Thomas Aquinas

“ Now unless some injury has been done, there is no question of vengeance: nor does any injury provoke one to vengeance, but only that which is done to the person who seeks vengeance: for just as everything naturally seeks its own good, so does it naturally repel its own evil. But injury done by anyone does not affect a man unless in some way it be something done against him. Consequently the motive of a man's anger is always something done against him. ”

“ I answer that, The cause of anger, in the man who is angry, may be taken in two ways. First in respect of the motive of anger: and thus excellence is the cause of a man being easily angered. Because the motive of anger is an unjust slight, as stated above (A [2] ) . Now it is evident that the more excellent a man is, the more unjust is a slight offered him in the matter in which he excels. Consequently those who excel in any matter, are most of all angry, if they be slighted in that matter; for instance, a wealthy man in his riches, or an orator in his eloquence, and so forth. ”

“ We speak of anger in God, not as of a passion of the soul but as of judgment of justice, inasmuch as He wills to take vengeance on sin. Because the sinner, by sinning, cannot do God any actual harm: but so far as he himself is concerned, he acts against God in two ways. First, in so far as he despises God in His commandments. Secondly, in so far as he harms himself or another; which injury redounds to God, inasmuch as the person injured is an object of God's providence and protection. ”

“ Wherefore the Philosopher says (Rhet. ii, 3) that "men are not angry---if they think they have wronged some one and are suffering justly on that account; because there is no anger at what is just." Now injury is done to another in three ways: namely, through ignorance, through passion, and through choice. Then, most of all, a man does an injustice, when he does an injury from choice, on purpose, or from deliberate malice, as stated in Ethic. ”

“ Further, anger is a desire for vengeance. But one may desire vengeance for things done against others. Therefore we are not always angry on account of something done against us.
Objection 3: Further, as the Philosopher says (Rhet. ii, 2) man is angry especially with those "who despise what he takes a great interest in; thus men who study philosophy are angry with those who despise philosophy," and so forth. But contempt of philosophy does not harm the philosopher. Therefore it is not always a harm done to us that makes us angry. ”

“ To be despised by one's friends seems also a greater indignity. Consequently if they despise us by hurting or by failing to help, we are angry with them for the same reason for which we are angry with those who are beneath us. ”

“ Each of those causes amounts to some kind of slight. Thus forgetfulness is a clear sign of slight esteem, for the more we think of a thing the more is it fixed in our memory. Again if a man does not hesitate by his remarks to give pain to another, this seems to show that he thinks little of him: and those too who show signs of hilarity when another is in misfortune, seem to care little about his good or evil. Again he that hinders another from carrying out his will, without deriving thereby any profit to himself, seems not to care much for his friendship. ”

“ Wherefore we are most of all angry with those who, in our opinion, have hurt us on purpose. For if we think that some one has done us an injury through ignorance or through passion, either we are not angry with them at all, or very much less: since to do anything through ignorance or through passion takes away from the notion of injury, and to a certain extent calls for mercy and forgiveness. ”

“ For slight is of three kinds, as stated in Rhet. ii, 2, viz. "contempt," "despiteful treatment," i.e. hindering one from doing one's will, and "insolence": and all motives of anger are reduced to these three. Two reasons may be assigned for this. First, because anger seeks another's hurt as being a means of just vengeance: wherefore it seeks vengeance in so far as it seems just. Now just vengeance is taken only for that which is done unjustly; hence that which provokes anger is always something considered in the light of an injustice. ”

“ Further, there is no greater defect than death. But anger ceases at the sight of death. Therefore defect of a person does not provoke anger against him.
Objection 3: Further, no one thinks little of a man through his being friendly towards him. But we are more angry with friends, if they offend us or refuse to help us ”

“ If we are angry with those who harm others, and seek to be avenged on them, it is because those who are injured belong in some way to us: either by some kinship or friendship, or at least because of the nature we have in common. ”