Sartre's name for the attitude that treats values, roles, and identities as properties of the world rather than products of human freedom — the most socially respectable form of bad faith.
The spirit of seriousness is the attitude that takes moral commitments as discoveries rather than positions, values as facts rather than choices, identities as natures rather than projects. The serious person does not experience her professional identity as a role she has chosen; she experiences it as what she is. She does not experience her values as commitments she has made; she experiences them as truths she has recognized. The seriousness conceals the choosing. It makes the choice feel like something that happened to the person rather than something the person did. In the AI moment the spirit of seriousness takes a specific form: the appeal to inevitability. This is happening whether we like it or not. You can't stop progress. The only question is whether you'll be left behind. Each statement converts a truth about the world into a concealment of freedom, and the conversion is Sartre's diagnostic signature for this form of self-deception.