According to D'Souza, "the presupposition of an afterlife and the realization of the ideal of cosmic justice makes sense of our moral nature better than any competing hypothesis" (168). He explains:
"Unlike material objects and all other living creatures, we humans inhabit two domains: the way things are, and the way things ought to be. We are moral animals who recognize that just as there are natural laws that govern every object in the universe, there are also moral laws that govern the behavior of one special object in the universe, namely us. While the universe is externally moved by 'facts,' we are internally moved also by 'values.' Yet these values defy natural and scientific explanation because physical laws, as discovered by science, concern only the way things are and not the way they ought to be. Moreover, the essence of morality is to curtail and contradict the powerful engine of human self-interest, giving morality an undeniable anti-evolutionary thrust. So how do we explain the existence of moral values that stand athwart our animal nature? The presupposition of cosmic justice, achieved not in this life but in another life beyond the grave, is by far the best and in some respects the only explanation. The presupposition fully explains why humans continue to espouse goodness and justice even when the world is evil and unjust." (166-67)There are at least four dubious claims here that I deny. First, the claim that an ought cannot be derived from an is. Second, that morality must contradict human self-interest. Third, that evolutionary science cannot explain morality. And, finally, that morality is impossible without the cosmic justice of heavenly rewards and hellish punishments in the afterlife.
HOW WE MOVE FROM IS TO OUGHT
In everything we do, 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, for D'Souza to say that science cannot tell us anything about the way things ought to be.
D'Souza 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.
On this point and others here, I am indebted to Richard Carrier, "Moral Facts Naturally Exist (and Science Could Find Them)," in John W. Loftus, ed., The End of Christianity (Prometheus Books, 2011), 333-64.
Similarly, D'Souza's categorical imperatives are reducible to a hypothetical imperative. If you desire to attain the eternal rewards of Heaven and to avoid the eternal punishments of Hell, then you ought to obey D'Souza's categorical imperatives. And, again, it becomes an empirical question as to whether this is what all human beings naturally desire and as to whether obeying those imperatives really will achieve those desired ends.
Some of my previous posts on hypothetical imperatives and the fallacy of the is/ought dichotomy can be found here, here, here, here., and here.
THE EVOLUTIONARY MORALITY OF SELF-INTEREST
D'Souza argues that evolutionary science cannot explain morality because morality requires selfless behavior that contradicts self-interest, and any evolutionary explanation of morality would have to reduce morality to self-interest. Even when evolutionary psychologists try to explain the evolution of altruism, they assume that altruism is a form of extended or long-term selfishness. For example, Robert Trivers' account of "reciprocal altruism" assumes that animals will be generous with others if they eventually get something beneficial in return. But this is not really altruism if we understand altruism as utterly selfless benevolence.
But this ignores the fact that every choice to do one thing rather than another is a choice for one course of action as more desirable than another. And thus all intentional action is motivated by self-interest or self-love. We do what we do because we think it's better for us to do it. Of course, we can often be mistaken about this. What we most desire is not what we happen to desire at any moment, but what we would desire if we were rational and sufficiently informed. All of this is open to scientific study because it's all a matter of empirical study. We can empirically study what human beings desire through the psychological study of the proximate and ultimate motivations of human beings. We can also empirically study the causal connections between behavior and outcomes.
These empirical studies--both through common sense experience and through natural science--show that human self-interest does not dictate selfishness, because being the naturally social animals that we are, we can see that the social virtues are necessary for our happiness.
D'Souza implicitly contradicts his claim that morality cannot be based on self-interest, because he assumes that a morality of cosmic justice in the afterlife appeals to our self-interest: he assumes that our pursuit of happiness requires attaining the rewards of Heaven and avoiding the punishments of Hell.
Some posts on the problem of self-interest and altruism can be found here and here.
THE COSMIC JUSTICE OF HEAVEN AND HELL
If I am right that the good is the desirable, and that the natural good for human beings is determined by the natural desires of their evolved human nature, then the good is relative to the nature of the human species. If we had evolved to be a radically different kind of species, with different natural desires, then our morality would have been different. Thus, our morality is anthropological rather than cosmological. There is no cosmic right or wrong beyond the right or wrong that we know as human beings.
D'Souza rejects this because he thinks that morality must necessarily be cosmic--there must be some cosmic right and wrong that is true independently of our human nature. What's the source of that cosmic morality? Apparently, it's God's command. We know what is good only insofar as we know what God has commanded us to do, with the threat of eternal punishment in Hell for our disobedience.
It seems, therefore, that D'Souza embraces a divine command theory of morality--that the good is whatever God commands, and the bad is whatever he prohibits. But D'Souza never explicitly defends this position or answers the objections to such a position. How do we know that what God commands is always good if we don't already know what the good is for us?
And is eternal punishment in Hell really good? How do people earn such punishment? If we are all sinful, as Christianity teaches, do we all go to Hell? Or do we avoid Hell by becoming Christians? It's clear that many Christians have done some evil deeds. And it's clear that some non-Christians have done some good deeds. Does this influence their fate in the afterlife? D'Souza is never very clear about this. And he never responds to those Christians today who doubt the reality of eternal punishment in Hell, because they think a merciful God should allow all to enter Heaven.
D'Souza generally speaks favorably about all those people who believe in an afterlife. But sometimes he suggests that some of those who have such a belief will be punished in Hell. He indicates, for example, that "the Islamic suicide bombers are not being attended by beautiful virgins in paradise but rather by big hairy guys with tattoos" (187). How does he know that? Does he believe that some people who sincerely believe they are obeying God's commands are mistaken, and God will punish their mistake with eternal punishment? Is D'Souza convinced that the intentional killing of innocent people must always be wrong? If so, how does he explain those many places in the Bible where God commands killing innocent people?
Such questions point to the implausibility of any divine command theory of morality.
Some of my posts on the divine command theory can be found here, here., and here.