The for-itself is the in-itself’s failed self-founding that nihilates it

Evidence

We must not confuse facticity with that Cartesian substance whose attribute is thought. To be sure, thinking substance exists only as it thinks; and since it is a created thing, it participates in the contingency of the ens creatum. But it is. It preserves the character of being-in-itself in its integrity, although the for-itself is its attribute. This is what is called Descartes’ substantialist illusion. … For us, on the other hand, the appearance of the for-itself or absolute event refers indeed to the effort of an in-itself to found itself; it corresponds to an attempt on the part of being to remove contingency from its being. But this attempt results in the nihilation of the in-itself, because the in-itself can not found itself without introducing the self or a reflective, nihilating reference into the absolute identity of its being and consequently degenerating into for-itself. — Jean-Paul Sartre, Being and Nothingness, 346

Categorization

• DEFINE: Cartesian substantialist illusion: treating the thinking being as a substance rather than as a nihilation of being.
• XREF: This is the ontological machinery Beauvoir inherits — freedom as the nihilation rather than the attribute of being. — connects to: In possession the for-itself seeks to become its own foundation as in-itself; The for-itself constitutes itself through an original negation of the thing — Jean-Paul Sartre, Being and Nothingness: An Essay on…, 571; The for-itself is only the emptiness where the in-itself detaches — Jean-Paul Sartre, Being and Nothingness: An Essay on…, 576 (+6 more)
• DEEPTHINKING: The paradox that being’s attempt to found itself produces its own nihilation into for-itself is the generative core of Sartre’s system.

Broader Connections

• In possession the for-itself seeks to become its own foundation as in-itself #corroborates (0.95)
• The for-itself constitutes itself through an original negation of the thing #expands (0.90) — Jean-Paul Sartre, Being and Nothingness, 571
• The For-itself adds nothing to being except its own negation #corroborates (0.90) — Jean-Paul Sartre, Being and Nothingness, 652
• The for-itself is only the emptiness where the in-itself detaches #complicates (0.85) — Jean-Paul Sartre, Being and Nothingness, 576
• The for-itself lacks a for-itself, not an in-itself, in its project of self-identification #expands (0.85) — Jean-Paul Sartre, Being and Nothingness, 373
• The for-itself is defined by self-withdrawal rather than self-identity #corroborates (0.80) — Jean-Paul Sartre, Being and Nothingness, 1145
• The for-itself is defined as an internal negation of the in-itself, bridged through knowledge #qualifies (0.80) — Jean-Paul Sartre, Being and Nothingness, 37