of Orientalism”, which presents


the facts we believe about other

Islamic cultures as intrinsically


cultures are often not objective

exotic, reactionary, and inferior,

truths, but are shaped by the

reflecting European colonial


power structures in which they are

interests rather than any objective

1930s Frantz Fanon argues

produced. In particular, Said argues

truth. In this way, Said argues,

that colonial racism leads

that European scholarship about the

reality is, to some extent, created

colonized peoples to

Middle East and Islam—what he calls

by language.

internalize a sense of

“Orientalism”—was distorted by the


colonial politics of the time.

Imagined realities

Said’s argument has been very

Said was born in Jerusalem and

1952 Fanon publishes

influential in post-colonial studies

grew up in both Palestine and

Black Skin, White Masks,

and critical theory. His central claim

Egypt. He was well placed to see

exploring the impact of

is that our knowledge and beliefs

how misleading and distorted were

colonialism on identity.

about other cultures are shaped by

many Western accounts of Middle

“imagined geographies” and systems

Eastern culture. Said argues that


of representation over which we

Orientalism is an example of how

1993 Indian critic Homi

have little control. These imagined

“imagined geographies”— fictional

Bhabha develops Said’s

geographies reify and distort

concepts of place that have little

ideas in The Location

complex realities.

to do with the real world—come to

of Culture.

Said applied this insight to

be accepted through repetition as

Western scholarship about the East,

facts. Works of scholarship create

or “Orientalism”—the academic

these imagined realities through

study of Islamic and Middle Eastern

the power structures of knowledge.

culture, history, and languages in


See also: Frantz Fanon 300–01 ■ Michel Foucault 308–13 ■ Noam Chomsky 333

Western scholars shape

Our knowledge of other

their portrayal of “the Orient” to

suit dominant Western stereotypes.

cultures is often distorted

The power of scholars

by the prejudices and

to shape knowledge means

interests of the West.

they construct imagined

geographies that distort Under Western colonialism, the

the complex realities

ability to construct knowledge

Edward Said

about colonized peoples was a way

Edward Said was born to Palestinian

and received his PhD in literature

to dominate and control them. By

Christian parents in British-

from Harvard University in 1964.

describing Islamic cultures as exotic,

administered Jerusalem in 1935.

He taught English and comparative

unchanging, and primitive, Western

The family moved to Egypt, where

literature for over 40 years at

scholars provided a justification for

Said was educated in British and

Columbia University in New York.

colonial rule. Yet all cultures contain

American schools. He graduated

complex realities that go far beyond

from Princeton University in 1957

Key works

such simplistic stereotypes.

By revealing Orientalism as an “imagined geography” created to serve the interests of colonial

1978 Orientalism 1993 Culture and Imperialism

domination, Said exposed how the

1996 Representations

construction of knowledge can be

of the Intellectual

shaped by relations of power. His

2003 Freelancing from

work has been profoundly influential

New York City: Edward

in alerting us to the political and

Said in conversation

ideological forces that inform all

with BPS

knowledge—especially knowledge

2008 Power, Politics and Culture:

of “the Other”. Orientalism remains

Interviews with Edward Said

a landmark work in post-colonial studies and critical theory. ■

See also: Frantz Fanon 300–01 ■ Robert Nozick 328 ■ Salman Rushdie 335

of the colonized.





restructures society and that we are



The phrase “the personal is

not merely victims of macro-level

political” is central to feminist

social forces, but active agents in


thinking. It suggests that aspects of

the social and political processes that

our lives that are often considered

shape our lives. It invites political


“private” or “personal”—such as

analysis and action on issues


gender roles in the family, sexuality,

that disproportionately affect and

and work–life balance—are deeply

discriminate against certain groups.


influenced by political and social

Aspects of our lives that might

1792 Mary Wollstonecraft argues

structures. They are not simply

seem “natural” or unchangeable

for women’s rights in her

“natural” or intrinsic to human

can be revealed as social constructs

essay A Vindication of the

nature, but are shaped by the

that serve to maintain relations

Rights of Woman.

distribution of power in society.

of power and dominance. That

1869 John Stuart Mill

The phrase expresses the idea

includes traditional gender roles,

argues for women’s equality

that there is no strict separation

assumptions about sexuality, and

and empowerment in The

between the public spheres of work,

the gendered division of labour both

Subjection of Women.

politics, and government on the one

in the home and workplace. Feminist

hand, and the supposedly private

activists argue that bringing issues


spheres of the family, sexuality,

such as violence against women,

1960s The feminist movement

and personal relationships on the

economic inequality, control of

analyses and challenges

other. The feminist movement

reproduction, and double standards

social and political

has applied this insight to show

of sexuality into the public sphere of

inequalities systematically

how gender inequality is sustained

politics is crucial to addressing the

shaping women’s lives.

through the gendered division of

root causes of gender inequality.

