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Darwin Meets Socrates

Steve Stewart-Williams on the implications of evolutionary theory for ethics.

“Morality is a collective illusion of the genes. We need to believe in morality, and so, thanks to our biology, we do believe in morality. There is no foundation ‘out there’ beyond human nature.” Michael Ruse, Evolutionary Naturalism: Selected Essays, 1995, p.250

Since its birth, Darwin’s theory of evolution has been uniquely controversial. It is not that the accuracy of the theory is in any doubt among biologists. On the contrary, it is one of the best-established theories in science. Outside the scientific arena, however, the theory seems to have a unique ability to inflame passions and provoke debate. One particularly heated area of debate concerns the impact of evolutionary theory for ethics. Some flatly deny that the theory has any relevance to ethical discourse, a view they support with arguments that values cannot be derived from facts. Others disagree, but among this group there is no consensus about what the moral implications of evolution are (surprise, surprise). Some have argued that the theory supports right wing social and economic policies. Another view is that we must recalibrate our values in the wake of evolutionary theory, and rethink the value we place on the lives of human beings versus other animals. Others draw a darker conclusion, and suggest that the truth of evolutionary theory undermines morality altogether. In the following pages, I will look at each of these views in turn.

Evolutionary Theory is Irrelevant to Ethics

The first view to consider is that evolutionary theory simply has no moral implications. This view has probably been motivated in part by some of the unpopular conclusions that have been drawn from the theory in the past. For instance, the Social Darwinists, whose position I will consider more carefully in the next section, argued that Darwin’s theory implied that society should be run according to laissez faire principles, and that the provision of aid to the weak, sick, and poor goes against nature. For those who wish to reject such a view, several options are available. One is to reject the truth of evolutionary theory. A more reasonable alternative is to argue that evolutionary theory does not have the ethical implications that are claimed. And one way to do this is to argue that evolutionary theory has no ethical implications whatsoever.

This position is commonly met, and is typically backed up with the suggestion that ethical systems derived from evolutionary theory commit an error of reasoning known as the naturalistic fallacy. More than a century before Darwin unveiled his theory, David Hume had pointed out that, in moral discourse, people often begin by making factual assertions (is statements), but then somewhere along the line quietly shift to making evaluative or normative assertions (ought statements). However, the leap from factual premises to evaluative conclusions is not deductively valid. Consider this argument:

• Efforts to aid the weak, sick, or poor go against nature.
Therefore, we ought not to aid the weak, sick, or poor.

The premise does not entail the conclusion, for the conclusion contains an element not present in the premise – the word ought. Thus, even if the premise were true, the argument is not valid and so fails to establish its conclusion. As Hume noted, no collection of solely factual premises could entail any moral conclusion. This principle, known as Hume’s law, may tempt us to assume that the fact of evolution can have no bearing on ethical issues, and that factual and ethical reasoning are completely independent domains of thought. However, Hume’s law does not in fact have this implication. The simple argument above is obviously invalid, but this could easily be remedied by including additional premises that would justify the leap from is to ought. (After all, it is possible in principle to construct a deductively valid argument from any premise to any conclusion, given the appropriate intervening premises.) For instance:

• We ought not to go against nature.
• Efforts to aid the weak, sick, or poor go against nature.
Therefore, we ought not to aid the weak, sick, or poor.

The argument is now deductively valid, and thus if the premises are true, the conclusion must also be true. Furthermore, the new premise is one that many would accept. It is commonly heard, for instance, in arguments against genetic engineering. In the next section, I will suggest that arguments such as these rest on false assumptions about evolutionary theory. Our concern for the moment, though, is the more general point that Hume’s law does not rule out the possibility that is statements can inform ought statements, as long as the former are conjoined with premises that are also ought statements. What it does show is that ultimate ethical statements (ethical statements that are not implications of other, more general ethical statements) cannot be derived from solely factual premises. Therefore, although ultimate ethical values cannot be read straight from the facts of evolution, this does not rule out the possibility that these facts could figure in our moral reasoning.

