Plotinus Born around 205 CE, probably in Roman Egypt, Plotinus studied for years in Alexandria under the enigmatic master Ammonius Saccas and later settled in Rome, where he founded a school and led a life of remarkable asceticism. His lessons were gathered and organized by his disciple Porphyry in the Enneads. He is the founder of Neoplatonism and the greatest philosopher of late antiquity, making Plato the starting point of one of the most grandiose metaphysics ever conceived. ...
Porphyry Porphyry of Tyre — in Greek Porphýrios, a name adopted in place of his Semitic birth name Malchus (“king” in Phoenician) — was born around 234 CE in Tyre (on the coast of present-day Lebanon) and died around 305 CE. A caveat: he should not be confused with Porphyry of Gaza (5th century), a Christian bishop with the same name, nor with other late-antique figures bearing it. After studying in Athens with Cassius Longinus, in around 263 CE he joined the circle of Plotinus in Rome, of whom he became the most celebrated pupil. He served as editor of the Enneads (posthumously published c. 301), arranging the master’s writings into six groups of nine treatises and prefacing them with the Vita Plotini (Life of Plotinus) — a fundamental biographical source on Plotinus. His influence, however, reaches far beyond his editorial work: through the Isagoge, Porphyry shaped the entry of Aristotelian logic into the medieval world. ...
Proclus Proclus Lycaeus Diadochus (in Greek Próklos Lýkios Diádokhos, “Proclus the Lycian, the Successor”) was born in Constantinople in 412 CE and died in Athens on 17 April 485 CE. A caveat: he should not be confused with Proclus Procopius (an orator of the 5th century) or other homonymous late-antique figures. The son of a wealthy family from Lycia (in the south of present-day Turkey), he was educated in Alexandria and soon moved to Athens, where he studied with Plutarch of Athens (not to be confused with the essayist of Chaeronea) and with Syrianus, whom he succeeded as head of the Academy — hence his title Diádokhos, “the Successor.” He was the last great systematizer of pagan Neoplatonism before the closure of the Academy by Emperor Justinian in 529 CE. His work organizes the Plotinian inheritance into a rigorous network of propositions and triads, in a project comparable, in ambition, to Aquinas’s Summa — but in an entirely pagan key. ...
Protagoras Born in Abdera around 490 BCE, Protagoras was the first and most famous of the Sophists — the itinerant teachers who, for a fee, taught the young the rhetoric and aretê (excellence) needed for success in the public life of the Greek cities. He frequented the circle of Pericles in Athens and even drew up the laws for the colony of Thurii. He is the figure who best embodies the spirit of the sophistic movement. ...
Pyrrho Founder of Ancient Skepticism. Accompanied Alexander the Great to India and encountered ascetics who influenced his thought. Left no writings; lived coherently with epoché. Tranquility (ataraxia) arrives naturally when one suspends all judgment: since we cannot know whether something is good or bad, beautiful or ugly, there is no reason for disturbance. Key Concepts Epoché: suspension of all judgment Aphasia: refraining from making assertions about reality Ataraxia as a consequence of epoché Phenomenalism: only phenomena (appearances) are accessible Influenced by Democritus — relativity of perceptions Gorgias — radical skepticism Indian ascetics (gymnosophists) Influenced Timon of Phlius — disciple New Academy (Arcesilaus, Carneades) Sextus Empiricus — systematization of Pyrrhonism Montaigne, Descartes (method of doubt) Works None. Sources: Diogenes Laërtius, Lives, IX; Sextus Empiricus, Pyrrhonian Outlines. ...
Pythagoras Born on the island of Samos around 570 BCE, Pythagoras emigrated to Croton, in southern Italy (Magna Graecia), where he founded a philosophical-religious community famous for its austere way of life, its rules of silence, and the secrecy of its teachings. Since he wrote nothing and his disciples attributed everything to the master, it is difficult to separate his ideas from those of the Pythagoreans who followed him; already in antiquity his figure blended with legend. ...
