XII. The following books are attributed to him. The dialogues entitled the Cephalion; the Icthyas; the Jackdaw; the Leopard; the People of the Athenians; the Republic; one called Moral Art; one on Wealth; one on Love; the Theodorus; the Hypsias; the Aristarchus; one on Death; a volume of Letters; seven Tragedies, the Helen, the Thyestes, the Hercules, the Achilles, the Medea, the Chrysippus, and the Œdipus.
But Sosicrates, in the first book of his Successions, and Satyrus, in the fourth book of his Lives, both assert that none of all these are the genuine composition of Diogenes. And Satyrus affirms that the tragedies are the work of Philiscus, the Æginetan, a friend of Diogenes. But Sotion, in his seventh book, says that these are the only genuine works of Diogenes: a dialogue on Virtue; another on the Good; another on Love; the Beggar; the Tolmæus; the Leopard; the Cassander; the Cephalion; and that the Aristarchus, the Sisyphus, the Ganymede, a volume of Apophthegms, and another of Letters, are all the work of Philiscus.
XIII. There were five persons of the name of Diogenes. The first a native of Apollonia, a natural philosopher; and the beginning of his treatise on Natural Philosophy is as follows: “It appears to me to be well for every one who commences any kind of philosophical treatise, to lay down some undeniable principle to start with.” The second was a Sicyonian, who wrote an account of Peloponnesus. The third was the man of whom we have been speaking. The fourth was a Stoic, a native of Seleucia, but usually called a Babylonian, from the proximity of Seleucia to Babylon. The fifth was a native of Tarsus, who wrote on the subject of some questions concerning poetry which he endeavours to solve.
XIV. Athenodorus, in the eighth book of his Conversations, says, that the philosopher always had a shining appearance, from his habit of anointing himself.