The Decent of Man In a phrase made famous by Charles Darwin, life is a “struggle for existence.” But if evolutionary success depends on competition, then it may seem difficult to explain how altruism, cooperation, and morality could have developed naturally. Biologists have long tried to resolve this apparent paradox, and recent work has shown that altruism and cooperation are in fact critical to success in nature — that we also see, in a phrase coined by Martin Nowak and Roger Highfield, that life is a “snuggle for existence.” Questions about the origins of human nature, including of our social and moral nature, are inevitably knotty, and disentangling them requires the efforts of scholars across many disciplines. The essays in this special section explore the implications of evolutionary biology, culture, and philosophy for our understanding of human cooperation and morality. Philosopher of science Michael Ruse (here) shows what evolution means for ethics, and biologist Kevin N. Laland explains how humans became the most cooperative species on earth. Publication of this special section was made possible through the support of a grant to The New Atlantis from the John Templeton Foundation; the opinions expressed are those of the authors and do not necessarily reflect the views of the John Templeton Foundation.

Darwin Made Me Do It

Michael Ruse

For the first hundred years after Darwin published his On the Origin of Species in 1859, most Anglophone philosophers didn’t think very highly of evolutionary ethics — the attempt to explain and justify moral feelings and behaviors on the basis of our simian (and pre-simian) past. Thus in the inaugural issue of the journal Mind, in 1876, we find the noted utilitarian philosopher Henry Sidgwick arguing that evolutionary theory is “ethically superfluous, whatever historical interest it may have.” His student G. E. Moore, in his argument about the “naturalistic fallacy,” famously attacked attempts to define “good” on the basis of some other property, like pleasure or desire — including, that is, on the basis of evolutionary progress. And, in turn, Moore’s student C. D. Broad wrote in 1944 that he was “unable to see” that evolutionary theory “has any direct bearing on the question whether certain states of affairs or processes or experiences would be intrinsically good or bad.”

In a way, this is all a little bit odd, because everyone recognized that the world after Darwin was very different from the world before Darwin. Surely, therefore, evolutionary theory in general and Darwin’s theory of evolution through natural selection in particular was going to have some major implications for how we think about right and wrong. And yet, not so: for various reasons (as discussed in Suzanne Cunningham’s 1996 book Philosophy and the Darwinian Legacy), evolutionary theory was of little interest to the philosophers, at least until recent decades. Still, some readers may be uncomfortable with the idea of deriving ethics from evolutionary processes — rather than, say, from divine decree or natural law or universal rational principles — but I hope to show here that a positive case for evolutionary ethics can be made. Although this type of ethics will not be objective in any absolute or transcendent sense, this lack of objectivity doesn’t mean that anything goes.

A Science of “Altruism”

The main task for evolutionary ethics is getting over Hume’s notorious is/ought distinction (the precursor to G. E. Moore’s naturalistic fallacy) that claims that you cannot derive matters of value from matters of fact. I see two different approaches to the problem.

One approach is simply to deny or downgrade the is/ought distinction. This is the way taken by such thinkers as Robert J. Richards, and it can also be found in Herbert Spencer and then later in Julian Huxley — the biologist grandson of Thomas Henry Huxley and older brother of the writer Aldous Huxley — and E. O. Wilson. They argued that the world itself has value — not just that the forests and the fish in the ocean are valuable to humans, but that value is intrinsic to the very mountains and lakes and seas — and so almost expectedly human values emerge through the evolutionary process. It is a view going as far back as Plato (in the Timaeus), appearing also in the German Romantics, Rachel Carson’s Silent Spring, and more recently in James Lovelock’s Gaia hypothesis. I suspect that nine-tenths of my fellow members of the Sierra Club subscribe to it. And although I do not myself accept it, I no longer think it silly or necessarily philosophically crude. A case can be made, is made very ably by Richards and like thinkers. The most beautiful place in the world is Stellenbosch, in the wine growing area of western South Africa. If a mining company came in and ripped off the tops of the mountains, I would be the first to decry them — so I might seem to regard the world as having value in its own right. But if a company put up yet another ugly factory building in Gary, Indiana, I doubt I would care at all. This rather suggests to me that I am reading my values into the world, rather than finding them there.

