Evil is thus a kind of parasite on goodness. If there were no good by which to measure things, evil could not exist. Men sometimes forget this, and say, there is so much evil in the world that there cannot be a God. They are forgetting that, if there were no God, they would have no way of distinguishing evil from goodness. The very concept of evil admits and recognizes a Standard, a Whole, a Rule, an Order. Nobody would say that his automobile was out of order if he did not have a conception of how an automobile ought to run.
~ Fulton J. Sheen