Mark Shea has written a post on doing bad things for a good end. Here’s an excerpt from near the beginning:
Truly Evil People get up in the morning thinking, “How can I further the cause of Evil today?” Charming rogues like us may, sure enough, look out for number one a bit, but we mean well and, gosh darn it, you can’t help admiring that, even when we may have to get a bit rough with Truly Evil People by torturing them or dropping A-bombs on them.
Truly Evil People are monsters, and it is blasphemous to even speak of their desiring something good, because to do so humanizes them instead of righteously condemning them as the monsters they are. We charming rogues, on the other hand, should we find ourselves having to “go to the Dark Side” to fight the Truly Evil, always do so out of a noble fundamental commitment to goodness and are, in a way, self-sacrificing martyrs bravely willing to face even damnation by God Almighty Himself if necessary, if only that the greater good may be done by defeating Truly Evil people.
In fact, however, this notion that Truly Evil people are distinguished from us because they desire evil ends is false. That’s because every sin, whether venial or mortal, is committed in the disordered attempt to achieve some good end. Everything from the Holocaust to your hand in the cookie jar is the disordered attempt to obtain some good. And indeed, the more exalted the good end, the more the sinner can feel justified in doing something monstrous to achieve it. For this reason, sins do not become “not sins” merely because we intend some good end.
For the simple fact is that everybody, from the kid fibbing about the piggy bank to Adolf Hitler, is seeking some good end. What makes a sin a sin is not that the end sought is not good, but that a good end is sought by evil means. The severity of a sin is measured not by the nobility of the end we seek — Hitler, after all, sought a glorious renewed Germany risen from the ashes of World War I — but by how radically disordered are the means we use to achieve that end (e.g., the death of millions innocent people).
To say, “But I meant well” if we merely mean, “There was some good thing I was pursuing because I loved it and thought it would bring me happiness” is no sign at all that we are a saint. After all, Judas Iscariot could say as much. He wanted something good (i.e., money, peace from his tormented conscience, etc.). Hitler wanted happiness and various good ends (power, a greater Germany, etc.) He was motivated by love for something (his own glory, the glory of the Fatherland, a perverted and swollen love of country that vaunted itself again the love of his non-German neighbor and even against the love of God, as nationalism tends to do).
Every freakish monster in history, from John Wayne Gacy to Jeffrey Dahmer to Ted Bundy, was, in some way or other, seeking a good end (sexual pleasure, power, etc.) So does every sinner, great and small, who says, “Let us do evil that good may come of it.”
Any idiot can want happiness, because it’s impossible for any idiot to not want happiness. The trick — always — is to pursue happiness without cutting moral corners — like, say, “You shall not murder.” It is only when we pursue the good end without using sinful means — not robbing the piggy bank to buy Mom the present, not destroying the baby to ward off poverty, not incinerating children in their beds to win the war, not torturing the prisoner to save your skin — that we can truly say we meant well.
Desiring happiness is a defining characteristic of what it means to be human. It is a great inbuilt faculty from God. But it is not the defining characteristic of a saint. For a saint seeks happiness by God’s means only and refuses the enticement of the devil to take shortcuts to Wisdom as he whispers, “You shall not surely die. Go ahead and disobey. In fact, it will make you like God if you do!”