The other approach is to accept fully the is/ought distinction but to do an end run around it by showing that the evolution of human beings has given us traits that we value, most notably altruism. If I say that this is the position found in Darwin, that is really only a half-truth because I don’t think that Darwin was interested in the problems of philosophers, particularly those of justification — of whether we ought to believe certain things, such as a given moral principle, to be correct — but it is at least a half-truth because the position does depend heavily on Darwin’s thinking, especially that of The Descent of Man (1871). Hints can be found in the works of later writers, particularly those of the paleontologist George Gaylord Simpson, and then later the philosopher (and my fellow student at the University of Rochester) Jeffrey Murphy. I think J. L. Mackie was going in the same direction. I myself set out as a fervent disciple of Moore, believing that there is a total barrier between factual statements and value statements. This was the position I articulated in Sociobiology: Sense or Nonsense? (1979). However, a review of that book by Mackie — gratifyingly favorable to a totally unknown philosopher, but taking me to task on biology and morality — set me thinking in new ways. Taking advantage of the fact that I was unknown and hence had no reputation to lose, I announced my new position in a 1986 article in the science and religion journal Zygon and then in the book Taking Darwin Seriously: A Naturalistic Approach to Philosophy (1986).

My argument for evolutionary ethics is simple. From Darwin on it has been virtually a truism that evolution by natural selection promotes “altruism.” The Darwinian reasoning goes like this: the key to evolutionary success is adaptation — the development of features that help their possessors to survive and reproduce — and behavioral features are as important as physical features. While at times strife and combat may be good adaptive strategies, cooperation also often pays major dividends. Half a cake is less than the whole cake but better than no cake at all. It is worth noting that the 1960s saw an explosion of interest among evolutionary biologists (all Darwinians) in social behavior, resulting in the devising of a number of powerful models to explain “altruism.” These included “reciprocal altruism” — you scratch my back and I’ll scratch yours — an idea with roots in The Descent of Man, and “kin selection” — helping relatives helps you at least vicariously via the success of your own shared genes, an idea not found in Darwin because it requires understanding modern Mendelian genetics.

I put “altruism” in quotes, because this is not necessarily literal, Mother Teresa altruism, wherein people consciously try to do the right thing. In evolutionary biology, altruism extends to all social behavior that benefits others, and indeed the paradigm examples are the hymenoptera — the ants, the bees, and the wasps — and no one thinks these creatures to be reflective. However, evolutionary biologists argue that genuine, conscious altruism is something promoted by natural selection to make us humans good “altruists.” As Darwin writes in The Descent of Man:

It must not be forgotten that although a high standard of morality gives but a slight or no advantage to each individual man and his children over the other men of the same tribe, yet that an advancement in the standard of morality and an increase in the number of well-endowed men will certainly give an immense advantage to one tribe over another.

Therefore, he continues:

There can be no doubt that a tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to give aid to each other and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection.

And so it follows that:

At all times throughout the world tribes have supplanted other tribes; and as morality is one element in their success, the standard of morality and the number of well-endowed men will thus everywhere tend to rise and increase.

So much for the basic science. I want now to turn to the philosophical questions, which, in the spirit of Philosophy 101, I take to be two. First, there is the question of substantive or normative ethics: What should I do? Second, there is the question of metaethics: Why should I do what I should do?

What Should I Do?

It is often believed that traditional evolutionary ethics, the so-called Social Darwinism, promotes attitudes favorable to warfare and extreme laissez-faire economics — “widows and children to the wall and let the robber barons take all.” But although there are certainly instances of such writing, and although the Social Darwinism of the late nineteenth century was linked in complicated ways to the eugenics movement of the early twentieth, many of the moral prescriptions of the Social Darwinists were inclined toward cooperation and helpfulness. Among the robber barons, John D. Rockefeller gave huge amounts of money to the fledgling University of Chicago and Andrew Carnegie supported public libraries, where the poor but gifted child could go and learn. In any case, traditional evolutionary ethicists tend to fall more into the camp of Herbert Spencer, where what evolves is bound to have value, and so if there is a harshness to the prescriptions, it is thought that this is simply being realistic about what is possible, given human nature. No one is really saying that you should be unkind to widows and children, but consider (for example) the incentives of government assistance programs: Yes, it is harsh to deny a single mother extra welfare beyond her fifth child, but it is not good for her, not good for the children, not good for society, if she simply goes on having more and more children who are bound to suffer emotionally and materially. There are times when you need to use sticks rather than carrots.

