This page is a survey, not an advocacy. Every philosophical school described here has produced serious thinkers working on genuine problems, and every one of them faces genuine objections. The goal is to present each school’s strongest version of its central claims, identify the problems it is responding to, and note where the objections bite hardest — without pretending that any one school has settled the questions it addresses.

The organisation is roughly chronological within the Western tradition, with sections at the end on Eastern philosophy and contemporary analytic philosophy. The divisions between schools are never as clean as a survey makes them appear — philosophers read and argue with each other across apparent boundaries — but the groupings are useful as first approximations.

Note - This page contains the detaills only about the schools of thought, about which I have read and have some understanding. There are many other schools of thought, which I have not read and do not have any understanding of, notably the schools of thought in Indian, Chinese and Islamic philosophy.

I — Ancient Greek Philosophy

The Pre-Socratics (6th–5th century BCE)

Philosophy in the Western tradition begins not with questions about how to live but with questions about what exists. The Milesian school — Thales, Anaximander, Anaximenes — asked what the world is fundamentally made of. Thales proposed water; Anaximenes, air; Anaximander, the apeiron, an indefinite, boundless substance from which all things emerge and to which all things return.

The significance of this is not the specific answers (which are wrong) but the form of the question: they were trying to explain natural phenomena without invoking myth or divine will. This is the beginning of naturalistic explanation — the assumption that the world has an internal order that reason can discover.

Heraclitus (c. 535–475 BCE) introduced the doctrine of flux — “you cannot step into the same river twice” — and the Logos, a universal rational principle underlying apparent change. Everything is in constant change; the stability we perceive is an illusion sustained by the Logos.

Parmenides took the opposite position: genuine change is impossible, because to say that something changes is to say that it goes from being to non-being, but non-being cannot exist. Therefore only Being exists — one, unchanging, eternal, and indivisible. This is the first fully explicit metaphysical argument, and it is startlingly powerful. The problem it poses — how to reconcile the appearances of change with the logical argument against it — drove much of subsequent Greek philosophy.

The Atomists — Leucippus and Democritus — proposed the solution: reality consists of tiny, indivisible particles (atoms) moving through void. Change is real but is just the rearrangement of atoms. Nothing is genuinely created or destroyed; the patterns change, the atoms do not. This is a position that, in its broad outlines, turned out to be correct.

Sophism (5th century BCE)

The Sophists — Protagoras, Gorgias, Thrasymachus, Callicles — were professional teachers of rhetoric and argument, and they introduced a significant shift from questions about the nature of the world to questions about human knowledge and values.

Protagoras’ famous claim: “Man is the measure of all things: of things which are, that they are; of things which are not, that they are not.” This is the first explicit statement of relativism: truth is relative to the individual or community doing the measuring. There are no mind-independent facts — only facts-for-someone.

Gorgias went further: nothing exists; if anything existed, it could not be known; if it could be known, it could not be communicated.

The Sophist problem. The relativism of the Sophists generates a self-refutation: is the claim that “all truths are relative” itself relatively true (in which case it can be denied) or absolutely true (in which case it contradicts itself)? Plato devoted much of his philosophical career to refuting the Sophists, and the Socratic method is in large part an instrument developed for that purpose.

Socrates and the Socratic Method (c. 470–399 BCE)

Socrates left no writings. What we know of him comes primarily from Plato’s dialogues, which represent his thought in a literary form that may or may not accurately report his actual views.

The Socratic method (elenchus) is a form of cooperative argumentation in which a claim is submitted to a series of questions designed to reveal its internal contradictions. The method typically proceeds by: (1) getting the interlocutor to commit to a definition of some concept (justice, piety, knowledge); (2) finding counterexamples that the interlocutor also accepts; (3) showing that the original definition is inconsistent with these counterexamples. The result is typically aporia — the recognition that one does not know what one thought one knew.

Socrates’ claimed virtue: he knows that he does not know. This is not scepticism but intellectual humility — the beginning of philosophy is the recognition of ignorance.

The political dimension: Socrates was tried and executed in 399 BCE on charges of corrupting the youth and impiety. His death — accepting execution rather than compromising his principles — became one of the founding narratives of Western philosophy.

Platonism (c. 428–348 BCE)

The Theory of Forms. Plato’s central metaphysical claim is that the world of sensory experience — the world of particular objects that change, are born, and die — is not the most fundamental reality. Behind it lies the world of Forms (or Ideas): eternal, unchanging, perfect templates of which particular things are imperfect copies. The Form of Beauty is perfectly beautiful; particular beautiful things are beautiful only to the extent that they participate in the Form of Beauty.

This is a response to two problems at once: Parmenides’ argument (there must be something genuinely unchanging) and the Sophists’ relativism (there must be objective standards of truth, beauty, and justice). The Forms provide the unchanging standards.

