The Darwinian Biology of Human Rights

A Darwinian analysis of the modern conception of human rights would turn on at least two main points. The first point would be the primacy of moral emotions in our grasp of human rights. The second would be the need for analyzing human rights as passing through three levels of human moral experience: generic human nature, specified human history, and individual human judgment.

The founding document for the modern human rights movement is the Universal Declaration of Human Rights. The Economic and Social Council of the United Nations established a Commission on Human Rights and mandated that it draw up an international bill of rights. The Commission worked on this for two years, from January 1947 to December 1948, when the Third General Assembly of the UN adopted the Universal Declaration.

A fascinating study of the drafting of the Declaration, based on the extensive records of the Commission, is Johannes Morsink's The Universal Declaration of Human Rights: Origins, Drafting, & Intent (1999). Recently, Morsink has published a second book elaborating the philosophic grounds implicit in the document--Inherent Human Rights: Philosophical Roots of the Universal Declaration (2009). Morsink argues that the Declaration assumes a "doctrine of inherent human rights," which rests on two complementary theses about the universality of human rights--the metaphysical universality of human rights as inherent in the human person from birth and the epistemological universality of the outrage felt towards brutality like that of the Nazis as expressing the universal conscience of mankind. He defends "moral intuitionism" as the best philosophic position for understanding the Declaration.

Although I generally agree with Morsink, I think that his unreasonable fear of "essentialism" leads him to play down the importance of human biological nature and the evolved moral emotions as expressed in the Declaration. I also think he is not as critical as he should be in considering some of the dubious rights asserted in the Declaration.

There continues to be great debate over the effectiveness and wisdom of the Declaration and the international human rights movement that it has fostered. But in some respects, its massive influence in the global history of the past sixty years is evident. A large body of international law has been formed to implement the Declaration. Hundreds of human rights groups--like Amnesty International and Human Rights Watch--have millions of members around the world. The governments of the world are under constant scrutiny for their human rights records.

The drafting of the Universal Declaration was in itself a remarkable event, because for the first time in human history, representatives of societies from around the world were able to agree on some universal principles of global morality. From the beginning, many people warned that it was impossible to formulate any universal principles of morality. For example, the American Anthropological Association sent a long statement to the Commission suggesting that the cultural relativism of morality would subvert any attempt to agree on any supposed universal morality; and they warned against the ethnocentrism of imposing Western cultural conceptions of rights on the rest of the world. The Universal Declaration and the human rights movement continue to be criticized today for failing to recognize the cultural relativity of all values and the dangers of asserting the universality of ethnocentric values.

Here is how the Declaration begins, with the first two recitals of the Preamble:

"(1) Whereas recognition of the inherent dignity and of the equal and inalienable rights of all members of the human family is the foundation of freedom, justice and peace in the world,
"(2) Whereas disregard and contempt for human rights have resulted in barbarous acts which have outraged the conscience of mankind, and the advent of a world in which human beings shall enjoy freedom of speech and belief and freedom from fear and want has been proclaimed as the highest aspiration of the common people."

Article 1 declares: "All human beings are born free and equal in dignity and rights. They are endowed with reason and conscience and should act towards one another in a spirit of brotherhood."

The reference to "barbarous acts which have outraged the conscience of mankind" reminds us, of course, that the Declaration was largely an expression of shared moral revulsion against the Holocaust and the other horrors of Nazism in World War II. Morsink is insightful in showing how the drafting of the document can only be explained as an expression of a universal repugnance towards the atrocities of Nazism. The phrase "conscience of mankind" generalizes from the feelings of outrage that people around the world felt in response to the radical evils of Nazism. Thus, the Universal Declaration of Human Rights shows us how we derive "rights from wrongs" (a phrase used as the title of a book by Alan Dershowitz). That is to say, we formulate "rights"--justified entitlements to special treatment--from our experience of shocking injustices. The Declaration shows how moral outrage against atrocities expresses a universal morality that can be formulated as human rights rooted in the inherent dignity of all human beings.

While the Commission on Human Rights was drafting the Declaration, UNESCO sponsored a survey of thinkers and writers who were asked to offer advice on the philosophic basis of human rights. Some of their responses were collected into a book with an Introduction by Jacques Maritain--Human Rights: Comments and Interpretations (1949). Maritain described the book as "devoted to the rational interpretation and justification of those rights of the individual which society must respect and which it is desirable for our age to strive to enumerate more fully" (9). He reports: "at one of the meetings of a UNESCO National Organization where human rights were being discussed, someone expressed astonishment that certain champions of violently opposed ideologies had agreed on a list of those rights. 'Yes,' they said, 'we agree about the rights but on condition that no one asks us why.' That 'why' is where the argument begins."

Maritain observes that the philosophic debate among those surveyed by UNESCO seemed to come down to a disagreement between those who accepted the idea of "Natural Law" and those who rejected it:

"In the eyes of the first the requirements of his being endow man with certain fundamental and inalienable rights antecedent in nature, and superior, to society, and are the source whence social life itself, with the duties and rights which that implies, originates and develops. For the second school man's rights are relative to the historical development of society, and are themselves constantly variable and in a state of flux; they are a product of society itself as it advances with the forward march of history" (13).

Although Maritain sees no theoretical resolution to this debate, he suggests that the dispute might be moderated if the disputants could see the partial truth in the opposing position. Proponents of natural law should distinguish between rights that secure a "prime necessity" and those that secure a "secondary necessity," while conceding that our knowledge of both depends on the evolution of moral consciousness in history. On the other side, opponents of natural law should see that while many rights are historically conditioned, there are "more primitive rights" that are necessary for the good order of any human society whatsoever.

Catholic Thomists like Maritain see natural law as grounded in God and Nature--or, as the American Declaration of Independence says, "the Laws of Nature and Nature's God." In the drafting of the Universal Declaration, Charles Malik of Lebanon was the leading spokesman for this Catholic Thomist position. Malik proposed an article on the family that read: "The family deriving from marriage is the natural and fundamental group unit of society. It is endowed by the Creator with inalienable rights antecedent to all positive law and as such shall be protected by the State and Society." The drafters rejected the second sentence, because they wanted to avoid any religious invocations of God as the source of rights. But they accepted the first sentence affirming the naturalness of the family as the fundamental unit of society, and this became Article 16 of the Declaration. At least implicitly, then, they accepted a purely secular version of natural law thinking, although this Article 16 is the only place where the Declaration refers explicitly to "nature."

At one point in the drafting process, there was another reference to nature. It was proposed that Article 1 should declare that all human beings "are endowed by nature with reason and conscience." As an alternative to this language, the Brazilian delegation proposed: "Created in the image and likeness of God, they are endowed with reason and conscience . . ." Similarly, the Dutch delegation proposed that the first recital of the Preamble should state: "Whereas recognition of the inherent dignity and of the equal and inalienable rights of all members of the human family, based on man's divine origin and immortal destiny, is the foundation of freedom, justice, and peace in the world."

