Diogenes Laėrtius in Wikipedia
Diogenes Laertius (ancient Greek: Διογένης Λαέρτιος, Diogenes Laertios; fl. c. 3rd century) was a biographer of the Greek philosophers. Nothing is known about his life, but his surviving Lives and Opinions of Eminent Philosophers is one of the principal surviving sources for the history of Greek philosophy.
Nothing is definitively known about his life. He must have lived after Sextus Empiricus (c. 200 AD), whom he mentions, and before Stephanus of Byzantium and Sopater (c. 500 AD), who quote him. His work makes no mention of Neoplatonism, even though it is addressed to a woman who was "an enthusiastic Platonist." It is probable that he flourished in the first half of the third century, during the reign of Alexander Severus (222235) and his successors.
The precise form of his name is uncertain. In the ancient manuscripts of his work, he is invariably referred to as "Laertius Diogenes," and this form of the name is repeated by Sopater, and the Suda. The modern form "Diogenes Laertius" is much rarer, and occurs in Stephanus of Byzantium, and in a lemma to the Greek Anthology. He is also referred to as "Laertes," or just "Diogenes."
The origin of his name "Laertius" is equally uncertain. Stephanus of Byzantium, in one passage, refers to him as "Diogenes of Laertieus," implying that he was the native of some town, perhaps the Laerte in Caria, or the one in Cilicia. An alternative suggestion is that one of his ancestors had for a patron a member of the Roman family of the Laertii. The modern theory is that "Laertius" is a nickname, to distinguish him from the many other people called Diogenes in the ancient world, and derived from the Homeric epithet "Diogenes Laertiade," used in addressing Odysseus.
His home town is unknown, assuming that his name does not refer to his place of origin. A disputed passage in his writings has been used to suggest that it was Nicaea in Bithynia.
The work by which he is known, Lives and Opinions of Eminent Philosophers, was written in Greek and professes to give an account of the lives and sayings of the Greek philosophers. Although it is at best an uncritical and unphilosophical compilation, its value, as giving us an insight into the private lives of the Greek sages, led Montaigne to exclaim that he wished that instead of one Laertius there had been a dozen. On the other hand, modern scholars advise that we treat Diogenes' testimonia with care, especially when he fails to cite his sources: "Diogenes has acquired an importance out of all proportion to his merits because the loss of many primary sources and of the earlier secondary compilations has accidentally left him the chief continuous source for the history of Greek philosophy."
Diogenes treats his subject in two divisions which he describes as the Ionian and the Italian schools; the division is somewhat dubious and appears to be drawn from the lost doxography of Sotion. The biographies of the former begin with Anaximander, and end with Clitomachus, Theophrastus and Chrysippus; the latter begins with Pythagoras, and ends with Epicurus. The Socratic school, with its various branches, is classed with the Ionic; while the Eleatics and sceptics are treated under the Italic. From the statements of Walter Burley (a 14th-century monk) in his De vita et moribus philosophorum the text of Diogenes seems to have been much fuller than that which we now possess.
His own opinions are uncertain. It has been suggested that Diogenes was an Epicurean, or a Skeptic. In favour of the view that he was an Epicurean, is the fact that he passionately defends Epicurus. Book 10, which discusses Epicurus, is of high quality, and contains three long letters, written by Epicurus, which explain Epicurean doctrines. In favour of the view that he was a Skeptic, is the way in which he is impartial to all the schools in the manner of the ancient skeptics, and he carries the succession of the school further than the other schools. At one point, he even seems to refer to the Skeptics as "our school." On the other hand, most of these points can be explained by the way he uncritically copies from his sources. It is impossible to be certain that he adhered to any school, and he is usually more interested in biographical details than in philosophical doctrines.
In addition to the Lives, Diogenes was the author of a work in verse on famous men, in various metres.