Is "Decent Behavior" Basically Instinct?—Mere Christianity by C.S. Lewis

"The Moral Law tells us the tune...our instincts are merely the keys."

C.S. Lewis said these two facts are foundational to all clear thinking about ourselves and the universe:

1. Human beings all over the world have the unshakable notion that they ought to behave in a certain way.
2. None of us do, in fact, behave that way: we know the Rule of Decent Behavior; we break it.

"If they are the foundation," Lewis begins in Chapter 2 of Mere Christianity, "I had better stop to make that foundation firm before I go on. Some of the letters I have had show that a good many people find it difficult to understand just what this Law of Human Nature, or Moral Law, or Rule of Decent Behaviour is. For example... 'Isn't what you call the Moral Law simply our herd instinct and hasn't it been developed just like all our other instincts?' Now I do not deny that we may have a herd instinct: but that is not what I mean by the Moral Law.... Feeling a desire to help is quite different from feeling ... you ought to help whether you want to or not....

"The Moral Law tells us the tune we have to play; our instincts are merely the keys.... There are no such thing as good and bad impulses... .A piano ... has not got ...'right' notes and 'wrong' ones.  Every single not is right at one time and wrong at another.... The most dangerous thing you can do is take any one impulse ... and set it up as the thing...to follow at all costs. There is not one of them which will not make us into devils if we set it up as an absolute guide. You might think love of humanity in general was safe, but it is not. If you leave out justice you will find yourself breaking agreements and faking evidence in trials 'for the sake of humanity', and become in the end a cruel and treacherous man....

Worth Reading

"We learn the Rule of Decent Behavior from parents and teachers, and friends and books, as we learn everything else. But some of the things we learn are mere conventions," such as what side of the road to drive on, "and others of them, like mathematics, are real truths. The question is to which class the Law of Human Nature belongs. There are two reasons for saying it belongs to the same class as mathematics. The first is ... that though there are differences between the moral ideas of one time or country and those of another, the differences are ... not nearly so great as most people imagine." Lewis mentions he devoted an appendix to citing the evidence for that fact in his book The Abolition of Man. In short, it is the reason you won't find people of any time or place exalting cowardice or treachery to friends.

The other reason for believing morality is like math is when you think about the differences between the morality of one people and another, "Do you think that the morality of one people is ever better or worse than that of another?.... Progress means not just changing, but changing for the better. If no set of moral ideas were any truer or better than any other, there would be no sense in preferring civilized morality to savage morality, or Christian morality to Nazi morality. In fact, of course, we all do believe that some moralities are better than others.... If your moral ideas can be truer, and those of the Nazis less true, there must be something—some Real Morality—for them to be true about....

"One word before I end. I have met people who exaggerate the differences [between moralities] because they have not distinguished between differences of morality and ... belief about facts. For example, one man said to me, 'Three hundred years ago people in England were putting witches to death. Was that what you call the Rule of ... Right Conduct?' But surely the reason we do not execute witches is that ... if we really thought that there were people ... who had sold themselves to the devil and received supernatural powers from him...to kill their neighbors or drive them mad...surely we would all agree that if anyone deserved the death penalty, then these filthy [traitors] did?... You would not call a man humane for ceasing to set mousetraps if he did so because he believed there were no mice in the house."

Highlights from chapter 2: Some Objections, book 1: Right and Wrong as a Clue to the Meaning of the Universe in Mere Christianity by C.S. Lewis. Click here for a clear view of how this chapter relates to the whole book.