These proposals for religious language about human beings as created in God's image provoked intense debate. Some of the drafters saw a stark opposition between God and nature as alternative sources for human reason and conscience. Bogomolov of the USSR attributed the phrase "by nature" to "French materialist philosophers." Finally, the Brazilians agreed to withdraw their religious language if the phrase "by nature" were dropped, and a consensus formed on this resolution of the dispute.

At one point, a proposed amendment would have changed "by nature" to "by their nature," which conformed to Malik's recollection that "the intention of the Commission on Human Rights had not been to imply that man was endowed with reason and conscience by an entity beyond himself" (UDHR, 287). It is regrettable, I think, that the drafters did not go with this phrase "by their nature," because this would have clearly suggested their understanding that the source of human rights is neither a transcendent God nor a transcendent Nature, but human nature.

But then how exactly does "human nature" give rise to "human rights"? It's easy to see how legal rights are created by legal enactment. But it's harder to see how moral rights can exist as standards for judging legal systems. Legal positivists would say that the only rights are legal rights, and that the idea of human rights as moral rights that exist independently of positive law is pure fiction.

How is it that all human beings are "born" with "inherent dignity" and equal human rights? How does a physical birth as a human being translate into a moral birth as a being endowed with rights? Moral philosophers have tried to find a rational proof for the existence of moral rights or of any standard of right and wrong. But philosophers have never reached any agreement on any such rational proof.

I agree with Morsink that this futile quest of philosophers to find a rational proof for moral standards indicates the fundamental mistake in assuming that morality is a product of pure reason. The shared moral outrage against Nazi atrocities that motivated the drafting of the Universal Declaration illustrates how our moral experience arises not from pure reason alone but from moral emotions, and particularly from emotions of disapproval and disgust.

Even as the memories of World War II and the Nazis fade into distant history, we can still see how the emotions of moral revulsion support the idea of human rights. Go to the websites of Amnesty International and Human Rights Watch and scan some of their reports. Mostly what these organizations do is simply prepare reports that describe cruelty around the world--torture, rape, murder, slavery, and so on. They don't offer any logical arguments to prove that such behavior is wrong, because they assume that a vivid description of cruel behavior will elicit powerful emotions of disapproval. Those they accuse of perpetrating the cruelty will respond by trying to persuade us that the reports from these human rights groups are factually inaccurate.

So reason does have a role to play here, because we need good rational judgment in gathering and assessing information about what is happening. But once we're confident about the facts of the case, our moral judgment of right or wrong depends on our emotional reaction of approval or disapproval. The Universal Declaration is right: to recognize human rights, we need both "reason and conscience"--reason for factual judgments of truth and falsity and conscience for emotional judgments of right and wrong. Reason also allows us to generalize our moral emotions into moral rules. So that, for example, we judge that as a rule human beings have a right to life because the killing of innocent people would elicit moral emotions of disapproval from any normal human being.

This view of moral judgments as ultimately based on emotions is best elaborated in the Darwinian ethics of Edward Westermarck, which best explains the human nature of human rights. As animals formed by natural selection for social life, Westermarck argues, we are inclined to feel resentment toward conduct that we perceive as painful, and kindly emotion toward conduct that we perceive as pleasurable. The mental dispositions to feel such emotions evolved in animals by natural selection because these emotions promote survival and reproductive fitness: resentment helps to remove dangers, and kindly emotion helps to secure benefits. For the more intelligent animals, these dispositions have become conscious desires to punish enemies and reward friends.

Moral disapproval, for Westermarck, is a form of resentment, and moral approval is a form of kindly emotion. In contrast to the non-moral emotions, however, the moral emotions show apparent impartiality. (Here one can see the influence of Adam Smith's idea of the "impartial spectator.") If I feel anger toward an enemy or gratitude toward a friend, these are private emotions that express my personal interests. In contrast, if I declare some conduct of a friend or enemy to be good or bad, I implicitly assume that the conduct is good or bad regardless of the fact that the person in question is my friend or my enemy. This is because it is assumed that when I call that conduct good or bad, I would apply the same judgment to other people acting the same way in similar circumstances, independently of how it would affect me. This apparent impartiality characterizes the moral emotions, Westermarck reasons, because social life gives birth to moral consciousness. Moral rules originated as tribal customs that expressed the emotions of an entire society rather than the personal emotions of particular individuals. Thus, moral rules arise as customary generalizations of emotional tendencies to feel approval for conduct that causes pleasure and disapproval for conduct that causes pain.

Although Westermarck stresses the moral emotions as the ultimate motivation for ethics, he also recognizes the importance of reason in ethical judgment. He follows Hume, Smith, and Darwin in arguing that ethical experience combines reason and emotion. Emotions, including the moral emotions, depend upon beliefs, and those beliefs can be either true or false. For example, I might feel the moral emotion of disapproval toward someone because I believe he has injured his friends, but if I discover by reflection that the injury was accidental and not intentional, or that his action did not actually cause any injury at all, my emotion of disapproval vanishes. Moreover, since our moral judgments are generalizations of emotional tendencies, these judgments depend upon the inductive use of human reason in reflecting on our emotional experience.

Westermarck's emphasis on the variability, relativity, and subjectivity of ethical experience has provoked some critics to complain that he does not recognize any enduring or universal standards of ethical conduct. It seems to these critics that Westermarck's Darwinian ethics is radically arbitrary. And so it might seem that Westermarck would be on the side of the historical or cultural relativists who deny the very possibility of universal human rights.

Yet Westermarck clearly relies on the uniformity of human nature as a ground for universal ethical principles. One can see this in his massive two-volume survey of the cross-cultural history of morality--The Origin and Development of the Moral Ideas--which shows both the unity and diversity of human moral experience. (Don Brown's book Human Universals (1991) shows that some anthropologists are reviving Westermarck's work.) Despite radical differences in ethical judgments, Westermarck concludes, "the general uniformity of human nature accounts for the great similarities which characterize the moral ideas of mankind." Such uniformity must exist, he argues, because despite individual and social variation, human beings belong to the same animal species and therefore display similarities in their mental constitution. Thus, Westermarck's ethical theory does not promote nihilism or irrationalism, for he sees the moral emotions that constitute the basis for his ethics as manifesting the natural propensities of a universal human nature. This appeal to the natural human inclinations makes his account of ethics a restatement of natural law reasoning, but one rooted in an empirical Darwinian science of human nature.

Consider how Westermarck's reasoning would apply to the concept of human rights. A right, he would say, is rooted in the emotion of moral disapproval. To have a right to do something means that it is not wrong to do it. So, for example, that someone has a right to life means that it would be wrong for other people to prevent him from living, that it is their duty to refrain from killing him. Similarly, we could formulate a list of natural moral rights that correspond to those natural human capabilities that elicit sympathetic emotions of approval.

