Diogenes Laërtius

Diogenes Laertius (pronounced 'die-OJ-uh-neez ley-UH-shus'; Greek: Διογένης Λαέρτιος, Diogenēs Laertios; lived c. 3rd century CE) was a biographer of the Greek philosophers. Nothing is known about his life, but his surviving Lives and Opinions of Eminent Philosophers is a principal source for the history of Greek philosophy.