Nothingness is an act of being putting itself into question, unique to consciousness.

Evidence

This perpetual act by which the in-itself degenerates into presence to itself we shall call an ontological act. Nothingness is the putting into question of being by being—that is, precisely consciousness or for-self. It is an absolute event which comes to being by means of being and which without having being, is perpetually sustained by being. Since being-in-itself is isolated in its being by its total positivity no being can produce being and nothing can happen to being through being—except for nothingness. Nothingness is the peculiar possibility of being and its unique possibility. — Jean-Paul Sartre, Being and Nothingness, 336

Categorization

• DEFINE: Defines ‘ontological act’ and nothingness as being’s self-questioning, the hinge of Sartre’s ontology.
• XREF: This is the systematic backdrop Beauvoir presupposes for the ambiguity of the ethical subject. — connects to: Consciousness grounds itself and precedes all nothingness — Jean-Paul Sartre, Being and Nothingness: An Essay on…, 138; Nothingness is logically subsequent to being, not its opposite. — Jean-Paul Sartre, Being and Nothingness: An Essay on…, 205; Being is logically prior to nothingness, which has only borrowed existence. — Jean-Paul Sartre, Being and Nothingness: An Essay on…, 208 (+11 more)

Broader Connections

• The human is the unique entity whose Being includes questioning Being itself. #corroborates (0.95)
• Human reality is constituted as the unique foundation of nothingness within being. #corroborates (0.90) — Jean-Paul Sartre, Being and Nothingness, 336
• Nothingness is a supported recoil from Being that enables consciousness to exist #corroborates (0.88)
• Nothingness grounds negation by being itself a negation, not an empty void #qualifies (0.82) — Jean-Paul Sartre, Being and Nothingness, 215
• Being-in-itself can found its nothingness but never its being #corroborates (0.80) — Jean-Paul Sartre, Being and Nothingness, 346
• Nothingness is expelled from being yet gives the world its outlines #expands (0.78)
• Nothingness is logically subsequent to being and always supposes a specified being #qualifies (0.75)