Diogenes Laertius

Diogenes Laertius was an ancient Greek author, usually placed in the 3rd century CE, and he is remembered above all for Lives and Opinions of Eminent Philosophers. That wide-ranging work gathers biographies, anecdotes, sayings, and summaries of philosophical teachings, making it one of the most important surviving sources for the history of Greek philosophy.

Very little can be said with confidence about his own life. Even standard reference works describe him as a figure who is otherwise largely unknown, and much of his reputation rests on this single surviving book. What has kept him important for centuries is not polished original theory, but the sheer amount of earlier material he preserved.

His writing mixes valuable historical detail with lively gossip, quotations, and memorable stories, so reading him can feel both scholarly and surprisingly human. For many readers, he offers not just a catalog of doctrines, but a vivid look at philosophers as real people with habits, rivalries, and strong opinions.