" But what of the lives that I had taken? Was I not equally culpable, and was that not why there now so many names, of both good men and bad, carved upon that palimpsest I bore, and for each of which I might justifiably be called to account? I could argue that by committing a smaller evil, I had prevented a greater one from occurring, but I would still bear the mark of that sin upon me, and perhaps be dammed for it. Yet, in the end, I could not stand by. There were sins that I had committed out of anger, touched by wrath, and for those I had no doubt that I would at last be charged and found wanting. But, the others? I chose to act as I did, believing that the greater evil lay in doing nothing. I have tried to make reparation, in my way.
The problem is that, like cancer, a little corruption of the soul will eventually spread throughout the whole.
The problem is that there are no small evils. "

― John Connolly , The Black Angel (Charlie Parker, #5)