In everything we do, I have argued, we move from "is" to "ought" through some hypothetical imperative in which "ought" means a hypothetical relationship between desires and ends. For example, "If you desire to be healthy, then you ought to eat nutritious food." Or, "If you desire safe air travel, you ought to seek out air planes that are engineered for flying without crashing." Or, "If you desire the love of friends, you ought to cultivate personal relationships based on mutual respect and affection and shared interests."
Such hypothetical imperatives are based on two kinds of objective facts. First, human desires are objective facts. We can empirically discover--through common experience or through scientific investigation--that human beings generally desire self-preservation, health, and friendship. Second, the causal connection between behavior and result is an objective fact about the world. We can empirically discover that through eating good food, flying on safe air planes, and cultivating close personal relationships, we can achieve the ends that we desire. For studying these objective facts, the natural sciences of medicine, engineering, and psychology can be instructive. It is false, therefore, to say that science cannot tell us anything about the way things ought to be.
We can restate this in Aristotelian terms--as suggested by Aristotle's Nicomachean Ethics: If you want to live a happy or flourishing life, if you want to have a deep and lasting satisfaction with life as a whole, then you need to cultivate the moral and intellectual virtues that are instrumental to achieving deep and lasting satisfactions in life. A science of ethics can study the empirical claims of such a hypothetical imperative.
Olsen might respond by saying that even if science can tell us about the ought of a hypothetical imperative, it cannot tell us about the ought of a moral imperative, which must be categorical rather than hypothetical. But this would ignore the fact that if a categorical imperative is to have any motivating truth, it must become a hypothetical imperative. So when Kant or some other moral philosopher tells us that we ought to do something, we can always ask, Why? And ultimately the only final answer to that question of motivation is that obeying this ought is what we most desire to do if we are rational and sufficiently informed.
Even Kant implicitly concedes this. In his Groundwork of the Metaphysics of Morals, he says that everyone desires to obey his categorical imperatives, because everyone--"even the most hardened scoundrel"--desires the "greater inner worth of his own person" [einen grosseren inneren Wert seiner Person] that comes only from obeying the moral law and thus becoming a "better person" (Ak 4.454). In this way, Kant's categorical imperatives are reduced to a hypothetical imperative: If you desire to be a better person with a sense of self-worth, then you ought to obey my categorical imperatives. This, then, rests on two kinds of empirical claims--that human beings most desire personal self-worth and that obeying Kant's categorical imperatives will achieve that desired end.
Olsen's insistence on the is/ought dichotomy is closely connected to his criticism of my argument as being crudely emotivist (122, 160, 187-90, 193-94). To show that I am an emotivist who believes that morality is merely a matter of following moral emotions, Olsen quotes from Darwinian Conservatism where I speak of Adam Smith as claiming that "our natural feelings often diverge from what purely rational principles might dictate" (160). Olsen ignores the fact that on that same page of Darwinian Conservatism (43), I indicate that my point is that "the moral sense is not a product of pure reason alone but is rather a humanly unique capacity for moral judgment that combines social emotions and rational reflection." Thus, as I indicate on the next page (44), "morality requires a combination of reason and emotion."
In Darwinian Conservatism (35-45, 124-29) and in Darwinian Natural Right (17-21, 24-25, 46-49, 70-73, 223-30), I have argued against those like Peter Singer who make the Kantian claim that morality is based on an abstract logic of pure reason alone without emotion or desire. Psychopaths prove that this cannot be true. Psychopaths are often intelligent people with a high capacity for abstract reasoning. But they are moral monsters because they do not feel moral emotions such as guilt, shame, pity, and love, and thus they can deceive, injure, and even brutally torture and murder their fellow human beings without any moral feelings.
Although he does not elaborate the point, Olsen seems to accept Singer's claim that morality is based purely on abstract reasoning free from moral emotion or desire (160). As I have indicated in one of my posts on Singer, he has suggested doubts about this in the "Afterword" to a new edition of The Expanding Circle. He notes "how ambivalent I was about the idea of ethics being objectively true and rationally based," and now "I no longer believe that this argument succeeds."
