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
(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
(222–235) and his successors.
The precise form of his name is uncertain.
When Thales was asked what was difficult, he said, "To know one’s self." And what was easy, "To advise another."
He said that men ought to remember those friends who were absent as well as those who were present.
The apophthegm "Know thyself" is his.
Writers differ with respect to the apophthegms of the Seven Sages, attributing the same one to various authors.
Solon gave the following advice: "Consider your honour, as a gentleman, of more weight than an oath. Never tell a lie. Pay attention to matters of importance."
As some say, Solon was the author of the apophthegm, "Nothing in excess."