A Cancer of the Mind and Soul

In Shakespeare's time, as in our own, there was also an awareness of the internal ravages of the urge to revenge. To nurture such a passion was understood to be dangerous to the would-be revenger as well as to his or her victim. This awareness is reflected in the drama of Shakespeare and his contemporaries, where we see revengers psychologically twisted by the animosity they harbor against their enemies.

Revenge is a kind of wild justice, which the more man's nature runs to, the more ought law to weed it out. For as for the first wrong, it doth but offend the law; but the revenge of that wrong putteth the law out of office. Certainly, in taking revenge, a man is but even with his enemy, but in passing it over he is superior, for it is a prince's part to pardon. And Solomon, I am sure, saith, It is the glory of a man to pass by an offense. [Proverbs 19:11] That which is past is gone and irrevocable, and wise men have enough to do with things present and to come: therefore they do but trifle with themselves that labour in past matters. --Francis Bacon, The Essays, Harmondsworth, Penguin Books, (1985) p. 72.

Dwelling on revenge was associated with depression. In his psychological writing on melancholy, Timothy Bright states that Satan will take advantage of the particular sensitivity of a person of a melancholic humor and advocate various blasphemes; among them, the sin of revenge.

Of this kinde are certaine blasphemies suggested of the Devill, and laying of violent handes of them selves, or upon others neither moved thereto by hate or malice: or any occasion of revenge: of the same sort is the dispaire and distrust of gods mercy, and grace. --Timothy Bright, A Tretise of Melancholie (1586), New York, Columbia Univ. Press / Facsimile Text Society, (1940), p. 228.

Above all, there was an awareness that harboring vengeful feelings keeps alive the wounds which originally motivated the desire for revenge.

This is certain, that a man that studieth revenge keeps his own wounds green, which otherwise would heal and do well... Nay rather, vindictive persons live the life of witches, who, as they are mischievous, so end they unfortunate. --Francis Bacon, The Essays, Harmondsworth, Penguin Books, (1985) p. 73.