René Descartes Often called the “father of modern philosophy,” René Descartes was born in 1596 in La Haye, in the French region of Touraine, and was educated at the rigorous Jesuit college of La Flèche. Dissatisfied with bookish learning, he enlisted as a volunteer in the armies of the Thirty Years’ War; it was during this period, by his own account, that in 1619 he glimpsed a universal method capable of giving philosophy the same certainty as mathematics. He spent most of his productive life in the Dutch Republic and died in 1650 in Stockholm, where he had been invited to tutor Queen Christina of Sweden. He was also a great mathematician: analytic geometry and the coordinate system that bears his name are his creations. ...
Richard McKay Rorty was an American philosopher who taught at Princeton, the University of Virginia, and Stanford. He began as an analytic philosopher formed in the Wittgenstein-Sellars tradition, but Philosophy and the Mirror of Nature (1979) projected him as one of the most radical critics of the Western epistemological tradition. Rorty is the principal representative of neopragmatism, which combines the American pragmatist heritage (Dewey, James) with elements of continental philosophy (Heidegger, Derrida) and late analytic philosophy (Wittgenstein, Quine, Sellars). ...
Robert Nozick was an American political philosopher and professor at Harvard, whose Anarchy, State, and Utopia (1974) became the most systematic and rigorous libertarian response to John Rawls’s theory of justice, reorienting anglophone political-philosophical debate for decades. Beyond political philosophy, he made original contributions to epistemology, metaphysics, and ethics. Key Concepts Rights as Side Constraints (Anarchy, State, and Utopia, 1974): Nozick holds that individual rights are side constraints on action — not factors to be maximised within a calculation, but limits that cannot be violated even when violation would produce better outcomes for the greatest number. Individual dignity prohibits using persons as mere means to others’ ends. ...
Rodolfo Kusch Born in Buenos Aires in 1922, into a family of German origin, Rodolfo Kusch united philosophy and anthropology in a rare way: instead of thinking America from European books, he traveled through northwestern Argentina and the Bolivian highlands in extensive fieldwork, listening to Quechua and Aymara thought. From this experience arose a radical question: is European ontology really capable of comprehending the greater part of human experience? His answer turns on a distinction that Spanish — and Portuguese — allow with singular clarity: that between being (ser) and dwelling (estar). “Being” expresses the modern Western mode: to be something, to produce, to assert oneself, to project oneself. “Dwelling” expresses another way of inhabiting the world: to be here, rooted in the land, in the community, in the here-and-now — the mode proper to the human being of deep America. For Kusch these are two distinct and irreducible ontologies. ...
Ronald Dworkin American legal and moral philosopher, professor at Yale, Oxford, and New York University; Dworkin’s work constitutes the most influential critique of legal positivism in the 20th century and a comprehensive normative theory integrating law, political morality, and ethics. Key Concepts Principles vs. rules: against Hart, Dworkin argues that legal systems include not only rules (which apply in an all-or-nothing fashion) but also principles and policies. Principles such as “no one may profit from his own wrong” have weight and dimension; they do not derive from any rule of recognition — which shows that positivism is an insufficient descriptive theory of law Critique of discretion: Hart concedes that in “hard cases” judges exercise discretion, thereby creating new law. Dworkin rejects this: even in hard cases there is a right answer (the one right answer thesis) — the judge discovers existing law rather than creating it Rights as trumps: in Taking Rights Seriously (1977), individual rights are “trumps” that override arguments of collective utility or policy — no social goal can justify violating them. Dworkin defends an egalitarian liberalism grounded in equal concern and respect Law as integrity: in Law’s Empire (1986), law is neither a collection of brute facts (positivism) nor a list of natural values (natural law theory) but an interpretive practice. Law as integrity requires judges to treat the legal system as expressing a coherent set of moral principles Chain novel (chain novel): a metaphor for the interpretive process — the judge deciding a hard case is like a writer continuing a novel by many authors; he must be