1990s “Third wave feminism”

labour in both public and private

focuses on issues of race,

life, as well as socially constructed

Sexuality and politics

class, sexuality

and he has worked at MIT

least, we should apply the same

since 1955. In the 1960s,

ethical standards to our own

• Noam Chomsky is best known for his political and ethical analyses.

Chomsky became a prominent

governments and policies that we

• He argues that we should apply the same ethical standards to our own

anti-war activist, and began to

apply to other governments and

governments that we apply to others. If we fail to do so, we live in illusion.

publish political works critiquing

policies. In other words, we should

• Governments often justify their actions with rhetoric rather than evidence.

US foreign policy. His political

not give our own government a free

We need to look at the actual evidence of what governments do.

works, such as American Power

pass on moral issues. If we assume

• For Chomsky, the key ethical principle is “universality”—we should judge

and the New Mandarins (1969),

that our own government is

all governments by the same moral standards. Mere rhetorical claims are

helped to shape left-wing

naturally more ethical than other

not enough.

thinking for decades.

governments simply due to a kind of patriotic allegiance, then we are

Key works

choosing “to live in a world of

1957 Syntactic Structures

comforting illusion.” To break with

1975 The Logical Structure of

this illusion, Chomsky argues, we

Linguistic Theory

need to subject our own

1985 Reflections on Language

government’s policies and actions

2002 Understanding Power:

to the light of evidence and reason.

The Indispensable Chomsky

And when a government calls on

(edited by Peter R. Mitchell

us to support some war or policy,

and John Schoeffel)







Though embracing some

ideas from Jacques Lacan

and Michel Foucault, the


Slovenian philosopher Slavo


Žižek takes contemporary


critical theory in a distinctive

Cultural criticism

direction. Building on an

analysis of contemporary

philosopher and cultural critic,


culture, Žižek argues that

Žižek explores how ideologies

1990 Michel Foucault’s lectures

we are embedded in an intricate

operate and maintain their grip. He

and works from the 1970s

web of illusion. We think and

suggests that in order to free

onward provide an analysis

talk in ways that mask more

ourselves from ideology, we need

of power, discourse, and

than they reveal. Breaking out

to analyze how the “symbolic

the social construction

of illusion means confronting

order” and cultural codes of

of knowledge.

the traumas and anxieties that

meaning work to spin “cocoons”

1972 Jacques Lacan’s Encore:

we normally keep hidden.

that trap us in illusion.

The Seminar of Jacques Lacan,

That is, how do ideologies arise

Book XX continues his

from the process of making meaning

We are born

meaningless realm of the

itself—from the basic human need

into a world of

“Real” with the symbolic

to symbolize the world, to make

order of language, culture,

it meaningful?

ideological meanings

yearned-for Real that remains elusive.

The society of the spectacle,

… and we have to

original meaninglessness of existence

in which we now live, bombards

make our way out of the

is the source of desire.

us with meaningful images that

and meaning

attempt to reconcile the

illusion they create.

idea that our distance from the

AFTER 1997 American social

have more to do with fantasy

than with facing hard truths. To

Slavoj i ek seeks for

escape the web of illusion created

philosopher Fredric Jameson

by these images, i ek argues, we

publishes The Cultural Turn,

trauma behind the web

have “traverse the fantasy”—to

calling for philosophy to turn

of meanings and social

face up to the anxieties and

its attention to culture.

practices that ensnare us.

traumas that the fantasies mask.

2000s i ek becomes the

This involves confronting both the

most prominent contemporary

meaninglessness of existence and

Critical Theorist, fusing Marxism,

the antagonisms that society

psychoanalysis, and culture.

conceals. Only then can we hope

to attain a kind of freedom.


See also: Michel Foucault 302–03 ■ Jacques Lacan 310–11 ■ Jean Baudrillard 312

We are born into a world of ideological

time about television, films, popular

meanings and meaning… and we have to

culture, politics, philosophy, and

make our way out of the illusion they create.

the social zeitgeist. He has been called “an Elvis of cultural theory.”

Slavoj Žižek

Though sometimes accused of overproduction, i ek’s works

Žižek’s suggestions here echo

are highly influential and help to

those of earlier philosophers

make complex ideas in critical

such as Foucault and Lacan, but

theory and postmodernism

his approach is distinctive. Rather

accessible to a wide audience.

than seeing ideology as simply

Key works

“imposed” upon us by those

Slavoj i ek

in power, i ek analyses how

Žižek was born in Ljubljana,

1989 The Sublime Object

ideologies emerge from the very

Slovenia (then part of Yugoslavia)

of Ideology

process of making meaning—

in 1949. He studied philosophy

1991 Looking Awry: An

from our need to symbolize and

at the University of Ljubljana,

Introduction to Jacques Lacan

render the world intelligible. The

gaining his PhD in 1981. He went

through Popular Culture

truths that ideologies mask are

on to teach at the University of

2000 The Fragile Absolute

not simply empirical facts but the

Ljubljana, and has held visiting

antagonisms inherent in human

positions at universities across

society and existence itself.

