DEMO'CRITUS was born at Abdera in Thrace, or, according to some, as we learn from Diogenes Laertius (ix. 34), at Miletus, in the year n.c. 460. He was thus forty years younger than Anaxagoras, and eight years younger than Socrates. He received his first lessons in astrology and theology from some Magi, who had been left with his father by Xerxes when passing through Abdera to the invasion of Greece; and he is said to have been afterwards a hearer of Leucippus and Anaxagoras. That he heard Anaxageras is doubtful, but, if he did, it must have been while Anaxagoras was at Lampsacus; for when this philosopher was banished from Athens (am 450) Democritus was only ten years old. Democritus appears to have been a great traveller. Ile is said to have visited Egypt, that be might learn geometry from the Egyptian priests; to have been in Persist, and with the Gymnoso phiets in India, and to have penetrated into Ethiopia. He sojourned for some time at Athens; but from contempt of notoriety, as it is said, was known to nobody in that city. It is for this reason that Demetrius Phalcreus, as cited by Diogenes Laertius (ix. 37), contended that Democritus bad never visited Athens. One result of his extensive travels was, that he expended all his patrimony, which is said to have exceeded 100 talents. Now, it was a law of his country, that any one who spent his whole patrimony should be refused burial In his native land ; but Democritus, having read his chief work aloud to his fellow-citizens, so impressed them with an admiration of his learning, that ho not merely obtained a special exemption from the above law, but was presented with 500 talents, and was, on his death, buried at the public expense. (Diog. Lacrt. ix. 39.) A story sub. stantially the same, though varying somewhat in detail, is given in Athenmus (iv. p. 193.) Ile is said to have continued travelling till lie was eighty years old. He died in the year n.c. 357 at the ago of 104. There is a story of his having protracted his life for three days after death seemed inevitable, by means of the smell of either bread or honey, ani in order to gratify his sister, who, had he died when first lie seemed likely to die, would have been prevented from attending a festival of Ceres. (Diog. Lnert. ix. 43 ; Athwn. ii. 7.) Democritus loved solitude, and was wholly wrapt up iu study. There are several anecdotes illustrative of his devotion to knowledge, and his disregard of everything else. They conflict somewhat with one another in their details; hut accuracy of detail is not to bo looked for, and, tending all to the same point, they prove, which is all that we can expect to know, what character was traditionally assigned to Democritus. Cicero (` De Fin.,' v. 29) speaks of him as, like Anaxago ras, leaving his lands uncultivated, in his undivided care for learning ; while, as an instance how these stories conflict, Diegenes Laertius represents him as having, on the division of the paternal estate with his two brothers, taken his own share entirely iu money, as being more convenient than laud for a traveller. Valerius Maximus (viii. 7) makes him show his contempt for worldly things by giving almost the whole of his patrimony to his country. He is said too to have
put out his eyes, that he might not be diverted from thought ; hut Plutarch (` De Curiositate, p. 521, C) rejects this story, and explains how it might have arisen. It was Democritus who, struck with the ingenuity displayed by Protagoras in the tying up of a bundle, raised him from the humble condition of a porter, and gained him for philosophy.
Democritus followed Leucippus at a very short distance of time, and preceded Epicurus by somewhat less than a century, as an expounder of the atomic or corpuscular philosophy. He viewed all matter as reducible to particles, which are themselves indivisible (hence called atoms), and which are similar in form. He included mind under the head of matter, recognising only matter and empty space as composing the uuiverse, and viewed mind as consisting of round atoms of fire. (Aristot. 'De Anim. 1, 2.) Arguing that nothing could arise out of nothing, and also that nothing could utterly perish and become nothing, he contended for the eternity of the universe, and thus dispensed with a creator. He further explained the difference iu material substances (mind, as has been said, being one of them) by a difference in the nature and arrangemeut of their component atoms, and all material (including mental) phenomena by different motions, progressive or regressive, straight or circular, taking place among these atoms and taking place of necessity. Thus the cosmology of Democritus was essentially atheistic.
In psychology ho explained sensation, as did Epicurus after him, by suposing particles, elluim, as he called them, or sensible images, to issue from bodies. He also thought to explain men's belief in gods by the supposed existence of large images of human form in the air. In moral philosophy he announced nothing more than that a cheerful state of mind Weal-44 eighipt(a) was the only thing to be sought after. The manner in which the follies of men affected him, and from which he derived his name of the 'laughing philosopher,' is well known. (Jim x. 33-55.) A list of the very numerous writings of Democritus is contained in Diogenes Lacrtius (ix. 46.49.) They are arranged under the five prin cipal heads of ethics, physics, mathematics, general literature, and arts ; and there are besides a few of miscellaneous character. The list, classified in the same manner, and enriched with critical remarks, is given iu Fabricius Bibliothem Grwea,' ed. Harks. vol. ii., p. 634 641.) The reader will see iu this work a list of the writings wrongly attributed to Democritus, and statements of the grounds on which they are severally pronounced spurious ; among them are the writings on magic which aro spoken of by Pliny (` Hist. Nat.' xxx. 1), and considered by him as genuine.
For an account of the philosophy of Democritus the reader is referred to Hill, 'De Philosophia Epicurea, Democritea 'et Thee plfrastea,' Genev., 1669; Ploucquet, Placitis Democriti Abieritm,' Tubing., 1767 ; Cudworth, 'Intellectual System,' chap. i. ; and to tho common histories of philosophy; and for general information con cerning his life to Bayle's 'Dictionary,' and Fabricius' Bibliothees Grmca,' ed. Hades., vol. ii., p. 628.