The possible is defined as a lack that qualifies the for-itself against its past.

Evidence

Now in that very flight from the past which I am toward the future which I am, the future is prefigured in relation to the past at the same time that it confers on the past all its meaning. The future is the past surpassed as a given in-itself toward an in-itself which would be its own foundation—that is, which would be in so far as I should have to be it. My possibility is the free recovery of my past in so far as this recovery can rescue it by providing its foundation. I flee the being without foundation which I was toward the founding act which I can be only in the mode of the I would be. Thus the possible is the lack which the for-itself makes itself be; that is, which is lacking to the present negation in so far as it is a qualified negation (a negation which has its quality outside itself in the past). As such the possible is itself qualified—not by virtue of being a given, which would be its own quality in the world of the in-itself, but as an indication of the recovery which would found the ekstatic qualification which the for-itself was. — Jean-Paul Sartre, Being and Nothingness, 624

Categorization

• DEFINE: Sartre pins down the ‘possible’ as the lack the for-itself makes itself be, tying futurity to the free recovery of the past that founds it.
• XREF: The future-as-‘past surpassed toward a self-founded in-itself’ is precisely the failure structure Beauvoir’s ethics builds on. — connects to: The possible is a real lack the For-itself projects beyond itself. — Jean-Paul Sartre, Being and Nothingness: An Essay on…, 387; The for-itself is its past yet cannot posit or thematize it; The possible is a lack constitutive of consciousness itself — Jean-Paul Sartre, Being and Nothingness: An Essay on…, 385 (+3 more)

Broader Connections

• The possible is a lack constitutive of consciousness itself #expands (0.90) — Jean-Paul Sartre, Being and Nothingness, 385
• Possibility exists only as an option on being that separates one from oneself #expands (0.85) — Jean-Paul Sartre, Being and Nothingness, 381
• Being one’s past is the foundation of being able not to be it #expands (0.85)
• Possibility is a concrete property of already existing beings, not a subjective construct #contradicts (0.80) — Jean-Paul Sartre, Being and Nothingness, 378