The more Darwinian approach is basically one of common-sense morality — help others, avoid cheating, and so forth. Widows and children deserve more attention and help than prosperous businessmen. Interestingly, the most influential American ethicist of the second half of the twentieth century, John Rawls, picked up on evolutionary biology and suggested that his position is one that emerges from the evolutionary process. In A Theory of Justice (1971) he argues for an understanding of “justice as fairness,” and to achieve fairness he invites us to put ourselves behind a “veil of ignorance” behind which we would not know where we stood in society. If we knew we were going to be healthy, white females, then we would promote the well-being of healthy, white females, but it might be that we are sickly, black males. The fair society is the one that maximizes the benefits for all, especially for those who are the least advantaged. This does not necessarily lead to equality — a fairer society might well be one where we pay our football coaches ten times what we pay our university presidents — but it is one where all benefit in some sense as much as possible. Rawls thought that it was most unlikely that a historical group of elders actually set up such a social contract, but he thought it likely that natural selection working on the genes might have done such a job.

In arguing for the greater stability of the principles of justice I have assumed that certain psychological laws are true, or approximately so.... [O]ne might ask how it is that human beings have acquired a nature described by these psychological principles. The theory of evolution would suggest that it is the outcome of natural selection; the capacity for a sense of justice and the moral feelings is an adaptation of mankind to its place in nature. As ethologists maintain, the behavior patterns of a species, and the psychological mechanisms of their acquisition, are just as much its characteristics as are the distinctive features of its bodily structures; and these patterns of behavior have an evolution exactly as organs and bones do. It seems clear that for members of a species which lives in stable social groups, the ability to comply with fair cooperative arrangements and to develop the sentiments necessary to support them is highly advantageous, especially when individuals have a long life and are dependent on one another. These conditions guarantee innumerable occasions when mutual justice consistently adhered to is beneficial to all parties.

Rawls only went so far with Darwin. Here he was writing about the origin of morality. He was still writing about substantive ethics. When it came to the justification of morality — metaethics — he pulled back. “These remarks are not intended as justifying reasons for the contract view.”

Does this kind of naturalistic approach to substantive ethics make everything somewhat relative? The answer is yes and no. In an importance sense, substantive ethics is very much a function of human nature, which means that if human nature were other than it is, ethics would be other than it is. Darwin put his finger on exactly this point:

If, for instance, to take an extreme case, men were reared under precisely the same conditions as hive-bees, there can hardly be a doubt that our unmarried females would, like the worker-bees, think it a sacred duty to kill their brothers, and mothers would strive to kill their fertile daughters; and no one would think of interfering.... The one course ought to have been followed: the one would have been right and the other wrong.

I don’t see this as much cause for concern or regret — although relativized in a sense, moral norms are still norms. This is simply what you get with a naturalistic ethics, including, let us note, natural law ethics, which tries to reason about human morality on the basis of the given natural order. If human sexual organs were other than they are, then natural law arguments about sexual ethics would be very different than they are. Keep in mind that there are all sorts of weird cases of reproduction in nature, for instance the Amazon molly, an all-female species of fish that needs to mate with males of other species.

Again, this doesn’t mean that you can just do what you want to do, that if it feels okay, then it is okay. The whole point about cooperation is that everyone has to be in it together; otherwise it doesn’t work. It is the same as with language. Because I come from the English middle classes, I speak English better than anyone else — with the possible exception of the royal family. But living where I do in the American South, it frequently doesn’t do me much good because people cannot understand a word of what I am saying. So I have to slow down and start again. There has to be some basic equivalence, whether in language or in morality. It may all be subjective but it cannot be completely relative.

Does this mean that taking (what I am calling) a Darwinian approach to substantive ethics makes no big difference to what we already believe or claim about morality? Here are three points to think about. First, some ethicists — Peter Singer springs to mind — argue that we have equal obligations to all, and some would even extend this to non-humans. Darwinians would certainly never say we have no obligations to any and all humans, and perhaps even some non-humans, but there would be differentials. You are surely going to feel stronger obligations to family and then to friends and acquaintances and only finally to strangers. Good Samaritans are to be praised, but (if I may mix parables) the feelings of the father toward the prodigal son are primary. This is not a new insight of Darwinism. Although I do not think him an evolutionist, it is right there in Hume, over a century before The Origin of Species:

A man naturally loves his children better than his nephews, his nephews better than his cousins, his cousins better than strangers, where every thing else is equal. Hence arise our common measures of duty, in preferring the one to the other. Our sense of duty always follows the common and natural course of our passions.

