We started our first discourse on lack in the context of the origin of philosophy in the Parmenidean presupposition of absolute being banishing the void; and its relationship to the emergence of psychoanalysis as a discipline that operates by necessity in the void of subjectivity.  In our second discourse, I propose to shift our context to Democritus, and his atomist ontology, which we may say is the spontaneous unofficial metaphysics of scientific materialism (i.e. the universe at base is divided between indivisible somethings and nothing (“the void”).  However, the complimentary opposite of atoms, the void, is often left unthought by scientific materialists, leaving open-ended the philosophical consequences of a presence that depends on absence.  For Democritus, a presence that depends on absence signifies an important distinction vis-a-vis thinking “the real” (or fundamental reality), namely, that the most essential cannot be either a being (atoms, something), and neither can it be a non-being (void, nothing), but a paradox of the two.  He referred to this paradox of the two as a “not-nothing”, or what we might call “Lack”.  What does thinking Lack as a fundamental reality mean for scientific materialism?