Philosophy of the Twentieth Century

Period: ~1900–2000 | Context: two World Wars, Holocaust, totalitarianisms, decolonization, globalization, crisis of the modern project

Panorama

The 20th century fragments philosophy into schools frequently incommunicable with each other:

I. Phenomenology

Edmund Husserl (1859–1938) — Founder

Project: to establish philosophy as a rigorous science, describing phenomena as they appear to consciousness, without presuppositions.

Intentionality

• All consciousness is consciousness of something — consciousness does not exist closed in itself, but always directs itself toward an object
• “All consciousness is intentional” (inherited from Brentano)
• Distinction: intentional act (noesis) and intended object (noema)

Phenomenological Reduction (Epoché)

• “Place in brackets” the question of the real existence of the world — suspend the “natural attitude”
• It is not negation of the world, but a shift in focus: study how the world appears to pure consciousness

Eidetic Reduction

• After the epoché, imaginatively vary the object until finding its invariant essence (eidos)
• Intuition of essences: phenomenology is a science of essences, not of facts

Life-World (Lebenswelt)

• Late work: modern science forgot the lived world (pre-scientific) that is its foundation
• The crisis of European sciences derives from this forgetfulness

Works

• Logical Investigations (1900–01)
• Ideas for a Pure Phenomenology (1913)
• Cartesian Meditations (1931)
• The Crisis of European Sciences (1936, incomplete)

Martin Heidegger (1889–1976)

The most influential German philosopher of the 20th century. His project: to repose the question of Being, forgotten by Western metaphysics.

Being and Time (1927)

Dasein (being-there): the specifically human mode of being — not subject, but openness to being

Existential structures of Dasein:

• Being-in-the-world (In-der-Welt-sein): Dasein is not a closed subject that subsequently “touches” the world — it is always already in the world
• Being-with (Mitsein): always with others; the Man (the “one,” the impersonal) tends to level existence
• Occupation and care (Sorge): primary mode of relation to the world (before theoretical knowledge)
• Facticity (Dasein is “thrown” into a situation it did not choose)
• Project (Entwurf): Dasein always projects itself into possibilities
• Fallenness (Verfallenheit): tendency toward the impersonal, toward inauthenticity

Temporality and being-toward-death:

• Dasein is essentially being-toward-death — one’s own death is the most extreme, certain, non-transferable possibility
• Anguish before death reveals the structure of Dasein and makes authenticity possible
• Temporality (past as facticity, future as project, present as fallenness) is the horizon of being

The Turn (Kehre) — Late Work

• Abandons the analytics of Dasein; the history of being replaces existential analysis
• Western metaphysics = “forgetfulness of being”; a history of decline
• Modern technology as the destiny of being: reduces everything to standing-reserve (Bestand) available for exploitation
• Art and Language as ways of openness to being: “Language is the house of being”

Politics — The Heidegger Question

• Heidegger joined Nazism in 1933 (rectorship in Freiburg)
• Never publicly retracted
• The Black Notebooks (published 2014–2015) contain philosophically articulated antisemitic passages
• The relation between his philosophy and his Nazism is an object of intense philosophical debate

Works

• Being and Time (1927)
• The Question Concerning Technology (1954)
• The Origin of the Work of Art (1935–36)
• Letter on Humanism (1946)
• Contributions to Philosophy (1936–38, posthumous)

II. Existentialism

Movement that places concrete individual existence — not abstract essence — as the starting point for philosophy.

Kierkegaard (1813–1855) — Precursor

• Criticizes Hegel for ignoring the concrete individual in favor of the abstract system
• Three stages of existence: aesthetic (living the moment, Don Juan) → ethical (duty, universal law) → religious (leap of faith, Abraham)
• Anguish as “the dizziness of freedom”
• Works: Either/Or, Fear and Trembling, The Concept of Anxiety, Concluding Unscientific Postscript

Jean-Paul Sartre (1905–1980)

“Existence precedes essence”

• Unlike objects (whose essence is defined before they exist), the human being exists before having a defined nature
• Human beings are condemned to be free — there are no excuses, no prior human nature
• Bad faith (mauvaise foi): fleeing from freedom by pretending to be determined (like a thing)

