I've seen this sentence
and I would like to know what is the meaning of まじくは so that I can understand the expression 許すまじくは許さない.
Making an attempt to get some hint through machine translation, I've got the following.
"Forgive me, but I won't forgive you. I myself don't have that kind of principled line, but that doesn't mean I don't look down on people who do."
Although I know there may be some flaws in this translation, is 許すまじくは許さない referring about a moral principal, about a way of being? I must say I'm somewhat lost when it comes to fully understanding the whole idea of the original sentence and translating it.