Olsen thinks that in grounding morality on 20 natural desires, I have no rational principle by which to rank those desires when they conflict, and thus I have no way to resolve moral disputes. He makes this point with the example of slavery. He writes:
"If we consider his example that slavery is naturally wrong because it violates the desire for justice as reciprocity, the question which it is most important that Arnhart answers is this: If 'justice as reciprocity' is only one of our natural desires, why should it trump the others, such as the desires for wealth and social ranking, both of which are on Arnhart's list? He refers favorably to Lincoln's comments about being 'consistent,' but the question is why the slave owner should care about consistency. If morality can be based in full on our desires, Arnhart's argument must presumably be, at the very least, the (quite plausible) claim that we have a natural desire for logical consistency. But, if this is the unstated premise, is Arnhart then saying that we are more motivated by this particular motivation than by other motivations, or that we ought to be? If the latter: why? Is it because satisfying our desires for reciprocity and logical consistency are more conducive of our own long-term happiness than satisfying the desire for selfish gain through exploitation of others--or because they are somehow morally superior? Again, either Arnhart is sneaking morality in the back door, since he has nothing beyond desires to ground his ought, or he must assume that satisfying our desires for reciprocity, justice and logical consistency is more conducive of long-term happiness for the agent than satisfying other, competing desires. Even if this latter assumption could be defended empirically, however, it might be asked whether neo-Darwinian natural right theory has produced a persuasive reason for why slavery is wrong if the reason is derived solely or primarily from a strong desire against it on the part of would-be slave owners? Similarly, Arnhart finds it relevant to argue that female genital mutilation makes intercourse less pleasurable for men, and that it in part for this reason does not really serve men's interests either" (193).Olsen here is referring to my account of Lincoln's five arguments for why slavery is wrong, which I identify as the historical argument, the Euclidean argument, the biblical argument, the intuitionist argument, and the biological argument (Darwinian Natural Right, 193-201). Lincoln shows that any attempt to defend slavery as just either contradicts the American political tradition, or contradicts itself, or contradicts the Bible, or contradicts our natural sense of right and wrong, or contradicts our shared humanity as members of the same species. The fifth argument--the biological argument for our shared humanity--is the most fundamental since the other arguments presuppose it.
Olsen is specifically pointing to what I call the Euclidean argument. Lincoln reasons as follows:
"If A. can prove, however conclusively, that he may, of right, enslave B.--why may not B. snatch the same argument, and prove equally, that he may enslave A?
"You say A. is white, and B. is black. It is color, then; the lighter, have the right to enslave the darker? Take care. By this rule, you are to be slave to the first man you meet, with a fairer skin than your own. You do not mean color exactly?--You mean the whites are intellectually the superiors of the blacks, and, therefore have the right to enslave them? Take care again. By this rule, you are to be slave to the first man you meet, with an intellect superior to your own.
"But, say you, it is a question of interest; and, if you make it your interest, you have the right to enslave another. Very well. And if he can make it his interest, he has the right to enslave you."No rational person would argue for his own enslavement. But any person who argues for the enslavement of others must appeal to some human difference that could be the basis for his own enslavement. Therefore, no rational person can endorse slavery without contradicting himself. Human beings differ in an infinite number of ways--color, intellect, interests, and so on--but each person believes that he has a right to liberty simply by virtue of his humanity--his human desire to be free from exploitation. Yet if I affirm that I as a human being have a right to liberty, then to be consistent, I must also affirm that other human beings have a similar right.
In our natural human inclination to secure the benefits of social cooperation while protecting ourselves from being exploited by others, we appeal to reciprocity as the fundamental principle of fairness in social relationships, which makes it impossible for us to justify enslaving others without contradicting ourselves. "This is a world of compensation," Lincoln declared, "and he who would be no slave must consent to have no slave." This is so because human social life is a world of reciprocal exchange in which exploiters are ultimately punished by the moral aggression of those they exploit.
But as long as slavery satisfies the slaveholder's natural desires for wealth and status, Olsen asks, why shouldn't he allow this to override his natural desire for justice as reciprocity? I have a twofold answer. First, as a fact of human psychology, while a psychopathic slaveholder would feel no desire for justice as reciprocity, normal slaveholders would; and indeed Southern slaveholders either elaborated moral justifications for slavery as beneficial for the slaves, or they admitted their moral guilt in being caught in a tragic conflict between self-interest and justice.
Second, the ultimate natural enforcement of justice as reciprocity is the natural inclination of the exploited to retaliate against their exploiters. The deepest fear of the Southern slaveholders was slave insurrection, because they knew that their slaves were not naturally adapted to slavery, and, on the contrary, they were naturally adapted for resisting their enslavement by violence if necessary. As classical liberals like John Locke have noted, the ultimate ground of natural rights is the natural human tendency to violent resistance to oppression.
Olsen seems to think that he has an alternative to this grounding of natural right in natural desires. But he never explains what that alternative is. He does imply that he thinks there is some Kantian cosmic normativity that is grasped by pure abstract reason without any grounding in human desires, but he never clearly explains or defends this idea.