The Allegory of the Cave. People are like prisoners in a cave, seeing only shadows on the wall and mistaking them for reality. Philosophical education is the process of turning around and ascending toward the sun — the Form of the Good — which illuminates all other Forms.

Epistemology. Knowledge (episteme) is possible only of the Forms; the sensory world yields only opinion (doxa). This produces a sharp distinction between genuine philosophical knowledge and the shifting opinions of everyday life.

Politics. The Republic argues that the ideal state is governed by philosopher-kings — those who have ascended to knowledge of the Good and can therefore govern justly. Democracy, on this view, is inferior because it privileges opinion over knowledge.

The objections. Aristotle’s Third Man Argument: if the Form of Man is invoked to explain what particular men have in common, we need a further Form to explain what particular men and the Form of Man have in common, generating an infinite regress. More broadly: the relationship between Forms and particulars (the “participation” relation) was never satisfactorily explained. The Forms are either explanatorily empty or they generate more problems than they solve.

Aristotelianism (384–322 BCE)

Aristotle was Plato’s student and the most systematic philosopher of antiquity. He rejected the Theory of Forms and developed a philosophy grounded in empirical observation and the analysis of particular things.

Hylomorphism. Every particular thing is a composite of matter (hyle) and form (morphe). The form of a thing is not a separate entity in another realm — it is the structural organisation of the matter. The form of a human being is the organisation of matter that makes it capable of rational activity; it does not exist separately from the body.

The four causes. To fully explain something you need to specify: the material cause (what it is made of), the formal cause (its form or structure), the efficient cause (what brought it into being), and the final cause (its purpose or telos). The telos is particularly important: things have a nature that involves characteristic activities and ends. The good of a thing is the realisation of its telos.

Ethics and the good life. Aristotle’s ethics is eudaimonist — centred on eudaimonia, often translated as “happiness” or “flourishing.” Eudaimonia is not a subjective feeling but the objective state of living and faring well, which involves the excellent exercise of those functions that are characteristic of human beings — especially rational activity. Virtue (arete) is a stable disposition to feel and act in appropriate ways; it is acquired by practice.

Logic. Aristotle invented formal logic — the syllogism, categorical logic, and the theory of valid inference. This remained the dominant logical system in the West for over two thousand years.

The objections. The teleological framework became difficult to sustain after Darwin: natural selection produces the appearance of design without any actual purpose. The concept of eudaimonia is contested — is it a single thing or a plural cluster of goods? The hylomorphic account of mind (the soul is the form of the body) raises difficulties about personal identity and survival of death.

Epicureanism (341–270 BCE)

Founded by Epicurus, the school taught that the highest good is ataraxia — tranquillity, freedom from mental disturbance — combined with aponia, the absence of physical pain.

Pleasure. Epicurus was a hedonist in a specific and qualified sense: the highest pleasure is not intense bodily pleasure but the stable, calm pleasure of ataraxia. Intense pleasures often lead to pain (the hangover, the consequence). The best life involves simple pleasures — friendship, philosophical discussion, moderate food and drink — that do not create dependency or disturb tranquillity.

Death and fear. The fear of death is the primary source of human suffering. Epicurus’s argument against it: “Death is nothing to us. When we are, death has not come, and when death has come, we are not.” Death is not a bad state for the person who dies, because there is no person who dies to experience it. This is the “symmetry argument” — the time after death is no worse than the time before birth, and we do not regret the latter.

Atomism and theology. Epicurus adopted the atomic theory of Democritus: the soul is made of atoms and dissolves at death. The gods exist but are indifferent to human affairs — they do not intervene and should not be feared.

The objections. The claim that death is nothing to us is disputed: many people rationally care about what happens after their death (to their loved ones, to their work) even if they will not experience it. The preference for simple pleasures over intense ones requires some standard other than pleasure itself to justify it. The Epicurean life of retreat from politics was criticised even in antiquity as a failure to meet civic obligations.

Stoicism (3rd century BCE – 2nd century CE)

Founded by Zeno of Citium, developed by Cleanthes, systematised by Chrysippus, and given its most enduring literary form by Seneca, Epictetus, and Marcus Aurelius.

The fundamental distinction. The most important Stoic idea is the distinction between what is up to us (eph’ hēmin) and what is not. What is up to us: our judgments, desires, aversions, and the responses we choose. What is not: our bodies, property, reputation, other people’s actions, and external events. The Stoics called the latter group adiaphora — indifferent things.

Virtue as the only good. Because happiness depends only on what is up to us, and what is up to us is our rational faculty and the virtues we develop through its exercise, virtue is both necessary and sufficient for eudaimonia. Wealth, health, and reputation are “preferred indifferents” — better to have than not to have, but not constitutive of the good life.

