Recently, I finished Alexander Miller's book "An Introduction to Contemporary Metaethics." After reading about Peter Railton's reductionism, I wondered if it would be possible to take the agent which the theory depends on, as God, and give a satisfactory theistic account of morality.
To me, it would seem to give the average theist everything he looks for. It would give objectivity, and universality, since the only reason morals aren't universal in Railton's scheme is that they are based on contingent human desires, which differ. If God is the only agent in question, what is and isn't moral only depends on the desire of one being. The only thing I'm not sure it could give that a theist might want is categoricity.
As a metaethical theory itself (aside from the issue of God's existence), could it stand? Would there be any flaws or contradictions to this theory, which aren't already problems of the theory as it originally was, etc.?