Sincerity is an unrealizable ideal because human reality never coincides with identity.

Evidence

Actually sincerity presents itself as a demand and consequently is not a state. Now what is the ideal to be attained in this case? It is necessary that a man be for himself only what he is. But is this not precisely the definition of the in-itself—or if you prefer—the principle of identity? … Thus in order that the concepts of bad faith can put us under illusion at least for an instant, in order that the candor of “pure hearts” (cf. Gide, Kessel) can have validity for human reality as an ideal, the principle of identity must not represent a constitutive principle of human reality and human reality must not be necessarily what it is but must be able to be what it is not. — Jean-Paul Sartre, Being and Nothingness, 296

Categorization

• DEFINE: Recasts the principle of identity as a merely regional axiom that fails for human reality, clarifying why self-coincidence is impossible for the for-itself.
• XREF: The claim that sincerity collapses into bad faith reappears in Beauvoir’s and later continental ethics as the critique of univocal self-identity. — connects to: Sincerity is impossible because consciousness’s structure prevents being what one is — Jean-Paul Sartre, Being and Nothingness: An Essay on…, 305; Sincerity aims at an ideal mode of being human nature prevents attaining — Jean-Paul Sartre, Being and Nothingness: An Essay on…, 312; Identity is perpetually in formation, never a completed essence. — Stuart Hall, Essential Essays, Volume 2: Identity…, 203 (+5 more)

Broader Connections

• Sincerity is impossible because consciousness’s structure prevents being what one is #corroborates (0.92) — Jean-Paul Sartre, Being and Nothingness, 305
• Sincerity aims at an ideal mode of being human nature prevents attaining #corroborates (0.88) — Jean-Paul Sartre, Being and Nothingness, 312
• Human reality arises as a lack of an impossible self-totality #corroborates (0.85) — Jean-Paul Sartre, Being and Nothingness, 362
• One is never identical with any of one’s own attitudes or actions #corroborates (0.82) — Jean-Paul Sartre, Being and Nothingness, 300
• Identity is perpetually in formation, never a completed essence. #expands (0.78) — Stuart Hall, Essential Essays, Volume 2, 203
• Identity can only be understood through difference, never self-sameness #expands (0.75) — Stuart Hall, Essential Essays, Volume 2, 1189
• Masochism fails on principle because one can never apprehend one’s own objectivity #exemplifies (0.72) — Jean-Paul Sartre, Being and Nothingness, 963