faithful to earlier chapters while making the work as good as it can be Judge Hercules: an ideal (not real) figure endowed with superhuman capacity to find the decision that best fits the system’s principles and renders it morally most coherent. The implicit normative claim: actual judicial decisions should approximate this ideal Equality of resources: in Sovereign Virtue (2000), just distribution requires that resources be divided so that no one envies another’s share, correcting disadvantages imposed by brute luck (illness, disability) while respecting personal choices Unity of value: in Justice for Hedgehogs (2011) — the title evoking Isaiah Berlin’s hedgehog that knows “one big thing” — Dworkin argues that ethical and moral values form a coherent system: living well and treating others justly are not competing demands but mutually dependent ones Religion without God: Religion without God (2013, posthumous) extends the unity-of-value thesis to a secular religious attitude that recognises intrinsic value and beauty in the universe without presupposing a personal God Influenced by H.L.A. Hart — the positivism Dworkin critiques in depth Lon Fuller — “inner morality of law” and the integrative function of principles John Rawls — egalitarian liberalism, debates on equality Isaiah Berlin, Kant, and the American liberal tradition Influenced The whole of contemporary legal philosophy (mandatory point of reference) Carlos Nino, Robert Alexy, and debates on the balancing of principles American and European constitutional adjudication Debates on judicial review and constitutional interpretation Works Taking Rights Seriously (1977); A Matter of Principle (1985); Law’s Empire (1986); Life’s Dominion (1993); Freedom’s Law (1996); Sovereign Virtue (2000); Justice in Robes (2006); Is Democracy Possible Here? (2006); Justice for Hedgehogs (2011); Religion without God (2013, posthumous). ...
Rudolf Carnap Rudolf Carnap was the most systematic and influential figure of the Vienna Circle and of logical empiricism, a movement that sought to refound philosophy on the rigor of modern logic and fidelity to experience. Trained in physics, logic, and philosophy in Germany, he studied with Gottlob Frege at Jena before joining the Vienna Circle in the 1920s. With the rise of Nazism he emigrated to the United States, where he taught at Chicago and at the University of California, Los Angeles. His work spans the logical construction of knowledge, the syntax and semantics of language, the theory of confirmation, and inductive logic, always guided by the ideal of conceptual clarity. ...
Saint Augustine Aurelius Augustine was born in 354 in Thagaste, in Roman North Africa, the son of a Christian mother (Monica) and a pagan father. A teacher of rhetoric in Carthage, Rome, and Milan, he traveled a long intellectual and spiritual road: he was kindled to philosophy by reading Cicero, adhered for years to Manichaeism, passed through skepticism, and found in the Neoplatonism of Plotinus the instrument that would lead him back toward Christianity. His conversion in Milan (386) — the famous “tolle, lege” (“take up and read”) scene narrated in the Confessions — was a turning point. He became bishop of Hippo and, until his death in 430, during the Vandal siege, was the greatest thinker of the Patristic age and one of the most influential figures in the whole history of the West. ...
Saul Kripke Saul Aaron Kripke was arguably the most technically gifted analytic philosopher of his generation. Born in Omaha, Nebraska, he showed extraordinary aptitude from adolescence: he published his first mature logical article — a completeness proof for modal logic — at seventeen, and corresponded with professional logicians while still in high school. A professor at Princeton and later at the CUNY Graduate Center, Kripke transformed metaphysics, philosophy of language, and modal logic to such a degree that virtually all analytic philosophy after the debates surrounding Naming and Necessity is, in some sense, a response to him. ...
Seneca Lucius Annaeus Seneca was born in Corduba, in Hispania, around 4 BCE, the son of Seneca the Elder, a renowned teacher of rhetoric. He was the most influential — and also the most controversial — of the Roman Stoics: a wealthy and powerful senator, he endured exile in Corsica under the emperor Claudius and, on his return to Rome, became tutor and later advisor to the young Nero, whom he sought to restrain in the early years of his reign. Accused of taking part in the Pisonian conspiracy, he was forced by Nero to take his own life in 65 CE — a death that, according to Tacitus’s account, he faced with the serenity his philosophy preached. ...
