Insufficient Christianity: 11:1

In this chapter of Mere Christianity, Lewis describes more of what a proper moral system means:

There is a story about a schoolboy who was asked what he thought God was like. He replied that, as far as he could make out, God was 'the sort of person who is always snooping round to see if anyone is enjoying himself and then trying to stop it'. And I am afraid that is the sort of idea that the word Morality raises in a good many people's minds: something that interferes, something that stops you having a good time. In reality, moral rules are directions for running the human machine.

Now, we agree to a certain extent here, Lewis is correct that morality, at it's core, is about determining whether actions benefit humanity (if we are charitable enough to interpret "running the human machine" along these lines).  True morality is not concerned with simply keeping people from having a good time.  The reason that people might get this impression of morality is because of people like you, Mr. Lewis, who make statements about moral principles without any evidence.

Think of it this way - many Christians protest the Harry Potter books as immoral.  Many people enjoy these books.  Has anyone ever even attempted to demonstrate, with evidence or logic in any way, that Harry Potter books are likely to cause humanity harm?  Do they infringe upon anyone's rights in any way whatsoever?  People sometimes have a "cosmic kill-joy" impression of religion because of moral outrage like this; insisting that something, something that is enjoyed by many people, is morally wrong, without any logical explanation of why it's wrong.

The reality is even more important than Lewis lets on.  Faulty moral logic is responsible for much worse than merely preventing people's fun.  There are some religious groups claim that it is immoral to receive or administer blood transfusions.  The Bible makes it quite clear that working on certain days of the week is a horribly immoral act, punishable by death.  To use an example extremely common in even mainstream Christianity, many, many Christians hold that educating teenagers about contraceptive use is immoral, as it could be seen as a stamp of approval on sexual immorality.  Of course, the obvious results of this are unwanted pregnancy, and rates of sexually transmitted diseases and infections that are very high, very absurd, and completely unnecessary.  The moral opposition to teaching comprehensive, contraceptive-based sex education is based on religious morality, and causes measurable and unnecessary harm to humanity.  Yet this doctrine is fervently maintained in the face of overwhelming evidence.

The entertaining part is that, after declaring that morality is not actually to "keep people from having fun," Lewis goes on to declare that it's useless to speak of moral "ideals," and we should certainly focus on actual doctrine and specific moral statements:

Some people prefer to talk about moral 'ideals' rather than moral rules and about moral 'idealism' rather than moral obedience. . .  But it is dangerous to describe a man who tries very hard to keep the moral law as a 'man of high ideals,' because this might lead you to think that moral perfection was a private taste of his own and that the rest of us were not called on to share it.. . .  It might lead you to become a prig and to think you were rather a special person who deserved to be congratulated on his 'idealism'. In reality you might just as well expect to be congratulated because, whenever you do a sum, you try to get it quite right.  To be sure, perfect arithmetic is 'an ideal'; you will certainly make some mistakes in some calculations. But there is nothing very fine about trying to be quite accurate at each step in each sum. It would be idiotic not to try; for every mistake is going to cause you trouble later on. In the same way every moral failure is going to cause trouble, probably to others and certainly to yourself. By talking about rules and obedience instead of 'ideals' and 'idealism' we help to remind ourselves of these facts.

. . . and it is in exactly this way that people come to have an impression of "you're not allowed to have any fun" from religious morality.  Leaving aside the obvious fact that Lewis has spent the entire book thus far dealing entirely with "ideals" (and not discussing actual detailed doctrine or "rules" in any way),  it is apparent that we do indeed have to speak of ideals at some point.

Most people (at least, the ones that I consider to be sane) base morality on what is beneficial to the freedom and security of humanity.  When a person makes a moral claim based on religious belief, they are, in fact, using a completely different moral ideal than mine.  I agree with Lewis that moral ideals should not be considered arbitrary, but if we are not to discuss ideals at all, then how to reason out a solution to opposing moral ideas?  To use one possible example, let's return to the Biblical prohibition against working on the Sabbath.  I could lecture Lewis, until I'm blue in the face, that punishing a person for working on a certain day of the week is completely in violation of any conceivable idea of freedom or human rights.  I feel confident in declaring that no follower of the Bible can, or will ever be able to, offer evidence that disobedience to this commandment poses any threat to humanity.  What can the believer say, except to insist that God knows something we don't?

This is why we have to discuss "ideals," because there are actually many people who insist that 0 + 0 = 1, and they base their entire mathematical system off of a fallacy.  It is not useless to point out that a person who is getting their sums wrong is using the system incorrectly, or is using a faulty system altogether.  Indeed, this is the only rational way to go about debating any moral issue.  Interestingly, he goes on to describe what's wrong with most people's idea of morality, and it will become blatantly apparent that his basic "ideals" of what morality actually is are quite misguided.

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