democritus

When we sense something, it is due to the movement of atoms in space. When I see the moon it is because "moon atoms" penetrate my eye.

The void is 'not-being,' and no part of 'what is' is a 'not-being,'; for what 'is' in the strict sense of the term is an absolute plenum. This plenum, however, is not 'one': on the contrary, it is a 'many' infinite in number and invisible owing to the minuteness of their bulk.