The challenge to objective values › Testing the theory's two commitments

A careful assessment can begin with a particular moral judgment. Ask what authority the judgment claims. Does it purport to bind independently of desire and convention? Is it instead a report about a rule, a personal commitment, or an expression of an attitude?

Then examine the case against the objective feature. Does moral variation support Mackie's preferred explanation? Does the proposed value require a peculiar kind of existence or knowledge? Could a different account preserve objectivity without accepting every feature Mackie assigns to it?

Finally, separate the truth of a judgment from its practical role. A belief can motivate cooperation without being true, and a useful belief is not made true by its usefulness. Equally, showing that a person benefits from making a claim does not show that its content is false.

Mackie's challenge is precise enough to permit disagreement at each of these points. We can question his account of ordinary moral thought, his explanation of variation, or his standards of metaphysical plausibility. What we should avoid is answering a second-order argument merely by insisting that moral conduct matters.