Europe and North America.

To “traverse the fantasy” in

i ek fuses Marxism,

this sense is to confront the

psychoanalytic theory, and

traumas and anxieties that fuel

postmodern philosophy to develop

our social meanings and practices.

an original and influential analysis

Rather than seeing ideology as

of contemporary culture, politics,

something imposed on us to

and society. He is an unusually

justify domination, i ek analyses

engaged and prolific writer, giving

it as a kind of spontaneous

frequent public lectures, appearing

symbolic “solution” to the enigma

in documentaries, and publishing

of the human condition itself.

on a very wide range of topics at a

or Why Lacan is Not an Anti-Philosopher 2008 In Defense of Lost Causes 2012 Less Than Nothing: Hegel and the Shadow of Dialectical Materialism 2015 Trouble in Paradise: From the End of History to the End of Capitalism 2017 Like a Thief in Broad Daylight: Power in the Era of Post-Humanity

prolific rate. He writes all the

In this picture, the possibility of

“freedom” lies in unflinchingly

confronting the antagonisms we

usually seek to avoid through the

weaving of shared social fictions. ■

Traversing the fantasy, in Zizek’s view, means confronting the anxieties and traumas behind the meanings and practices of

ideology. It is not about simply rejecting current beliefs in favor of “the facts”, but involves acknowledging deeper existential truths.







Graham Harman is one of

the central

Here is a summary of Derrida’s key ideas:

hors-texte”), we first need to understand a little more about his approach.

• Texts are not self-contained wholes that we can fully understand or interpret. They are riddled with “aporias”, or contradictions and paradoxes.

• Our everyday assumption that speech is primary and writing is secondary is misguided. Writing shapes thought in complex ways (“grammatology”).

• The word “différance” points to the endless ways in which meaning is deferred in language. Meaning is always pushed off into the future, different from itself.

• Deconstruction aims to identify the aporias and paradoxes within texts to show how they unravel themselves. It is not a method or theory but an activity.

• Derrida is skeptical that we can distinguish clearly between “inside” and “outside” of a text, or between “literal” and “metaphorical” meanings. There are only complex webs of meaning.

• Ethics and justice cannot be defined traditionally through abstract concepts or rules. They emerge through radical openness to the Other. Deconstruction has an ethical impulse.

• We are all mediators and translators. Meaning is produced through the endless play of signification in the act of reading. There are no stable meanings or origins to uncover.

• Derrida’s work leads to a notion of “undecidability”, recognizing that we can never achieve a final interpretation or understanding of a philosophical problem. We must remain open.

That covers some of the central ideas in Derrida’s thought and his radically different way of approaching how we understand language, meaning, ethics, and our relationship to texts. Let me know if you would like me to explain anything in the summary in more detail.

Here is a summary of Richard Rorty’s view:

  • Rorty rejects the notion that we have an eternal, unchanging “soul” or self that relates to some absolute truth. Instead, he sees human beings as social constructs, shaped by the cultures and communities we are a part of.

  • Rorty advocates a pragmatic view of truth and knowledge. For pragmatists like Rorty, concepts are not judged based on how well they correspond to some ultimate reality. Rather, they are judged based on how useful they are in helping us achieve our goals and purposes.

  • Rorty thinks philosophy should not aim for metaphysical truths or a “God’s-eye view” of reality. Instead, philosophy should aim to create new vocabularies and ways of thinking that are useful for accomplishing our shared human ends, like reducing cruelty and suffering. Philosophical progress happens through expanding our imaginations, not through discovering absolute truths.

  • For Rorty, there are no universal moral rules or absolutes. Our moral values are shaped by the communities we are a part of. But we can still make moral progress by enlarging our sense of shared community and shared moral purpose with others. The test of any belief is whether or not it helps create a more just and equitable society.

  • Rorty believes human beings are fundamentally undetermined by any eternal essence or nature. We have the freedom and responsibility to shape ourselves and our societies. By expanding our imaginations and sense of shared community, we can create the kind of world we want to live in. But there are no guarantees in life or philosophy - we simply have to make it up as we go.

That covers the essence of Rorty’s pragmatic and anti-foundationalist philosophy. Let me know if you would like me to explain anything in the summary in more detail.

Here is a summary of Richard Rorty:

  • Richard Rorty was an American philosopher who worked in the pragmatist tradition. He rejected the notion that knowledge is a matter of accurately representing an independent reality.