Nor is it a sentiment confined only to non-believers. In Bleak House (1853), Charles Dickens — a Christian, even if not entirely conventional in his beliefs — makes a similar point. He is totally scornful of the philanthropist Mrs. Jellyby, who devotes all of her attention to the well-being of an African tribe while ignoring the needs of her own daughter and husband, not to mention the needy members of her own society, notably Jo the crossing sweeper. A Darwinian approach to ethics would affirm our general sense that obligations to kin are greater than to strangers.

Second, I do not expect to find that substantive ethics always works in a totally rational fashion. The name of the Darwinian game is being better than the competitors, not being perfect in some absolute sense. I fully expect to find tensions, especially with the kinds of artificial cases so beloved of philosophers. Suppose you are a prisoner of war in Nazi Germany faced with the dilemma of bribing a guard to be able to escape. On the one hand, you have vital information needed by the allies. Utilitarianism suggests bribing the guard. On the other hand, Kantianism deplores the way in which you are using the guard as a means to your ends, and therefore forbids bribery. Generations of philosophy students have sweated over how best to answer this paradox. My sense is that the substantive ethics that can be discerned from our evolved biology approves of maximizing happiness and also approves of treating people as worthwhile in their own right. Generally, these do not come into conflict. By and large, most of us do not spend our days in prison camps or worrying about the morality of corrupting guards. Ordinary actions, such as when I help a student with a paper, both maximize the happiness of the participants and involve them treating one another as persons. But sometimes there are conflicts and we just have to live with that. And often when we do face complex moral problems, it is because the circumstances are complex, not the morality. If I were a physician, I should save life when I can; morally that’s straightforward, but complications often arise in coming up with the right course of treatment.

I suspect that other notorious paradoxes are open to a similar robust dismissal. To offer a famous example, the trolley problem — where we might happily pull a switch to save six people over one but would not throw the one on the tracks to save the six — seems to me to be such a case. Formally the two situations are the same. It is just that our biology makes us easier about pulling switches because they are not part of our evolutionary past. Not being mean to neighbors, even when the end result might be better if we are, is part of our biology. Too often, the ends turn out anyway not to be quite what we thought they might be. So there just isn’t a definitive rational solution. It is more a matter of muddling through, which has obviously on average worked pretty well in the past. Darwinian substantive ethics, then, helps to deal with some of the cliché conflicts between existing ethical systems, by showing that they mostly don’t matter very much and that rigid rationality is not necessarily what is needed for moral behavior.

The third point, however, is that Darwinian ethics really ought to make some difference to our moral understanding. Keen to stress the respectability of Darwinian ethics, for many years I downplayed such possibilities. Now, having written a book that focuses on the literary response to Darwinism, I think I had actually totally overlooked the extent to which in a Darwinian world vigor and success are valued. I don’t mean that we should now revert to crude Social Darwinism, but that while it is obviously not enough on its own, being prepared to “have a go” is morally admirable. The Darwinians don’t buy into the value of meekness often preached by Christianity. No one wants to deny that the meek can have great moral worth, but seeking out meekness on its own, as it were, is not that admirable. A novel like George Gissing’s New Grub Street (1891) makes this point very clearly. One character (a writer named Edwin Reardon) is very talented but basically isn’t prepared to make the effort to succeed. The other chap (Jasper Milvain, also a writer) is far less talented but has a certain zest for living. Consider this conversation between Jasper and the woman he wishes to marry:

“You hear?” Marian had just caught the far-off sound of the train. She looked eagerly, and in a few moments saw it approaching. The front of the engine blackened nearer and nearer, coming on with dread force and speed. A blinding rush, and there burst against the bridge a great volley of sunlit steam. Milvain and his companion ran to the opposite parapet, but already the whole train had emerged, and in a few seconds it had disappeared round a sharp curve. The leafy branches that grew out over the line swayed violently backwards and forwards in the perturbed air. “If I were ten years younger,” said Jasper, laughing, “I should say that was jolly! It inspirits me. It makes me feel eager to go back and plunge into the fight again.” “Upon me it has just the opposite effect,” fell from Marian, in very low tones.

By the book’s close, Edwin is dead, Marian loses out, and Jasper ends up with Edwin’s wife and the editorship of a prestigious journal and is able to move forward and contribute to society.

