From the Zen point of view, anger is one of the three poisons, a great affliction. The rush we get from anger is counterfeit, a substitute for real strength. And the fragile self it is seen to protect doesn't even really exist. It is a figment of our imagination. Others and ourselves can only be harmed by negative outbursts.
Anger is often justified by saying that some individuals are "bad" and deserve the punishment inflicted upon them. In fact, punishment is thought to straighten them up, give them due, or in some way or other teach the bad guys a lesson.
Zen rejects the hypothesis that individuals are either good or bad. Human life is fluid. Zen points to the fact that one moment we can be saints, the next moment, devils. Good turns to bad and the other way around — our lives can be described as a process that contains all permutations. As we practice we learn not to hate hell, but to recognize it for what it is and recognize the danger and pain it contains.
When anger and hate arise within us, when domination, cruelty, and ambition arise, we maintain balance and simply experience them for what they are. We do not repress and deny the energy, but experience it fully and let it go. To stay steady and centered during the experience of anger, not to lash out, is a mark of the ripened person.
— Brenda Shoshanna in Zen Miracles