  • Instead, Rorty argued that knowledge is shaped by social conventions and what we are able to get away with saying. There are no absolute moral truths or fundamental essences to be discovered.

  • Rorty followed Wilfrid Sellars in rejecting the “myth of the given”—the idea that we have direct access to raw sensory data. Our perceptions are shaped by the concepts and language we have learned. Knowledge is a matter of conversation and social practice, not mirroring nature.

  • Rorty argued against the idea of knowledge as representation. He claimed we do not need to believe in absolute moral laws or deeper truths in order to live ethical lives. Conversation, social solidarity, and hope for the future are enough.

  • Rorty maintained that we do not need metaphysical comforts like the idea of an eternal soul. We are finite beings whose existence is limited to life on Earth. But we can work to create a world worth living in for future generations.

  • Key works: Philosophy and the Mirror of Nature (1979), Contingency, Irony and Solidarity (1989)

Here is a summary of Oruka’s key ideas:

showing some influence from

and activities, to study philosophers

African traditions.

in oral cultures who had not studied

  • Philosophy is not limited to written texts. Oral traditions can also contain

Western-type philosophy formally.

1960s With decolonization in


This approach allowed Oruka to

Africa, philosophers such as

  • Oruka proposed “philosophic sagacity” - an ethnographic approach to studying

identify and interview several sages

Oruka begin to explore African

philosophy within oral cultures. This involves observing and interviewing people

in Kenya and show that philosophy

thought and philosophies.

within their everyday setting.

was alive and active in the oral


  • Using this approach, Oruka identified several “sages” in Kenya who engaged in

traditions of Africa. ■

2000s Philosophers such as

philosophical thinking and discussion within their communities.

Kwame Gyekye continue to

  • Oruka argued that philosophy should not be limited to academics in universities

explore and articulate

but can be found in everyday life. Philosophers within oral cultures who have not

specifically African traditions

studied Western philosophy formally can still be recognized as philosophers.

of thought.

  • Overall, Oruka wanted to challenge the notion that philosophy only resides within written academic texts and show that it can be found within everyday life and oral cultures. His work helped bring recognition and legitimacy to African philosophies that had previously been overlooked.

Zeno’s paradoxes discussed the contradiction between the reality of an infinitely divisible material world and our perception of the world as composed of discrete and separate objects moving between locations. He aimed to prove that motion is impossible, through arguments like “Achilles and the tortoise” - by the time Achilles reaches the place the tortoise started, it will have moved on; when Achilles reaches the new place the tortoise will have moved on again, and so on infinitely. Though his paradoxes aimed to disprove the reality of motion, they instead highlighted certain problems in logical reasoning itself and spurred subsequent philosophical work in various fields including logic and the philosophy of space and time.

Zeno’s paradoxes were important precursors to philosophical problems that remain relevant today in fields like logic, mathematics, metaphysics, and physics.

Here is a summary of key points about the philosophers you mentioned:

• Plotinus founded Neo-Platonism, dividing the cosmos into layers from the One at the top to the material world at the bottom. He believed in reincarnation and the immortality of the soul.

• Hypatia taught mathematics, astronomy and philosophy in Alexandria. She was murdered by a Christian mob though little of her work survives. She is credited with inventing several scientific instruments.

• Proclus succeeded Syrianus as head of the Academy in Athens. He wrote influential commentaries on Euclid and Plato’s Timaeus. He was a Neo-Platonist but also a scientist, mathematician, lawyer and poet.

• Al-Kindi helped introduce ancient Greek ideas to the Islamic world. He worked in Baghdad translating classical texts into Arabic and wrote on psychology, cosmology and more.

• Al-Farabi was influenced by Plato and Aristotle. He saw philosophy as the route to knowledge and believed philosophers should guide society. He described a utopia ruled by philosopher prophets in The Ideas of the Citizens of the Virtuous City.

• Al-Ghazali was a Neo-Platonist who became a Sufi preacher. He came to believe God caused all events and that truth comes through faith and mysticism, not philosophy.

• John Philoponus studied with Ammonius Hermiae in Alexandria. A Christian philosopher and scientist, he argued the universe had a beginning caused by God. He criticized Aristotle, influencing later thinkers like Galileo.

• Johannes Scotus Eriugena said reason and revelation were compatible. He tried to show Christian doctrine had a rational basis though this brought him into conflict with the Church.

• Pierre Abelard was a logician who criticized the belief in universal forms inherited from Plato. He set up his own school and became head at Notre Dame Cathedral in Paris. He is better known for his affair with Heloise than his philosophy.

• Ibn Bajja used Plato and Aristotle to show reason and faith were compatible. He said the path to enlightenment and God was through reason and action. But individuals must make their own journey and the enlightened should not impose their views on others.

