Leucippus and Democritus on Like to Like and ou mallon

Abstract The central issue for this paper is whether for Leucippus and Democritus, 1 the like to like principle, which is critical to cosmos formation once a vortex forms, operates outside of the vortices. Should we consider like to like in the early atomists to be akin to a ‘fundamental force’, with a universal application, as some commentators have suggested?3 Or should we rather consider it to be a sorting effect generated by certain types of motion, occurring only when those types of motion occur? As a matter of detail this is interesting in itself and it also bears on several important interpretive issues for Leucippus and Democritus. What are the intrinsic properties of atoms, if any, beyond their size and shape? Is the initial formation of a vortex a matter of necessity or a matter of chance? Is what happens in a cosmos a matter of necessity or chance? Although not immediately obvious, this will also raise issues concerning to what extent Leucippus and Democritus are committed to the principle of sufficient reason. I will argue that there are good theoretical and textual reasons to believe that like to like occurs only in the vortices. I will also argue that just as there are no preferred sizes and shapes for atoms for Leucippus and Democritus, no preferred distribution of the atoms in the void and there are no preferred times or places for vortex/cosmos formation either. This I suggest gives Leucippus and Democritus a coherent and interesting position relative to Parmenides. Where Parmenides denies multiplicity and raises sufficient reason issues about the time and place of cosmos formation, Leucippus and Democritus assert multiplicity but without preferred shapes and sizes of atoms and cosmogony without preferred times and places of cosmos formation. Of importance here will be an interesting paradox in cosmogony - if we begin with a uniform entity or uniform distribution of entities how does a non-uniform state such as a cosmos arise, while if we begin with a non-uniform entity or non-uniform distribution of entities how do we explain this non-uniformity?