Morsink interprets human rights as corresponding to the "transcultural species-wide capabilities normally inherent in human beings" (IHR, 38). He relies on Martha Nussbaum's "capabilities approach" to justice. She identifies ten "central human capabilities" of which the fulfillment constitute full human flourishing: (1) life, (2) bodily health, (3) bodily integrity, (4) senses, imagination, thought, (5) emotions, (6) practical reason, (7) affiliation, (8) other species, (9) play, (10) control over one's environment. Morsink shows how the articles of the Universal Declaration correlate to Nussbaum's ten capabilities and argues that we should read the Universal Declaration as saying that all human beings have equal rights to develop the ten human functional capabilities.

There is a lot of overlap between Nussbaum's list of ten human capabilities and my list of twenty natural human desires. Both lists correspond to the moral regularities of evolved human nature that arise in Westermarck's Origin and Development of the Moral Ideas.

One problem with Morsink's argument, however, is that he fails to see the distinction between the generic propensities of human nature and the specific entitlements of human rights. Human rights can be humanly universal insofar as they satisfy the natural desires of evolved human nature. But these rights are also culturally contingent insofar as their specific entitlements depend on cultural conditions and individual judgments that are constrained but not determined by human nature.

So, for example, we can agree with the Universal Declaration that family life and marriage are natural and should be protected as human rights, because we can see that human beings as a species are familial animals. At birth, children depend on parental care, and we can agree with Darwin that natural selection has favored the social instincts of parent-child bonding as the primal root of all human sociality. We can see, then, that the physical birth of a child becomes a moral birth insofar as the parents (or other adults assuming parental roles) invest their child with the dignity that comes from their emotional attachment to the child. We know that there are complex neurophysiological mechanisms for reinforcing parental attachment to children, and these same mechanisms can be extended to other human beings.

And yet the Universal Declaration speaks of family life and marriage in generic terms without specifying any particular form of marriage or familial arrangements, which are left up to the cultural circumstances of particular societies. Whether we favor monogamous or polygamous marriages, for example, will depend upon variable cultural history.

As I have indicated in my posts on the incest taboo, Westermarck is most famous for his Darwinian account of the moral rules surround incest avoidance, which illustrates the natural universality and cultural variability of morality. We are naturally inclined to learn to avoid sex with those with whom we have been reared from an early age. So in all human societies, there is a strong tendency to prohibit the marriage of siblings or of parents and children, because this tends to arouse strong emotions of repugnance. But beyond the nuclear family, there is great variation in marriage rules. In some societies, the marriage of cousins is encouraged, while in others it is prohibited.

We should also note that not only is there variation accross societies, there is also variation across individuals. The tendency to learn incest avoidance is a natural propensity for most human beings. But some individuals will not show this propensity. We recognize such natural propensities as "normally" present in human beings. But the temperamental variability of human beings will always produce some people who lack these normal propensities. In extreme cases--psychopaths, for example--we might see human beings who have none of the normal moral emotions, and we must treat these people as moral strangers. The Nazis who carried out the Holocaust showed a "disregard and contempt for human rights" so that their natural human sympathy was somehow blunted or blinded by individual temperament or social circumstances.

One common way in which the moral sense is blunted or blinded is through xenophobia--the natural human disposition to care more for those close to us than for strangers, to distinguish friends and enemies, those in our group and those outside. In extreme cases--as with Nazi Germany--some human beings are dehumanized and thus treated as outside the circle of human sympathy.

The modern human rights movement is obviously an attempt to extend the circle of our moral emotions to embrace all of humanity, or as the Declaration says, "all members of the human family." A Darwinian ethics like that developed by Westermarck allows for such humanitarian or cosmopolitan ethics but within the realistic limits set by human nature.

Darwin saw a history of moral progress in which human sympathy has been gradually extended from the family to small tribes, then to large nations, and eventually to all of humanity. In the Descent of Man, he wrote: "As man advances in civilization, and small tribes are united into larger communities, the simplest reason would tell each individual that he ought to extend his social instincts and sympathies to all the members of the same nation, though personally unknown to him. This point being once reached, there is only an artificial barrier to prevent his sympathies extending to the men of all nations and races." Robert Wright used this quotation as the epigram for his book Nonzero in which he surveyed the entire history of the world as an ever-expanding series of nonzero-sum games of cooperation that moves ultimately to a global community. Darwin believed that this advance of sympathy would eventually extend even beyond humanity to include the lower animals, so that we would see "the most noble attribute of man" in the "disinterested love for all living creatures."

Although this can appear to be a utopian view of morality, I think Darwin indicates that he is realistic in recognizing that our moral concern will always tend to favor those close to us. Westermarck indicates this clearly, and biologists like Frans de Waal have confirmed it. Morsink recognizes this when he speaks of how human rights and duties move outward through a series of concentric circles. We care first and most strongly for ourselves and those bound to us by ties of kinship and friendship. Our moral concern can expand to ever-wider circles to include our extend kin, our clan, our group, our nation, all of humanity, and perhaps even all life forms. But the expansion to the wider circles will occur only in those cases where our provisioning of the inner circles is secure.

Here is where the utopian cosmopolitanism of someone like Peter Singer fails (as I have indicated in chapter 9 of Darwinian Conservatism). Singer is a moral rationalist, who insists--against those like Westermarck who stress the primacy of moral emotions--that morality is ultimately based on pure reason. And the logic of moral reasoning, according to Singer, leads to one fundamental principle--the impartial consideration of the similar interests of all sentient creatures. So, for example, it is immoral to spend money caring for our dying parents that could have been better spent to save distant strangers from starvation. Singer himself admits that he acted immorally when he spent money to care for his dying mother who was suffering from Alzheimer's, because he should have given this money to Oxfam to save the lives of some strangers somewhere in the world. That almost everyone recognizes the absurdity in such positions testifies to the emotional reality of our moral concern as naturally constrained by love of one's own.

Similarly, the human rights movement becomes utopian when it strives for a new world order in which patriotism has been abolished for the sake of absolute cosmopolitanism. To some degree, and in some circumstances, our moral emotions can be extended to "all members of the human family." But that humanitarian morality will always be limited by our naturally predominant concern for ourselves and those close to us.

October 23--The Anniversary of Creation

"In the beginning, God created the heaven and the earth."

That occurred on October 23, 4004 BC. So today is the 6013th anniversary of the Creation of the world.

At least, that is what we learn from Archbishop James Ussher's Annals of the World, published first in Latin in 1654, with an English translation published in 1658. Ussher used the Bible and secular works of ancient history to calculate a chronology of world history going back to the very beginning with God's Creation.

When I first began reading the Bible as a child, I noticed that the top of the first page of Genesis had 4004 BC as the date. It was a long time before I discovered that this date was not actually in the original text of the Bible, but was added later to some of the texts of the King James translation after Ussher's work.

