Philosopher AC Grayling, in a recent Prospect Magazine column, summarizes three ways to argue against a relativist:
The first way to argue against the relativist is to point out that if there is no such thing as truth, except from a given perspective, then one must accept one of the following three assertions: the claim “there is no truth except from a given standpoint” is true only from a given standpoint, or it is self-refuting, or it is a very special kind of truth in being the only one that is true from all standpoints. Each of these makes a nonsense of the original claim, so the relativist position is incoherent.
The second way is to point out that when people assert that their beliefs are true, they typically do not mean “only for me”. This phrase applies in cases of taste or preference, and sometimes when there is known to be no way to settle a choice of view. But if I say that camels have humps, I do not mean to imply that it is simultaneously the case that camels have no humps just because someone else believes as much.
The third way is to point out that if relativism is true, enquiry (in science and elsewhere) is pointless, because if there is no objective truth, there is nothing to enquire about. If fairy tales and physics are equally true “in their own ways,” one might as well rest content with whatever one currently happens to believe, and seek no further.
What is astonishing is that these responses were first given by Plato 2,500 years ago, in his work Protagoras. But, despite their ancient origin, I suspect that they will do little to convince those who hold to a popular conception of relativism. Very few people embrace relativism - or any position, for that matter - due to an assessment of its philosophical cogency and logical coherence. Therefore, to wave a philosophical response in their face is hardly going to make much difference. And, this is one reason why I doubt whether rationally-based apologetics really do much good.
Nevertheless, it is always a fun exercise to reveal how certain strongly-held beliefs have very unwelcome implications. And, when an adherent is confronted with these implications, their sense of foolishness tends to be more persuasive than a rational argument. I’m sure we would recoil at the idea of making people feel foolish as part of an apologetic strategy. But when a philosophical or theological position is foolish, is it really a problem if we allow people to have a sense of its foolishness?
