Stealing Darwin.

A Darwinian Left: Politics, Evolution,
and Cooperation, by Peter Singer (Yale, 70 pp., $9.95)
Writings on an Ethical Life, by Peter Singer (Ecco, 361 pp., $27.50)

Why are conservatives afraid of Darwinian biology? When I recently asked some conservative friends, I was surprised when our discussion turned quickly not to Darwin himself but to Peter Singer, a professor of bioethics at Princeton who identifies himself as a Darwinian leftist. Best known for his advocacy of animal liberation, infanticide, and euthanasia, Singer is an atheist who rejects the sanctity of human life as a religious prejudice refuted by modern biological science. He has also gained notoriety by arguing that Americans should give away all their yearly income over $30,000 to help needy strangers around the world.

This is what happens, my friends insisted, when you adopt a Darwinian view of human nature-you become a loony leftist. But I disagreed. Singer's moral and political arguments are not really Darwinian at all. Moreover, despite Singer's confused (and confusing) intellectual efforts, the truth is that Darwinism actually supports a conservative view of morality as rooted in human nature.

In two recent books-A Darwinian Left and Writings on an Ethical Life- Singer lays out his ethical philosophy and draws what he believes are its political implications. The thought behind all of his arguments is that the logic of ethical reasoning leads to one fundamental principle- the impartial consideration of the similar interests of all sentient creatures. This principle runs throughout Singer's Writings on an Ethical Life, the starting point of which is Darwin's idea that ethics evolved out of our human nature as shaped by our social instincts and our capacity for reasoning. As social animals, we need the cooperation of our fellow human beings. As intellectual animals, we win their cooperation by defending our conduct in terms of its contribution to the common good. Originally, such ethical impartiality would have been limited to the good of one's racial or tribal group. But as the circle of social interaction expanded, people were eventually led to see that the interests of all human beings deserve equal consideration.

Now, Singer argues, we should expand the circle of ethical concern to include all sentient animals. "Speciesism" is just as unethical as racism, because it is just as arbitrary to deny the moral claims of different species as it is those of different races. Insofar as sentient animals feel pleasure and pain and are capable of enjoyment and suffering, they have legitimate interests that must be given equal weight with those of human beings. (Nonsentient organisms do not deserve such consideration, because they cannot feel pleasure and pain. If a tree feels nothing, then chopping it down just doesn't matter to it.) Singer concedes that special treatment for human beings is sometimes justified, but only in cases where human beings have special interests-such as in education, aesthetic pleasure, and planning for the future-that other sentient creatures lack.

Singer believes that logical reasoning from the principle of ethical impartiality supports his most controversial conclusions. Many people are disturbed, for example, by his claim that the lives of some animals are more valuable than the lives of some human beings. In his Writings on an Ethical Life, Singer asserts that "a chimpanzee, dog, or pig . . . will have a higher degree of self-awareness and a greater capacity for meaningful relations with others than a severely retarded infant or someone in a state of advanced senility." Killing a normal human being is more serious than killing another sentient animal only to the extent that human beings normally can plan for the future, while nonhuman creatures cannot. But the lives of human infants with irreversible brain damage are no more valuable than the lives of nonhuman animals that lack the ability to plan for the future. So if we think it morally permissible to kill a nonhuman animal for some good purpose-perhaps to harvest its organs for transplantation in a normal human being-then it should be equally permissible to kill a severely brain-damaged infant.

Moreover, even normal human newborns lack the rational capacities for self-awareness found in some animals; therefore the life of a newborn is not necessarily more valuable than that of an animal with greater intellectual capacities. During the first month of life, a human baby has less self-conscious awareness than many nonhuman animals; and therefore the baby is not a "person" with the full legal right to life until it is at least a month old. To insist that the baby deserves better treatment than nonhuman animals with similar or superior capacities would violate Singer's principle of ethical impartiality.

Based on the same logic, Singer exhorts American families to give away their excess income above $30,000 a year. If all normal human beings are entitled to be free from suffering and death, then we are morally justified in spending whatever we need for the necessities of life. Spending our money on luxuries is immoral because it could have been sent to needy strangers elsewhere in the world who will otherwise suffer and die.

But in presenting such judgments as logical deductions from the principle of ethical impartiality, Singer must reject the very Darwinian view of human nature that he professes to accept.

Darwin thought he could explain the human "moral sense" as a joint product of the social emotions and intellectual capacities of the human animal. As social animals, we are moved by social emotions such as sympathy, love, anger, and guilt. Parental emotions move us to care for our children. Sexual emotions move us to care for our mates. Affiliative emotions move us to care for family members and for friends with whom we have developed special bonds. We can feel sympathetic concern for distant strangers, but usually our humanitarian feelings are weaker than our feelings for family, friends, and fellow group members. As intellectual animals, we can generalize these social emotions into customary or legal rules for judging behavior as right or wrong, just or unjust.

Singer claims to accept this sensible, Darwinian view of ethics as combining reason and emotion. "If emotion without reason is blind," Singer explains, "then reason without emotion is impotent." But whenever he defends his left-wing ethics, he assumes that purely logical reasoning from an abstract principle of impartiality should override the social emotions of human nature.

