This article is about the philosopher. There was also a Greek mythological Leucippus (mythology)
Leucippus or Leukippos (5th century BC) was the originator of atomism, the philosophical belief that everything is composed entirely of various imperishable, indivisible elements called atoms.
There are no existing writings which we can attribute to Leucippus, since his writings seem to have been enfolded into the work of his famous student Democritus (q.v. for more on atomism). In fact, it is virtually impossible to identify any views about which Democritus and Leucippus disagreed.
Leucippus was born at Miletus (or some said Elea, for his philosophy is associated with the Eleatic philosophers), a contemporary of Zeno, Empedocles and Anaxagoras of the Ionian school of philosophy. His fame was so completely overshadowed by that of Democritus, who systematized his views on atoms, that Epicurus doubted his very existence, according to Diogenes Laertius x. 7. But Aristotle and Theophrastus expressly credit him with the invention of Atomism.
This article is part of The Presocratic Philosophers series
Leucippus is variously said to have been born in Elea, Abdera or Miletus (DK 67A1).
Leucippus is named by most sources as the originator of the theory that the universe consists of two different elements, which he called ‘the full’ or ‘solid,’ and ‘the empty’ or ‘void’.
Leucippus apparently formulated this position in response to the Eleatic claim that ‘what is’ must be one and unchanging, because any assertion of differentiation or change within ‘what is’ involves the assertion of ‘what is not,’ an unintelligible concept.
Leucippus is the older, and Democritus perfected what the former began, but it is difficult to say what properly speaking belongs to him historically.
Leucippus is the originator of the famous atomic system which, as recently revived, is held to be the principle of rational science.
Since Leucippus and Democritus wished to go further, the necessity of a wore definite distinction thaii this superficial one of union and separation was introduced, and they sought to bring this about by ascribing diversity to atoms, and, indeed, by making their diversity infinite.