The last pre-Socratics: approximately contemporary with Socrates, but they follow in the tradition of those occupled by physls - above all, in the line of Eleatic philosophy.
The atoms - (the final division of the Entity of Parmenides).
The atomoi, the uncuttable or indivisible parts which cannot be broken down further.
Distinguished from one another in form - their properties depend on their forms. They move in whirlwinds and unite in various ways, and so produce things.
There are many worlds - some in the process of formation, some disintegrating - some in existence.
The atoms retain the fundamental attributes of Parmenides' Entity [to on, Being], - as it were, completely pulverized.