The Logos and cosmopolitan ethics. The Stoics believed the universe is pervaded by the Logos — divine Reason that organises everything. Human rational souls are fragments of this Logos. Because all humans share in the Logos, the Stoics were among the first cosmopolitans: all human beings are members of a single world community, and our duties extend beyond the polis.

The three Stoic disciplines:

  • The discipline of desire: desire only what is genuinely good (virtue); accept what happens as the expression of the Logos
  • The discipline of action: act for the common good with “reservation” — do your best but accept whatever outcome follows
  • The discipline of assent: control your judgments; do not let external events disturb your inner rational faculty

Key thinkers:

  • Epictetus (c. 50–135 CE): a former slave whose Discourses and Enchiridion are among the most direct expressions of Stoic practice. “Men are disturbed not by things but by the opinions about things.”
  • Marcus Aurelius (121–180 CE): Roman emperor, Meditations — a personal journal of Stoic practice. Uniquely valuable as evidence that the philosophy could be genuinely lived.
  • Seneca (c. 4 BCE–65 CE): letters and essays of extraordinary literary quality. More willing than Epictetus to engage with Epicurean arguments.

The objections. The claim that virtue is sufficient for happiness is counterintuitive: torture, severe illness, and the death of loved ones seem to matter more than the Stoics allow. The “preferred indifferents” category is contested — if health and friendship are truly indifferent, why care about them at all? The picture of complete rational control over one’s responses can seem psychologically unrealistic and potentially alienating.

Cicero and the Roman Reception (106–43 BCE)

Marcus Tullius Cicero (106–43 BCE) occupies a unique position in the ancient philosophical tradition: not an original systematic thinker but the most important transmitter of Greek philosophy to the Latin-speaking world, and a political figure of the first rank who tested philosophical ideas against the realities of Roman republican life. His De Finibus surveys and evaluates the competing accounts of the highest good (Epicurean, Stoic, Aristotelian); De Officiis — written in the last months of his life as Caesar’s heir was consolidating power — is a sustained treatment of duty derived largely from Stoic sources but addressed to practical political life. His Tusculan Disputations cover death, pain, grief, and the emotions from a broadly Stoic perspective. The De Re Publica and De Legibus transpose Platonic and Stoic political philosophy into a Roman republican framework. Cicero’s significance is threefold: he created the Latin philosophical vocabulary that the medieval church would inherit (translating Greek terms like logos and phronesis into Latin equivalents that persisted for fifteen centuries); he provided the fullest surviving account of Stoic and Academic ethics; and he demonstrated, through his own career and death — assassinated on Antony’s orders after refusing to abandon his principles — that the question of how to live philosophically in political life is not merely academic.

Cynicism (4th century BCE)

Founded by Antisthenes, given its most vivid expression by Diogenes of Sinope. The Cynics took the Socratic insight that conventional goods (wealth, status, pleasure) are not genuine goods and pushed it to its logical extreme.

Diogenes lived in a barrel, masturbated in public, and told Alexander the Great to stand out of his sunlight. The point was not eccentricity for its own sake but a deliberate rejection of social conventions as obstacles to genuine virtue. The good life requires only virtue, which requires only rational self-sufficiency, which requires the deliberate stripping away of every conventional comfort and social role.

The legacy. Cynicism influenced Stoicism heavily — the Stoic distinction between genuine goods and preferred indifferents is a moderated version of the Cynic position. Diogenes’ cosmopolitanism — he called himself a citizen of the world — was adopted by the Stoics. The Cynic critique of power and convention anticipates aspects of anarchist and counter-cultural thought two thousand years later.

Scepticism (3rd century BCE onward)

Academic Scepticism (Arcesilaus, Carneades): no belief can be known with certainty; the appropriate response is epoché — suspension of judgment. This position grew out of the Academic engagement with the Stoics, who claimed that some impressions are self-evidently certain.

Pyrrhonian Scepticism (Pyrrho of Elis, Sextus Empiricus): more radical. The Modes of Scepticism (the Agrippan trilemma) — all justification is either circular, regressive, or based on an undefended assumption. Therefore, suspend judgment on everything, including on the claim that judgment should be suspended.

The practical problem for Pyrrhonism: if you suspend all judgment, how do you act? Pyrrho’s answer was to follow appearances and customs without commitment. The school produced the most systematic surviving critique of dogmatic philosophy in antiquity: Sextus Empiricus’s Outlines of Pyrrhonism and Against the Mathematicians.

Neoplatonism (3rd–6th century CE)

The final major school of ancient Greek philosophy, centred on Plotinus (204–270 CE) and later Porphyry, Iamblichus, and Proclus. Neoplatonism developed Plato’s thought into a comprehensive metaphysical system organised around a hierarchy of being.

The One. At the summit is the One — entirely beyond being, thought, and language. Below it is Intellect (Nous), which contemplates the Forms. Below Intellect is Soul, which generates the material world. The emanation from the One downward is not a temporal event but an eternal structure.

