"It's my nature": truth or excuse?
On the axis: Essence and existence · a person appealing to their nature
To appeal to one's nature, "that's how I am, I can't change," is it an honest acknowledgment of what one is, or an excuse to flee what one remains answerable for?
This problem is brought out by the thought experiment "That's just how I am":
Someone you know well keeps doing the same thing: they bolt the moment things get hard, let down those who were counting on them, then vanish. One day you tell them so. They don't even defend themselves. They answer, almost gently: "I know. But that's how I am, I always have been. You can't change your nature." It isn't an excuse they throw back at you, it's a fact they note about themselves, the way one might note the color of one's eyes. What remains is to know what that claim is worth.
Sartre, Existentialism Is a Humanism (1946)
When someone says "it's my nature, I can't change," what is that worth?
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Justification
For a manufactured object, the paper-knife, essence (the artisan's concept) precedes existence; tradition thought of man likewise, created according to a human nature conceived by God. Remove the creator, and the order reverses for man alone: he exists first, with no prior definition, and it is from being nothing at the outset that he draws the full responsibility of making himself.
Man first exists, encounters himself, surges up in the world, and defines himself afterward. If man as the existentialist conceives him is indefinable, it is because at first he is nothing. He will not be anything until later, and then he will be what he makes of himself.Existentialism Is a Humanism
Existentialism Is a Humanism (1946) · Being and Nothingness, Introduction and Part 1 (the for-itself)
Justification
Beauvoir takes up the existentialist thesis that, for the human being, existence precedes essence: no nature defines in advance what one must be. Her formula one is not born, but rather becomes, a woman is its most famous application: the feminine is not a given essence but a becoming shaped by culture, which each woman must nonetheless take up in a free project.
One is not born, but rather becomes, a woman. No biological, psychic, or economic destiny defines the figure that the human female assumes within society.The Second Sex, vol. II
The Second Sex (1949), vol. II, opening ("one is not born a woman") · The Ethics of Ambiguity (1947)