Objections to Moral Realism Part 4: Moral Beliefs Can’t Motivate

There is evidence that moral values involve desires. When we say “human life has intrinsic value,” we expect a desire to promote human life and a pro-attitude towards human life. The connection between moral beliefs and desires is not clear, and some people have argued that morality is only about desires. If morality is only about desires, then we should reject the existence of intrinsic values because our intrinsic value beliefs would merely state our desires. These concerns reflect Humean psychology, which states that there are beliefs and desires, and beliefs can’t motivate. Mark Platts, John Searle, and others have disputed Humean psychology. Although not all philosophers agree with Humean psychology, I will not question it here. Instead, I will attempt to prove that Humean psychology is compatible with moral realism.

Objections to Moral Realism Part 3: Argument from Queerness

If morality is irreducible to nonmoral facts, it might still be part of the materialist worldview like any other domain, but we would merely be unable to fully describe morality in nonmoral terms. (To say that moral facts are reducible is to say that we can find out that moral facts “are really something else.”) I have argued that morality must be irreducible, but this is a substantial metaphysical claim. Such a metaphysical claim must be especially justified due to Occam’s razor—We must not multiply entities beyond necessity.¹ (Or, more specifically, we shouldn’t multiply irreducible domains of reality beyond necessity.) I will present three objections against the claim that morality is irreducible, then I will attempt to reply to those objections in order to show them to be unconvincing. In particular I want to show that morality’s irreducibility is just as justified as psychology’s irreducibility, that we have reason to believe psychology is irreducible, and that we have more reason to accept that morality is irreducible than to reject it.