Richard

“Macbeth's self-justifications were feeble – and his conscience devoured him. Yes, even Iago was a little lamb, too. The imagination and spiritual strength of Shakespeare's evildoers stopped short at a dozen corpses. Ideology—that is what gives evildoing its long-sought justification and gives the evildoer the necessary steadfastness and determination. That is the social theory which helps to make his acts seem good instead of bad in his own and others' eyes, so that he won't hear reproaches and curses but will receive praise and honors. That was how the agents of the Inquisition fortified their wills: by invoking Christianity; the conquerors of foreign lands, by extolling the grandeur of their Motherland; the colonizers, by civilization; the Nazis, by race; and the Jacobins (early and late), by equality, brotherhood, and the happiness of future generations.... Without evildoers there would have been no Archipelago.”
― Aleksandr Solzhenitsyn, The Gulag Archipelago 1918–1956

“What is morally wrong can never be advantageous, even when it enables you to make some gain that you believe to be to your advantage. The mere act of believing that some wrongful course of action constitutes an advantage is pernicious.”
― Marcus Tullius Cicero