• Meister Eckhart followed Aquinas but was accused of heresy for his mystical sermons on God’s presence in the soul. He acknowledged his florid language may have led him to stray from doctrinal orthodoxy.

Here are the main points summarized:

  • Grosseteste: 13th-century English philosopher and scientist. He studied Aristotelian logic and emphasized both inductive reasoning from particular observations to universal laws, and deductive reasoning from universal laws to predictions of particulars.

  • Llull: 13th-century Catalan philosopher. He tried to use reason and logic to persuade people of different faiths to convert to Christianity. He wrote the Ars Magna, which combined basic tenets of monotheistic religions in different ways to demonstrate Christian truths.

  • Duns Scotus: Influential 13th-century Franciscan friar and philosopher. He argued against Aquinas that attributes applied to God have the same meaning as when applied to ordinary things. He said we perceive particulars directly, without general concepts. Knowledge comes through the senses, not divine illumination.

  • Ockham: 14th-century Franciscan friar and philosopher. Known for “Ockham’s Razor”: the simplest explanation is the best. He argued universals are abstractions from experience of particulars. Precursor to British empiricism.

  • Suarez: 16th-century Jesuit philosopher. Argued only particulars exist. Said there is “middle knowledge”: God knows what would have happened if things were different, without causing events or making them unavoidable.

  • Mandeville: Early 18th-century Dutch philosopher. In The Fable of the Bees, argued society progresses through vice, not virtue. Said virtues are lies rulers tell people to control them. Economic growth comes from pursuit of self-interest, not virtue.

  • Condorcet: 18th-century French philosopher and mathematician. Advocated equal rights, free education for all. Noted voting paradoxes. Played key role in Revolution but opposed executing Louis XVI and died in prison.

  • Schelling: 19th-century German idealist philosopher. Said nature is ongoing evolutionary process driven by spirit. Mind and matter are in continuous organic process. Mechanistic views inadequate. Human consciousness is nature become conscious. In man, nature reaches self-consciousness.

An individual’s ability to satisfy his self-interest and greed.

See also: Descartes, Voltaire, Rousseau

Here are some of the key terms used in philosophy and their definitions:

cannot both be true together.

“emotive meaning” refers to the

emotive use of language,

The opposite is consistent.

Anthropic principle The idea

emotional attitude or feeling

that fundamental laws of physics

Cosmology The study of the origin,

expressed by the words used.

must be compatible with the

structure, and development of the

existence of self-aware observers.

universe as a whole.

Epistemology The branch of

philosophy that studies the nature

Appearance How something

Critical philosophy Kant’s

and possibility of knowledge. Key

appears to be, which may or may

revolutionary attempt to subject

debates include whether knowledge

not coincide with how it really is.

all knowledge to critical scrutiny.

comes from senses alone, from

This led him to distinguish between

reason alone, or from a combination;

matter and mind, phenomena

whether any knowledge is certain,

and noumena.

or whether there are limits to what

The opposite is reality.

Aristotelian Aristotle’s teachings

and methods, including the

we can know.

doctrines of the “golden mean”,

Critical theory A method of

four causes, and essentialist view

social analysis associated with the

Essay A short piece of nonfiction

of nature. Opposed to Platonic.

Frankfurt School in the early 20th

writing, typically on a single

century. It aimed to subject social

subject and reflecting the writer’s

Axiom A proposition or statement

and political doctrines and practices

own reasoning and opinions.

that is self-evident or accepted

to scrutiny to discover their hidden

without proof as the basis for

assumptions and interests, and to

Essence The fundamental attribute

further arguments or deductions.

transform society and human

that makes a thing what it is:

experience for the better.

without which it would not be that thing. For Aristotelians, essences are eternal, unchanging, and mind-



matism The view that God does

Mind–body problem The puzzle

Postmodernism A movement in

not intervene directly in the world

of how the mind relates to the

culture, especially arts and philosophy,

he has created, which follows its

body. In particular, how can a non-

since around the 1970s characterized

own autonomous laws. Associated

physical mind interact with the

by rejection of the idea of universal

especially with deism. The opposite

physical realm, and how can a non-

objective truths about the world or

is occasionalism.

material mind be affected by material

“metanarratives” encompassing

events in the brain and body.

it. Postmodernists emphasize the role of language, power relations,

Metaphysics The branch of

Modus ponens A form of logical

and personal inclinations in

philosophy that studies the ultimate

argument comprising two premises

shaping beliefs and the impossibility

nature of existence and reality.

and a conclusion: P implies Q, P;

of attaining objective knowledge

Key issues include whether the world

therefore Q. For example:

of the world. They celebrate

contains only physical objects, or also

If it is raining, the streets are wet.

pluralism, relativism, irony, and

minds, abstract entities, and values;

It is raining.

pastiche. Leading postmodernist

whether things have essences or

Therefore, the streets are wet.

thinkers include Jean-François Lyotard,

natures; whether free will and

Jacques Derrida, and Michel Foucault.

determinism can be reconciled;

Monism The view that reality

whether God exists; and the relation

consists of only one thing, or

Pragmatism A philosophical

between particular things and

substance, such as matter or mind.

movement developed in the USA

universals. Key philosophers include

The opposite is dualism.

around the turn of the 20th century.

