What is evil neither can nor should be loved; for it is not one’s duty to be a lover of evil or to become like what is bad; and we have said that like is dear to like. Must the friendship, then, be forthwith broken off? Or is this not so in all cases, but only when one’s friends are incurable in their wickedness? If they are capable of being reformed one should rather come to the assistance of their character or their property, inasmuch as this is better and more characteristic of friendship. But a man who breaks off such a friendship would seem to be doing nothing strange; for it was not to a man of this sort that he was a friend; when his friend changed, therefore, and he is unable to save him, he gives him up.
Aristotle, The Nicomachean Ethics
friendship, toxic-friends, toxic-people