听Syd唠嗑: 07/2010

by Larry Arnhart

Libertarians need Charles Darwin. They need him because a Darwinian science of human evolution supports classical liberalism.

In his review of Darwin’s Origin of Species in 1860, Thomas Huxley declared, “every philosophical thinker hails it as a veritable Whitworth gun in the armory of liberalism.” The Whitworth gun was a new kind of breech-loading cannon — a powerful weapon, then, for liberalism.

In 1860, liberalism meant classical liberalism — the moral and political tradition of individual liberty understood as the right of individuals to be free from coercion so long as they respected the equal liberty of others. According to the liberals, the primary aim of government was to secure individual rights from force and fraud, which included enforcing laws of contract and private property. They thought the moral and intellectual character of human beings was properly formed not by governmental coercion, but in the natural and voluntary associations of civil society.

Although Darwin in his scientific writing was not as explicit as Herbert Spencer in affirming the evolutionary argument for liberalism, those like Huxley saw that Darwin’s science supported liberalism. Darwin himself was a fervent supporter of the Liberal Party and its liberal policies. He was honored when William Gladstone (the “Grand Old Man” of the Liberal Party) visited him at his home in Down in 1877.

Like other liberals, Darwin admired and practiced the virtues of self-help, as promoted in Samuel Smiles’ popular book Self-Help, with its stories of self-made men. Darwin was active in the charitable activities of his parish. He was the treasurer of the local Friendly Society. In Great Britain, friendly societies were self-governing associations of manual laborers who shared their resources and pledged to help one another in time of hardship. In this way, individuals could secure their social welfare and acquire good character through voluntary mutual aid without the need for governmental coercion.

Darwin was also active in the international campaign against slavery, one of the leading liberal causes of his day. In their recent book Darwin’s Sacred Cause, Adrian Desmond and James Moore have shown that Darwin’s hatred of slavery was one motivation for his writing The Descent of Man, in which he affirmed the universality of humanity as belonging to one species, against the pro-slavery racial science of those who argued that some human beings belonged to a separate species of natural slaves.

Also in The Descent of Man, Darwin showed that the moral order of human life arose through a natural moral sense as shaped by organic and cultural evolution. He thus provided a scientific basis for the moral liberalism of David Hume, Adam Smith, and the other Scottish philosophers, who argued that the moral and intellectual virtues could arise through the spontaneous orders of human nature and human culture.

Darwin and the Libertarians

One might expect that today’s libertarians — who continue the tradition of classical liberalism — would want to embrace Darwin and evolutionary science as sustaining their position.

But libertarians are ambivalent about Darwin and Darwinism. That ambivalence is evident, for example, in The Encyclopedia of Libertarianism, edited by Ronald Hamowy, under the sponsorship of the Cato Institute. There is no entry in the encyclopedia for Charles Darwin. But there are entries for Herbert Spencer, Social Darwinism, and Evolutionary Psychology. In these and other entries, one can see intimations that libertarianism could be rooted in a Darwinian science of human nature. But one can also see suggestions that Darwin’s science has little or no application to libertarian thought.

The entry on Evolutionary Psychology is written by Leda Cosmides and John Tooby, the founders of the research tradition that goes by the name of “evolutionary psychology.”
They indicate that evolutionary psychology was begun by Darwin. They say that its aim is to map human nature as rooted in the evolved architecture of the human mind. They summarize some of this evolved human nature, including reasoning about social exchange and cheater detection that provides the cognitive foundations of trade and the moral sentiments that make moral order possible. They contrast this idea of a universal human nature with the idea of the human mind as a blank slate that is infinitely malleable by social learning. They say that the false idea of the blank slate explains the failure of those experiments in social engineering that denied human nature, as illustrated by the failed communist regimes. This all suggests that a Darwinian evolutionary psychology could support a libertarian view of human nature.

But Cosmides and Tooby also cast doubt on this conclusion. Although the implementation of public policy proposals needs to take human nature into account, they say, “the position most central to libertarianism — that human relationships should be based on the voluntary consent of the individuals involved — makes few if any assumptions about human nature.” They don’t explain what they mean by this. One interpretation is that they are making a fact-value distinction, and suggesting that while the calculation of means to ends is a factual judgment that might be open to scientific research, the moral assessment of ends — such as the value of individual liberty — is a normative judgment that is beyond scientific research.

Perhaps their thought is more clearly stated by Will Wilkinson in his essay on “Capitalism and Human Nature”

We cannot expect to draw any straightforward positive political lessons from evolutionary psychology. It can tell us something about the kind of society that will tend not to work, and why. But it cannot tell us which of the feasible forms of society we ought to aspire to. We cannot, it turns out, infer the naturalness of capitalism from the manifest failure of communism to accommodate human nature. Nor should we be tempted to infer that natural is better. Foraging half-naked for nuts and berries is natural, while the New York Stock Exchange and open-heart surgery would boggle our ancestors’ minds.