Plato, Aristotle, Aquinas, Descartes,

Pragmatists argue that the meaning

Hume, Kant, Hegel, and Schopenhauer.

Naturalism The view that

of beliefs and concepts should be

everything that exists is part of the

judged by their practical implications

Modern In philosophy, the period

natural world and should be

and consequences. Truth is what is

from around the 17th century to the

explained using the methods of

useful and works. The leading

19th century, as opposed to ancient

science. Naturalists believe there

pragmatists were Charles Sanders

and medieval. Key figures include

are no supernatural or mystical

Peirce, William James, and John

Descartes, Locke, Hume, Kant, Hegel,

entities and that philosophy and

Dewey. Their ideas influenced

Schopenhauer, Nietzsche, and Marx.

ethics should be based on scientific

20th-century philosophical movements

knowledge of human nature and the

such as analytical philosophy.

Modernism A cultural movement,

laws of the universe. Key proponents

including in philosophy, spanning

include David Hume, Bertrand

Rationalism The view that reason

the late 19th and early 20th centuries.

Russell, and W. V. O. Quine.

alone, not sense experience, is

Modernists believed that traditional

the basis of certain kinds of

forms and beliefs were becoming

Necessary Cannot be otherwise;

knowledge, especially knowledge of

outdated in an era of scientific and

it must be the case. The opposite

fundamental principles in mathematics,

technological progress. They aimed

is contingent.

ethics, and metaphysics. Key rationalists

to find new ways of capturing the changing experience of modernity

include Plato, Descartes, Spinoza, Neurath’s boat An analogy used by

through experimental styles and

Otto Neurath to illustrate how

Realism The view that (i) an

subjects in art, architecture, and

science progresses through small

external world exists independently

literature. In philosophy, modernists

incremental changes rather than

of our perceptions and representations

such as Russell aimed to make

through revolutions. Scientists are

of it; and (ii) truth consists in the way

knowledge more scientific and logical.

like sailors who must rebuild their

statements correspond with this

Postmodernism reacted against

ship while at sea, replacing planks

external world. Realists typically

these modernist values.

one by one.

believe in objective truths that can be

and Leibniz.

discovered through reason and experience.


The opposite view is idealism. Prominent realists include Aristotle, Aquinas, Russell, Moore, and David Lewis.

Reductionism The aim or belief

Solipsism The view that one can

Theory of types A logic proposed

that complex things can be explained

only know that one’s own self and

by Bertrand Russell to avoid paradoxes

by analyzing them into their

experiences exist. It is taken by

caused by self-reference. It does this

constituent parts or reduced to

some as an inescapable conclusion

by distinguishing types of expressions

simpler component elements or

of Cartesianism or subjective

and stipulating that expressions

relations between them. Reductive


of one type can only refer to, or

explanations are common in science,

quantify over, expressions of the

as when chemical reactions are

Sophism deceptive or fallacious

same type or a lower type. So no

explained by appealing to the

reasoning. In ancient Greece,

expression can refer to or quantify

behavior of molecules. In philosophy,

Sophists were traveling teachers

over itself. This avoids the paradoxes

reductionism is often associated

who, for a fee, taught rhetoric,

that arise from self-reference.

with physicalism or logical atomism.

logic, and philosophy. Plato was highly critical of them in some

Transcendence Something

dialogues, accusing them of using

Relativism The view that truth,

supersensible or metaphysical that


Summary: The term epithet is often used in a derogatory way for utterances that pretend to be objective or impartial while in fact expressing emotional attitudes, as for example in “emotive definition.”

166, 170, 171

Jean-Jacques Rousseau 153

Critique of Urteilskraft, Immanuel Kant 171

discrimination 288, 288, 289, 290, 303, 304,

Croce, Benedetto 337

305, 337

characteristic; for example “fur or hair is a defining property of a mammal.”


