There are two sides to the Stoic virtue of temperance. There is the ideal of taking the pleasures of life in moderation and there is the ability to moderate one’s emotional response. The latter is a rare art, it seems and recently I’ve seen a few examples of people spewing meaningless hatred towards various groups. At one time I would feel anger at this. Now my emotions tend towards pity. Hatred is often quoted as being harmful to both sides of any issue, but not only that it is my feeling that hatred is a truly useless emotion that should be purged wherever possible.
Anger can be a useful motivator in the right circumstances and channeled in the correct way. When that crosses in to the extremes of rage and hatred, though, we see any possible value eliminated entirely. The Stoics of course hold that any extreme emotion and they make a powerful case. Even love, taken to its extreme is more harmful than anything. We’ve all been sixteen and brokenhearted, after all. It’s far healthier to temper such emotions with practicality.
I think that pragmatism is the key. You can disagree with a person or an ideal without feeling hate. I find it helps to remember that the number of people who actually view themselves as evil is practically zero. Once you understand that their motives, though perhaps not in line with your own morality, are nevertheless not driven by wickedness we can begin a dialog to find common ground. Felling hatred towards someone makes this impossible.
Imagine for a moment that something you hold dear is viewed as immoral by a certain group. even if they were polite to your face (perhaps hiding behind some “love the sinner, hate the sin” hypocrisy) you would have a hard time controlling your own feelings of anger and resentment towards them. This would cause them to be completely unable to win you over to their side. I know I have a hard time agreeing with someone who I know hates me or something I do..
This to me is one of the strongest arguments in favour of stoic temperance in emotions. Your best chance of winning any debate is to do so rationally. You do have some degree of control over your emotions and exercising this control prevents your emotions from controlling you.