Motargument till värderelativism?

Other people wrote to me saying, "Isn't what you call the Moral Law just a social convention,
something that is put into us by education?" I think there is a misunderstanding here. The people who ask that question are usually taking it for granted that if we have learned a thing from parents and
teachers, then that thing must be merely a human invention. But, of course, that is not so. We all
learned the multiplication table at school. A child who grew up alone on a desert island would not know it. But surely it does not follow that the multiplication table is simply a human convention, something human beings have made up for themselves and might have made different if they had liked?

I fully agree that we learn the Rule of Decent Behaviour from parents and teachers, and friends and
books, as we learn everything else. But some of the things we learn are mere conventions which might
have been different—we learn to keep to the left of the road, but it might just as well have been the
rule to keep to the right—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, as I said in
the first chapter, that though there are differences between the moral ideas of one time or country and
those of another, the differences are not really very great—not nearly so great as most people
imagine—and you can recognise the same law running through them all: whereas mere conventions,
like the rule of the road or the kind of clothes people wear, may differ to any extent. The other reason
is this:

When you think about these 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? Have any of the changes
been improvements? If not, then of course there could never be any moral progress. Progress means
not just changing, but changing for the better. If no set of moral ideas were truer or better than any
other, there would be no sense in preferring civilised 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. We
do believe that some of the people who tried to change the moral ideas of their own age were what we
would call Reformers or Pioneers—people who understood morality better than their neighbours did.
Very well then.

The moment you say that one set of moral ideas can be better than another, you are, in fact, measuring them both by a standard, saying that one of them conforms to that standard more nearly than the other. But the standard that measures two things is something different from either. You are, in fact, comparing them both with some Real Morality, admitting that there is such a thing as a real Right, independent of what people think, and that some people's ideas get nearer to that real Right than others. Or put it this way. 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.