How does Marcus Aurelius suggest handling other people's wrongdoing?

Marcus does not tell himself to punish, avoid, or even confront wrongdoers first. He tells himself to retire into his own soul and check his judgments before he does anything else. In Meditations 4.3 he asks himself directly: with what are you discontented? With the badness of men? And his answer is to recall a short set of principles rather than to act on the irritation.

The first principle is that rational animals exist for one another, and that to endure is a part of justice (Meditations 4.3). This is not a call to be a doormat. It is a claim about what human beings are for. If people are made to work together the way hands or eyes work together in a body, then someone else's bad behavior is a kind of malfunction within a shared project, not an attack from outside it that you must repel at all costs. Bearing with it, on this view, is itself doing justice, because justice is the virtue of treating others as fellow parts of one whole.

The second principle is the harder one, and Marcus states it flatly: men do wrong involuntarily (Meditations 4.3). This is easy to misread as an excuse, as if Marcus thinks bad people are not responsible for what they do. That is not the claim. The Stoic view is that every person acts toward what looks good to them in the moment. Nobody chooses evil as evil. They choose it because their judgment about what is good has gone wrong. So the wrongdoer is not maliciously choosing harm, he is mistaken about where his own good lies. Seeing it this way does not excuse the act, but it changes what you owe the person emotionally: pity for a faulty judgment fits the case better than hatred for a chosen evil.

Marcus backs this up with two further moves in the same passage. He reminds himself how many people who fought each other in hatred and suspicion are now simply dead and reduced to ashes, which puts the present irritation inside a much longer and more indifferent timeline. And he offers himself a dilemma: either the universe runs by providence or it is only atoms colliding by chance. If there is providence, then the world including its wrongdoers is part of an order you did not design and are not in charge of correcting. If it is only atoms, then there is no cosmic scorekeeper to be outraged on behalf of, so outrage adds nothing. Either way, he tells himself, be quiet at last.

What changes for someone who actually takes this seriously is where the labor goes. You stop spending your effort managing your reaction to other people's badness as if it were the main event, and you spend it instead on making sure your own judgments are sound. This connects to the wider Stoic claim, visible elsewhere in the Meditations, that things like dishonor and pain happen to good and bad people alike and so are not themselves good or bad (Meditations 2.11). If that is true of what happens to you, it is also true of what other people do: their wrongdoing is bad for their own character, but it need not become bad for yours, because your character is measured by your judgments and actions, not by what you suffer at their hands.

The concrete practice Marcus models is not a technique for dealing with the wrongdoer at all. It is a technique for dealing with yourself first: retreat, recall the principle, check whether your discontent is tracking something real or just an unexamined impression, and only then decide what, if anything, to do.