The mystical ascent. The goal of the philosophical life is to ascend this hierarchy through purification and contemplation, ultimately achieving henosis — union with the One. This is an essentially mystical programme, and it deeply influenced Christian, Jewish, and Islamic theology.

II — Medieval Philosophy

Christian Philosophy: Augustine (354–430 CE)

Augustine synthesised Neoplatonism with Christian doctrine. God is the One beyond being; knowledge of God is achieved through interior illumination, not external sense perception. The Confessions — a philosophical autobiography — presents the soul’s restless search for God as the central human narrative. The City of God provides a philosophy of history organised around the distinction between the earthly city (organised by self-love) and the City of God (organised by love of God).

Original sin and free will. Augustine’s account of the Fall and its consequences — humanity’s will is corrupted, unable to achieve good without divine grace — generated the problem of free will and predestination that occupied Christian philosophy for over a millennium.

Scholasticism and Thomas Aquinas (1225–1274 CE)

Scholasticism was the dominant intellectual method of the medieval universities: the systematic reconciliation of Christian theology with Aristotelian philosophy. Thomas Aquinas’s Summa Theologica is its crowning achievement.

The Five Ways. Aquinas offered five arguments for the existence of God:

  1. From motion: there must be an unmoved mover
  2. From efficient causation: there must be an uncaused first cause
  3. From contingency: there must be a necessary being
  4. From degrees of perfection: there must be a most perfect being
  5. From teleology: the order of nature implies an intelligent designer

Each argument moves from an observed feature of the world to a necessary condition for that feature.

Natural law. Moral principles are knowable by reason because they are grounded in human nature and its teleological orientation toward the good. The natural law tradition is one of the most influential frameworks in the history of ethics and law.

Faith and reason. Aquinas held that faith and reason are not in conflict — they address the same truths from different directions. Reason can establish many theological truths (God’s existence, some divine attributes); faith supplements reason with revealed truths that reason alone cannot reach.

William of Ockham (c. 1287–1347): Nominalism and Ockham’s Razor

Ockham’s nominalism: there are no universals — no Forms, no essences, no real categories beyond individuals. When we call both Socrates and Plato “human,” we are using the same word, not pointing to a shared universal.

Ockham’s Razor: Entia non sunt multiplicanda praeter necessitatem — entities should not be multiplied beyond necessity. Explanations should not invoke more entities than are required. This methodological principle became one of the most influential in the history of science.

Niccolò Machiavelli (1469–1527): Political Realism

Machiavelli is not a systematic philosopher but a political thinker of the first importance whose work constitutes a fundamental break from the classical tradition.

The Prince (1513): a manual for political power that begins from the observation that moral idealism in politics is self-defeating. The effective ruler must know how to use both force and cunning, how to appear virtuous while acting otherwise when necessary, and how to think in terms of outcomes rather than principles.

The break: every political philosopher before Machiavelli — Plato, Aristotle, Cicero, Augustine, Aquinas — asked “what is the best state?” and answered in terms of justice or the common good. Machiavelli asks “how does power actually work?” and answers empirically, not normatively.

Virtù and Fortuna. Political success requires virtù — not classical virtue but something closer to prowess, skill, and determination — deployed against Fortuna, the goddess of chance. A prince who can impose his will on circumstances, adapting to changing conditions, achieves stability.

The legacy. Machiavelli is the founder of modern political science and the ancestor of political realism in international relations. The Discourses on Livy — his republican masterpiece, less read than The Prince — argues for the superiority of republics grounded in civic virtue. The full picture is more complex than the caricature of “the end justifies the means.”

III — Early Modern Philosophy

Rationalism (17th–18th century)

Rationalism holds that knowledge — at least the most important and certain knowledge — is obtained through reason alone, independent of sensory experience. The a priori truths of mathematics are the model.

René Descartes (1596–1650): cogito ergo sum — “I think, therefore I am” — is the first indubitable starting point surviving systematic doubt. The method of doubt (doubt everything that can be doubted; what remains is certain) produces the cogito as the Archimedean point of knowledge. From this Descartes argues for the existence of God and the external world.

The mind-body problem: Descartes is a substance dualist — mind and body are entirely distinct substances (thinking thing vs. extended thing). They interact, but how remains deeply problematic (Descartes’ own answer involved the pineal gland). This is one of the hardest unsolved problems in philosophy of mind.

Baruch Spinoza (1632–1677): rejects Cartesian dualism. There is one substance — God or Nature (Deus sive Natura). Mind and body are not distinct substances but two attributes of the one substance. The Ethics, written in the geometric style of Euclid, derives an entire metaphysics and ethical framework from definitions and axioms.

Gottfried Leibniz (1646–1716): the world is composed of monads — indivisible, non-spatial, non-interacting mental substances. The appearance of causation and physical interaction is the result of God’s pre-established harmony. Every monad’s entire history is contained in it from creation.

