Existence Precedes Essence
The most famous formula of existentialist philosophy reverses the essentialist tradition that runs from Plato through Aquinas to the Enlightenment. Where the essentialist holds that each being has a nature — a defining set of properties and purposes — that precedes and explains its concrete existence, Sartre insists that for human beings the order is reversed. The human being is not manufactured according to a design, does not discover a predetermined purpose, does not inherit a fixed nature. She exists first. Only then, through the accumulated weight of her choices, does she acquire an essence — a specific configuration of character, commitments, and capabilities that makes her the particular person she has become. The essence is never final; it is always being constituted through ongoing choice.
In the AI Story
The formula compresses a philosophical revolution. Western thought from Aristotle through medieval theology treated human beings as creatures with a determinate nature — rational animals, imago Dei, bearers of a specific telos. Even Enlightenment humanism, which rejected theological foundations, retained the essentialist structure by locating human nature in reason, sympathy, or the social contract. Sartre rejected the entire tradition: no God to conceive of human beings, therefore no concept that precedes them.
The thesis has immediate practical consequences. If there is no human nature, there is no authority to appeal to when justifying or evading a choice. One cannot say 'I am a coward by nature' or 'my family has always been weavers' or 'I am a backend developer' as though these were descriptions of what one is rather than descriptions of the choices one has been making. The appeal to nature is always, in Sartre's analysis, a flight from the recognition that the nature was chosen.
The AI moment exposes this philosophical structure with unusual clarity. When AI tools can perform the functions through which knowledge workers have defined themselves, the workers are forced to confront the fact that the identification of self with function was a choice — one they made many times, over many years, until the repetition created an illusion of necessity. The paper-knife cannot have this crisis because its essence really does precede its existence. The developer can have it because her essence never did.
Origin
The phrase l'existence précède l'essence appears in Existentialism Is a Humanism (1946), though the underlying argument was developed in Being and Nothingness (1943). Sartre borrowed and radicalized a theme from Kierkegaard and Heidegger, turning it from a phenomenological observation into a metaphysical and ethical claim about what human beings fundamentally are.
Key Ideas
No human nature. There is no fixed essence of 'the human' that precedes actual humans and determines what they must be.
Self-creation through action. A person becomes who she is through the accumulated weight of her freely made choices, not through the unfolding of a predetermined design.
The refusal of essentialism. Every appeal to nature — 'I am by nature X' — conceals a choice and is, in Sartre's diagnosis, a form of bad faith.
Ongoing constitution. The essence a person acquires is never final; it is continuously reconstituted through each new choice, which means it can always be revised.
Debates & Critiques
Critics including MacIntyre have argued that the thesis dissolves human identity into pure voluntarism and leaves no stable ground for ethics. Sartre's reply, sharpened in later work, is that the absence of a fixed essence does not eliminate moral weight — it concentrates it, because without an authority to defer to, the full responsibility for each choice falls on the chooser.
Appears in the Orange Pill Cycle
Further reading
- Jean-Paul Sartre, Existentialism Is a Humanism (Yale, 2007)
- Jean-Paul Sartre, Being and Nothingness (Washington Square Press, 1956)
- Sarah Bakewell, At the Existentialist Café (Other Press, 2016)
- Gary Cox, The Sartre Dictionary (Continuum, 2008)