Diogenes Laërtius, a Greek historian, born at Laerte, in Cilicia; flourished in the 2nd century A.D.; author of “Lives of the Philosophers,” a work written in 10 books; is full of interesting information regarding the men, but is destitute of critical insight into their systems.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Diodorus Siculus * Diogenes of Apollonia