Twentieth-Century Philosophy

Léopold Sédar Senghor Léopold Sédar Senghor (9 October 1906, Joal, Senegal — 20 December 2001, Verson, France) was a poet, philosopher of culture, and statesman. The first president of independent Senegal (1960–1980) and the first African elected to the Académie française (1983), he was also, alongside Aimé Césaire and Léon-Gontran Damas, one of the founders of Négritude in 1930s Paris. While Césaire gave the movement its poetic force, Senghor set out to give it a systematic philosophical and aesthetic elaboration, making of it a general theory of the African contribution to human civilization. His work is today the object of both recognition and lively controversy. ...

Ludwig Wittgenstein Born in Vienna in 1889, into one of the wealthiest and most cultured families of the Austro-Hungarian Empire, Ludwig Wittgenstein began by studying aeronautical engineering, but reflection on the foundations of mathematics led him to logic and from there to Cambridge, to study with Bertrand Russell. His biography is as singular as his thought: he fought in the First World War, gave away his inherited fortune, worked as a village schoolteacher, a gardener, and even an architect, before returning to academic philosophy. He is the most influential figure in twentieth-century analytic philosophy — and, very rarely, the author of two distinct and equally decisive philosophies, both centered on language. ...

Martha Nussbaum American philosopher, professor at the University of Chicago. One of the most influential contemporary thinkers, she works at the intersection of ethics, political philosophy, law, and literature. Trained in the Aristotelian tradition, she developed with Amartya Sen the capabilities approach as an alternative to utilitarianism and contractualism in theories of justice. She argues that emotions have cognitive content and are essential for ethical judgment. Key Concepts Capabilities approach: justice is not measured by GDP or aggregate utility, but by the real capabilities each person has to be and do — to live, to have health, to think, to participate politically, etc.; a list of 10 central capabilities as a minimum threshold of human dignity The fragility of goodness: the good life depends on external conditions (luck, relationships, body) that escape our control — against Stoic and Platonic self-sufficiency; vulnerability is constitutive of moral excellence Emotions and reason: emotions are not irrational impulses but evaluative judgments (appraisals) — fear, compassion, indignation contain cognitive assessments of what matters; ethics without emotions is blind Cosmopolitan justice: obligations of justice do not stop at national borders — duties to all of humanity, inspired by the Stoics and Kant Humanistic education: the humanities (philosophy, literature, arts) are indispensable for forming democratic citizens capable of empathic imagination and critical thought Animal capabilities: extends the capabilities approach to include the rights of non-human animals Influenced by Aristotle — virtue ethics, phronesis, the good human life John Rawls — justice as fairness (but critiques the limits of contractualism) Amartya Sen — development as freedom; capabilities approach Kant — cosmopolitanism and dignity Stoics — ancient cosmopolitanism Influenced Human development theory (UN Human Development Index) Philosophy of law and human rights Contemporary animal ethics Philosophy of education Works The Fragility of Goodness (1986); The Therapy of Desire (1994); Cultivating Humanity (1997); Women and Human Development (2000); Upheavals of Thought: The Intelligence of Emotions (2001); Frontiers of Justice (2006); Creating Capabilities (2011); The Monarchy of Fear (2018). ...

Martin Heidegger Martin Heidegger was born in Meßkirch, in southern Germany, in 1889, into a modest Catholic family, and came to philosophy by way of theology. Assistant and later successor to Husserl at Freiburg, he published Being and Time in 1927, the work that established him as one of the most influential — and most controversial — philosophers of the twentieth century. The controversy is inseparable from his biography: in 1933 he assumed the rectorate of Freiburg and joined the Nazi party, a commitment he never publicly renounced and which the Black Notebooks, published decades later, revealed to be shot through with antisemitism. The moral and philosophical weight of this engagement remains an open debate. ...

Maurice Merleau-Ponty Born in 1908 in France, Maurice Merleau-Ponty trained at the École Normale Supérieure alongside Sartre and Simone de Beauvoir, with whom he would found the review Les Temps Modernes before a political break. In 1952 he became the youngest holder of the chair of philosophy at the Collège de France. He died suddenly in 1961, leaving his last work unfinished. He is the great phenomenologist of the body. ...

Max Horkheimer Born in Stuttgart in 1895, Max Horkheimer was the organizing soul of the Frankfurt School: in 1930 he took over the directorship of the Institute for Social Research and gathered around him thinkers such as Adorno, Marcuse, and Walter Benjamin. A Jew and a Marxist, he went into exile in the United States during Nazism and, after the war, returned to Frankfurt, where he served as rector. He died in 1973. ...

