Most people who have ever lived have subscribed to principles about how to act and doctrines about what is valuable, ethical views they regard as handed down from an authoritative source, usually from a being or beings far more powerful and insightful than themselves. Most philosophers, by contrast, have supposed that any approach to ethics along these lines is erroneous, and have substituted the thought that insights into right action and the good life must be discovered by some special sort of investigation, perhaps by using reason alone, perhaps by mixing reason with some exercises in ordinary or extraordinary types of perception. (These investigations are typically viewed as importantly different from standard - broadly scientific - inquiries; they are the special province of philosophers.) In my view, both of these perspectives on ethics are fundamentally mistaken.

I want to offer a different vision. Ethics is something human beings have been working out together for most of our history as a species. The needs that prompt the cooperative activity of the ethical project lie deep in our human characteristics, and were focused sharply in our human past. Over tens of thousands of years, different human societies have conducted "experiments of living", in Mill's apt phrase, trying to find ways of attending to the difficulties inherent in a form of social life to which evolution inclined our pre-human ancestors. As Dewey says, "Moral conceptions and processes grow naturally out of the very conditions of human life".

"Ethics is something human beings have been working out together for most of our history as a species. The needs that prompt the cooperative activity of the ethical project lie deep in our human characteristics, and were focused sharply in our human past."

My account comes in three parts. I begin with an analytical history, one specifying the starting point for the ethical life, as I conceive it, showing how the capacities we reasonably attribute to our hominid and human ancestors give rise to recurrent problems in living together, and exploring the ways in which their first attempts to deal with those difficulties initiated a process of cultural evolution that was able to engender the forms of ethical life visible at the time of the invention of writing (5000 years B.P.+) and present today. Second, that analytical history is deployed to address questions about whether we can talk of any kind of objectivity in ethics, or whether we must settle for viewing the evolutionary process out of which our ethical ideas have emerged as a sequence of "mere changes". Because this question cannot be completely answered without adopting a substantive view about how the ethical project should continue, the second part leads to a third, and to the proposal of a normative stance. It is important to understand, from the beginning, that this third part can only propose. No philosopher can do more - for there are no experts here, and there never have been any. The ethical life belongs to human beings, living together in ever larger groups, and working out their shared lives with one another. Philosophy's task is to facilitate that working out.

"The ethical life belongs to human beings, living together in ever larger groups, and working out their shared lives with one another. Philosophy's task is to facilitate that working out."

Fifty thousand years ago, our ancestors lived, as chimpanzees still do, in groups of about thirty members, mixed by age and sex. To live in this way was itself a social achievement, one that required psychological capacities that are rare in the natural world. As primatologists have discovered, chimpanzees are able to recognize the wants and needs of other members of their species, and to react in helpful ways. At cost to themselves, chimpanzees sometimes give aid to an impaired relative, or carry out a task that another has tried without success. These altruistic tendencies make their social lives possible.

Nevertheless, these capacities for sympathy are easily strained. Chimpanzee social life is often tense, because loyalties are discarded and selfish impulses override their limited altruism. There is much breaking-up - and consequently making-up, long periods of huddling together for mutual reassurance. This, too, would have been the lot of our ancestors, restricting their opportunities for cooperation and the size of the societies in which they could live.

We became fully human when we were able to find ways of inhibiting tendencies to socially disruptive action, ways of reinforcing our altruistic capacities. Practices of punishment may well have played a role at early stages of the process. The crucial step, however, consisted in internalizing the check on our behavior. We became able to formulate rules for ourselves, or to remind ourselves of exemplary cases of conduct. We invented a crude system of ethics.

"We became fully human when we were able to find ways of inhibiting tendencies to socially disruptive action, ways of reinforcing our altruistic capacities."

This was both a psychological and social achievement, tied to the full use of language and to the ability to discuss potential rules for behavior with one another. So there grew up the rules of kinship still evident in contemporary hunter-gatherer societies, rules designed to settle issues about alliances in cases of conflict and about potential mates - exactly those issues that cause trouble for chimpanzee societies. Yet this was only the beginning. Different bands could experiment with different systems of ethical rules, and the successful experiments were passed on. A product of the success was an ability to engage with a larger number of people, eventually, about ten thousand years ago, to form permanent settlements containing hundreds of inhabitants.

Finally, with the arrival of writing, we can see the ethical practices of our ancestors more directly, in the fragmentary legal codes of the earliest documents. These reveal a piecemeal adoption of new rules, designed to cope with unprecedented situations, rules that are passed on to other societies with very different religious beliefs. Instead of thinking that the same rules were announced by many different deities, we do better to think that the rules come first, as practical solutions to social problems, and that they are then absorbed within a religious framework that serves to give them extra force. For, as ancient societies discovered, the idea of an all-seeing being who scrutinizes conduct is a wonderful way to increase compliance.

"Instead of thinking that the same rules were announced by many different deities, we do better to think that the rules come first, as practical solutions to social problems, and that they are then absorbed within a religious framework that serves to give them extra force."

Over the five thousand years of recorded ethical practice, there have been significant further changes. Some of these must surely count as progressive: we have become able to recognize the claims of those who look different, to repudiate the idea of slavery, to accept women as full members of at least some societies. Yet the primary cause of these advances has surely not been that human beings have understood the ethical project clearly, and have found reasons for improving it. Instead, the resistance of those who have suffered has finally proved overwhelming. Progress has been blind, the result of force rather than of insight.

It is possible to talk of ethical truth, but it is not "out there", awaiting divine revelation or discovery by especially astute philosophers. Rather the true ethical statements are those people adopt in making progress - that is solving the problems that stem from living together - statements that are retained in their further progressive modifications of their ethical practices. Ethics is a social technology, and ethical truths are the enduring successful contributions to it. In William James' happy phrase, "truth happens to an idea."

"Progress has been blind, the result of force rather than of insight. It is possible to talk of ethical truth, but it is not "out there", awaiting divine revelation or discovery by especially astute philosophers."

Understanding the historical roots of our ethical practices can help us to do better in going on from where we are. For the past refinements of our ethics might have been achieved more intelligently, by recognizing the consequences of maxims and policies. That recognition would not be the careful prudence of the self-interested agent, but an attention to the needs of all. Ethical debate requires both an understanding of the factual details, and the constant expansion of sympathies. It cannot be reduced to the exchanging of dogmas from rival traditions, or to the simple acceptance of irreconcilable disagreement. We have to continue the project begun thousands of years ago, by working through the places at which our inherited ethical maxims conflict. The only tools we have for doing so are our ability to fathom, as precisely and thoroughly as we can, the impact of actions on people's lives and our capacity to extend our sympathies and to view the situation from a large number of perspectives.

"Ethical debate requires both an understanding of the factual details, and the constant expansion of sympathies. It cannot be reduced to the exchanging of dogmas from rival traditions, or to the simple acceptance of irreconcilable disagreement."

The ethical project is of vital importance to us - it is, in large measure, what has made us human, giving us the rich possibilities we have and the problems that continue to occupy us. In continuing it, we have no hope (or need) of divine revelation, nor chance of philosophical insight into independently existing ethical facts. We must go on as our ancestors began, in conversations with one another, informed as well as they can be, and undertaken in a spirit of mutual engagement. Those are the resources for fulfilling the promise of the altruism that has enabled us to live together and for overcoming the troubles caused by its limits. We have no higher road to ethical insight - but the path already trodden can now be followed with greater consciousness of what we are about. And that, I believe, is enough.