One of the hardest parts of Stoicism for people to wrap their heads around is that evil people are vicious exactly because they’re ignorant. This doesn’t mean they’re ignorant of society’s expectations, the law, or even a definition of what good behavior is. They’re ignorant in the sense that they lack the wisdom necessary to understand that virtue leads truly to the good life (eudaimonia).
So when I hear people say, “well, murderers know exactly what they did was wrong but they did it anyway.” But if they really understood the good life, virtue, and excellence, surely they wouldn’t have committed their crime because they’d be cheating themselves of something much greater. Instead, murderers mistakenly believe they’re getting something good by murdering someone (perhaps a temporary satisfaction to their jealousy) but they’re absolutely mistaken. Their need for their negative passion to be exemplified in action is transient and soon will be replaced with a new need to maybe seek vengeance on someone else or do harm in another way.
If you could take a criminal mind and show them truly what wisdom and knowledge of the good entails, they wouldn’t trade that knowledge of the good for their previous petty notions of “goods” for a second. They would understand what the good life entailed and would act to be as virtuous as possible. Socrates knew this, Plato knew this, and so did Zeno of Citium.
Am I mistaken that bad people do bad things out of ignorance? Maybe so. I’m always keeping and open mind about this position. But let’s just entertain that people do bad things not because of lack of wisdom but because of lack of willpower. I’m open to such a possibility but oddly enough it seems pretty compatible with Stoicism to hold this view as well. People who lack willpower are just as hard to be angry at as people who lack knowledge of good and evil. After all, if they lack willpower, they can’t help themselves. But what about the third possibility that people completely 100% voluntarily do bad because they know it’s wrong but do it anyway?
Well, let’s just go down that road. For these people who supposedly do bad voluntarily, it’s still difficult to be righteously indignant at those sorts of people because by not following virtue, they’re hurting themselves by feeding their negative passions. They give into anger and hate and have an ill soul. So even with that position, the Stoic will have difficulty being righteously mad at such a person because these bad people have irrationally chosen to go against the good even though they knew better (supposedly).
I still think that bad people do bad things out of ignorance/amathia. But even with the slim possibility of incontinence/akrasia/weakness of will, people still seem to harm themselves and their actions seem almost beyond their control at times.