Social Darwinism

Having established this point, I can now consider what ethical implications evolutionary theory might have. To begin with, I will consider a notorious answer to this question: that associated with the Social Darwinist movement of the late nineteenth and early twentieth centuries. Actually, Social Darwinism was not so much an organized movement as a trend of thought only identified and named in retrospect. As the name suggests, it involved applying (supposed) Darwinian principles to society. The Social Darwinists believed that society should be organised according to the principle of the survival of the fittest, and thus advocated laissez faire economic and social policies. Some capitalists found moral support for an unrestrained free market in Darwin’s theory. According to John D. Rockefeller, for instance, “the growth of a large business is merely a survival of the fittest…. This is not an evil tendency in business. It is merely the working out of a law of Nature”. And as I have already noted, the Social Darwinists viewed efforts to aid the weak, sick, and poor as undesirable. To be fair, some of the more eloquent Social Darwinists, such as the philosopher Herbert Spencer, did not use Darwin’s theory solely to justify ruthless social and economic practices. Nonetheless, it is those conclusions that have unjustly tarnished evolutionary theory by association, and therefore it is with those conclusions we will wrestle.

Based on Hume’s law, we can reject any Social Darwinist argument that proceeds from is statements directly to ought statements. However, this only rules out a certain class of arguments. It does not show the falsity of Social Darwinist conclusions. So let’s consider on what grounds it might be argued that society should be organised according to the principle of the survival of the fittest. One approach would be to argue that it is the way of nature and the way of nature is good. This ties in with the premise discussed earlier that we should not go against nature, and basically treats the survival of the fittest as a good thing in itself. An alternative approach would be to argue that it is a means to other ends. The Social Darwinists were impressed with the idea that evolution produces ongoing progress, and believed the crucial ingredient producing this progress is the survival of the fittest. They could thus argue that the survival of the fittest simply provides the means to ends that, quite independently of evolution, we consider good. On this view, state interference and social welfare are undesirable not because they go against the way of nature, but because the way of nature produces progress, and efforts to constrain the market or to aid the needy prevent progress.

Of course, we may wish to ask whether the means justify the ends. However, there are more fundamental problems with these ideas. Social Darwinist thought is based on several misunderstandings of evolutionary theory. For a start, the phrase survival of the fittest is somewhat misleading. (Note that the phrase was introduced not by Darwin but by Spencer.) Evolutionary history is not simply a Hobbesian war of all against all. There is plenty of warring and competitiveness in nature, but selection can also produce cooperation and even limited altruism among organisms. (In biological terms, altruism is defined as any action that advantages another organism at the altruist’s expense, as distinct from cooperation, which benefits all involved parties.) Thus, such tendencies are not necessarily going against nature. This is the Social Darwinist’s first misunderstanding.

According to many modern evolutionary theorists, it is only at the level of the gene that nature always and inevitably operates according to principles analogous to those the Social Darwinist favours. The only genes that survive are those whose contribution to the phenotype results in them being copied at a greater rate than other versions of the same genes. Genes often ‘cooperate’ with one another (for example, to build coherent organisms that will preserve and propagate them), but they do so only if this is in their own ‘interests’. There is no altruism among genes, and there is no gene equivalent of social welfare. In order to salvage his position, the Social Darwinist would have to maintain the (rather peculiar) view that human societies should mimic the conditions of gene selection. But to establish such a social system, we would have to suppress our natural altruistic tendencies, and artificially emphasize our natural selfish and competitive tendencies. Consequently, to pursue this line of argument, the Social Darwinist would have to let go of the view that we should follow the way of nature.

That would leave only the argument that selection produces progress. But this idea represents another significant misunderstanding of Darwin’s theory. Evolution is not synonymous with progress. First, evolution is not a matter of ongoing betterment. As the environment changes, the criteria for goodness of design change with it. More important, selection favours any trait that increases the likelihood that the genes contributing to it will be copied, regardless of whether we consider it good or desirable in any sense. Although gene selection accounts for some things we consider good, such as altruism, it also accounts for plenty we consider bad. As a result, there is no reason to think that the selective principles that operate among genes would necessarily lead to the betterment of society or an increase in the sum total of happiness, and consequently no reason to accept that society should be run according to these principles. These considerations undermine the Social Darwinist viewpoint, and show that there is no necessary connection between evolutionary theory and laissez faire social policies. In fact, if anything, the suffering constitutive of natural selection could support an argument against such policies.

