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Who Is Diotimus? An Introduction To The Man Who Made An Extraordinary Mistake



Of the Ancient Stoics, we know the least about Diotimus. He lived sometime around the early-first-century BC, and he might have known the brilliant polymath Posidonius. That’s about it—that’s about all we learn from the sources that are typically rich with details and stories on the lives of the Stoics. When or where Diotimus was born, when or how he died, when or how he was introduced to philosophy, who his students were, what he taught them—we don’t know. 

But the reason we don’t know much about Diotimus, paradoxically, tells us a great deal. The single story we have from the life of Diotimus is one that has baffled historians and students of Stoicism for more than two thousand years.

Which brings us immediately to what we can learn from the life of this Stoic


Revenge Is A Dish Best Not Served

Sometime around the turn of the first century BC, Diotimus committed what can only be described as an act of indisputable malice. He forged dozens and dozens of “licentious letters” that framed the rival philosopher Epicurus—who was enjoying a resurgence in Athens amid the rising splendor and power of Rome. Diotimus portrayed Epicurus as some kind of depraved maniac—a reputation that Epicurus has struggled to completely shed even to this day—in order to bolster his arguments against the philosophy. 

The Epicurean school at this time was under the leadership of Apollodorus, who we are told by Diogenes Laërtius, smeared Chrysippus, claiming that the Stoic had filled his books with quotes he had stolen from others. Such defamation of the great Stoic, we imagine Diotimus decided, could not go unaddressed. Diotimus avenged slander with slander, committing a crime far worse than what Apollodorus was falsely alleging against Chrysippus.

We don’t know exactly what happened to Diotimus next, unfortunately, or how his story ended. It would be, then, Diotimus’s sole contribution to the history of Stoicism, making himself a cautionary tale. 

Seneca, who writes expansively on all sorts of philosophers and their behaviors, and about the Epicureans more than eighty times across his surviving works, never once mentions this incident and the sad failing of his own school. He did, however, write plenty about how the Stoic is supposed to be beyond grudges, beyond revenge, beyond petty competition or the need to win arguments. “How much better to heal than seek revenge from injury,” Seneca wrote. “Vengeance wastes a lot of time and exposes you to many more injuries than the first that sparked it. Anger always outlasts hurt. Best to take the opposite course. Would anyone think it normal to return a kick to a mule or a bite to a dog?” Marcus Aurelius agreed: “The best revenge is not to be like that.”

Nothing Is Durable

Diotimus proved not only that the Stoics were hardly perfect and that no matter how much training or reading we have done—but also that a snap decision made in the moment can undo all of it.

It was Seneca who said that building anything—whether a reputation or an empire—is a long process, but its undoing can be instant. “The growth of things is a tardy process and their undoing is a rapid matter,” he wrote. “Nothing is durable…We should be anticipating not merely all that commonly happens by all that is conceivably capable of happening.”

He could not have captured the folly of Diotimus better. Nor could Shakespeare’s funeral oration of Caesar be any more apt. For in that play, the once-Stoic Brutus’s single deed—the assassination of Julius Caesar—would come to overwhelm and obscure everything else the man would do in his life. And so it went for Diotimus, a philosopher who may well have had many interesting and profound things to say about the pursuit of moral perfection and well-being, but instead is known to us only for his one evil and vengeful decision to attempt to destroy the reputation of the founder of his rivals’ school.

Ask This Question

If only Diotimus—before he acted in retaliation against Apollodorus—could have heard this line from Anthony de Mello: “The question to ask is not, ‘What’s wrong with this person?’ but ‘What does this irritation tell me about myself?’”

This question—this pause and then reversal—is an essential element of Stoicism. It goes back to Epictetus who said that we are complicit in the offense anytime someone hurts our feelings or makes us upset. We are choosing to react to something. We have to remember that. We have to remember that we have the power, not them, that it’s not the things they do that upset or offend us but our judgment about those things.

The irritant is never the other person. It’s always something within you. So when you inevitably get frustrated with someone today, remember to ask:  “What does this irritation tell me about myself?”

P.S. The bestselling authors of The Daily Stoic, Ryan Holiday and Stephen Hanselman, have teamed up again in their new book Lives of the Stoics: The Art of Living From Zeno To Marcus. Along with presenting the fascinating lives of all the well-known and not so well-known Stoics, Lives of the Stoics distills timeless and immediately applicable lessons about happiness, success, resilience, and virtue. The book is available for pre-order and is set to release on September 29!


Meet The Stoics:

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Who Is Seneca? Inside The Mind of The World’s Most Interesting Stoic

Who Is Epictetus? From Slave To World’s Most Sought After Philosopher

Who Is Cleanthes? Successor to Zeno & Second Head of the Stoic School

Who Is Chrysippus? The ‘Second Founder of Stoicism’ Who Died Laughing

Who Is Cato? Roman Senator. Mortal Enemy of Julius Caesar.

Who Is Zeno? An Introduction to the Founder of Stoicism

Who Is Cicero? Getting To Know Rome’s Greatest Politician

Who Is Posidonius? The Most Academic Stoic

Who Is Panaetius? Spreading Stoicism from Greece to Rome

Who Is Paconius Agrippinus? An Introduction To The Red Thread Contrarian

Who Is Porcia Cato? An Introduction To The Stoic Superwoman

Who Is Gaius Rubellius Plautus? An Introduction To Nero’s Rival

Who Is Publius Rutilius Rufus? An Introduction To The Man Who Could Not Be Corrupted