Empiricism (17th–18th century)

Empiricism holds that all knowledge — or all substantive knowledge about the world — is derived from sensory experience. The mind begins as a tabula rasa (blank slate).

John Locke (1632–1704): the mind starts empty; all ideas come from experience. The Essay Concerning Human Understanding distinguishes primary qualities (shape, size, motion — genuinely in objects) from secondary qualities (colour, taste, smell — dependent on our perception). Two Treatises of Government provides the founding arguments for liberal political theory: natural rights, consent of the governed, right of revolution.

George Berkeley (1685–1753): takes empiricism to its idealist conclusion. Primary qualities (shape, size) are as mind-dependent as secondary qualities. All that exists are minds and ideas. “Esse est percipi” — to be is to be perceived. This eliminates the problematic distinction between mind-independent objects and our perceptions of them, at the cost of making the external world entirely mental.

David Hume (1711–1776): the most rigorous and devastating empiricist. If all ideas come from experience, we should find in experience the foundations of our most important beliefs — causation, the self, moral facts. The result:

  • Causation: we perceive only constant conjunction and temporal succession — A followed by B. The “necessary connection” we believe in is not observed but projected by habit. This is Hume’s problem of induction: no amount of past regularities logically justifies predictions about the future.
  • The self: introspect, and you find only a bundle of perceptions — no unified, persistent self is observed.
  • Moral facts: moral claims do not describe facts; they express sentiments. “You cannot derive ‘ought’ from ‘is’” — the is-ought gap.

These three arguments remain among the most important in philosophy. Kant said Hume “awoke him from his dogmatic slumber.”

Immanuel Kant (1724–1804): The Critical Philosophy

Kant attempted a synthesis of rationalism and empiricism — a “Copernican revolution” in philosophy. Rather than asking how the mind conforms to reality, he asked how reality as we experience it is structured by the mind.

The transcendental framework. The mind imposes certain structures on experience: space and time (the forms of intuition) and the categories of the understanding (causality, substance, unity, etc.). These are not derived from experience — they are the conditions of any possible experience. This explains why mathematics (which concerns pure intuitions of space and time) and natural science (which applies the categories) yield necessary and universal knowledge.

The limit of reason. The categories only apply within possible experience. When we try to apply them beyond experience — to God, the soul, and the world as a whole — we generate antinomies: contradictions that arise because reason overreaches its legitimate domain.

Ethics: the categorical imperative. Moral worth comes from acting from duty — from a rational principle rather than inclination. The categorical imperative: “Act only according to that maxim whereby you can at the same time will that it should become a universal law.” A second formulation: “Act so that you treat humanity, whether in your own person or that of another, always as an end and never as a means only.”

The objections. The transcendental framework raises the question: if we can only know phenomena (the world as structured by our cognitive apparatus) and not things-in-themselves (Ding an sich), are we not forever cut off from reality as it is? The categorical imperative has been criticised as too formal — it seems to rule out any action whatsoever when universalised, depending on how you describe it.

IV — 19th Century Philosophy

German Idealism: Hegel (1770–1831)

Hegel accepted Kant’s insight that reality is structured by mind but rejected the limitation to individual consciousness. Absolute Idealism: reality is the self-unfolding of Absolute Spirit (Geist) — a rational process in which Mind comes to know itself through history, culture, and philosophy.

The dialectic. The standard formulation (not Hegel’s own): thesis → antithesis → synthesis. More accurately: a position encounters its contradictions, is negated (Aufhebung), and sublated into a higher position that preserves and transforms both. This is the logical structure of reality.

Philosophy of history. History is the progress of freedom — the Absolute coming to self-consciousness through the institutions and cultures of successive peoples. The Prussian state of Hegel’s time is presented (controversially) as the culmination of this process.

The Phenomenology of Spirit: begins with the most immediate form of consciousness (sense-certainty) and traces its development through self-consciousness, reason, spirit, religion, and absolute knowing. One of the most demanding and influential texts in philosophy.

Utilitarianism: Bentham (1748–1832) and Mill (1806–1873)

Jeremy Bentham established utilitarianism as a systematic ethical theory: the morally right action is the one that maximises utility — pleasure minus pain — summed over all affected individuals. The felicific calculus proposed measuring pleasure and pain by intensity, duration, probability, and other dimensions.

John Stuart Mill refined and deepened Bentham’s framework. Utilitarianism introduces quality distinctions: “it is better to be Socrates dissatisfied than a fool satisfied.” On Liberty defends the harm principle: the only legitimate basis for limiting individual freedom is to prevent harm to others — not the person’s own good, not offence to others’ sensibilities.

