We Are Our Choices

From Existentialism Is a Humanism (1945, published 1946). Sartre uses this as the practical corollary of "existence precedes essence": because there is no pre-given human nature, what you are at any moment is simply the sum of the choices you have made. This makes choice morally inescapable — refusing to choose is itself a choice — and eliminates every excuse based on circumstances, upbringing, or character. Sartre saw this not as a burden but as a source of dignity: the human being is the one kind of being that is entirely responsible for what it becomes.