Democritus and Leucippus

Democritus's name means 'chosen of the people.'  None of his work has survived. Modern scholars doubt the accuracy to many of the anecdotes to Democritus's life. Some writers claimed that  he lived to be very old, perhaps more than 100 at the time of his death. 

The theory of Democritus held that everything is composed of 'atoms.' Atoms are physically, though not geometrically, indivisible. Between atoms would lie empty space. Atoms were indestructible, have always been and always will be in motion. The atoms, which are infinite in number, differ in shape and size.