The objections. The utility monster: a being who gets more pleasure from resources than anyone else would, on utilitarian grounds, deserve all resources. The replaceability problem: pure utilitarianism seems to imply that any person could be replaced by another with higher utility. The separateness of persons: by aggregating utility across individuals, utilitarianism seems to license sacrificing some people for others in ways that violate their rights.

Marx and Marxism (1818–1883)

Historical materialism. History is driven by the material conditions of production — the means of production (technology, resources) and the relations of production (ownership, class structure). The superstructure (politics, law, religion, philosophy) is shaped by and serves the base.

Class struggle. History is the history of class conflict: master and slave, lord and serf, bourgeoisie and proletariat. The capitalist system is inherently exploitative: workers produce surplus value that is appropriated by capitalists.

Alienation. Under capitalism, workers are alienated from their labour (which is not their own), from the product of their labour (which belongs to capital), from other workers (with whom they are in competition), and from their species-being (the creative, cooperative nature of human beings).

The Communist Manifesto and Capital. The Manifesto is a polemical political document; Capital is a detailed theoretical analysis of capitalism and its contradictions. The prediction: capitalism contains internal contradictions that will lead to its eventual supersession by communism.

The objections. The predictions about capitalism’s collapse have not come to pass in the form Marx envisaged. The theory of value (labour theory of value) is contested by economists. The historical record of regimes claiming to implement Marxism is bleak. But the analysis of class, power, ideology, and the material determinants of consciousness remains influential across the social sciences.

Nietzsche (1844–1900)

Nietzsche resists classification into a school. He is a diagnosis, not a system — an attempt to understand the cultural situation of 19th-century Europe and what it demands.

The death of God. Not primarily a claim about religious belief but about the collapse of the metaphysical and moral framework that Christianity had provided. “God is dead. God remains dead. And we have killed him.” The question: now what? Without a transcendent ground for morality, how do we avoid nihilism?

Nihilism and its overcoming. Nietzsche was not a nihilist — he was a diagnostician of nihilism and its pathologies. The passive nihilist gives up; the reactive nihilist resents life and takes revenge on it. The task is active overcoming: the creation of new values.

The Will to Power. Not the crude “will to dominate others” but something closer to the drive toward self-overcoming, the expansion of capacities, the creation of meaning. Life itself is characterised by the will to power in this sense.

The Übermensch (Overman). Not a racial or political category but a philosophical one: a being who does not inherit values but creates them. The Übermensch is the response to the question “what do we do after the death of God?”

Eternal recurrence. The thought experiment: if you had to live your life over, in exactly the same way, infinitely many times, would you choose it? The answer is a test of one’s relationship to life — whether one genuinely affirms it or merely endures it. Amor fati — love of fate.

Master and slave morality. The Genealogy of Morals traces how Christian-derived morality is a sublimated form of resentment (ressentiment) — the morality of the weak who, unable to overcome the strong, revalue weakness as virtue and strength as vice. Good/evil is the slave’s revaluation; good/bad is the master’s.

The objections. The concept of the Will to Power is vague enough to be applied to almost anything. The Übermensch is an ideal so demanding as to be practically useless. Nietzsche’s glorification of self-overcoming has been misappropriated (by the Nazis and others) in ways he would have found repugnant, but the writing is genuinely susceptible to misreading. His critique of morality presupposes evaluative standards (health, vitality, creativity) whose justification remains unclear.

V — 20th Century Philosophy

Phenomenology (early 20th century)

Edmund Husserl (1859–1938): phenomenology begins with the analysis of consciousness as it presents itself — without prior theoretical commitments about the external world. The method of epoché (bracketing): set aside the question of whether the objects of experience exist independently and attend only to the structure of the experience itself.

The central concept: intentionality — all consciousness is consciousness of something. There is no experience that is not an experience of an object (even an imaginary or impossible one). The structure of intentionality — the relation between the intending act and the intended object — is the primary subject matter of phenomenology.

Martin Heidegger (1889–1976): Being and Time (1927) transforms phenomenology into an analysis of human existence. The central question: what is Being? The analysis starts from Dasein (“being-there”) — the kind of being we ourselves are — because Dasein is the being for whom its own Being is an issue.

Key concepts: thrownness (we find ourselves already in a world, a culture, a body, a situation we did not choose); projection (we are always oriented toward possibilities, toward the future); fallenness (we tend to lose ourselves in the anonymous public world of “das Man” — the They). Authentic existence involves owning one’s thrownness and projection — taking responsibility for one’s own existence.

Being-toward-death: the authentic confrontation with one’s own mortality is what individualises Dasein and pulls it back from the They.

Maurice Merleau-Ponty (1908–1961): phenomenology of the body. Consciousness is not a pure subject confronting an objective world — it is embodied, and the body is not an object but the lived perspective through which the world is experienced.

Existentialism (1930s–1960s)

Existentialism is not a single school but a cluster of thinkers united by the priority they give to individual existence, freedom, and the construction of meaning.

