Democritus, answered from the texts and cited to the page.
The only existing things are atoms (atoma — indivisible, eternal, infinite in number, infinitely varied in shape and size, internally unchanging, possessing only the primary properties of size, shape, motion, and arrangement) and void (kenon — the empty space in which atoms move).1 All phenomenal qualities, composite bodies, organisms, souls, gods, and worlds reduce to atomic configurations.
This is the fundamental ontology — not a derivative or a half-doctrine, but the whole of what is. David Furley has rightly argued that atomism was also a response to Parmenidean monism: each atom satisfies Parmenidean criteria for genuine being (ungenerated, indestructible, internally unchanging, of a single nature), and void is "what is not" preserved as the gap that allows multiplicity and motion without violating Parmenidean strictures on what genuinely is.
The Furley reading is a substantively correct specification of how the doctrine was reached; it is not an alternative ontology. The ontology is atoms and void, and the historical-philosophical context in which it was articulated is the Eleatic challenge that Leucippus and I worked to answer.234
'the uninhabited'). But it would then need to be explained why the atomists spoke of atoms and the void, rather than of atoms and space. Further, did their attempted reply to the Eleatics commit them to the view that space itself is unreal?The Atomists, Leucippus and Democritus, pp. 172–173
So the atomists did not shrink from the conclusion that what is is no more than what is not (46a). Again, the assertion that what separates distinct objects is nothing leads straight to incoherence; either there is nothing which separates those objects from one another, in which case they are not separate from one another, or there is something which separates them, in which case 'nothing' is the name of something.The Atomists, Leucippus and Democritus, p. 172
But while our evidence makes it clear what the theoretical role of the void was, that same evidence makes it doubtful whether they arrived at a coherent conception of what it was that was posited to fill that role.The Atomists, Leucippus and Democritus, p. 171
If that is so, Simplicius' testimony that precosmic atoms were moved by weight may be construed as a reference to this causal role of while the app ntly evidence of ps-Plutarch and Stobaeus may be read as denying that precosmic atoms had weight as standardly conceived, i.e., as connoting a tendency to downward motion. modification to the orthodox view thereby required is slight.13 D. Furley (Furley 29, chs.The Atomists, Leucippus and Democritus, pp. 170–171
Atomism's ontology has been the central interpretive question since Aristotle. The standard reading — atoms-and-void as the fundamental ontology — is articulated in the Metaphysics A 4 report and has been the consensus through the doxographic tradition and the modern scholarship. Furley's Two Studies in the Greek Atomists (1967) and The Greek Cosmologists Vol. I (1987) gave the most influential modern reading of atomism as specifically engineered to satisfy Parmenidean criteria for genuine being while saving phenomena. Taylor (1999) is broadly compatible. KRS (1983) and Guthrie (1965) take the standard position with characteristic care. The Aristotelian framing that treats atomism as inadequate physics ("necessity without reason") has been corrected by the modern philological work but persists in some popularizing accounts. The continuous- substance alternatives (Aristotle's own hyle, Stoic continuous matter) and the substance-dualist alternatives (Platonic forms-plus-receptacle) are the principal opposing ontologies that the atomist position is in argument with.