Being-in-itself and Being-for-itself

• In-itself (en-soi): the being of things — opaque, massive, without consciousness, identical to itself
• For-itself (pour-soi): the being of consciousness — always distant from itself, always projecting itself
• Consciousness is “nothingness” (néant) in the heart of being — it is what it is not and is not what it is

Radical Freedom

• We are always responsible: we cannot hide behind nature, society, or the past
• Authenticity: accepting one’s own freedom and responsibility without bad faith

Social and Political Philosophy (late work)

• Critique of Dialectical Reason (1960): Marxism and existentialism as synthesis; freedom within material conditions

Works

• Being and Nothingness (1943)
• Existentialism Is a Humanism (1945)
• Nausea (novel, 1938)
• Critique of Dialectical Reason (1960)

Simone de Beauvoir (1908–1986)

• Intellectual companion of Sartre; founder of existentialist feminism
• “One is not born a woman, one becomes one” — the feminine as social construction, not biological given
• Work: The Second Sex (1949)

Albert Camus (1913–1960) — Absurdism

• The absurd arises from the confrontation between human desire for meaning and the world’s silence
• There is no solution to the absurd (rejecting both suicide and the religious “leap of faith”)
• Revolt as a response: continuing to live and create despite the absurd
• “One must imagine Sisyphus happy”
• Works: The Myth of Sisyphus (1942); The Stranger (novel, 1942); The Rebel (1951)

Maurice Merleau-Ponty (1908–1961)

• Phenomenology of Perception: the lived body (corps propre) as the subject of experience
• Against Cartesian dualism: there is no mind without body; we are embodied beings
• Work: Phenomenology of Perception (1945)

III. Frankfurt School — Critical Theory

Institute for Social Research founded in Frankfurt (1923). Synthesis of Hegelianism (dialectic), Marxism (social critique), and Freudianism (social unconscious). Exiled in the USA during Nazism.

Theodor Adorno (1903–1969)

Negative Dialectics

• Refuses Hegelian dialectics of synthesis and reconciliation
• Reality is not rational; the identity between reason and reality is ideology
• Defends non-identity: the object always exceeds the concept; the particular resists subsumption by the universal
• Philosophy as defense of differences against the oppressive universal

Dialectic of Enlightenment (with Horkheimer, 1944/1947)

• Enlightenment, in seeking to dominate nature through reason, destroys itself — becomes myth anew, this time the myth of progress and technique
• Instrumental reason: reason that only calculates means for given ends, without questioning the ends

Culture Industry

• Mass culture (film, television, radio, popular music) is produced as standardized commodity
• Molds individuals as replaceable beings, inhibits creativity, creates conformism
• “Free time” is controlled in the same way as work time

Art as Resistance

• Authentic art (Schoenberg, Beckett, Kafka) preserves non-identity; resists totalization
• After Auschwitz, all culture is problematized: “To write poetry after Auschwitz is barbarism” — yet art remains necessary as the antithesis of society

Works

• Dialectic of Enlightenment (1947, with Horkheimer)
• Negative Dialectics (1966)
• Aesthetic Theory (1970, posthumous)
• Minima Moralia (1951)
• The Authoritarian Personality (1950, collective)

Max Horkheimer (1895–1973)

Critical Theory (1937)

• Distinguishes traditional theory (descriptive, specialized) from critical theory (reflexive, totalizing, oriented toward emancipation)
• Social research should treat society as a whole — not fragmented into specialties

Instrumental Reason (Eclipse of Reason, 1947)

• Objective reason (orients the ends, determines what is good and just) was eclipsed by
• Subjective/instrumental reason (calculates only efficient means for externally given ends within the system)
• The disease of reason: “born from the need to dominate nature”
• Fascism is “the truth of modern society” — its most transparent form of domination

Works

• Eclipse of Reason (1947)
• Dialectic of Enlightenment (1947, with Adorno)
• Critical Theory (essays, 1968)

Herbert Marcuse (1898–1979) — “Guru of the New Left”

Eros and Civilization (1955)

• Returns to Freud: civilization requires repression of instincts (reality principle vs. pleasure principle)
• But Marcuse distinguishes necessary repression (minimum for coexistence) from over-repression (excess imposed by capitalism for maintenance of alienated labor)
• A non-repressive civilization is possible: “Great Refusal” to the dominant reality principle