Søren Kierkegaard (1813–1855): the proto-existentialist. The three stages of existence — aesthetic (sensory pleasure, living in the moment), ethical (commitment to universal moral rules), and religious (the “leap of faith,” the individual’s direct relationship to God) — cannot be mediated by reason. Either/Or, not Both/And.

Jean-Paul Sartre (1905–1980): “existence precedes essence.” Unlike a manufactured object (whose essence — its purpose — precedes its existence), human beings have no pre-given nature or purpose. We exist first and define ourselves through choice. This is the ground of absolute freedom — and absolute responsibility.

Bad faith (mauvaise foi): the attempt to deny one’s freedom by treating oneself as a thing — as if one’s choices were determined by one’s nature, role, or situation. The waiter who plays at being a waiter, the coward who claims he cannot be otherwise — both are in bad faith.

Simone de Beauvoir (1908–1986): The Second Sex — woman is not born but made. Femininity is not a biological fact but a social construction, an existential situation imposed on women by a patriarchal society. The analysis of woman’s situation as Other — not the absolute Subject but the object of the male gaze — is the most important application of existentialist concepts to social critique.

Albert Camus (1913–1960): associated with existentialism but explicitly not an existentialist. The central concept is the Absurd — the confrontation between the human demand for meaning and the world’s radical silence. The world does not answer our call for purpose; there is no inherent meaning.

The question of suicide: if life is absurd, why not end it? Camus’ answer — The Myth of Sisyphus — is that suicide is a philosophical error: it refuses the absurd rather than living within it. The right response is revolt — the passionate, lucid continuation of life in full awareness of its absurdity. “One must imagine Sisyphus happy.”

The Plague: the most fully worked out statement of Camus’ ethics — solidarity, compassion, and resistance in the face of indifferent suffering, without the consolation of transcendence.

Analytic Philosophy (early 20th century onward)

Analytic philosophy is not a set of doctrines but a style of doing philosophy: rigorous argument, attention to language, respect for the results of natural science, and a preference for clarity over system-building.

Gottlob Frege (1848–1925): invented modern mathematical logic — predicate calculus, the quantifier, and the distinction between sense and reference. The foundation of the entire analytic tradition.

Bertrand Russell (1872–1970) and G.E. Moore (1873–1958): rejected British idealism (the dominant philosophy of the late 19th century) in favour of a direct realism and logical analysis.

Ludwig Wittgenstein (1889–1951): two entirely different philosophies.

Tractatus Logico-Philosophicus (1921): the world is the totality of facts, not things. Language pictures facts; the limits of language are the limits of the world. What cannot be said must be passed over in silence — including ethics, aesthetics, and the mystical.

Philosophical Investigations (1953): the picture theory of meaning is wrong. Words get their meaning from use in a form of life, not from their reference to facts. Philosophical problems are not genuine problems but confusions generated by misuse of language. Philosophy is therapy — dissolving pseudo-problems rather than solving genuine ones.

Logical Positivism (Vienna Circle, 1920s–1930s)

The Vienna Circle — Schlick, Carnap, Neurath, Ayer — sought to base philosophy on science and logic. The verification principle: a statement is meaningful only if it is either analytic (true by logic alone) or empirically verifiable. Metaphysical claims (about God, the soul, the nature of Being) are not false but meaningless — they fail the test of verifiability.

The demise. The verification principle cannot itself be verified by the standards it sets. The principle is neither analytic nor empirically verifiable, so it appears to be meaningless by its own lights. Later logical empiricists (Hempel, Quine) tried to reformulate it, but the original programme largely collapsed.

Pragmatism (late 19th century – present)

American philosophy’s primary contribution to world philosophy. Founded by Charles Sanders Peirce, developed by William James and John Dewey.

Peirce (1839–1914): the meaning of a concept lies in its practical consequences — what difference does it make to our experience whether one concept or another is correct? This is the “pragmatic maxim.” If two competing theories make no difference to practice, the difference between them is not real.

William James (1842–1910): truth is what works. An idea is true if believing it is useful — if it helps us navigate experience successfully. This produced the famous objection: does this mean that comfortable lies are true?

John Dewey (1859–1952): applied pragmatism to democracy, education, and science. Knowledge is not a mirror of nature but an instrument for solving problems. Education is not the transmission of fixed knowledge but the cultivation of problem-solving capacities.

Contemporary pragmatism: Richard Rorty (1931–2007) combined pragmatism with Wittgenstein and Heidegger to produce neopragmatism — a radical rejection of the idea that philosophy can provide foundations for knowledge or ethics. We should replace the vocabulary of “truth” and “representation” with the vocabulary of solidarity and conversational justification.

