Leucippus

Almost nothing is known about the life of Leucippus.[1] He is described as having lived during the 5th century BCE.[2][3] Miletus, Elea, and Abdera have all been suggested as places where he lived, but these are most likely described as his home city because of their associations with other philosophers. There is no evidence from Leucippus's own life about where he lived or whether he even existed.[1] Since ancient times, Leucippus has languished in obscurity compared to Democritus, who is said to be his student.[4][5] Two works are attributed to Leucippus: The Great World System and On Mind.[4][6]

Leucippus is described as the founder of atomism, the theory that all things are made up of atoms. These atoms are microscopic, indivisible objects that interact and combine to produce all the things of the world.[4][5] They are described as constantly holding the same shape and size but always changing their position and their arrangements with one another.[7] Leucippus held that atoms can take on any shape, size, or position because there is no reason why they should not.[8] He also described the existence of multiple cosmos being created and destroyed.[9] Leucippus asserted the existence of void, or empty space, and he said that atoms moved around the void as a vortex until they formed the cosmos.[10] A similar idea was later explored by Plato in his Timaeus.[11]

Aristotle recorded the ideas of Leucippus and Democritus, but he did not distinguish who developed which atomist ideas. According to Aristotle, Leucippus developed his philosophy as a challenge to the Eleatics. The Eleatics believed that nothingness, or the void, cannot exist. They also believed that everything can be infinitely divided. From these ideas, they came to the conclusion that motion and plurality are illusions. Aristotle tells that while Leucippus agreed with their concept of void, he challenged the idea that it is nonexistent and the idea that things can be divided forever.[12][13]

Only one extant fragment is attributed to Leucippus, taken from On Mind: "Nothing happens at random, but everything from reason and by necessity".[14][15] It is common practice in modern philosophy to consider the atomist ideas of Leucippus and Democritus collectively rather than attempting to distinguish them.[16] The ideas of Leucippus and Democritus continued to influence Greek philosophy for centuries, including the work of Aristotle and Epicurus.[17] Ancient atomism was also revived for a time during the 17th century.[18]

Epicurus alleged that Leucippus never existed—an allegation that triggered extensive philosophical debate.[4][19] Modern philosophers disagree over the historicity of Leucippus, and among those who maintain his existence, there is disagreement whether his work can be meaningfully distinguished from that of Democritus.[20] Scholars who maintain that Leucippus existed argue that he only taught orally or that any written works he produced were never meant for publication. Among scholars who argue against Leucippus's existence, alternate ideas have been proposed: Leucippus may have been a pseudonym of Democritus, or he may have been a character in a dialogue.[1]

The existence of Leucippus was a major issue in 19th century German philosophy, where it spawned a debate between Erwin Rohde, Paul Natorp, and Hermann Alexander Diels.[21] Rohde and Natorp disputed the attribution of On Mind to Leucippus, and Rohde argued that Democritus should be credited with The Great Cosmology. Rohde also argued that there was no extant writing of Leucippus by the time of Epicurus.[22] In response, Diels defended the attribution of On Mind to Leucippus.[1]

Adolf Dyroff developed a set of distinctions between Leucippus and Democritus: he proposed that Leucippus was responsible for the atomist response to the Eleatics while Democritus responded to the Sophists and that Leucippus was a cosmologist while Democritus was a polymath.[1] Cyril Bailey proposed another system to differentiate the two philosophers, attributing atomism and belief in the void to Leucippus while attributing The Great Cosmology to Democritus as an application of Leucippus's philosophy.[23]

• Indeterminism
• Kanada

• Gregory, Andrew (2013). "Leucippus and Democritus on Like to Like and ou mallon". Apeiron. 46 (4): 446–468. doi:10.1515/apeiron-2013-0021. ISSN 2156-7093.
• Graham, Daniel W. (2008). "Leucippus' Atomism". In Curd, Patricia; Graham, Daniel W. (eds.). The Oxford Handbook of Presocratic Philosophy. Oxford University Press. ISBN 978-0-19-514687-5.
• Skordoulis, Constantine D.; Koutalis, Vangelis (2013). Tsaparlis, Georgios (ed.). Concepts of Matter in Science Education. Springer. ISBN 978-94-007-5914-5.
• Taylor, C.C.W. (1999). Long, A. A. (ed.). The Cambridge Companion to Early Greek Philosophy. Cambridge University Press. doi:10.1017/ccol0521441226. ISBN 978-0-521-44122-3.
• Zilioli, Ugo (2020). Atomism in Philosophy: A History from Antiquity to the Present. Bloomsbury Publishing. ISBN 978-1-350-10750-2.
  • Gregory, Andrew. "Early ancient atomism". In Zilioli (2020).