Rethinking our Ethical Commitments

Social Darwinism represents a failed attempt to derive ethical implications from evolutionary theory. In this section, I will consider another attempt, one consistent with a more sophisticated understanding of evolution. This was presented by James Rachels in his 1990 book Created From Animals: The Moral Implications of Darwinism. Rachels identified an important trend in traditional Western morality, which he called the doctrine of human dignity. According to this trend of thought, human life has a supreme value whereas the lives of animals may be sacrificed for our purposes – as Kant put it, human beings are an end in themselves whereas animals are merely a means to our ends. Although the Darwinian worldview does not directly contradict this position, it does undermine the foundations upon which it rests, and the worldview within which it makes sense. The doctrine of human dignity has its roots in the pre-Darwinian anthropocentric view of the universe, and is supported by such beliefs as that human beings alone are made in God’s image, and that reason distinguishes us from other animals in some significant way. But evolutionary theory challenges these views. First, given that the raw materials with which selection works are a product of random mutations, and that evolutionary history is shaped by capricious and unpredictable events, it is difficult to maintain that human beings are created in God’s image or in accordance with any pre-existing design. Furthermore, the evolutionary perspective challenges the view that we are distinguished in some important way by our possession of reason. Reason is simply one adaptation among many, and we are one animal among many.

Viewed in this light, the idea that human life is infinitely valuable begins to look like a vast and unjustified overvaluation of human life. According to Rachels, this suggestion has important implications for a number of issues in applied ethics. If human life is not supremely valuable after all, there is no reason to assume that the duty to preserve human life always takes precedence over other considerations, such as human happiness. So, for instance, suicide and voluntary euthanasia are no longer ruled out as absolute evils. If they are good for the individual, it is difficult to maintain that they are necessarily wrong under any circumstance.

A second set of implications relates to the moral status of nonhuman animals. Evolutionary theory stresses our kinship with other animals, and undermines the idea that our species is the pinnacle of evolutionary progress, except when judged against arbitrary and self-chosen criteria. It also lowers our confidence in Descartes’ idea that nonhuman animals are nonconscious automata; after all we are conscious beings (conscious automata perhaps), and we came about through the same process as every other animal. As such, we cannot ignore the possibility that other animals experience pain and suffer, just as humans do. These considerations support the claims of ethicists who hold that we have undervalued the lives of other animals. If such views are taken seriously, they have important implications. The bio-ethicist, Peter Singer, argues that when we accord nonhuman animals the moral standing they deserve, we recognise that prejudice against other species is as objectionable as any other form of prejudice, including racism and sexism. Moreover, he argues that the amount of suffering and pain caused by the tyranny of human beings over other animals (particularly in food production and experimentation) far outweighs that caused by sexism, racism, or any other existing form of discrimination, and thus that the animal liberation movement is the most important liberation movement in the world today. Such suggestions, although they are not logically necessary conclusions of evolutionary theory, would be virtually unthinkable from a pre-Darwinian standpoint.

Evolutionary Theory & the Death of Right and Wrong

The ethical conclusions I have outlined were informed by facts about evolution. However, implicit in the arguments were some more general ethical principles that were not derived from evolutionary theory – for instance, that we should value any life form in proportion to its capacity to suffer. Thus, the discussion was consistent with the earlier conclusion that, although facts can inform ethical decisions, they cannot entail ultimate ethical principles. But this leaves us with a difficult question: How do we arrive at ultimate ethical principles? How do we gain knowledge of moral truths? Many answers to this question have been proposed. Some people maintain that we know moral truths through a mysterious faculty of intuition. Another popular answer is linked to the idea that science and religion have distinct and non-overlapping domains. The suggestion is that science is limited to providing empirical knowledge, whereas it is the role of religion to provide knowledge of moral truths. The position to be explored in this section is that all and any such suggestions must be rejected in light of evolutionary theory. The argument is not with the idea that science can only directly uncover empirical knowledge – no one imagines that there could ever be an experimental procedure that would detect the rightness or wrongness of an action or intention. The argument is that, rather than religion or intuition providing us with knowledge of moral truths, knowledge of moral truths is simply not possible, for there are no moral truths. This view should not be confused with ethical relativism, which is, in effect, the view that all moral beliefs are true, at least within the culture in which they are held. The position under discussion is ethical nihilism, the view that all moral beliefs are false.

