There is an interesting contrast between Aristotle and Friedrich Nietzsche when it comes to the notion of a good man and whether such a man should change and despise himself.
Aristotle, in his Nicomachean Ethics, writes that the good man “desires the same things with respect to every part of his soul” and feels pain and pleasure with himself most of all “for it is always the same thing that is painful or pleasant, not one thing at one time and another at another time, since he has, so to say, no regrets” (1166a15/29, translation by Apostle). Bad people, however, “are in conflict with themselves, and they desire certain things but wish things which are different from those desired, like incontinent men” (1166b7-9). As a result, bad men having nothing lovable about them because they don’t love themselves; they despise themselves and are “full of regrets” (116b25).
But Friedrich Nietzsche asserts “Only he who changes remains akin to me” (Beyond Good and Evil, section 204). Moreover, he has his character Zarathustra say the following: “Alas, the time of the most despicable man is coming, he that is no longer able to despise himself. Behold, I show you the last man” (Zarathustra’s Prologue, Part 5, translated by Walter Kaufmann).