How should a Stoic respond to insults or mockery?

Epictetus does not tell you to develop a thicker skin. He makes a sharper claim: the insult does not exist until you supply the judgment that makes it one. "Not he who gives ill language or a blow insults, but the principle which represents these things as insulting" (Handbook 20). The words leave someone's mouth, reach your ears, and stop there. What happens next, whether you feel wounded or shrug, is an act of your own mind, not something the other person did to you.

This is easy to hear as a trick of framing, a kind of mental jujitsu you perform so the words sting less. That is the shallow reading. The real claim is about where good and bad actually live. For Epictetus only your own judgments, desires and choices are up to you, and only these can be genuinely good or bad. An insult is a sound. It cannot touch your faculty of choice unless you hand it the power to. So when he says "it is your own opinion which provokes you" (Handbook 20), he is not offering a coping technique. He is telling you that you have been mistaken about what can hurt you at all.

Epictetus pushes this further in a passage that many people find harder to accept. When someone insults or harms you, he says, that person is acting on what seems right to him, however mistaken. "It is not possible that he should follow what appears right to you, but what appears so to himself" (Handbook 42). If his judgment is false, the damage lands on him, not on you, in the same way that a person who mistakes a true statement for a false one has deceived only himself. Epictetus draws the conclusion plainly: "you will meekly bear a person who reviles you, for you will say upon every occasion, 'It seemed so to him'" (Handbook 42). The insulting person has already lost something real, his own good judgment. You have lost nothing unless you choose to.

Epictetus also addresses a specific, practical case: the ridicule that comes with visibly trying to live philosophically. He tells the beginner to expect it. "Prepare yourself from the very first to be laughed at, to be sneered by the multitude" (Handbook 22). The advice is not to become smug or superior in response, since a supercilious look just invites more mockery. Instead, hold steadily to what seems best to you. He adds a claim about how this plays out over time: people who first ridicule you for taking philosophy seriously will later admire you for it, but if you cave to their mockery you earn a double ridicule, for the original failing and for the capitulation (Handbook 22).

Marcus Aurelius arrives at the same discipline from a different angle. He starts his day by expecting to meet the arrogant, the deceitful, the ill-tempered, and he traces their behavior to a single cause: ignorance of what is actually good and bad (Meditations 2.1). Because he has seen that the good is beautiful and wrongdoing is ugly, and because he recognizes the wrongdoer as akin to him, sharing the same reason and the same portion of the divine, he concludes that no one can "fix on me what is ugly" and that anger or contempt toward such a person is itself unnatural, like a hand turning against a foot (Meditations 2.1). The insulting person is not an enemy to be defeated by wit. He is a kinsman who has gone wrong, and you were built to work with him, not against him.

None of this means you cannot correct someone or walk away from an insulting person. It means the correction is for their sake and for the shared order you belong to, not a defense of your own standing, because your standing was never at risk. The next time you feel the sting of mockery, ask where the sting actually came from: the words, or the opinion you formed about them. That question, asked honestly, is the whole practice.