Aristotle, Nicomachean Ethics
H. Rackham, Ed.

implacable, and remain angry a long time, because they keep their wrath in; whereas when a man retaliates there is an end of the matter: the pain of resentment is replaced by the pleasure of obtaining redress, and so his anger ceases. But if they do not retaliate, men continue to labour under a sense of resentment—for as their anger is concealed no one else tries to placate them either, and it takes a long time to digest one's wrath within one. Bitterness is the most trouble some form of bad temper both to a man himself and to his nearest friends. [11] Those who lose their temper at the wrong things, and more and longer than they ought, and who refuse to be reconciled without obtaining redress or retaliating, we call Harsh-tempered. [12]

We consider the excess to be more opposed to Gentleness than the defect, because it occurs more frequently, human nature being more prone to seek redress than to forgive; and because the harsh-tempered are worse to live with than the unduly placable. [13]

But what was said above¹ is also clear from what we are now saying; it is not easy to define in what manner and with whom and on what grounds and how long one ought to be angry, and up to what point one does right in so doing and where error begins. For he who transgresses the limit only a little is not held blameworthy, whether he errs on the side of excess or defect; in fact, we sometimes praise those deficient in anger and call them gentle-tempered,