Postmodernism and Post-Structuralism (1960s–present)

Michel Foucault (1926–1984): not a system but a genealogical method — tracing the historical construction of what appears to be natural or universal. Madness and Civilization, The Birth of the Clinic, Discipline and Punish, The History of Sexuality: each analyses how knowledge, power, and subject-formation are intertwined. There is no neutral knowledge — all knowledge is implicated in power relations.

Jacques Derrida (1930–2004): deconstruction — the attempt to show that texts undermine their own apparently secure distinctions. Every text privileges one term of a binary (speech/writing, presence/absence, man/woman) while depending on the excluded term. Deconstruction reads the text against its apparent grain to expose this structure.

Jean-François Lyotard (1924–1998): postmodernism is “incredulity toward metanarratives” — the rejection of grand stories (Enlightenment progress, Marxist revolution, Christian salvation) that legitimate knowledge or politics.

The objections. Postmodernism generates the self-refutation problem: if all claims are equally power-laden, what gives the postmodern critique its authority? The style of much postmodern writing — deliberately obscure — is either a feature (the form enacts the content) or a vice (obscurantism dressed as profundity). Whether Foucault’s genealogies are compelling historical analyses or just narratives is contested.

Hedonism

Hedonism as a philosophical position — not a lifestyle choice — is the view that pleasure is the sole intrinsic good and pain the sole intrinsic evil. It comes in several forms:

Psychological hedonism: we are psychologically incapable of desiring anything except pleasure (Bentham). This descriptive claim is almost certainly false — people demonstrably act for many reasons besides pleasure.

Ethical hedonism: we ought to maximise pleasure. This is the utilitarian core. The questions it raises: whose pleasure? All pleasures equally? Are there quality distinctions (Mill) or only quantitative ones (Bentham)?

Preference hedonism: good is the satisfaction of preferences, not pleasure directly. Preferences can be about the world — not just about my own states.

The deepest objection: Robert Nozick’s experience machine — a device that gives you any experiences you want (the experiences of writing a great novel, making friends, achieving goals) without any of it being real. Would you plug in? Most people say no, which suggests we care about reality, not just experience.

VI — Eastern Philosophy (Selected Schools)

Confucianism (551–479 BCE)

Founded by Kongzi (Confucius). Ethics built around human relationships and the virtues appropriate to them: ren (benevolence/humaneness), yi (righteousness), li (ritual propriety), zhi (wisdom), xin (faithfulness). The cultivation of virtue begins in the family and extends outward to the state.

The rectification of names: things should be called by their correct names — the beginning of order. A ruler who does not rule should not be called a ruler.

Mencius (372–289 BCE) argued that human nature is fundamentally good — the sprouts of virtue are present in all people. Political legitimacy requires the endorsement of the people. Xunzi (310–235 BCE) took the opposite view: human nature is bad; virtue is an achievement of education and ritual.

Taoism (4th–3rd century BCE)

Laozi (traditional author of the Tao Te Ching): the Tao (道) is the ultimate reality — the unnameable source and principle of all things. Human wisdom lies in aligning with the Tao through wu wei — non-action, or action that is in harmony with the natural flow of things.

Zhuangzi (c. 369–286 BCE): the most philosophically sophisticated Taoist thinker. The butterfly dream — I dreamt I was a butterfly; am I a man dreaming of being a butterfly, or a butterfly dreaming of being a man? The boundaries between things are conventional, not absolute. Perspectivism: every claim about the world is made from a particular perspective; no perspective is final.

Buddhism (5th century BCE onward)

The Four Noble Truths: life involves suffering (dukkha); suffering arises from craving (tanha); suffering ceases with the cessation of craving; the Eightfold Path leads to the cessation of craving.

Anatman (no-self): there is no permanent, unchanging self. The self is a construction — a process, not a substance. This is one of the deepest and most challenging doctrines in philosophy, and it connects to modern debates in philosophy of mind about personal identity.

Madhyamaka (Nagarjuna, 2nd century CE): the philosophy of the Middle Way between existence and non-existence. All things are empty of inherent existence (sunyata) — they exist only in dependence on other things. This is not nihilism (things do not exist) but the denial of svabhava (inherent, independent existence).

A Note on How to Read This Survey

The schools surveyed here disagree about almost everything — about what exists (idealism vs. materialism), about what we can know (rationalism vs. empiricism vs. scepticism), about what we should do (virtue ethics vs. utilitarianism vs. deontology), about what makes life worth living (Stoicism vs. Epicureanism vs. existentialism). This is not a failure of philosophy — it is evidence that the questions are genuinely hard.

The right attitude is neither to pick a school and adopt it wholesale nor to conclude that all schools are equally wrong (which is itself a philosophical position that requires argument). The philosophical tradition is best approached as a long conversation in which positions are refined, objections are answered, and genuine progress is sometimes made — not toward a final system, but toward a clearer understanding of what the problems are and why they resist easy resolution.

Last updated March 2026.