Wilkinson argues that while our evolved human nature constrains the possibilities of social order, the historical move to liberal capitalism — the transition from personal to impersonal exchange — was a “great cultural leap,” as Friedrich Hayek emphasized. Within the limits set by evolved human nature, the emergence of liberal capitalism depends on cultural evolution. “We have, through culture, enhanced those traits that facilitate trust and cooperation, channeled our coalitional and status-seeking instincts toward productive uses, and built upon our natural suspicion of power to preserve our freedom.”

This dependence of classical liberalism on cultural evolution is also stressed by George Smith in his encyclopedia entries on Social Darwinism and Herbert Spencer. Smith argues that Spencer’s view of evolution was Lamarckian, and therefore quite different from Darwin’s view. While Spencer’s Lamarckian conception of evolution through the inheritance of acquired characteristics has been discredited as biological theory, Smith observes, this is actually a better approach for understanding social history than is Darwin’s biological approach. Social evolution — including the evolution of liberal capitalism — really is Lamarckian in that the social practices successful for one generation can be passed on to the next generation through social learning as a system of cultural inheritance. Most importantly for Spencer, the move from regimes of status based on coercive exploitation to regimes of contract based on voluntary cooperation was a process of cultural rather than biological evolution. Smith suggests, therefore, that the liberal principle of equal liberty arose not from biological nature but from cultural history.

Furthermore, Smith argues, Spencer and other classical liberals understood that market competition differed radically from biological competition. Biological competition is a zero-sum game where the survival of one organism is at the expense of others competing for the same scarce resources. But market competition is a positive-sum game where all the participants can gain from voluntary exchanges with one another. In a liberal society of free markets based on voluntary exchanges, success depends on persuasion rather than coercion, because we must give to others what they want to get what we want. Smith concludes: “It is precisely in a free society that Social Darwinism does not apply.”

There’s a big problem with Smith’s analysis. If Social Darwinism means explaining all social order through biological evolution based on zero-sum competition, then Darwin was not a Social Darwinist.

Darwin saw that social animals are naturally inclined to cooperate with one another for mutual benefit. Human social and moral order arises as an extension of this natural tendency to social cooperation based on kinship, mutuality, and reciprocity. Modern Darwinian study of the evolution of cooperation shows that such cooperation is a positive-sum game.

Moreover, Darwin accepted Lamarckian thinking about what he called “the inherited effects of the long-continued use or disuse of parts.” And he saw that the moral and social progress of human beings came much more through cultural evolution by social learning than biological evolution by natural selection. Darwin’s reasoning has been confirmed by recent research on gene-culture co-evolution. As Eva Jablonka and Marion Lamb have shown, a broad understanding of evolution must encompass four systems of evolutionary inheritance — genetic, epigenetic, behavioral, and symbolic.

Darwin’s liberalism combines an Aristotelian ethics of social virtue and a Lockean politics of individual liberty. This is the sort of liberalism that has been recently defended by Douglas Rasmussen and Douglas Den Uyl in their books Liberty and Nature and Norms of Liberty and by Den Uyl in his book The Virtue of Prudence.

To anyone who knows about my advocacy of “Darwinian conservatism,” it must seem odd that I am now arguing for “Darwinian liberalism.” But the conservatism I have defended is a liberal conservatism that combines a libertarian concern for liberty and a traditionalist concern for virtue. This is similar to the “fusionist” conservatism of Frank Meyer, which is close to the Aristotelian liberalism of Rasmussen and Den Uyl.

To see how Darwinian science supports classical liberalism, we must see how the liberal principles of equal liberty have arisen from the complex interaction of natural desires, cultural traditions, and individual judgments.

Natural Desires

If the good is the desirable, then a Darwinian science can help us understand the human good by showing us how our natural desires are rooted in our evolved human nature. In Darwinian Natural Right and Darwinian Conservatism, I have argued that there are at least 20 natural desires that are universally expressed in all human societies because they have been shaped by genetic evolution as natural propensities of the human species. Human beings generally desire a complete life, parental care, sexual identity, sexual mating, familial bonding, friendship, social status, justice as reciprocity, political rule, courage in war, health, beauty, property, speech, practical habituation, practical reasoning, practical arts, aesthetic pleasure, religious understanding, and intellectual understanding.

In Darwin’s writings on human evolution — particularly, The Descent of Man and The Expression of the Emotions in Man and Animals — he accounts for these 20 desires as part of human biological nature. We now have anthropological evidence — surveyed by Donald Brown and others — that there are hundreds of human universals, which are clustered around these 20 desires. Psychologists who study human motivation across diverse cultures recognize these desires as manifesting the basic motives for human action.

Rasmussen and Den Uyl identify the natural ends of human action as corresponding to a list of generic goods that resembles my list of 20 natural desires. Their list of generic goods includes health, beauty, wealth, honor, friendship, justice, artistic pursuits, and intellectual pursuits.

My assertion that the good is the desirable will provoke a complaint from some philosophers that I am overlooking the distinction between facts and values or is and ought. They will insist that we cannot infer moral values from natural facts. From the fact that we naturally desire something, they say, we cannot infer that it is morally good for us to desire it.

But I say that there is no merely factual desire separated from prescriptive desire, which would create the fact/value dichotomy. Whatever we desire we do so because we judge that it is truly desirable for us. If we discover that we are mistaken — because what we desire is not truly desirable for us — then we are already motivated to correct our mistake. Much of Darwin’s discussion of moral deliberation is about how human beings judge their desires in the light of their past experiences and future expectations as they strive for the harmonious satisfaction of their desires over a whole life, and much of this moral and intellectual deliberation turns on the experience of regret when human beings realize that they have yielded to a momentary desire that conflicts with their more enduring desires.

Whenever a moral philosopher tells us that we ought to do something, we can always ask, “Why?” The only ultimate answer to that question is because it’s desirable for you — it will fulfill you or make you happy by contributing to your human flourishing.

But even if we know what is generally or generically good for human beings, this does not tell us what is good for particular individuals in particular circumstances. Although the 20 natural desires constitute the universal goods of human life, the best organization or ranking of those desires over a whole life varies according to individual temperaments and social situations. So, for example, a philosophic life in which the natural desire for intellectual understanding ranks higher than other desires is best for Socrates and those like him, but not for others.

Evolutionary biology allows us to generalize about natural desires as the universals of evolved human nature. And yet evolutionary biology also teaches us that every individual organism is unique. After all, the Darwinian theory of evolution requires individual variation. Even identical twins are not really identical. Evolutionary biology also teaches us that human evolutionary adaptations enable flexible responses to the variable circumstances of the physical and social environment, which is why the human brain has evolved to respond flexibly to the unique life history of each individual.

If there is no single way of life that is best for all individuals in all circumstances, then the problem for any human community is how to organize social life so that individuals can pursue their diverse conceptions of happiness without coming into conflict. And since human beings are naturally social animals, their individual pursuit of happiness requires communal engagement. Allowing human beings to live together as children, parents, spouses, friends, associates, and citizens without imposing one determinate conception of the best way of life on all individuals is what Rasmussen and Den Uyl identify as “liberalism’s problem.”

Liberalism’s solution to this problem is to distinguish between the political order of the state as protecting individual liberty and the moral order of society as shaping virtuous character. While a liberal political community does not enforce one determinate conception of the human good, it does enforce procedural norms of peaceful conduct that secure the freedom of individuals to form families, social groups, and cooperative enterprises that manifest their diverse conceptions of the human good.

Cultural Traditions

Natural desires constrain but do not determine cultural traditions. If I am right about my list of 20 natural desires, this constitutes a universal standard for what is generally good for human beings by nature, and we can judge cultural traditions by how well they conform to these natural desires. So, for example, we can judge the utopian socialist traditions to be a failure, because their attempts to abolish private property and private families have frustrated some of the strongest desires of evolved human nature. We can also judge that political traditions of limited government that channel and check political ambition are adapted for satisfying the natural desire of dominant individuals for political rule, while also satisfying the natural desire of subordinate individuals to be free from exploitation. But cultural traditions like socialism and limited government arise as spontaneous orders of human cultural evolution that are not precisely determined by genetic nature or by individual judgment.

Recognizing that natural desires constrain but do not determine cultural traditions, Darwinian liberalism avoids the mistaken assumption of biological determinism that biology is everything, culture nothing, while also avoiding the mistaken assumption of cultural relativism that culture is everything, biology nothing.

The interaction of human nature and human culture is manifest in the cultivation of moral and intellectual character through the spontaneous order of civil society. Classical liberals believe that while we need the coercive powers of the state to secure those individual rights of liberty that are the conditions for a free society, we need the natural and voluntary associations of civil society to secure the moral order of our social life. The associations within civil society — families, churches, clubs, schools, fraternal societies, business organizations, and so on — allow us to pursue our diverse conceptions of the good life in cooperation with others who share our moral understanding.

Darwin showed how this moral order of civil society arises from the natural and cultural history of the human species. The need of human offspring for prolonged and intensive parental care favors the moral emotions of familial bonding, and thus people tend to cooperate with their kin. The evolutionary advantages of mutual aid favor moral emotions sustaining mutual cooperation. And the benefits of reciprocal exchange favors moral emotions sustaining a sense of reciprocity, because one is more likely to be helped by others if one has helped others in the past and has the reputation for being helpful. “Ultimately,” Darwin concluded, “our moral sense or conscience becomes a highly complex sentiment — originating in the social instincts, largely guided by the approbation of our fellow-men, ruled by reason, self-interest, and in later times by deep religious feelings, and confirmed by instruction and habit.” Recent research in evolutionary psychology has confirmed and deepened this Darwinian understanding of moral order that arises in civil society through the spontaneous order of human action rather than the coercive order of governmental design.

Individual Judgments

Natural desires and cultural traditions constrain but do not determine individual judgments. Classical liberals recognize that the human good or flourishing is complex in conforming to the natural ends, the cultural circumstances, and the individual choices of human life. Our shared human nature gives us a universal range of natural desires that constitute the generic goods of life. Our diverse human cultures give us a multiplicity of moral traditions that shape our social life. But ultimately, individuals must choose a way of life that they judge as best conforming to their natural desires, social circumstances, and individual temperaments. For that reason, liberals believe that the fundamental human right is liberty of judgment or conscience.

Darwinian moral psychology explains the evolutionary history of the human capacity for individual moral judgment. Most recently, neuroscience has begun to uncover the emotional, social, and cognitive capacities of the brain that make moral judgment possible. For example, while Darwin explained the evolutionary importance of sympathy for human moral experience, contemporary neuroscientists have studied the “mirror neurons” in human beings and other primates that allow animals to imaginatively project themselves into the experiences of other individuals.

Created from Animals

I have argued that Darwinian science is compatible with a classical liberal understanding of how moral order in a free society arises from natural desires, cultural traditions, and individual judgments. But does Darwinism make any unique contribution to liberal thought — something that could not have been derived from the moral and political thought of liberalism without the help of Darwinian science?

Yes, I think it does. Evolution provides a purely naturalistic grounding for liberal thought, so that there is no necessity to appeal to the supernatural. That’s important, because if liberal thought required supernatural beliefs, this might seem to require a coercive enforcement of those supernatural beliefs, which would subvert the individual liberty of conscience.

From Locke’s Two Treatises of Government to Jefferson’s Declaration of Independence to Spencer’s Social Statics, liberal thought has justified equal liberty as an expression of the unique dignity that human beings have as created in God’s image. For Locke, our natural desires give rise to natural rights because they have been implanted in us by God, and we are all naturally equal in our rights to life, liberty, and property, because we are all “the Workmanship of one Omnipotent and infinitely wise Maker.” For Jefferson, looking to the “Laws of Nature and of Nature’s God,” we can hold it to be self-evident “that all men are created equal” and that “they are endowed by their Creator with certain unalienable Rights.” For Spencer, since God wills human happiness, He also wills that human beings should have equal liberty as the condition for satisfying their desires.

If liberalism requires such religious beliefs, then the liberal doctrine of religious toleration cannot include tolerating atheists. This was Locke’s conclusion, because he warned that denying the existence of God as the Creator of human beings and of the moral law dissolved the moral bonds of human society.

Darwin offered an alternative. In one of his early notebooks, he wrote that “man in his arrogance thinks himself a great work, worthy of the interposition of a deity, more humble, and I believe true, to consider him created from animals.” Although scientists and philosophers had long speculated on the possibility of a purely natural evolution of life, Darwin was one of the first thinkers to lay out a rigorous theory of how this could have happened, which included an evolutionary theory of the natural moral sense.

In his review of The Origin of Species, Huxley explained that Darwin’s book was a great weapon for liberalism because it refuted the Biblical doctrine of “special creation.” To protect liberty of thought from coercive theocratic authority, liberals needed to explain all of nature, including human nature, as the product of purely natural causes.

And yet, despite the claims of some of its religious opponents, Darwinism does not dictate atheism. Although Darwin by the end of his life was an agnostic, he recognized that religious beliefs were often important for the cultural evolution of morality. Recently, evolutionary theorists such as David Sloan Wilson have shown how the evolution of religion through group selection can strengthen the cooperative moral dispositions of religious believers.

But even without religion, Darwin suggested, believing that we were “created from animals,” we can see that moral order stands on purely human grounds—human nature, human tradition, and human judgment.

That’s why libertarians need Charles Darwin.