Ussher was an Anglican Archbishop of Ireland who was a prodigious scholar of the Bible and ancient history. When he died in 1656, he was honored by Cromwell with a burial in Westminster Abbey.

A few years ago, Larry and Marion Pierce--a Canadian couple--spent over four years in editing a new English revision of the Annals, which was published in a beautifully printed leather-bound edition that is available at Amazon.com. The book is widely read by Christians who see it as the alternative to Darwin in laying out a chronology of the history of the world based on biblical revelation rather than the false science of evolution.

Whenever Ussher and his chronology are mentioned today, people are usually ridiculing his work, although it's clear that these people have never actually read Ussher's book. Anyone who reads the book will have to be impressed by the extraordinary range and depth of his thinking, even if one is not persuaded by his reasoning.

As I have indicated in some previous posts on Ussher, reading his book should expose the weakness in the assumption of the "scientific creationists" that the Bible was intended to be a work of divinely revealed scientific history. To derive his chronology, Ussher relies on assumptions and inferences that go well beyond anything in the text of the Bible. For example, the text of Genesis never identifies the exact day of Creation. Ussher assumes that since the Jews used to start their year in autumn, this must reflect some ancient memory of Creation. He then uses astronomical tables to determine that the first Sunday after the autumnal equinox would be October 23 in the Julian calendar. On the Gregorian calender, which we use today, the date would be September 21. So, I guess we're actually a month late in celebrating this anniversary!

To get the year 4004 BC, Ussher relies on dating and particularly genealogies in the Bible. But to fill in the gaps in the biblical dating, Ussher has to go to the texts of ancient historians like Herodotus and Xenophon. The Pierces report that Ussher's book "contains more than twelve thousand footnotes from secular sources and over two thousand quotes from the Bible or the Apocrypha." If the Bible were intended to be a scientific history, why is Ussher forced to rely on secular historical texts to fill in his chronology? Doesn't this suggest that the Bible is more concerned with salvational history rather than scientific history?

My earlier posts on Ussher can be found here.

The Genetic Basis of Human Rights

The modern human rights movement begins with The Universal Declaration of Human Rights of 1948. The idea of human rights would seem to depend on the idea of human nature. Although the Declaration never speaks of "human nature," it does refer once to nature in declaring that the family "natural"(Article 16). Moreover, the references to the "inherent dignity" of "all members of the human family" and the declaration that "all human beings are born free and equal in dignity and rights" implies some shared human nature that is the source of human rights.

Originally, Charles Malik a Lebanese Christian and Thomist proposed the following language for Article 16: "The family deriving from marriage is the natural and fundamental group unit of society. It is endowed by the Creator with inalienable rights antecedent to all positive law." The drafters accepted the first sentence but rejected the second, because they wanted a purely secular statement that did not depend on religious belief. Similarly, proposals to refer in Article 1 of the Declaration to human beings as "created in the image and likeness of God" were not adopted. According to someone like Richard Weikart, in his warnings about the "Darwin to Hitler" connection, disregarding the traditional Judeo-Christian doctrine of human beings as created in God's image makes healthy morality impossible. But clearly, the drafters of the Declaration disagreed, because they thought that the shared repulsion towards Nazi barbarism and the determination to declare a universal morality of human rights that would condemn such barbarism manifested a natural morality that did not depend on religious belief.

This cosmopolitan morality of human rights must somehow be grounded in human biological nature. And yet many of the theorists of human rights are nervous about recognizing such an appeal to human nature because they fear that this would require an indefensible "essentialism." The problem here, as I suggested in a post from a few weeks ago, arises from a false story about "essentialism"--the story that beginning with Aristotle, biological species were regarded as absolutely eternal and invariable in their logically defined "essences."

This will be the first of a series of posts on how a Darwinian conception of human nature supports the modern conception of human rights.

In at least one of the recent documents on human rights, the biological basis of human rights is explicitly recognized. The Universal Declaration on the Human Genome and Human Rights was adopted by UNESCO in 1997 and then ratified by the General Assembly of the United Nations in 1998. The text can be found here.

The first four articles are put under the title "Human dignity and the human genome":

Article 1
The human genome underlies the fundamental unity of all members of the human family, as well as the recognition of their inherent dignity and diversity. In a symbolic sense, it is the heritage of humanity.

Article 2
a. Everyone has a right to respect for their dignity and for their rights regardless of their genetic characteristics.
b. That dignity makes it imperative not to reduce individuals to their genetic characteristics and to respect their uniqueness and diversity.

Article 3
The human genome, which by its nature evolves, is subject to mutations. It contains potentialities that are expressed differently according to each individual's natural and social environment, including the individual's state of health, living conditions, nutrition and education.

Article 4
The human genome in its natural state shall not give rise to financial gains.

Here we can see much of the complexity and tension in appealing to human biology as a ground for human rights. Universal human rights assume a "fundamental unity of all members of the human family," which in turn assumes an underlying unity in the human genome, because membership in the human species requires some shared genetic basis. But the human genome brings about not only the unity of humanity but also its diversity. No two human beings are genetically identical. So even if human beings are roughly equal at birth in being identifiably human, they are not completely identical. Here we can see the implicit worry that some human beings might be excluded from the human family because of genetic differences that some people would consider abnormal or inferior.

We can also see here the fear of genetic reductionism. Although being genetically human is the precondition for being treated with the dignity that human beings deserve, human beings are not fully reducible to human genetics.

The human genome is recognized as a product of evolution and thus subject to evolutionary change through mutations. But there is enough genetic stability to sustain the reality of the human species.

That genetic humanity consists of potentialities that are diversely expressed in each individual through the interaction with the natural and social environment of the individual, which includes physical conditions, bodily functioning, and social learning.

Human genes by themselves do nothing. They shape human life only though genetic potentialities that work through complex interactions with the physical and social world. That's why human biology is much more than genetics. The biological nature of human beings depends on the coevolution of innate tendencies, social history, and individual judgment.

The universality of human genetic nature allows for universal human rights. But the moral history of human rights will reflect the complex contingencies of social and political history.

That we can treat human beings with "dignity" depends on certain natural moral sentiments and on practical judgments about how best to express those sentiments. That requires more thought about how Darwinian science might support the modern language of human rights as a language of cosmopolitan morality.

Incest, Again

Marlene Sokolon was a graduate student of mine who now teaches at Concordia University in Montreal. When she was my student, we had a standing joke between us whenever she would complain about how often in class I wanted to talk about incest.

And here I am bringing it up again! I do that because understanding our moral condemnation of incest touches in some way on almost all of the topics that come up on this blog.

The incest taboo is one of the clearest cases of a human universal, because every human society has some rules about prohibited incest. But there is also variation as to what counts as incest. Even within the same society, there can be great variation, as in the United States where state laws differ as to whether cousins can legally marry.

Our condemnation of incest as immoral illustrates how hard it is to rationally justify moral judgments that depend on deep moral emotions of repugnance.

The Darwinian explanation for the incest taboo--particularly as developed by Edward Westermarck--is the most fully developed example of how Darwinian ethics works. That's why Edward O. Wilson brings it up so often in his writing, and why some of the proponents of evolutionary psychology have devoted so much attention to it.

Three of my previous posts on the incest taboo can be found here, here, and here.

The 24 comments on the first post are fascinating in showing the range of responses that this provokes.

Darwinism and Religion in Canada: My Lecture at the University of Regina

Last Friday, I lectured at the University of Regina in Canada on "Does Darwin Subvert or Support Morality?" The lecture was sponsored by the Departments of Philosophy and Classics and Political Science. The funding for the lecture was provided by Shadia Drury as holder of the Canada Research Chair in Social Justice at the University of Regina.

The lecture was attended by about 70 students and faculty from many different departments. Everyone seemed seriously engaged in the topic, as indicated by the fact that everyone stayed attentive for two hours or more of lecturing and discussion.

The religious objections to Darwinian science are more common in the United States than in Canada, and generally I find that Canadian academics think this is a distinctly American debate that has no resonance in a predominantly secular country like Canada. But I noticed that some of the students who spoke with me after the lecture were serious religious believers who were looking for ways to reconcile their religious beliefs with Darwinism, and they were pleased that I was open to that possibility. I suspect that religious belief is taken far more seriously by many Canadians than Canadian academics are willing to admit.

I also noticed this in some of my dinner-table conversation with faculty members. We were discussing some of the most prominent Canadian academics, and some of them expressed shock that one of the most influential academics in Canada--Charles Taylor--was a Catholic who has argued for the importance of religious belief and warned about the dangers of "secularization." Taylor's recent book A Secular Age seems to be part of a "return to religion" movement sweeping across large areas of academic life in Europe and Canada.

Shadia Drury is one of those fearful of the influence of academics like Taylor, who give too much importance to religious belief as an expression of multicultural freedom.

Shadia is open to some of my arguments for using Darwinian science to support the idea of natural right or natural law as rooted in evolved human nature. But she is uncomfortable with my claim that war is a natural desire, because she fears this gives too much encouragement to a militaristic view of the world that is dangerous. This is related to her condemnation of the Straussians for supporting what she regards as an unduly aggressive view of American foreign policy.

On my way to Regina, I finished reading Peter Minowitz's new book Straussophobia: Defending Leo Strauss and Straussians against Shadia Drury and Other Accusers. It's a comprehensive and detailed defense of Strauss and the Straussians against critics like Drury. Shadia told me that she hasn't yet seen the book. It would be helpful to have her write a response to Minowitz's book as well as the book by the Zuckerts--The Truth About Leo Strauss.

The Emergent Evolution of the Soul in the Neocortex

In Darwinian Conservatism, I have a chapter on "Emergence" (104-111). Against the charge that Darwinian science is reductionistic because it denies the uniqueness of human mental freedom in denying that the mind has any freedom from the material mechanism of the brain, I argue that Darwinian evolution actually denies both reductionism and dualism and sustains the idea of emergence as a third alternative.

The simplest expression of the idea of emergence is that the whole can be greater than the sum of its parts. As we pass through levels of complexity in evolution, we see new properties at higher levels that are not fully reducible to the lower levels. That's why, for example, biology is not fully reducible to physics and chemistry. So the idea of emergence denies strong reductionism, because it denies that the higher levels of organization can be completely reduced to the lower levels. But the idea of emergence also denies dualism, because it denies any radical separation of matter and mind.

Part of my argument here concerns the "emergent evolution of the soul in the brain" (109-111). We should say that only human beings have a soul, which gives them an intellectual and moral freedom that other animals do not have. And we should explain this soul as an emergent product of the evolution of the brain once it passed over a critical threshold of size and complexity in the neocortex, particularly in the frontal lobes.

The evolution of the primate brain shows a trend towards increasing size and complexity of the neocortex, which allows for greater behavioral flexibility in these animals. This trend reaches its peak in the human brain. Larger and more complex frontal lobes give animals the capacity for voluntary action, in the sense that they can learn to alter their behavior in adaptive ways. In human evolution, the growth in the size and complexity of the frontal lobes passed over a critical threshold allow human beings to use words and images to compare alternative courses of action through mental trial and error. Consequently, human beings are capable not just of voluntary action but of deliberate choice, by which they self-consciously choose present courses of action in the light of past experiences and future expectations to conform to some general plan.

Recent research in neuroscience on the evolution of the neocortex gives some support to this kind of reasoning. A short review of this research is Pasko Rakic's article "Evolution of the Neocortex: A Perspective from Developmental Biology," Nature Reviews Neuroscience, 10 (October 2009): 724-35. Here's the abstract for the article:

"The enlargement and species-specific elaboration of the cerebral neocortex during evolution holds the secret to the mental abilities of humans; however, the genetic origin and cellular mechanisms that generated the distinct evolutionary advancements are not well understood. This article describes how novelties that make us human may have been introduced during evolution, based on findings in the embryonic cerebral cortex in different mammalian species. The data on the differences in gene expression, new molecular pathways and novel cellular interactions that have led to these evolutionary advances may also provide insight into the pathogenesis and therapies for human-specific neuropsychiatric disorders."

Normally, this article would be available only to subscribers. But for the next six months, it can be accessed online along with some other articles on the evolution of the brain.

Some previous posts related to this topic can be found here, here, and here.

Does the Death of God Mean the Death of Morality? A Darwinian Response to Nietzsche's Challenge

"As the will to truth thus gains self-consciousness--there can be no doubt of that--morality will gradually perish now: this is the great spectacle in a hundred acts reserved for the next two centuries in Europe--the most terrible, most questionable, and perhaps also the most hopeful of all spectacles." Thus declares Nietzsche in The Genealogy of Morals (third essay, sec. 27).

Nietzsche's prediction of the gradual disappearance of morality over the 20th and 21st centuries was based on his claim that this would follow from the decline in the belief that morality was founded in some eternal, divine order of the universe. Traditional morality could not survive once human beings saw the truth that all morality was only a human invention with no support in divine will or natural order.

This is what Jonathan Glover calls "Nietzsche's challenge" in his book Humanity: A Moral History of the Twentieth Century (2000). Glover's book is a disturbing history of the inhuman brutality of the twentieth century--from Stalin to Hitler to Mao to Pol Pot, and so on. This might make us worry that Nietzsche's prediction was accurate--that the "death of God" really has brought on a nihilistic collapse of morality. And that's why we hear so much talk now about the need for a "return to religion." How else can we preserve our most cherished moral concepts based on the belief in the sacred dignity of human life if we have no belief in the sacred?

Glover tries to answer Nietzsche, however, by arguing that his moral history shows that despite the evil cruelty of that history, morality survives even without any necessary foundation in an eternal moral law. "The alternative is to keep ethics afloat without external support. If there is no eternal moral law, morality needs to be humanized: to be rooted in human needs and human values" (406). We can see a "humanized ethics" founded in human psychology that does not require any external metaphysics to support it.

Glover sketches a human moral psychology that has a number of elements. To a large degree, morality is a matter of self-interest. As social animals, we need the cooperation of others, and that cooperation is fostered by social trust based on reciprocity: human beings are naturally inclined to punish cheaters and reward the trustworthy. One can see the logic of reciprocal cooperation in the research of evolutionary game-theorists who show how cooperation can arise among egoists who discover that "tit-for-tat" is the best strategy for social behavior. These norms for social cooperation can then be enforced through social pressure and conventional moral rules.

Of course, Glover recognizes that narrow self-interest is not sufficient for morality, because clever cheaters often succeed. But there are other psychological propensities favorable to morality. Human beings do show natural inclinations for sympathy and respect for others: we feel disgust when people are mistreated, and we feel grateful to those who are generous and compassionate.

We also care about our moral identity. We want to have the character of a certain kind of person, and we feel shame and guilt when we fall short of the character to which we aspire. That's what we mean when we speak of "living at peace with oneself."

And yet even with all of these psychological propensities to morality, our moral history is replete with failure--as Glover indicates in his vivid and painful history of cruelty in the twentieth century. Human psychology includes propensities to evil as well as good. And some individuals in some circumstances give in to--even enjoy--those evil inclinations.

The most common problem for morality, Glover indicates, is the "moral gap" between "insiders" and "outsiders." We are inclined to cooperate with those who belong to our moral community--friends, relatives, fellow citizens, fellow believers, and so on. But we are inclined to be nasty to those outside our community. We seem to be naturally tribal animals. That's why so much of our moral history is about the difficulties of extending our circle of moral concern to wider groups.

A Darwinian science of morality would support all of these points about human moral psychology as a ground for morality that is independent of any religious or metaphysical conception of moral order.

The logic of cooperation through reciprocity is clearly Darwinian. In fact, the famous research of Robert Axelrod on the "tit-for-tat" strategy is explicitly presented as an evolutionary conception. Evolutionary game-theory is all about the Darwinian grounds for moral cooperation. The core ideas can be found in Darwin's Descent of Man, who recognizes the natural human propensity to reciprocal behavior--returning good for good and bad for bad.

Darwin also recognizes the importance of social pressure--praise and blame--and conventional moral rules in enforcing norms of good conduct. Darwin believes that human beings are uniquely moral because they have linguistic and cognitive capacities that allow them to formulate and enforce social standards of cooperative behavior.

Darwin also stresses the importance of sympathy or respect for others--the ability to imaginatively share the experiences of others--as a foundation for the moral sense. Here he follows the lead of Adam Smith, David Hume, and the Scottish moral philosophers in emphasizing the moral sentiments as sustaining social cooperation. Now, neuroscientists can investigate the neural bases of such social emotions--perhaps through systems of "mirror neurons," for example.

And just as Glover speaks about moral identity--our concern for having a certain kind of character--so does Darwin speak about how we use our cognitive capacities for self-reflection to organize our moral and intellectual lives into coherent patterns.

But also like Glover, Darwin recognizes our natural tribalism. If Darwin is right about the evolution of morality, then all morality is biopolitical. Morality does not arise as an imperative of cosmic order, divine will, or pure reason. Nor does morality arise as an arbitrary choice of individual whim or cultural artifice. Rather, morality arises from the emergent evolution of human nature. If Darwin is right about the evolution of human morality as a process of evolutionary group selection, then human morality is not absolutely disinterested or universalizable, because it is biased in favor of insiders and against outsiders.

This circle of group identity can be expanded. Darwin writes: "As man advances in civilization, and small tribes are united into larger communities, the simplest reason would tell each individual that he ought to extend his social instincts and sympathies to all the members of the same nation, though personally unknown to him. This point being once reached, there is only an artificial barrier to prevent his sympathies extending to the men of all nations and races." Eventually, this can become a "disinterested love for all living creatures." In fact, Robert Wright's book Nonzero is a history of the world understood as a progressive expansion of nonzero-sum cooperation as human beings discover ever wider and more complex ways to cooperate with others for mutual benefit.

But many moral philosophers (like Peter Singer, for example) make a mistake in interpreting this as meaning that morality strives for the abstract principle of complete impartiality or disinterestedness. For Singer, the fundamental moral principle is the impartial consideration of the interests of all sentient creatures. Moral reasoning does require that we generalize across our moral community in the service of the common good. But complete impartiality would make morality impossible. If we were completely impartial, we wouldn't care about anything--nothing would matter. Contrary to Singer's "animal liberation," it is impossible for a moral system to give equal consideration to all life on earth. We might well want to minimize animal suffering, but we will properly care more for our fellow human beings than we do for nonhuman animals. Moreover, even within the community of humanity, we will care more for those close to us than for those far away. So there will always be some tension between loyalty and moral inclusion. Our humanitarian sympathy will typically be weaker than our love for our own.

This explains the complex tension in our moral lives, including international political debates over the nature and enforcement of "human rights." We are naturally tribal animals. And while our tribalism inclines us to cruelty towards outsiders, it also sustains loyalty, which is a moral duty.

This Darwinian moral psychology can be judged by how well it accounts for our human moral history. Religious belief and metaphysical conceptions of eternal moral order have been part of that moral history. But even if we doubt the truth of religious or metaphysical conceptions of morality, we can still sustain morality based on our natural human psychology.

Elizabeth Blackburn's Nobel Prize

Elizabeth Blackburn has just received the Nobel Prize in Medicine. The news stories about her are reviving the debate over how Leon Kass arranged to have her expelled from the President's Council on Bioethics and then replaced by Kass's friend Diana Schaub.

My posts on this debate can be found here and here. The New York Times article on Blackburn's prize can be found here.

The Religious Longings of Strauss and Nietzsche

"Beyond Good and Evil always seemed to me to be the most beautiful of Nietzsche's books."

That's the first sentence of Leo Strauss's article on Nietzsche's Beyond Good and Evil, which is the only substantial piece of writing by Strauss on Nietzsche. I have often puzzled over that first sentence, because Human, All Too Human has always seemed to me to be the most beautiful of Nietzsche's books. In my recent series of posts on Nietzsche, I've explained why I rank that book as Nietzsche's best. It's one of the books from Nietzsche's middle period, when he fully embraced Darwinian evolutionary science, and broke away from the religious longings that run through his earlier and later writings. The fundamental idea of Human, All Too Human is stated near the beginning: "everything has evolved," and "man has evolved."

In his later writings, and certainly in Beyond Good and Evil, Nietzsche reverts back to his earlier fear of Darwin's "science of universal becoming" as "true but deadly," and he uses "the eternalizing powers of art and religion" to give "eternal meaning to existence." This move from evolution to eternity includes an affirmation of the eternity of the human species--"the eternal basic text of Homo natura.

