All the sources I’ve looked at call Lives of Eminent Philosophers a work of great value but do not go into specifics. The Oxford Companion to Philosophy complains that Diogenes has no discernible philosophy; less charitable, but not unreasonable commenters do not deign to call him an author at all. It’s not easy to prove that Diogenes is worth reading.
Perhaps the title of another lost work from Diogenes’ endless list provides a clue: Against Wisdom, by Aenesidemus, the follower of Pyrrho. The Pyrrhonians took skepticism quite far, insisting they determined nothing, and did not even determine that they determined nothing. Diogenes rightly doubts whether Pyrrho really was as skeptical in everyday life, of carts, deep holes, dogs, and the like, as he was in philosophy. To opponents who claimed that he could not live without making some affirmations, he answered that custom was sufficient and did not imply a judgment. From Pyrrho’s standpoint, anyone who went further was a dogmatist.
The question of how far we should venture in setting down beliefs does not concern only Pyrrho and the skeptics. Diogenes writes what is still true today, that “There is great division of opinion between those who affirm and those who deny that Plato was a dogmatist.” He doesn’t even have to comment on the divisions that arose among the successors of Socrates; the lives speak for themselves: Antisthenes the Cynic and the hedonist Aristippus clearly took things in different directions than Plato. Controversy between dogmatists and skeptics shows that the nature of a philosophical work is itself a question for philosophy. Should it propound theory or attack it, or should it only report impressions? It also showed how Diogenes was faced with a wider range of philosophical positions than I am accustomed to bear in mind. Therefore I am more intrigued by his equanimity than I am disappointed in his lack of a position.
I would like to think that one can explain some of the odd features of the Lives on the basis of this equanimity, rather than on sheer muddled credulity. Diogenes sees fit to include many things not to the credit of his eminent subjects. He describes Menedemus as a vain slacker but a particularly good friend. This story concerning Arcesilaus I found rather touching:
“He also attended the lectures of the geometer Hipponicus, at whom he pointed a jest as one who was in all besides a listless, yawning sluggard but yet proficient in his subject. ‘Geometry,’ he said, ‘must have flown into his mouth while it was agape.’ When this man’s mind gave way, Arcesilaus took him to his house and nursed him until he was completely restored.”
Diogenes’ anecdotes of the most various philosophers show them at their most humane, from Pyrrho’s dusting furniture in the house he shared with his sister to the flat contention that all of the detractors of Epicurus must be ignorant of how much people liked the man. This is an aspect of the philosophic life that is easy to lose sight of in an era where even the surviving names are few. Surely to take Diogenes to task for lack of a position is to lose sight of the idea that philosophy might make us not just wiser, but better.