Evolutionary theory supports moral nihilism in a number of ways. First, many hold that the existence of moral truths depends on the existence of God. As Dostoyevsky stated, “If God does not exist, then everything is permitted” – in other words, nothing is right or wrong. Although the truth of evolutionary theory is not incompatible with the existence of God, it does weaken the case for God. Prior to Darwin, the design exhibited in life forms was viewed as some of the best evidence for a creator. However, Darwin’s theory provided a naturalistic explanation for this design. Furthermore, natural selection is a cruel and wasteful process, which raises the problem of evil as an argument against God’s existence. So, if Dostoyevsky was right, then to the extent that evolutionary theory undermines God’s existence, it also undermines morality. Second, promising evolutionary explanations have been proposed for some of our basic moral inclinations and feelings. For instance, according to Robert Triver’s theory of reciprocal altruism, many of our basic moral impulses were crafted by natural selection to facilitate mutually cooperative relationships, and to avoid being exploited in such arrangements. According to some philosophers, such results reveal that our moral beliefs are illusions, held not because they are true but because they are biologically useful in regulating the social life of a highly social animal.

As with earlier examples, the truth of evolutionary theory does not entail the conclusion that there are no objective moral truths, and some have argued against this conclusion. Many ethicists have noted that the existence of moral truths is not logically dependent on the existence of God. Similarly, even if our moral nature has an evolutionary basis, it might be that it meshes with an objective moral order, just as physical adaptations mesh with the physical environment of the organism. In other words, the existence of objective moral truths is still a logical possibility. Nonetheless, if this is all that can be said in support of such truths, people could be forgiven for remaining unconvinced. After all, it is equally a logical possibility that there are no moral truths. In addition, even if there are moral truths, evolutionary theory poses another challenge to morality. On a materialist Darwinian perspective, the mind is the activity of an evolved brain, and consequently could not survive the death of the body any more than could the beating of the heart. But if there is no life after death then there could be no final balancing of the scales of justice in an afterlife or future incarnation. This raises the salience of a pivotal question in moral philosophy: Why be moral?

Some may find these suggestions frightening, and perhaps this an appropriate reaction. Then again, maybe it is not. For it is certainly possible to frame an ethic consistent with the Darwinian view of the world. Such an ethic might emphasize the virtue of being honest and courageous enough to acknowledge unflinchingly that there is no objective basis to morality, that there is no higher purpose behind our suffering, that we are insignificant in a vast and impersonal universe, that existence is ultimately without purpose or meaning, and that the effects of our actions will ultimately fade away without trace. We would acknowledge all this but struggle on as if life were meaningful and strive to make the world a better place anyway, without any expectation of ultimate victory, eternal reward, or good karma, and indeed for no good reason at all. Of course, nothing can be said to argue that people are morally obliged to accept this ethic, for to do so would be inconsistent with the very ideas that prompted it in the first place. It is an ethic that will be adopted, if it all, by those who find a certain stark beauty in kindness without reward, joy without purpose, and progress without lasting achievement.


Steve Stewart-Williams is a Lecturer at the School of Psychology at Massey University in New Zealand. His research interests include the placebo effect, the implications of evolutionary psychology for philosophy, and the evolution of mating preferences. He likes cheese.

Further Reading:

Dawkins, R. (1989). The Selfish Gene (2nd ed.). Oxford Univ. Press.
Rachels, J. (1990). Created from Animals: The moral implications of Darwinism. Oxford Univ. Press.
Richards, J.R. (2000). Human Nature after Darwin: A philosophical introduction. Routledge.
Singer, P. (1990). Animal Liberation (2nd ed.). Jonathon Cape.

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