Democritus of Abdera (c. 470–400 BC)
| "Nothing exists but atoms and the void. "
Democritus was a Greek materialist philosopher who developed the ideas of atomism, originally put forward by Leucippus. Democritus maintained that all phenomena were explicable in terms of the nomic motion of atoms in the void. In the hands of Epicurus and Lucretius, atomistic philosophy was popularized and used to argue for the existence of extraterrestrial life. Democritus was the first to claim that the Milky Way is made up stars.