Diogenes Laertius, an ancient historian of philosophy, who probably lived about the beginning of the 3d century, though the dates of his birth and death are unknown, and his life has been placed as early as the time of Augustus, and as late as that of Constantino the Great. He wrote a history of philosophy in Greek, divided into 10 books, and giving an account of the philosophers, anecdotes of their Uvea, and illustrations of their teachings. He considers Grecian philosophy to have been indigenous, and divides it into two schools: the Ionic, commencing with Anaximander and ending with Clitomachus, Chrysippus, and Theophrastus, and of which the Soeratic school forms a part; and the Italian, whoso founder is Pythagoras, and whose last master is Epicurus, and which includes Heraclitus, the Eleatics, and the Skeptics. The account of these two schools comprises the whole of the work, with the exception of the first book, which contains the history of the seven wise men of Greece. The work of Diogenes is valuable for information which we could obtain from no other source; but it is ill digested, without critical judgment, and often inaccurate. Diogenes is supposed to have written some other works, among which was a volume of epigrams, but these have been entirely lost.

A good edition of his history is that of II. G. Hubner (2 vols. 8vo, Leipsic, 1828-31). A translation into English was published in 1868 (2 vols. 8vo, London), and there is one by C. D. Yonge in Bohn's "Classical Library."