Let us sum up what we have reached so far. In the case of stones and trees and things of that sort, what we call the Laws of Nature may not be anything except a way of speaking. When you say that nature is governed by certain laws, this may only mean that nature does, in fact, behave in a certain way. The so-called laws may not be anything real-anything above and beyond the actual facts which we observe. But in the case of Man, we saw that this will not do. The Law of Human Nature, or of Right and Wrong, must be something above and beyond the actual facts of human behaviour. In this case, besides the actual facts, you have something else-a real law which we did not invent and which we know we ought to obey.
–C.S. Lewis, Mere Christianity