Democritus

Democritus was a Pre-Socratic philosopher from Abdera who developed the first systematic theory of atomism: the view that all reality consists of indivisible, indestructible particles moving through empty space. This materialist account of nature — anticipating modern physics by over two millennia — extended to the soul, which he held to be composed of fine, spherical atoms. He reportedly wrote more than seventy works, almost none of which survive.