It isn’t just a matter of success, but a feeling that if you are going to do good you had better have the energy and drive to do it properly. In her novel The House of Mirth (1905), Edith Wharton chronicles the decline of Lily Bart — not a bad woman at all and in some respects genuinely kind, but unable to make decisions and in the end the victim of a (possibly suicidal) overdose. Wharton doesn’t exactly despise Bart, but seems rather to look down on her. Wharton herself exemplified her own philosophy, in the Great War doing huge amounts for Belgian and French refugees, driven by her own energies and refusals to take no for an answer.

Put another way, Darwinism points us away from seeing morality as a series of Mother Teresa moments inserted into regular life. It is much more a matter of character and how it works itself out over a lifetime. This is an approach to ethics with a long and honorable history, being focused less on rules and more on virtues. It is particularly associated with Aristotle, and also with Christian Thomistic thought, and has seen a revival in the second half of the twentieth century with philosophers such as Elizabeth Anscombe, Alasdair MacIntyre, and Rosalind Hursthouse. In Darwinian ethics, one of the important virtues is the oomph to succeed, which can often be more admirable than strict adherence to a moral code.

Why Should I Do What I Should Do?

What about metaethics and the question of justification? Why, in Darwinian ethics, should I act one way rather than another, or prefer virtue over vice? Here’s the rub! If the is/ought barrier is impenetrable — if you can’t get values from facts — then you simply cannot get justification out of the evolutionary process or its products. And if you refuse to look elsewhere — Rawls for instance is a Kantian who thinks that morality emerges as a necessary condition for rational interaction — then there is no justification. The Darwinian, however, does not take this as a mark of failure, but as the starting point of thinking about ethics. There is no objective justification of substantive ethics. As a Darwinian, one is an ethical skeptic, meaning not skeptical about substantive ethics but skeptical about justifications — skeptical to the point of non-belief: there simply is no rational justification why one should behave morally.

In a way, of course, this is not so very novel a position. The emotivists, analyzing moral sentiments in terms of emotion, were also moral skeptics in this sense, arguing that all we ever do when discussing morals is that we express our preferences and dislikes and try to get others to share our feelings — “I don’t like lying. Boo-hoo, don’t you like lying either.” In a moment, we shall see a bit of a difference between Darwinian ethics and emotivism, but first, let us turn to the obvious objection. “You have derived substantive ethics from the evolutionary process,” says the critic. “For the sake of argument I will grant you this first step. But you have not shown us why ethics has no foundation. Take the comparable case of how we come to believe the objective truth about our physical surroundings. You want to argue that the claim that lying is wrong has no objective foundation because our belief that it’s wrong emerges from the process of natural selection. Why should we not equally argue that the speeding train bearing down on us has no objective foundation because our beliefs in the train emerge from the process of natural selection? Those that believed in trains survived and reproduced and those that did not, did not.”

But there is a difference. If evolution does not make you believe in trains, you are going to die before reproducing. You might not obtain knowledge of trains in the way humans do — perhaps you could use a kind of bat-like sonar — but in the end, belief in trains wins out, and so evolutionarily speaking, all roads lead to belief in trains. But for moral dicta like “love your neighbor,” it is not the same. There is no absolute moral direction to evolution through selection. The parallel to belief in trains is not the love commandment but some general kind of cooperation — cooperation that could be grounded in other moral rules than the injunction to love your neighbor. If you could get the cooperation in another way, then so be it. Suppose that instead of “love your neighbor” you had “hate your neighbor but recognize that your neighbor thinks it a sacred duty to hate you, so you had better get along.” I call this the Dulles system of morality, after Eisenhower’s secretary of state, John Foster Dulles, who hated the communists but knew they felt the same way about him and so cooperated with them during the early Cold War, forging alliances but maintaining a firm stance. Or perhaps you don’t have any morality at all and you cooperate strictly on game-theoretic reasoning, calculating what you need to give in order to get what you want — although, whether this is practically viable is another matter. The point is that there are many different types of behavior that all deliver the cooperation demanded by natural selection, and so ethics has no rational foundation. Moral behavior, even if it does not always work to your advantage, gives you a quick and dirty solution to the cooperation problem, and that is enough to go on.

