 Sartre’s dialectic of being (in-itself) and nothingness (for-itself) makes progress over philosophies of reflection insofar as it recognizes the ecceity of the world, with which the subject engages not as one being alongside others but rather as a nothingness, that is, as a determinate negation of a concrete situation that can co-exist alongside other determinate negations. Even so, for Sartre, pure nothingness and pure being remain mutually exclusive, ambivalently identical in their perfect opposition, which brings any movement of their dialectic to a halt. The “philosophy of negation” is therefore shown to be a totalizing or “high-altitude” thought that remains abstract, missing the true opening onto the world made possible by the fact that nothingness is “sunken into being” (V&amp;I: 121–122/88–89). This “bad” dialectic must therefore give way to a “hyperdialectic” that remains self-critical about its own tendency to reify into fixed and opposed theses (V&amp;I: 129/94).