One-Dimensional Man (1964)

• Advanced industrial society integrates opposition — even critique is absorbed and neutralized
• The “one-dimensional” man: lost the capacity to think negatively, to imagine alternatives
• “Repressive tolerance”: liberal tolerance tolerates everything equally, neutralizing critique

Works

• Reason and Revolution (1941) — Hegel and Marx
• Eros and Civilization (1955)
• One-Dimensional Man (1964)

Walter Benjamin (1892–1940)

Aura and Technical Reproducibility

• “The work of art in the age of its technical reproducibility” (1935/1936): technical reproduction destroys the aura (unique presence, here-and-now, authenticity) of the work
• Emancipatory potential: reproduction democratizes access; but can lead to aestheticization of politics (fascism)

Philosophy of History

• Against linear progress: the history of the vanquished must be redeemed
• “Every work of culture is also a document of barbarism” (Thesis VII on the concept of history)
• Messianic: revolution is not linear progress, but an eruption that redeems past suffering

The Flâneur and Modernity

• The flâneur (urban stroller) as figure of the modern observer
• The Passages of Paris as archaeology of capitalist modernity

Works

• The Work of Art in the Age of Its Technical Reproducibility (1935/36)
• On the Concept of History (1940, posthumous Theses)
• The Arcades Project (Passagenwerk, posthumous)
• The Origin of German Tragic Drama (1928)

Jürgen Habermas (1929–2026) — 2nd Generation

Communicative Reason

• Against Adorno and Horkheimer: reason is not totally corrupted — there is an irreducible communicative dimension
• Communicative action vs. instrumental action: in communicative relations oriented toward mutual understanding, there is a rationality that cannot be reduced to calculation

Theory of Communicative Action (1981)

• Society = life-world (Lebenswelt) + system (market + state)
• Colonization of the life-world: the system invades and replaces symbolic communication with instrumental imperatives
• Deliberative democracy as a way to rationalize the life-world

Works

• Knowledge and Human Interests (1968)
• Theory of Communicative Action (1981, 2 vols.)
• The Philosophical Discourse of Modernity (1985)
• Between Facts and Norms (1992)

IV. Analytic Philosophy

Context

Emerges with Frege, Russell, and the early Wittgenstein; dominates the English-speaking world in the 20th century. Focus: logical analysis of language as philosophical method.

Gottlob Frege (1848–1925)

• Founder of modern logic (predicate logic); distinction between sense and reference
• Works: Begriffsschrift (1879); The Foundations of Arithmetic (1884)

Bertrand Russell (1872–1970)

• Theory of definite descriptions; Russell’s paradox; Principia Mathematica (with Whitehead, 1910–1913)
• Logical atomism: the world is composed of atomic facts

Ludwig Wittgenstein (1889–1951)

Phase 1 — Tractatus Logico-Philosophicus (1921):

• The world is the totality of facts; language represents the logical structure of facts
• What cannot be said clearly must be passed over in silence: “Whereof one cannot speak, thereof one must be silent”
• Ethics and aesthetics are ineffable — they show themselves, they are not said

Phase 2 — Philosophical Investigations (posthumous, 1953):

• Abandons the representational picture of language
• Language games: meaning is use; there is no private language
• Family resemblances (Familienähnlichkeiten): concepts have no common essence, only overlapping features
• Philosophy as therapy: dissolve confusions generated by misuse of language

V. Structuralism and Post-Structuralism

Claude Lévi-Strauss (1908–2009) — Anthropological Structuralism

• Myths have universal logical structure (like language): binary oppositions (raw/cooked, nature/culture)
• “Myths think themselves in men without men knowing it”
• Works: Tristes Tropiques (1955); The Savage Mind (1962); Mythologiques (4 vols., 1964–71)

Michel Foucault (1926–1984)

Archaeology and Genealogy

• Archaeology: analyzes knowledge systems (épistémès) of each epoch — how the “archive” of what can be said is organized
• Genealogy (from Nietzsche): how practices of power produced truths, subjects, categories (the mad, the criminal, the homosexual, etc.)

Power-Knowledge

• Power is not merely repressive — it is productive: