Wednesday, July 16, 2008

Natural Right and Biology: Marc Hauser on The Moral Instinct

As Leo Strauss showed in Natural Right and History, one can view the entire history of political philosophy as turning on the question of whether there is any natural right. Some people would say there is no natural right, because all right is determined by custom or convention, and what is customarily right or wrong varies radically across different societies and across history. Others would say that despite this variation in customary standards of right, there are some principles of right by nature that are universal, because they are rooted in a universal human nature. As Strauss indicates, in the central section of his book (156-63), Aristotle would seem to be the best exponent of natural right, and yet Aristotle's teaching is unclear. According to Aristotle, in Book 5 of the Nicomachean Ethics, there is something that is right by nature, and yet "all is changeable." How can there be a universal standard of natural right if all conceptions of right are changeable according to variable moral traditions?

Aristotle was a biologist who studied human beings as moral and political animals. One way of explaining his account of natural right is to say that for him natural right is a universal biological propensity of the human species that is diversely expressed in the variable circumstances of individual habituation and social learning. All social animals have natural instincts for social learning. Social life emerges as a joint product of nature and nurture. Just as human beings have a natural instinct for learning language, but the specific languages they learn will depend on their social circumstances, so too do human beings have a natural instinct for judging right and wrong, but the specific content of their moral rules will depend on their social learning.

I have developed this Aristotelian biology of morality and politics in Darwinian Natural Right: The Biological Ethics of Human Nature (1998), and I have argued there that modern Darwinian science supports this Aristotelian understanding of natural right.

Although Marc Hauser shows no knowledge of Aristotle or the history of political philosophy, Hauser's Moral Minds: How Nature Designed Our Universal Sense of Right and Wrong (2006) provides support for my argument. He surveys the recent research on the biological evolution of morality. He concludes that morality is grounded in biology in a manner similar to the biological grounding of language. Human beings are born with a natural capacity for learning language, which Noam Chomsky has explicated as an innate universal grammar, but the specific content of language varies across different languages within the broad constraints of universal grammar. Similarly, Hauser argues, human beings are born with a natural capacity for learning morality, which depends on a universal moral grammar that belongs to the human species as a product of evolutionary history, but the specific expression of that morality will vary across different moral systems within the constraints set by the innate moral instinct.

Last January, The New York Times Magazine published an article by Steven Pinker on "The Moral Instinct," which surveys the reasoning of Hauser and others on the biological roots of morality. I wrote a post on Pinker's article.

Although I generally agree with Hauser's argumentation, I find some of his reasoning vague and confusing. Here I will indicate a few points where I find it hard to follow what he is saying.

In my book Political Questions: Political Philosophy from Plato to Rawls, I noted that John Rawls often appealed to conceptions of human nature rooted in evolutionary biology. In particular, he argued that the very capacity for any sense of justice requires a psychological disposition for reciprocity that must have been shaped by human evolutionary history. He also suggested that we might see this innate propensity to morality as analogous to language as understood by Chomsky: there might be an innate moral grammar underlying our moral experience. A few years ago, John Mikhail wrote a philosophy dissertation at Cornell on "Rawls' Linguistic Analogy: A Study of the 'Generative Grammar' Model of Moral Theory Described by John Rawls in A Theory of Justice." Hauser has organized his book around Mikhail's account of the Rawlsian linguistic analogy.

The problem, however, is that in arguing that the moral instincts show the judgments of a "Rawlsian creature," Hauser never explains how this supports Rawls' argument that justice is based on the principles that human beings in the "original position" would choose behind a "veil of ignorance." One of the most controversial of Rawls' principles is the "difference principle" that inequalities in economic resources are permitted only as long as they benefit the least advantaged. When Norman Frohlich and Joe Oppenheimer put some people in a laboratory setting with the rules specified by Rawls, they selected principles of justice that were not exactly as Rawls predicted. In particular, they did not embrace the difference principle. They prescribed that the worst off should not fall below a set level of income, but then they allowed all others to have whatever higher incomes they might earn by contributing more to society. When Rawls was told about this, he responded: "If the results hold up it may be that the difference principle cuts across the grain of human nature." Oddly enough, Hauser tries to save Rawls from refutation by asserting that his difference principle might be embraced by all human beings unconsciously (90-91). But then Hauser never explains how human evolution would have favored an unconscious difference principle as an innate component of the moral instinct, and in fact, he says almost nothing about the difference principle as a fundamental principle of moral judgment.

What Hauser says about the "Rawlsian creature" depends on his contrast with the "Humean creature" and the "Kantian creature." But his cartoonish depictions bear little resemblance to their philosophic proponents. Hauser quotes Hume's famous declaration that "reason is, and ought only to be the slave of the passions." But he does not notice the context of this remark that makes clear that Hume believes that reason can direct but not motivate action. Hume writes: "Reason and judgment may, indeed, be the mediate cause of an action, by prompting, or by directing a passion." Ignoring what Hume actually says, Hauser depicts the "Humean creature" as a purely emotivist being with no need for reason at all. Thus, Hauser never considers that the "action analysis" that he attributes to the "Rawlsian creature" was a crucial part of Hume's explanation of moral judgment.

Throughout much of the book, Hauser suggests that morality can best be explained as the work of the "Rawlsian creature" rather than the "Humean creature" or the "Kantian creature." But sometimes he suggests that morality is generally a continuing struggle between all three (418). Unless I am missing something fundamental in this book, he never resolves this confusion.

To test the claims of competing positions in moral philosophy, Hauser relies on research that depends on presenting people with moral dilemmas framed in artificial scenarios--such as the famous "trolley problem." Hauser admits that these scenarios are so artificial and abstract in their distance from everyday experience that they are little more than "toy examples." And yet he insists that the scientific method requires such abstract simplifications. He admits, however, that these "artificial examples" will not be persuasive if they are not combined with "real-life cases" (34-35). He often refers to real historical cases in his book. But he never develops any of these cases beyond a few sentences. For example, he refers to the American debate over slavery. But his remarks are so brief that they cannot capture the complexity of that debate (106, 167, 187). To speak of Abraham Lincoln as a moral "visionary," as he does, misses the reality of Lincoln as a statesman exercising prudence in making compromises that rejected the extremes of the abolitionist and proslavery positions. To say that applying the scientific method to morality requires "toy examples" begs the crucial question of whether there can be a science of morality that is not a historical science of irreducible complexity and uncertainty.

Hume sought to turn moral philosophy into a natural science. But he doing that, he relied as much on historical narrative--like his History of England--as on abstract theorizing. Doesn't a science of morality require such a combination of theory and history?

As I have argued here and elsewhere, a full science of morality would have to move through three levels of study--moral nature, moral culture, and moral judgment. We need to understand the universal moral principles of human nature as they interact with the variable cultural traditions of moral history. And we need to understand how individual moral judgments--like Lincoln deliberating about the Emancipation Proclamation--manifest the peculiarities of individual agents in particular circumstances as constrained by universal moral nature and specific moral traditions. Occasionally, Hauser recognizes this, as when he remarks: "What we need is a better sense of what real people do in real situations in real cultures" (131). But, unfortunately, in this book, we rarely see real people in real situations in real cultures.

If Hauser had devoted more attention to real historical cases, he might have clarified how exactly the universal moral instincts constrain particular moral traditions and individual moral judgments. As it is, Hauser's book leaves us in a fog on this crucial point. This was the problem that Richard Rorty stressed in his review of Hauser's book in The New York Times.

Hauser's problem is Aristotle's problem: if there is a universal, natural standard of right, then why do judgments of right and wrong across individuals and societies show so much variation? The general answer is that this variation is not arbitrary or unlimited, because it shows recurrent patterns that manifest the universal propensities of the natural sense of justice. On the one hand, Hauser explains, the "Weak Rawlsian" would say that the human species has "the capacity to acquire morally relevant norms, but nature hasn't provided any of the relevant details" (298). On the other hand, the "Staunch Rawlsian" would say that human beings are "equipped with specific moral principles about helping and harming, genetically built into the brain and unalterable by culture." Against these two opposing extremes--cultural determinism and genetic determinism--Hauser looks for middle ground: "A Temperate Rawlsian is equipped with a suite of principles and parameters for building moral systems. These principles lack specific content, but operate over the causes and consequences of action. What gives these principles content is the local culture. Every newborn child could build a finite but large number of moral systems."

But by itself, this general answer provokes more questions than it answers. "A finite but large number of moral systems"? How large? What are the finite limits? Sometimes Hauser says the natural moral instinct sanctions only "a narrow range of possible moral systems" (420). At other times, he says it would support "any of the world's moral systems" (426). Does this mean that the universal moral grammar does not allow us to judge any specific moral system as better or worse than others? If so, then moral progress is impossible, because we have no ground for ranking moral systems. So would this mean that moral systems prohibiting slavery are no better or worse than moral systems favoring slavery?

What we need--and what Hauser does not provide--is Darwinian moral history. We need to apply the Darwinian explanation of morality to human history to see how exactly the logic of that explanation works in the complex interaction of moral nature, moral culture, and moral judgment.

Two possible examples are the cases of incest and slavery. Edward Westermarck's Darwinian account of the incest taboo is one of the best examples of Darwinian moral history, because we can see how an evolved natural propensity to avoid incest is diversely expressed in different cultures and different individuals. Although Hauser often mentions the Westermarck theory of incest, he never elaborates it as an example of how a natural moral sense constrains the moral diversity of cultures and individuals (22-23, 166, 199-200, 299, 301). A couple of my blog posts on incest can be found here and here.

I have commented on Abraham Lincoln and the slavery debate many times on this blog. In Chapter 7 of Darwinian Natural Right, I extend my argument for Darwinian natural right by applying it to the history of slavery. I begin with a comparison of ant slavery and human slavery, in which I argue that while slavery among ants and human beings manifests a natural inclination to exploitation, the uniquely human opposition to slavery shows a natural moral sense that resists exploitation. I then argue that throughout the history of the debate over slavery--from Aristotle to Hume, to Thomas Jefferson, to Charles Darwin, to Lincoln--one can see the natural moral sense expressed as a joint product of emotional capacities for feeling moral passions like sympathy and anger and rational capacities for judging moral principles like kinship and reciprocity.

Hauser looks forward to the development of a "science of morality," in which "inquiry into our moral nature will no longer be the proprietary province of the humanities and social sciences, but a shared journey with the natural sciences" (425). I agree with this aspiration towards a unification of knowledge--or "consilience" as Ed Wilson would call it--which would unite the natural sciences, the social sciences, and the humanities. Darwinian moral history would be an important part of this project. In a previous post, I have called this "Darwinian liberal education."

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