Since starting this blog, I have argued for moral realism in some form or other, but that is not to say that I have not entertained other metaethical positions before then – I used to be something of a moral nihilist that accepted morality as some type of social contract that was motivated by self-preservation. I have come to think that the facts are best explained by a rationalist account of moral realism, but all of this is to say that I think objections to moral realism based on a skepticism of human rationalizing are not without merit. Put another way, I must grant that there is something prima facie mysterious about a natural order in which reason requires us to make personal sacrifices for strangers.
Robert Audi has an answer to this mystery that I think is very plausible. The basic idea is that we have desires, which are rational in virtue of our seeing them on reflection as being the foundations of our actions. Audi’s point is that when we reflect on our desires they take a certain form in their basicness, which is roughly, “I want x”, and not “I want ME to have x”. Thus, what is rationally desirable, as a source of reason for action, is impartial as to whether that good should obtain for me or another person. Here’s Audi in his own words,
“Rational persons have, among other things, rational intrinsic desires as motivational foundations for their conduct, even if not the only foundations. There are things we (normal persons) rationally want for their own sake, not as means to something further, and on the basis of at least some of these desires we want other things. What rational persons want regarding these things is not in general that they have them, but, typically, the things themselves or something intrinsic to them. I want to read Shakespeare for the rewards of so doing; I do not want my reading him. I can want that; but such egoistic wants are not the primitive case. Similarly, when I have pain, I want it to stop. That it is my pain need not enter my mind, and I need not conceptualize the pain as mine in order to have a rational desire to be rid of it. […] The foundations of rational desire, and thereby the basic normative reasons for action, are impersonal. […] I need not favor others over myself, but I have no rational ground to favor myself over others. The impersonal foundations of practical reason require scrupulous equality. The intrinsic desirability of our pleasures, like the rationality of our wanting them, supervenes on what they are, not on whose they are” (Audi, “Moral Epistemology and the Supervenience of Ethical Concepts”, in Moral Knowledge and Ethical Character, page 105-106).