Sextus Empiricus Greek physician and philosopher, the principal systematizer of Pyrrhonian skepticism. His works are the most complete source on the ancient skeptical tradition founded by Pyrrho. While the dogmatists (Stoics, Epicureans, Platonists) claimed to reach definitive truth, Sextus defends the suspension of judgment (epoché) as the path to tranquility (ataraxia). His influence was decisive on modern philosophy, especially on Montaigne, Descartes, and Hume. Key Concepts Epoché (suspension of judgment): faced with equipollent arguments, the skeptic suspends assent — neither affirming nor denying Isostheneia (equipollence): equal strength of contrary arguments — for every argument in favor, there is one of equal force against Tropes (modes of suspension): systematization of skeptical arguments — 10 tropes of Aenesidemus (relativity of perceptions), 5 tropes of Agrippa (disagreement, infinite regress, relativity, hypothesis, circularity) Phenomenon (phainomenon): the skeptic accepts appearances as a practical guide to life, without affirming that they correspond to reality Practical criterion: the skeptic lives according to nature, customs, laws, and arts — without claiming absolute truth Anti-dogmatism: systematic critique of all philosophical schools that claim to know the ultimate nature of things Influenced by Pyrrho — founder of Pyrrhonian skepticism Aenesidemus — renewal of Pyrrhonism; 10 tropes Timon of Phlius — disciple of Pyrrho Influenced Montaigne — skepticism of the Essays (Apology for Raymond Sebond) Descartes — methodical doubt as a response to skepticism Hume — skepticism about causation and induction Pascal — limits of human reason Francisco Sanches — Quod nihil scitur (1581) Works Outlines of Pyrrhonism (Pyrrhōneioi Hypotypōseis, 3 books) — systematic exposition of the skeptical method; Against the Mathematicians (Adversus Mathematicos, 11 books) — refutation of dogmatic disciplines (grammar, rhetoric, geometry, arithmetic, astrology, music, logic, physics, ethics). ...
Sigmund Freud Neurologist and founder of psychoanalysis. Although not strictly a philosopher, his theory of the unconscious, drives, and repression became one of the most influential philosophical matrices of the 20th century, especially for the Frankfurt School, existentialism, and post-structuralism. Key Concepts Unconscious: the greater part of mental life escapes consciousness; repressed desires, traumas, and conflicts determine behavior. The unconscious does not obey logic or linear time Psychic topography: First topography: Unconscious / Preconscious / Conscious Second topography: Id (primitive drives) / Ego (mediation with reality) / Superego (internalization of social norms) Drives: Eros (drive for life, love, creativity) and Thanatos (death drive, aggression, repetition) — fundamental conflict of the psyche Repression: civilization demands the repression of drives; the cost is neurosis. Central theme of Civilization and Its Discontents (1930) Oedipus complex: desire for the parent of the opposite sex and rivalry with the same-sex parent; structure of entry into culture and formation of the superego Dreams, slips, and symptoms: “Royal road to the unconscious” — encrypted language of repressed desires Critique of religion: The Future of an Illusion (1927) — religion is childish illusion of a protective father; Totem and Taboo — origin of religion in primordial patricide Influenced by Charles Darwin — drives and biological evolution Nietzsche — critique of morality, unconscious forces (notable parallels) Franz Brentano — philosophy of mind and intentionality Influenced Marcuse — Eros and Civilization: freedom vs. capitalist over-repression Adorno and Horkheimer — social unconscious, authoritarianism Walter Benjamin — dream, dialectical image Sartre — critiques psychoanalysis but engages with it (bad faith vs. repression) Simone de Beauvoir — psychoanalysis and the construction of the feminine Derrida — trace, différance and the unconscious as writing Foucault — critiques the apparatus of sexuality in The History of Sexuality Jacques Lacan — structuralist rereading of Freud Works The Interpretation of Dreams (1900); Three Essays on the Theory of Sexuality (1905); Totem and Taboo (1913); Introductory Lectures on Psychoanalysis (1916–17); The Ego and the Id (1923); The Future of an Illusion (1927); Civilization and Its Discontents (1930); Moses and Monotheism (1939). ...
