A preference for chocolate over vanilla ice cream is a natural phenomenon, as is a preference for the comic Sarah Silverman over Bob Hope. Are we to imagine that there are universal truths about ice cream and comedy that admit of scientific analysis? Well, in a certain sense, yes. Science could, in principle, account for why some of us prefer chocolate to vanilla, and why no one’s favorite flavor of ice cream is aluminum. Comedy must also be susceptible to this kind of study. There will be a fair amount of cultural and generational variation in what counts as funny, but there are probably basic principles of comedy — like the violation of expectations, the breaking of taboos, etc. — that could be universal. Amusement to the point of laughter is a specific state of the human nervous system that can be scientifically studied. Why do some people laugh more readily than others? What exactly happens when we “get” a joke? These are ultimately questions about the human brain. There will be scientific facts to be known here, and any differences in taste among human beings must be attributable to other facts that fall within the purview of science. If we were ever to arrive at a complete understanding of the human mind, we would understand human preferences of all kinds. Indeed, we might even be able to change them.
However, morality and values appear to reach deeper than mere matters of taste — beyond how people happen to think and behave to questions of how they should think and behave. And it is this notion of “should” that introduces a fair amount of confusion into any conversation about moral truth. I should note in passing, however, that I don’t think the distinction between morality and something like taste is as clear or as categorical as we might suppose. If, for instance, a preference for chocolate ice cream allowed for the most rewarding experience a human being could have, while a preference for vanilla did not, we would deem it morally important to help people overcome any defect in their sense of taste that caused them to prefer vanilla — in the same way that we currently treat people for curable forms of blindness. It seems to me that the boundary between mere aesthetics and moral imperative — the difference between not liking Matisse and not liking the Golden Rule — is more a matter of there being higher stakes, and consequences that reach into the lives of others, than of there being distinct classes of facts regarding the nature of human experience.