DemocritusBorn: c. 460 BC
Birthplace: Abdera, Thrace
Died: c. 370 BC
Executive summary: Early atomic theorist
Democritus was born at Abdera, Thrace, sometime around 458 BCE. He was described as well traveled, probably visiting Babylon, Egypt, and Ethiopia, and perhaps India. He appears to have spent all of his time on scientific and philosophical studies, teaching, and writing— some 60 works have been listed. Of his voluminous writings, only a few fragments of his ethical theory remain. But these fragments and the descriptions by other writers of his atomic theory put him among the foremost thinkers of his time.
Aristoxenus wrote that Plato wanted to burn all the works of Democritus, but could not do so because the books were already in wide circulation. Failing this, he avoided any mention of Democritus in his own writings. Certainly, Socrates’ brand of argument might not have fared well against Democritus, who was described by Timon as "the guardian of discourse, a keen witted disputant".
Democritus’s theory of the atomic nature of the physical world, developed from that of Leucippus, is known only through the works of critics of the theory such as Aristotle and Theophrastus. It resolved the question of how a world evidently in a state of flux could nevertheless have an underlying nature that was eternal and unchanging. By positing infinitely small things that remained the same but formed different combinations with each other, Leucippus initially, and Democritus in greater detail, managed to answer the question in a way that has been subject to increasingly successful elaboration ever since. One can trace the physical theory of atoms through Epicurus, Lucretius, and Galileo to modern times.
