Leucippus

It is likely that Leucippus (fl. 440 BC) proposed the atomic system sometime around 440 to 430 BC thus he is contemporary with the other post-Eleatic thinkers Anaxagoras and Empedocles as well as Melissus.

Two books are attributed to Leucippus: On Mind and The Great World System (Makrokosmos). The Great World System was Leucippus principle work.

Leucippus is unanimously held to be founder of the Greek atomic theory. The uncertainty which prevails in the biographical notices of the first philosophers is strikingly illustrated by the conflicting accounts transmitted to us of the circumstances of his life.

Together, Leucippus and Democritus are often called the ‘early’ atomists, to distinguish them from their famous later successors, Epicurus and his school, who took over and developed their teaching.
Leucippus