See also primary and secondary qualities.

divine command theory 98

Daniel Dennett 113, 325, 339

divine commands 97

Dard, Émile 284

existentialism 17, 213, 213, 214, 242, 331

Darwin, Charles 24, 142, 162, 164, 193, 194

divine right theory 107

external ideals 84, 85

Darwinism 164, 164, 165

Doctor Angelicus 91

external world 14, 132, 133, 135, 136, 139,

David Hume 150, 151, 152, 153, 154, 343, 167

Doctor Subtilis 333

140, 142

de Beauvoir, Simone 214, 276, 283

Dostoevsky, Fyodor 90, 216

extreme idealism 139, 139

de Unamuno, Miguel 233–5

Dualism 16, 122, 127, 312

The Synthesis project 14, 17, 166, 170, 171, 185

death 86, 179, 180, 181, 181, 182, 183, 184, 186, Duns Scotus, John 95, 333

186, 204, 212, 243, 244, 245, 284

Durkheim, Émile 291

Democritus 14, 16, 45, 45, 65, 66, 93, 330

Dying for Ideas, Otto Hintze 285

deontology 195, 325 Derrida, Jacques 309–13, 310 Descartes, René 53, 63, 120–27, 122, 124, 134, 166, 167


ego 78, 109, 111, 112, 118, 119, 127, 132, 145, 148, 176, 182, 189, 203, 204, 205, 221, 222, 233, 236, 245, 265, 269, 279, 291, 310, 320, 322

human instantiation of innate knowledge 81

Theory of Universals 43, 51

Einstein, Albert 191, 197 Eleatics 40, 41, 330

human nature 156, 340

The Universal 95 Thesis 334

Emotive theory of ethics 206

The Universal Base of Knowledge and Morals 92

Empiricism 13, 49, 58, 60, 81, 101, 133, 140,

Deities emulate universal forms 84

Enemy, the 306

348, 340

Theories that narrow all knowledge to a single framework hold a distrust of overarching narratives

they manifest themselves in our consciousness, without making any assumptions about their nature as independent things.

ends and means 196, 196

David Hume 150–53

Engels, Friedrich 16, 145, 158, 159, 159,

ego 278, 278

289, 299

interpretation 209, 261, 290

human flourishing 235

Enlightenment, the 15, 133, 140, 160, 172, 201,

means and ends 96, 196

275, 334

metaphysics 341

The city-state of classical Greece espoused the principle of equality for its citizens 50

equality 50, 203, 288, 322

observation 58

Ereignis 335

property 13, 342

The philosopher seeks to understand the totality of human knowledge and experience, recognizing that knowledge does not come packaged in disciplines, but is deeply unified

essence 55, 56, 57, 58, 59, 342

the 353

Tiberius Claudius Marcus Aurelius 22

essentialism 55, 56, 89

The core of philosophy is not to give answers or prescribe solutions, but to ask the right questions and explore ideas

esse 91, 92, 93, 94

The Enlightenment political Thinkers emphasized the importance of reason and progress for society 20

ethics 13, 15, 64, 74, 84, 85, 86, 92, 97, 98,

The philosophical historian seeks to understand the totality of human knowledge and experience

106, 189, 196, 206, 235, 236, 243, 294,

Social and politcal philosophies often reflect the prevailing values, assumptions and ideologies of a time 19

295, 325

The ancient Athenians believed that eternal abstract forms or essences existed apart from particular objects 57

Epicureanism 64, 65

Existential philosophy focuses on individuals and personal choice 17

G. E. Moore 203

The foundations for moral philosophy were laid down by the ancient Greek philosophers 75

Immanuel Kant 165

The speculative God of medieval theology dictated what was morally right or wrong through divine commands 97

John Dewey 209, 228, 230

Religion and philosophy were not clearly distinguishable in the ancient world 82

John Rawls 294

Many Enlightenment political philosophers emphasized social contract theory and the rights of the individual 107

John Stuart Mill 193

At the core of Plato’s philosophy is the Theory of the Forms 51

Jürgen Habermas 299, 300, 300

The Christian church was not strictly separated from temporal power during much of the medieval period 91

Karl Popper 262

A basic principle of ethics is that the means are as important as the ends 96

Max Scheler 240

empiricism 60, 101

Michel Foucault 303

The core of existential philosophy is the commitment to human freedom and the resolve to shape one’s existence 214

end, the 64

Niccolò Machiavelli 106

The core concerns of philosophy have remained remarkably consistent over time 17

Otto Hintze 285

Philosophy probes beneath the surface of things to investigate their ultimate meaning and significance 16

Paul Feyerabend 297

The essence of utilitarianism is that the ultimate standard of moral rightness is the greatest happiness for the greatest number

Peter Singer 325

The core of philosophical pragmatism is its focus on human practice and experience 228

Plato 46, 47, 48, 50

Logical positivism arose in the early 20th century and held that the only meaningful statements were those that could be verified empirically 257

R. M. Hare 294 slavery and morality 337

  • Jean-Jacques Rousseau: Swiss-French philosopher known for his contributions to social contract theory and modern political philosophy. Key works include The Social Contract and Emile.

  • Rene Descartes: French philosopher and mathematician known as the “Father of Modern Philosophy”. Key works include Meditations on First Philosophy and Discourse on the Method.

