 Atomism—a theory which thrives in Hellenistic times as the physical theory of Epicureanism, and is thus an interlocutor of skepticism—leads into difficult epistemological questions. The atomist can argue that sense perceptions are explicable as complex events, initiated by objects each one made up of a lot of atoms floating in the void, from which atoms proceed and traverse the intervening space, and affect the senses. It is certain objects, made up by the atoms proceeding from the objects in question (filmy images) that we actually perceive. We neither perceive ‘real reality’ (atoms and void), nor even macroscopic objects and their properties (for example, a square tower). Democritus seems to have argued along these lines (SE M 7.135–9; cf. fr. 9, SE M 7.136; Theophrastus, De Sensibus 2.60–1, 63–4), and accordingly his atomist view of perception can be seen as grounding a kind of proto-skepticism.