To the Darwinian, there is nothing sacred about the way that we have evolved, any more than there is anything sacred about having five digits rather than eight (as was the case with some early vertebrates). So there is nothing sacred about fixing onto “love your neighbor” rather than “hate but get along with your neighbor.” Hence, it seems now that you are faced with two options. You can go straight to arguing that substantive morality has no backing and that its apparent objectivity is an illusion of the genes put in place by natural selection to make us good cooperators. To make us “altruists” nature has made us altruists. Or you can claim that there exists an objective morality but, like it or not, we don’t know about it. Perhaps objective morality demands that we hate our neighbors but Christianity (or some other historical force) has deluded fools into thinking that we should love our neighbors. But in my opinion, if it is possible for humans to live full and satisfying lives doing the very opposite of what is demanded by objective morality, this gets pretty close to being a reductio ad absurdum of objective morality.

So because of the non-directionality of Darwinian evolution, there are no reasons to think that we have homed in on an objective morality and good reasons to think that there is no such morality to home in on. Of course, I have so far presented the objectivity of morality in a somewhat Platonic or Christian way, assuming that it exists outside our perceptions in another realm. What if you argue that morality is objective but not because it exists independently, but because it is the necessary condition of cooperative behavior and living? I have less of a quarrel here, although I still don’t think it works. I would concede that perhaps all morality ultimately must share the same formal structure of cooperation. If there is no reciprocation, it will not work. But as Kant himself pointed out, this is not enough for morality. We might say, looking at the poor around us: “Let everybody be as happy as Heaven wills or as he can make himself; I shall take nothing from him nor even envy him; but I have no desire to contribute anything to his well-being or to his assistance when in need.” Whether or not this is truly viable, Kant recognized that it is not a moral position or strategy. To get morality, we need something filling it out, something referring to human nature. But both Christianity and the Dulles form of morality could do that job, and there is no reason to think that the evolutionary process will necessarily lead us to one option rather than the other.

Moral by Nature

Why might this argument be difficult to accept? Simply because our biology is working flat out to make it seem unconvincing. Go back to emotivism and ask why so many people find it not just false but somehow rather immoral. Surely some actions, such as murder and rape, really are objectively wrong and not just as a matter of emotions and preferences. If they aren’t objectively wrong, then they wouldn’t be wrong for those without those emotions and preferences. So what is going on here? I have said that morality has no foundation and yet I criticize emotivism for arguing that morality has no foundation and for saying that moral judgments, like “murder is evil,” are just expressions of emotions. The crucial point is that, although morality has no foundation, we are naturally inclined to think that it does. To use an ugly term of J. L. Mackie’s, we “objectify” morality. The meaning of morality incorporates objectivity. “Rape is wrong” means that it really is truly, objectively wrong to rape, that it is not a matter up for grabs. And, thanks to biology, we mean this even if there is no actual objective foundation for that moral judgment.

There are obvious reasons why biology would make us think this way. If we did not, if we simply could puzzle out that morality has no foundation, we would start to ignore it and soon others would too and before long it would break right down. So natural selection has tweaked the meaning of morality. I think of it as the Raskolnikov problem, for it shows that what I have told you will not at once make you free to do whatever you want. In Crime and Punishment the young student Raskolnikov murders for gain. The detective knows that he has done it but waits until he confesses. The truth does not set you free, or at least it does in one sense, confessing, but not in another — recognizing that morality has no foundation does not set you free to act immorally. We are biologically disposed to think morality objective, and so even if philosophically we can puzzle out otherwise, we cannot live by denying our human nature. Again, Hume is ahead of us here. You worry that morality has no ultimate basis?

Most fortunately it happens, that since reason is incapable of dispelling these clouds, nature herself suffices to that purpose, and cures me of this philosophical melancholy and delirium, either by relaxing this bent of mind, or by some avocation, and lively impression of my senses, which obliterate all these chimeras. I dine, I play a game of back-gammon, I converse, and am merry with my friends; and when after three or four hours’ amusement, I wou’d return to these speculations, they appear so cold, and strain’d, and ridiculous, that I cannot find in my heart to enter into them any farther.

The daily needs of human nature often have a way of teaching us that the puzzles of philosophy are not always that important. The question of how we can act as though morality were objective even when we know it is not requires no further philosophical reasoning. Indeed, philosophical reasoning is just what gets us into trouble!

Darwinian evolutionary ethics is, in this sense, very much part of the British empiricist tradition that recognizes the limitations of reason, philosophy, and metaphysics — not only for gaining knowledge about the world, but also for practical or moral guidance.