  • Friedrich Nietzsche: German philosopher known for his critiques of Christianity and traditional moral values. Key works include Thus Spoke Zarathustra and The Gay Science.

  • Plato: Ancient Greek philosopher, student of Socrates, and founder of the Academy in Athens. Key works include The Republic, Symposium, and The Apology.

  • John Locke: English philosopher known as the “Father of Liberalism”. Key works include Two Treatises of Government and An Essay Concerning Human Understanding.

  • Emmanuel Kant: German philosopher considered central to modern philosophy. Key works include Critique of Pure Reason, Critique of Practical Reason, and Metaphysics of Morals.

  • Socrates: Ancient Greek philosopher who lived in Athens and founded Western philosophy. Known primarily through the works of his student Plato.

  • Aristotle: Ancient Greek philosopher and polymath, student of Plato and founder of Aristotelianism. Key works include Nicomachean Ethics, Politics, Metaphysics, and Poetics.

  • William James: American philosopher and psychologist, leader of the philosophical school known as pragmatism. Key works include Pragmatism and The Varieties of Religious Experience.

  • Voltaire: French Enlightenment writer, historian, and philosopher known for his advocacy of civil liberties, including freedom of religion, freedom of speech, and separation of church and state.

Here are summaries of the requested entries:

Of Grammatology, Jacques Derrida: Derrida critiques the privileging of speech over writing in Western philosophy. He argues that writing is not merely a representation of speech, but shapes meaning and thought.

Mandeville, Bernard: An Anglo-Dutch philosopher and political economist. He is best known for The Fable of the Bees, which argues that private vices can lead to public benefits.

Mishneh Torah, Moses Maimonides: A code of Jewish religious law compiled by the medieval philosopher Moses Maimonides. It summarizes the laws and practices from the Torah and Talmud.

Offray de la Mettrie, Julien: An 18th-century French philosopher and physician. He is considered an early pioneer of materialism and atheism. His book Man a Machine argued that humans are purely material beings that can be explained by the laws of physics.

Here is a summary of the index entries:

  • Aldo Leopold: American ecologist and environmentalist
  • Tanabe, Hajime: Japanese philosopher; helped introduce phenomenology to Japan
  • Warhol, Andy: American artist and pioneer of Pop art movement
  • Watsuji, Tetsuro: Japanese philosopher; studied Western philosophy and Buddhism
  • Weber, Max: German sociologist and philosopher; studied rationalization and bureaucracy
  • The Second Sex: Influential 1949 book on the treatment of women in society by Simone de Beauvoir
  • The Social Contract: 1762 book by Jean-Jacques Rousseau on the relationship between individuals and the state
  • The Structure of Scientific Revolutions: 1962 book by Thomas Kuhn on the development of scientific theory
  • Thus Spoke Zarathustra: 1883 book by Friedrich Nietzsche featuring the prophet Zarathustra
  • Time: central concept in philosophy relating to change, motion, and causality
  • Tragic Sense of Life: 1913 book by Spanish writer Miguel de Unamuno on humanity’s desire for eternal life
  • Transcendental idealism: theory that our knowledge of the external world depends on innate concepts of the mind
  • Truth and Method: 1960 book by Hans-Georg Gadamer on philosophical hermeneutics
  • Wittgenstein, Ludwig: Austrian-British philosopher; proposed that philosophical problems arise from conceptual misunderstandings
  • Wollstonecraft, Mary: British writer and women’s rights advocate
  • Women’s rights: the rights of women to political, social and economic equality
  • Yeats, William Butler: Irish poet and mystic
  • Zen Buddhism: school of Mahayana Buddhism emphasizing meditation and intuition
  • Zeno of Citium: Greek philosopher; founded the Stoic school of philosophy
  • Žižek, Slavoj: Slovenian philosopher and cultural critic; incorporates psychoanalytic, Marxist and postmodern theory

Here is a summary of the images in 3 sections:

Section 1: Images 291-323

  • Images from major photographic archives and image libraries including Getty Images, Corbis, Alamy, etc. Mostly photographic portraits and artworks. Includes images of philosophers like Aristotle, Avicenna, Descartes, etc. as well as images related to philosophical ideas like “all is flux”.

Section 2: All other images

  • Artworks and diagrams used as illustrations for philosophical concepts and ideas. Includes images representing ideas such as “nothing exists except atoms”, “the soul is distinct from the body”, “God has no attributes”, etc.

Section 3: Further information

  • Reference to Dorling Kindersley, a publisher, for further information about the images.

The summary outlines the types of images used (photographs, artworks, diagrams) as well as the sources for the images (major image libraries and archives) and credits Dorling Kindersley as the publisher. The specific images and their captions are not summarized since that level of detail does not seem necessary for this high-level summary. Let me know if you would like me to elaborate on any part of this summary.

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