Philosophy › The 20th century
Existentialism
1940s onward· School or movement· Ethics & how to live
Well documentedSolid records, texts or physical evidence.
A 20th-century movement holding that humans exist first and must define themselves through free choices, with no fixed nature or given meaning.
See it on the Philosophy map →The idea
Idea: 'existence precedes essence' (Sartre). A paper knife is made for a purpose; we are not, so we create ourselves by choosing. Freedom brings anxiety, responsibility and the temptation of 'bad faith', pretending we had no choice. Roots run through Kierkegaard, Nietzsche, Husserl and Heidegger; it flourished in postwar Paris with Sartre, de Beauvoir and Camus. Main objection: it underrates how much class, upbringing and biology limit choice, and gives no clear basis for shared morality.
Why it matters
It shaped postwar literature, theater, film and psychotherapy, and popularized the idea that meaning is made, not found.
Think of it like
Like raw land with no zoning: nothing dictates what goes up, but whatever you build is yours to answer for.
Where it comes from
Key texts: Sartre's Being and Nothingness (1943) and 'Existentialism Is a Humanism' (1945), de Beauvoir's The Ethics of Ambiguity (1947), Camus' essays. Gabriel Marcel coined the label.
Still debated
Who counts is disputed: Heidegger and Camus rejected the label, and Kierkegaard died almost a century before it existed.
Inside this (11)
- Søren Kierkegaard
- Husserl and phenomenology
- The Kyoto School (Nishida Kitaro)
- Martin Heidegger, Being and Time
- Albert Camus and the absurd
- Jean-Paul Sartre
- Does life have meaning?
- Simone de Beauvoir, The Second Sex
- The Axial Age (Jaspers' idea)
- Hannah Arendt
- Postmodernism and post-structuralism (Foucault, Derrida)
Connections (5)
▸Søren Kierkegaard anticipated ExistentialismWell documented
The connection
Kierkegaard insisted that what matters is how a person lives, chooses and commits, not abstract systems like Hegel's: 'truth is subjectivity'. His themes of anxiety, despair, the lone individual and the 'leap' of faith became existentialism's core vocabulary a century later, though he wrote as a Christian.
When and how
He wrote in Copenhagen in the 1840s (Either/Or and Fear and Trembling, 1843; The Concept of Anxiety, 1844). German translations from about 1909 brought him to Jaspers, Heidegger and later Sartre.
How we know
Jaspers, Heidegger and Sartre all cite him; Being and Time footnotes him, and Sartre wrote the essay 'Kierkegaard: The Singular Universal' (1964).
Debates and open questions
Whether a Christian thinker whose goal was faith belongs in a largely atheist movement is debated; he is called its 'father' only in hindsight.
▸"God is dead" set the stage for ExistentialismMostly agreed
The connection
Nietzsche's claim left humans with no given purpose or moral rulebook. Existentialists accepted this starting point and drew a demanding conclusion: since no God defines human nature, each person must define it through choice. Sartre wrote that without God we are 'forlorn', with no excuses, entirely responsible for ourselves.
When and how
The line runs from Nietzsche's books of the 1880s to Paris in the 1940s, especially Sartre's lecture 'Existentialism Is a Humanism' (1945).
How sure are we?
Sartre's lecture argues directly from God's absence; Heidegger lectured on Nietzsche for years, and Camus' The Rebel (1951) discusses him at length.
Debates and open questions
Not all existentialists were atheists: Kierkegaard, Gabriel Marcel and Karl Jaspers were religious, so the 'death of God' is one root among several.
▸Jean-Paul Sartre defined ExistentialismWell documented
The connection
Sartre gave the movement its public face and slogan: 'existence precedes essence'. In a packed 1945 lecture he defended existentialism against charges of despair, arguing that because we are not designed for any purpose, we are free and fully responsible. The talk, printed as a short book, became the movement's manifesto.
When and how
Club Maintenant, Paris, 29 October 1945, before a crowd so dense that people reportedly fainted; published in 1946 as Existentialism Is a Humanism.
How we know
The lecture text survives, and Paris newspapers covered the evening as a sensation.
Debates and open questions
Sartre reportedly came to regret publishing it as too simple; scholars debate how well it represents Being and Nothingness.
▸Existentialism was applied to gender by Simone de Beauvoir, The Second SexWell documented
The connection
De Beauvoir applied existentialism's core claim, that we have no fixed essence at birth, to women. If existence precedes essence, then 'woman' is not a natural destiny but a situation made by society. The existentialist idea of 'the Other' explained how men cast women as secondary, and existential freedom pointed toward liberation.
When and how
The Second Sex, published by Gallimard in Paris in two volumes in 1949; it reportedly sold 22,000 copies in its first week.
How we know
The book frames itself in existentialist terms; its introduction says its perspective is 'that of existentialist ethics'.
Debates and open questions
Older readings saw her as applying Sartre's ideas; many scholars now argue she reshaped existentialism by stressing the body, history and social situation.
▸Analytic philosophy became the rival camp to ExistentialismMostly agreed
The connection
Both traditions grew from German-language philosophy around 1900, Frege's logic and Husserl's phenomenology, but they diverged. Analytic philosophers prized logic, science and clarity; existentialists and their continental heirs prized lived experience, history and literature. Carnap mocked Heidegger's 'the Nothing itself nothings' as meaningless, while Heidegger held logic cannot reach the deepest questions. Each side doubted the other was doing philosophy.
When and how
Carnap's attack on Heidegger appeared in 1932; the split hardened after 1945 between Anglo-American and French and German departments, as a 1958 meeting at Royaumont, near Paris, showed.
How sure are we?
Michael Dummett compared the traditions to the Rhine and the Danube, rising close together and then flowing in opposite directions.
Debates and open questions
Many philosophers now think the divide is fading, or was always more about style and university culture than substance; others think it marks real disagreements.