Text #9166"Leucippus", in .
Leucippus (fl. 5th century BCE) is reported in some ancient sources to have been a philosopher who was the earliest Greek to develop the theory of atomism — the idea that everything is composed entirely of various imperishable, indivisible elements called atoms. The name Leucippus is often associated as master to pupil with that of Democritus, the philosopher who was also touted as the originator of the atomic theory. However, a brief notice in Diogenes Laertius’s life of Epicurus says that on the testimony of Epicurus, Leucippus never existed. As the philosophical heir of Democritus, Epicurus’s word has some weight, and indeed a controversy over this matter raged in German scholarship for many years at the close of the 19th century. Furthermore, In his Corpus Democriteum, Thrasyllus of Alexandria, an astrologer and writer living under the emperor Tiberius (14–37 CE) compiled a list of writings on atomism that he attributed to Democritus to the exclusion of Leucippus. The present consensus among the world’s historians of philosophy is that this Leucippus is historical. The matter must remain moot unless more information is forthcoming from the record.
Leucippus was most likely born in Miletus, although Abdera and Elea are also mentioned as possible birth-places.
Leucippus was indeed a shadowy figure, as his dates are not recorded and he is often mentioned in conjunction with his more well-known pupil Democritus. It is therefore difficult to determine which contributions to an atomic theory come from Democritus and which come from Leucippus.
The Leucippus of record was an Ionian Greek (Ionia, being the Asiatic Greece or Asia Minor, forms western Turkey today). And he was a contemporary of Zeno of Elea and Empedocles (Magna Graecia, now part of southern Italy). He belonged to the same Ionian School of naturalistic philosophy as Thales, Anaximander, Anaximenes, and he was interested in reality and not idealism as the Italic Eleatics were.
Aristotle and his student Theophrastus, however, explicitly credit Leucippus with the invention of Atomism. In Aristotelian terms Leucippus agreed with the Eleatic argument that true being does not admit of vacuum, and there can be no movement in the absence of vacuum. Leucippus contended that since movement exists, there must be empty space. However, he concludes that vacuum is identified with non-being, since “nothing” cannot really be. According to Aristotle Leucippus differed from the Eleatics in not being encumbered by the conceptual intermingling of being and non-being, and Plato made the necessary distinction between grades of being and types of negation.
The title attributed to Leucippus’ is the lost work Megas Diakosmos (“Big World-System,” but this title was also attributed to Democritus whose companion work was Micros Diakosmos, “Little World-System).
Fragments and doxographical reports about Leucippus were collected by Hermann Diels (1848–1922), firstly in Doxographi Graeci (Berlin, 1879, reprint Berlin: de Gruyter, 1929) and then in Die Fragmente der Vorsokratiker, Berlin, 1903, 6th ed., rev. by Walther Kranz (Berlin: Weidmann, 1952; the editions after the 6th are mainly reprints with little or no change.) Diels was the leading proponent for a historical Leucippus.
Some sources claim that around 440 or 430 BCE Leucippus founded a school at Abdera, in which his pupil, Democritus, was closely associated. And there is mention that a Leucippus founded the city of Metapontum, which honored this Leucippus with a coin.
A. A. Long (ed.), The Cambridge Companion to Early Greek Philosophy (pgs. xxiii, 185)
Diels-Kranz, Die Fragmente der Vorsokratiker [I] 67A
Diogenes Laërtius, Lives and Opinions of Eminent Philosophers, IX.30-33