As I have argued in an earlier post, Nietzsche moved from the Christian Pietism of his childhood to the Dionysian Pietism of maturity, and this required a move away from the Darwinian evolution of his middle writings to the Dionysian eternity of his later writings.

Is Strauss moved by the same religious longing for eternity that Nietzsche shows in his earlier and later writings? In his article, Strauss certainly does stress the importance of Nietzsche's atheistic religiosity and his appeal to the "religious instinct."

That Strauss and Nietzsche might share a similar religious longing is suggested by the following story about Strauss told by Hans Jonas in his Memoirs (p. 49):

". . . His family had been Orthodox, and it had cost Leo intense spiritual pain to tear himself away from his traditional upbringing. It hadn't been easy for him to make philosophy his guide, to free himself, that is, from all preexisting dogmatic assumptions when it came to the ultimate questions bearing on God and the world. This freedom, which was essential to being a philosopher and incompatible with adherence to a specific religion or revelation or god, this intellectual necessity of becoming an atheist in order to be a philosopher, tormented him all his life. He did make the leap, but he could never shake off the sense that he'd committed an act whose correctness could never be proved once and for all. That hurled him time and again into a fundamental state of doubt as to whether following the path of rational enlightenment, which requires the denial of established articles of faith, is consistent with the truth and beneficial to the human being. He suffered from the necessity of being an atheist. An experience we had as emigres made this clear to me. When I got to England in 1933, he was there, too, and we saw each other quite often. Leo Strauss was living in London at the time with his young wife and her little son from her first marriage. On a fall day--it must have been in 1934--we went for a walk in Hyde Park. We'd walked along in silence for quite a while. Suddenly he turned to me and said, 'I feel terrible.' I said, 'Me too.' And why? It was Yom Kippur, the day of atonement, and both of us were not in the synagogue but were walking through Hyde Park. That was telling. For him much more than for me, for in my case relinquishing our traditional faith had been much easier, having already been accomplished by my parents; I'd grown up in a climate in which you could think freely about such things. But for Strauss it was a source of torment. 'I've done the equivalent of committing murder or breaking a loyalty oath or sinning against something.' This 'I feel terrible' came straight from his soul."

Doesn't this sound a lot like Lou Salome describing Nietzsche's anguish in struggling with his religious yearnings from his Lutheran childhood and his fear that modern scientific naturalism could not satisfy him?

Some of my earlier posts on these points can be found here, here, here, here, here, here, and here.

"Darwin's Darkest Hour": A PBS Film

Tuesday evening, October 6, PBS television stations will broadcast a special two-hour "Nova" film--"Darwin's Darkest Hour." The story in the film turns on the domestic life of Darwin during the weeks around the time that he received the famous letter from Alfred Russel Wallace indicating that Wallace was ready to announce his own theory of evolution, which forced Darwin to publish the work that he had kept hidden from the public for many years. The film will also depict the tension between Darwin and his wife Emma over the religious implications of his theory.

PBS has a good website for the program. The interview with the script writer--John Goldsmith--suggests that the film is based on some good historical research.

Arnhart in Canada

On Friday, October 9, at 3:30 pm, I will be lecturing at the University of Regina in Canada. The title for my lecture is "Does Darwin Subvert or Support Morality?" (Can you guess my answer?)

My host is Shadia Drury, a member of the Departments of Philosophy and Political Science and the holder of the Canada Research Chair in Social Justice at Regina.

A few months ago, I wrote a post on Shadia's new book on Aquinas. She's best known as the leading critic of Strauss and the Straussians. Catherine and Michael Zuckert have shown--in their book The Truth About Leo Strauss--that Drury's books on Strauss were the primary source for all the journalistic coverage of the Straussian influence in the Bush administration, which was a big story a few years ago.

Darwin, Thucydides, and International Relations

Any general theory of politics assumes a theory of human nature. A small but growing number of political scientists have been applying a Darwinian theory of human biological nature to various topics in political science. The final aim of such work would be to turn political science into a biopolitical science. So, for example, research in human biology and Darwinian theory can illuminate the study of international relations. One can see this in two books: Bradley Thayer's Darwin and International Relations: On the Evolutionary Origins of War and Ethnic Conflict (2004) and Stephen Rosen's War and Human Nature (2005).

Although they agree on many points, Rosen and Thayer disagree on the implications of a biological approach to international relations for assessing rational choice theory. Rational choice theorists assume that human beings are by nature rational egoists who rationally maximize their interests. Applying rational choice theory to international relations means that decisions of war and peace are explained as rational calculations of interests by states competing with one another. Thayer believes that a Darwinian view of international relations confirms rational choice theory by explaining the human nature of rational egoism as ultimately caused by natural selection in the evolutionary competition of human beings for scarce resources. Rosen believes, however, that a biological understanding of human nature shows that rational choice theory is only partially true, because in stressing rational calculations of interest, it ignores the emotional dispositions of fear and honor as factors shaping human decisions in international relations.

In his history of the Peloponnesian war, Thucydides has some Athenian envoys in Sparta say that the imperial policies of Athens are motivated by fear, interest, and honor. Rosen says that the aim of his book is to show "that there is a biological argument that Thucydides was right, that fear and honor play a role in human politics along with calculations of interest, but also that the other issues he analyzed, such as the nature of the political systems present in the ancient Greek world, matter as well" (2). Human beings are inclined by their biological nature to be rational egoists, and so the rational choice theorists are right about this. But that same biological nature also inclines human beings to feel social emotions that make them care about others and about their status in relation to others. So, for example, their emotional desire for honor and fear of being dishonored might move them to act contrary to their material interests. Moreover, Rosen argues, these complex motivations of human biological nature are manifested in the military and political behavior of states in international relations.

Rosen applies research in neuroscience on the complex interplay of reason and emotion in the brain and endocrine system to explain the decision-making of leaders in times of international crises. Through case studies, he argues that American presidents have had to make quick decisions in complex international circumstances through emotional pattern recognition shaped by memories of emotionally charged experiences from the past. They thus employed neural pathways of information gathering and decision-making shaped by natural selection in human evolutionary history.

Rosen argues that while the termination of war can result from calculated decisions about material interests, this can also result from a collapse of the will to fight among the losers, which arises from emotional distress with a neurophysiological basis. Again, Rosen's general point is that decisions about war and peace arise from the complex interaction of reason and emotion as shaped by the evolved nature of the human brain.

One prominent manifestation of evolved human nature in international relations is the natural desire for status and dominance. Those who fill the highest offices for deciding issues of war and peace tend to be ambitious people who desire dominance over others. Rosen identifies such people as mostly high testosterone men who manifest a desire for dominance shaped in evolutionary history where men competed with one another for preeminence. People like Abraham Lincoln, Franklin Roosevelt, and Winston Churchill are moved by a desire for distinction--for honor and glory--tht goes beyond any selfish calculation of material interests.