For example, when Singer lays down the conditions justifying infanticide, he insists that "we should put aside feelings based on the small, helpless, and-sometimes-cute appearance of human infants," although he admits that "there are no doubt very good evolutionary reasons why we should instinctively feel protective toward them." Here, he believes, ethical impartiality should override the natural emotions of sympathy because these emotions are "morally irrelevant." But he invokes the same emotions that he earlier dismissed when he goes on to say that killing infants is wrong in most cases because this would "inflict a terrible loss on those who love and cherish the child."

Similarly, when he argues that it is immoral to spend our money on luxuries rather than give it to starving strangers, Singer admits that his argument contradicts the social emotions that give us a stronger attachment to kin and friends than to strangers. He even concludes, "Perhaps a viable ethic must allow us to show a moderate degree of partiality for ourselves, our family, and our friends." But again it would seem that allowing even a "moderate degree of partiality" would deny Singer's purely rational ethics.

When Singer's mother developed Alzheimer's disease, he spent a lot of money to support special care for her. In an interview, Singer admitted that this action contradicted his ethical principles. "In a sense, my spending money on my mother's care is in conflict with that principle. But so is the fact that I flew back to Australia to visit my daughters at Christmas. That money could also be better spent elsewhere. I've never claimed that I live my life perfectly in accordance with those principles of sharing my money as much as I should." This is a strange confession from someone who has declared that "an ethical judgment that is no good in practice must suffer from a theoretical defect as well, for the whole point of ethical judgments is to guide practice." It is therefore hard to accept that Singer really believes what he is saying. Surely even a Princeton philosopher cannot be so confused as to think that in caring for his sick mother or visiting his children at Christmas, he is acting immorally.

The real source of this confusion is not Singer's Darwinism but his leftism. As Singer indicates in A Darwinian Left, the Left has traditionally believed that human nature is so malleable that it can be shaped in almost any direction; therefore social problems can be solved through utopian programs that would make human nature conform to rational norms of social harmony. Although Marx and Engels accepted Darwinism in explaining the animal world, they thought that human history manifested the uniquely human freedom to transcend nature. Contemporary Marxist biologists such as Richard Lewontin and Stephen Jay Gould continue this tradition when they insist on human freedom from the constraints of biological nature.

At some points in A Darwinian Left, Singer seems to reject this utopian tradition. According to Singer, a Darwinian Left would accept "that there is such a thing as human nature, and seek to find out more about it, so that policies can be grounded on the best available evidence of what human beings are like." Such a Left would have to realize that natural tendencies (such as social ranking, male dominance, sex roles, and attachment to one's kin) cannot simply be abolished by decree. But the strain in his argument is clear when he confesses, "In some ways, this is a sharply deflated vision of the Left, its utopian ideas replaced by a coolly realistic view of what can be achieved. That is, I think, the best we can do today." In fact, some of his "deflated" leftism would be acceptable to conservatives, who have long assumed that conformity to human nature is a fundamental standard for good social policy. For example, Singer agrees with Adam Smith about the benefits of a market economy in channeling the selfish motivations of human nature in ways that serve the public good.

Singer concludes A Darwinian Left by expressing his hope that the human capacity for abstract reasoning will one day "take us beyond the conventional Darwinian constraints on the degree of altruism that a society may be able to foster." This would create "a new kind of freedom" based on a purely rational ethic of impartial concern for all sentient beings, transcending the emotional attachments of biological nature. Presumably, such progress would also free human beings from the natural emotions that promote friendship, familial love, and private property, making it easy for people to kill infants and give away property to strangers.

Of course, most human beings would find the prospect of a society untethered to traditional emotional attachments morally repugnant. We use reason to determine how best to satisfy our desires and justify our actions. Abstract reason by itself would never move us to moral action without the motivation of our desires. Singer's mistake-shared by many left-wing reformers-is to assume that we can organize our moral lives around norms derived from abstract reasoning without guidance from our natural emotions. As Singer sometimes concedes, emotions are important because without them nothing would matter to us. Psychopaths have no moral sense, not because they lack intelligence or the ability to reason logically, but because they lack the social emotions (such as sympathy, love, guilt, and shame) that support morality in normal people. Our emotional recoil at the thought of infanticide, for example, is one way we know it's immoral. Of course, when our moral emotions conflict, then we must employ practical reasoning to develop rules of action to resolve the conflict. But even so, those purely abstract rules of reason move us to act only to the extent that they can elicit the motivational power of our emotional desires.

Ethical naturalists from Aristotle and Aquinas to Adam Smith have shown how our ethical concerns manifest natural human desires. Darwin extended that tradition by showing how those desires were rooted in human biological nature. Consequently, Darwinian social theory provides scientific confirmation for what conservatives already know by common sense: Despite the variability of our moral judgments in different circumstances, enduring standards of right and wrong are rooted in our natural instincts. Singer's confused attempt to justify a Darwinian Left therefore actually helps us to see the potential justification for a Darwinian Right.