Simone de Beauvoir French philosopher; intellectual companion of Sartre. Founder of existentialist feminism. The Second Sex is one of the most influential books of the 20th century. Key Concepts “One is not born, but rather becomes, a woman”: the feminine is a social and historical construction, not a biological given Woman is the Other in relation to man as universal subject — a structure of oppressive alterity Existentialist freedom applied to gender: woman must recognize herself as a free subject, not as an object or complement to man Ethics of ambiguity: human freedom is ambiguous — we are free and situated; ethics demands assuming this ambiguity and acting in solidarity Influenced by Sartre — existentialism; radical freedom Hegel — master/slave dialectic (applied to gender) Husserl and Heidegger — phenomenology of situation Influenced Second-wave feminism (Betty Friedan, Kate Millett) Judith Butler — performativity of gender Queer theory Works The Second Sex (1949); The Ethics of Ambiguity (1947); The Mandarins (novel, 1954, Prix Goncourt). ...
Simone Weil French philosopher, mystic, and activist. A student of Alain (Émile Chartier) at the École Normale Supérieure, she worked alongside factory laborers and fought in the Spanish Civil War. Her work, almost entirely posthumous, crosses philosophy, Christian mysticism (without formal adherence to the Church), social critique, and reflection on labor. She died at 34 in London, weakened by tuberculosis and her refusal to eat more than those rationed in occupied France. An unclassifiable thinker who fascinated Camus, who edited her first published books. ...
Slavoj Žižek Slovenian philosopher and cultural theorist, researcher at the University of Ljubljana. He combines the psychoanalysis of Jacques Lacan with the dialectic of Hegel and the critique of ideology in the Marxist tradition. Prolific and provocative, he is known for analyzing pop culture phenomena (cinema, jokes, advertising) as illustrations of deep ideological structures. A critic of both liberal capitalism and identity-based leftism, he defends an emancipatory universalism. Key Concepts Ideology as fantasy: ideology is not false consciousness (an illusion dispelled by knowledge) but a structuring fantasy — “they know what they are doing, and yet they do it” (cynicism as the dominant ideological form) The Real, the Symbolic, and the Imaginary: takes up the Lacanian triad — the Real is what resists symbolization; irruptions of the Real destabilize the symbolic order (trauma, social antagonism) Jouissance (enjoyment): the subject is trapped in paradoxical modes of satisfaction that sustain the ideological order — ideology functions not through belief but through the enjoyment invested in social practices Parallax (parallax view): a shift in perspective that reveals the object is constituted by the very displacement of the gaze — there is no neutral point of view; antagonism is irreducible The big Other (grand Autre): the symbolic order (language, law, social norms) — the subject constitutes itself in relation to the Other, but the Other is inconsistent, barred The barred subject: the subject is not a full identity but a constitutive lack — it is what emerges in the failure of the symbolic order Pop culture as philosophy: films (The Matrix, Hitchcock), jokes, and anecdotes are read as enactments of Lacanian and Hegelian structures Influenced by Hegel — dialectic, negativity, contradiction as the motor of thought Jacques Lacan — structural psychoanalysis; Real, Symbolic, Imaginary Marx — critique of ideology and commodity fetishism Kant — transcendental subject and antinomies Schelling — freedom and the abyss of the ground Influenced Contemporary critical theory Cultural studies and ideological analysis of cinema Post-Marxist left and contemporary political debate Alain Badiou — interlocution on subject and event Works The Sublime Object of Ideology (1989); For They Know Not What They Do (1991); The Parallax View (2006); Living in the End Times (2010); Less Than Nothing: Hegel and the Shadow of Dialectical Materialism (2012); How to Read Lacan (2006). ...