Michel Foucault Michel Foucault was born in Poitiers in 1926 and trained at the École Normale Supérieure, where his teachers included Jean Hyppolite and Louis Althusser. A psychologist by training as well as a philosopher, from 1970 he held the chair of “History of Systems of Thought” at the Collège de France and was a politically engaged intellectual — above all in the struggle for prison reform. He became one of the most cited figures in the human sciences worldwide. He died in Paris in 1984 of an AIDS-related illness. ...

Mikhail Bakhtin Mikhail Mikhailovich Bakhtin (16 November 1895, Oryol — 7 March 1975, Moscow) was a philosopher of language and a theorist of literature and culture. Marginalized and almost unknown during his lifetime in the Soviet Union — arrested and sent into exile in 1929, he taught for decades at provincial universities — he was rediscovered from the 1960s onward and became one of the most influential Russian thinkers in the world across the humanities. He was the center of the so-called Bakhtin Circle, which also included Valentin Voloshinov and Pavel Medvedev (the authorship of some works signed by them is a matter of scholarly debate). ...

Nikolai Berdiáev Nikolai Alexandrovich Berdyaev (18 March 1874, Kyiv — 24 March 1948, Clamart, France) was a Russian religious and political philosopher, often described as a “Christian existentialist.” Of aristocratic origin, he began as a Marxist — he was even internally exiled under the tsarist regime for his activities — but broke early with materialism toward idealism and Orthodoxy. He took part in the critical collection Vekhi (1909). Expelled from Soviet Russia in 1922, in the episode of the “philosophers’ ships,” he lived in Berlin and then in Clamart, near Paris, where he edited the journal Put and became the best-known voice of Russian thought in exile. He was nominated several times for the Nobel Prize. ...

Peter Singer Australian philosopher, professor at Princeton University. He is the most influential living utilitarian philosopher and one of the founders of the contemporary animal rights movement. His book Animal Liberation (1975) introduced the concept of speciesism and transformed the ethical debate on the treatment of animals. He defends a preference utilitarianism (later revised toward hedonistic utilitarianism) and applies moral philosophy to practical issues: global poverty, euthanasia, abortion, the environment, and effective altruism. ...

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). ...

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. Born in Paris in 1908, Beauvoir studied philosophy at the Sorbonne and passed the agrégation examination in 1929, becoming one of the first women in France to earn that distinction. A central figure in the post-war Parisian existentialist circle, she co-founded the journal Les Temps Modernes and engaged actively in the major political and moral debates of her time, from anticolonialism to critiques of Stalinism. Her core philosophical project was to apply existentialist categories — facticity, situation, project — to the concrete condition of women, demonstrating that female oppression is not rooted in nature but in historical and social structures that can, and must, be transformed. ...

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). ...

Theodor W. Adorno Born in Frankfurt in 1903, Theodor W. Adorno was, alongside Horkheimer, the most rigorous figure of the first generation of the Frankfurt School. Also trained in music — he studied composition in Vienna — he united philosophy, sociology, and aesthetics in a radical critique of modern society. A Jew and a Marxist, he went into exile in the United States during Nazism, where he observed mass culture at close range; he returned to Frankfurt after the war and died there in 1969. ...

Thomas Kuhn American historian and philosopher of science. The Structure of Scientific Revolutions (1962) completely transformed the understanding of scientific progress and introduced the concept of paradigm into global intellectual vocabulary. Born in Cincinnati, Ohio in 1922, Kuhn trained as a physicist at Harvard University. While preparing a history of science course for humanities students, he wrestled with Aristotelian theories of motion. The puzzle of why Aristotle — a remarkably acute thinker — had made what seemed like obvious errors from a Newtonian standpoint led Kuhn to realize that the standards of scientific rationality themselves change across historical periods. Rather than asking “who was right?”, he began asking “how does a scientific community come to see the world in a particular way?”. That question shaped all his subsequent work, culminating years later in the book that would redefine how philosophers, historians, and scientists understand science itself. ...

Walter Benjamin Born in Berlin in 1892, Walter Benjamin was one of the most original and unclassifiable figures of twentieth-century thought — philosopher, literary critic, translator, and essayist, peripherally linked to the Frankfurt School and a friend of Adorno. His academic career failed (his habilitation thesis was rejected), and he lived by his writing, always in difficulty. In 1940, fleeing the Nazis, he found himself blocked at the Franco-Spanish border, in Portbou, and took his own life — one of the most tragic fates of the European intelligentsia. ...