In a recent blog post, William Lane Craig (an apologist for the Christian religion) argues that the reality of necessary moral truths can, or is plausibly, explained by the existence of a necessary being that possesses perfect moral character in all possible worlds. There are two aspects of Craig’s argument that require further elaboration.First, Craig maintains that some moral statements (e.g. “love is valuable”) are necessarily true. This claim can be interpreted in (a) the broad sense that there are no possible worlds in which they are false, or (b) as a supervenience relation, such that in no possible world where all the physical facts are fixed do different moral facts obtain. Supervenience is a necessary relation in the sense that the covariance between physical facts and moral facts is fixed in every possible world in which those physical facts obtain. My impression is that Craig prefers interpretation (a), though perhaps his argument can be made along the lines of (b) as well.
Second, Craig implies that the need for explanation does not always terminate when we arrive at necessary truths. Why? Because some necessary truths have logically prior explanations. The principle, an object cannot both exist and not exist at the same time and in the same sense is necessary, but its necessity derives from the principle of non-contradiction, that x does not equal non-x. Both principles are true in all possible worlds, but the necessity of one is explained in terms of the other. In a similar way, says Craig, the necessary existence of moral values can, or is plausibly, explained by the necessity of God’s existence and moral character.
Craig’s argument raises some concerns that will need to be ironed out in order to be successful:
First, just because God’s necessity and essential moral character can explain something, doesn’t mean it does a better job than other alternatives. Why can’t Platonism do the job equally well? Could we not instead argue that necessary moral truths are grounded in necessarily existing abstract entities (a.k.a intrinsic values) such as Love, Beauty, Justice, the Good, etc?
Second, perhaps a single concrete object (like God) is preferable to myriads of abstract objects because (on Occam’s razor) it is the simpler option. Fair enough. But if simplicity is an adequate reason for rejecting Platonism about moral values, then should we not also draw the same conclusion about all necessary truths, not just moral ones? This was the conclusion of various medieval theologians who viewed necessary truths as propositions in the Divine Intellect. But if Craig’s case is predicated on a more general rejection of Platonism, then it ceases to be a specifically moral argument.
What do you, the reader, think about the explanatory value of Theism and Platonism vis-à-vis necessary moral truths? Are there necessary moral truths? Is theism a simpler explanation of these truths than Platonism? If so, in what sense? If Craig’s case ends up leading to the more controversial view that all necessary truths have a theistic ground, then hasn’t his original argument lost some of its appeal?