Democritus ("chosen of the people") (ca.

460 BCE – ca.

370 BCE) is an Ancient Greek philosopher born in Abdera, Thrace, Greece.

He is an influential pre-Socratic philosopher and pupil of Leucippus, who formulated an atomic theory for the cosmos.

His exact contributions are difficult to disentangle from his mentor Leucippus, as they are often mentioned together in texts.

Their speculation on atoms, taken from Leucippus, bears a passing and partial resemblance to the nineteenth-century understanding of atomic structure that has led some to regard Democritus as more of a scientist than other Greek philosophers; however their ideas rested on very different bases.

Largely ignored in ancient Athens, Democritus was nevertheless well known to his fellow northern-born philosopher Aristotle.

Plato is said to have disliked him so much that he wished all his books burned.

Many consider Democritus to be the "father of modern science".