Tyrants show a similar desire for dominance. But Rosen argues that ambitious leaders like Lincoln, FDR, and Churchill do not have the tyrannical souls of people like Hitler, Stalin, and Mao. He claims that tyrannical behavior emerges from "the personal character of tyrants combined with the institutional character of tyrannies" (178). Rosen's point here is unclear. But the idea seems to be that those of tyrannical temperaments will rise to the top in turbulent circumstances where there are few institutional checks or limits on the ruthless and opportunistic pursuit of power.

One fundamental lesson that emerges from Rosen's biopolitical analysis is the need to channel the rivalry of politically ambitious people through an institutional structure of checks and balances so that ambition counteracts ambition. Here, again, Rosen agrees with Thucydides, who suggested that factional conflict in the ancient Greek cities could have been tamed by mixed regimes in which oligarchic and democratic elements balanced one another.

Although Thayer agrees with Rosen in using biological science to explain international relations, Thayer sees biological explanations as apply only to the level of ultimate causes in the genes, as distinguished from social and cultural explanations as applying to the level of proximate causes in the environment. Human behavior arises from a complex interaction of ultimate and proximate causes.

Thayer argues that evolutionary biology contributes to the general theories of international relations by explaining the ultimate causes of the rational egoism assumed by realist theory and rational choice theory. Human beings are rational egoists because natural selection has favored the rational calculation of selfish interests as best adapted to the survival and reproduction of individuals in evolutionary history.

According to Thayer, evolutionary biology also contributes to the particular topics of international relations by explaining the ultimate causes of war and ethnic conflict. Human beings wage war to acquire and defend resources, because this was favored by natural selection in evolutionary conditions where competing for scarce resources enhanced fitness. Human beings are inclined to ethnic conflict because in-group/out-group distinctions, xenophobia, and ethnocentrism conferred competitive advantages in human evolutionary history.

Unlike Rosen, Thayer does not argue that biology goes beyond rational choice theory by showing the importance of emotional motivation in human decision-making. And yet Thayer repeatedly acknowledges the power of emotions in human social behavior. For example, he speaks of the "profound emotions" of war, which include "profound love of comrades, the deepest hatred of the enemy, fear of death, and fear of disappointing the other men" (191). He also refers to the "emotional depth of national identity" (232). I think he's mistaken in not considering how such emotions--deeply rooted in the brain and endocrine systems of human nature--might go beyond "rational choice."

Nor does Thayer consider the moral emotions as expressions of human biological nature. He quotes Adam Smith as describing the egoism of Homo economicus, and he claims that evolutionary theory confirms this economic understanding of human nature. But he says nothing about Smith's account of the "moral sentiments" as the natural ground of moral judgment. Nor does he mention the influence of Smith on Charles Darwin's theory of the "moral sense" as rooted in human biological nature.

This is an important point because many social scientists have recently been employing experiments in evolutionary game theory that confirm the importance of moral sentiments for instilling a sense of right and wrong that motivates people to punish wrongdoers, even when this punishment requires some sacrifice of material interests. Moreover, neuroscientists are now uncovering the neural roots of these moral sentiments in the emotional control pathways of the brain. This natural moral sense manifests itself in international relations when individuals and nations act out of a sense of justice to aid the perceived victims of injustice and to punish those who have injured them. The tradition of "just war" arises out of such moral sentiments.

Like many of the proponents of "evolutionary psychology," Thayer assumes that biological science cannot explain moral experience because science is concerned with factual claims rather than value judgments, and he attributes this fact/value distinction to David Hume. But Thayer misses Hume's point. Hume distinguishes is and ought in order to show that moral assessments are derived not from pure reason alone but from moral emotions. Yet far from denying that moral judgments are judgments of fact, Hume claims that moral judgments are accurate when they correctly report what our moral judgments would be in a given set of circumstances. Correct moral judgments are factual statements about the species-typical pattern of moral sentiments in specified circumstances.

Darwin saw that the ethical naturalism of Smith and Hume allowed morality to become an object of scientific study, because scientists could study the natural roots of moral judgment in the evolved moral emotions of the human animal. Recently, biologists such as Edward Wilson and economists such as Robert Frank have renewed Darwin's project for a scientific study of morality as founded on natural moral emotions. Thayer says that the question of whether rational choice theorists should include "moral commitment" as a factor in human behavior constraining egoism is "beyond the scope of this book" (86). But then we must wonder why a Darwinian theorist would reject the Darwinian tradition of ethical naturalism.

Explaining morality is important for political science, because political controversy is driven by moral passions, and therefore a complete science of politics must include a scientific account of morality. A biopolitical science would explain morality in politics as an expression of the natural moral desires of evolved human nature.

Such a broadly conceived biopolitical science would have to study not only the genetic evolution but also the behavioral and cultural evolution of human beings and other poltical animals. Thayer tends to reduce human biology to genetics, and so when he speaks of "ultimate causes," he seems to assume that these are genetic causes. This follows from his acceptance of Richard Dawkins' claim that all Darwinian explanation is ultimately about "selfish genes." Thayer believes that "the organism evolved largely to satisfy the wants of the gene, and in a similar manner egoism evolves through a population" (70). There are two problems with this. Biology is much more than genetics. And a purely genetic science is not going to explain much about politics, which depends on higher levels of complexity far beyond the genes.

As I have argued in some previous posts, DNA by itself does nothing. The causal power of DNA depends on interactions at many levels of biological complexity--interactions within a cell, between cells, between organisms, and within ecological and social communities. These interactions determine the expression of genes, and the patterns of gene expression can evolve in response to behavioral and cultural evolution.

Studying the genes by themselves would tell us almost nothing about politics. But studying the genetic interaction with behavioral and cultural evolution would tell us quite a lot about politics. For example, Thayer stresses that warfare is not unique to human beings, because other animals (such as ants and chimpanzees) wage war in ways that resemble human warfare. But Thayer does not indicate that the patterns in animal warfare show behavioral and cultural evolution. When Jane Goodall wrote about war among her chimpanzees in the Gombe Stream Preserve, she wrote a historical chronicle that was unique to Gombe. Now many primatologists have reported diverse behavioral traditions among various chimpanzee groups, not only in war but in other activities, that suggest that each chimpanzee community has its own repertoire of cultural traditions. Thayer downplays the importance of environment or culture as "proximate causes." But he does not clearly indicate that cultural evolution is just as much a part of biology as genetic evolution.

To develop a scientific understanding of politics, we need a science of human nature that studies the coevolution of many causes at many levels of complexity--from genes to brains, then to behavior and culture, and finally to symbolic communication as the uniquely human adaptation. If we could achieve that, then political science could become a true science by becoming a biopolitical science. And such a biopolitical science might confirm that ancient political scientists like Thucydides got it right after all.