The title of this essay is “Let Our Conscience Be the Guide.” Not “your conscience.” Not “Our consciences.” By using the term “Our Conscience” I want to start right off with the assertion that everybody has the same kind of conscience, it is part of our genetic inheritance, and it is something every human being is born with. It is as common to all of us as is the fact that we walk upright rather than swinging around in trees.

What do I mean by the human conscience? It’s not that mysterious. It is an inherited, instinctive propensity for the individual to be loyal to his group. It means the individual cares for other members of the group, wants to treat them decently and expects them to reciprocate. The Golden Rule is a classic expression of this kind of behavior.

I arrived at the conclusion that this propensity is instinctive, part of our genes, without benefit of any religious instruction. Nor do I base it on some sort of wishful thinking growing out of my humanist world view. I base it entirely on scientific studies that have inquired into human origins, and on contemporary game theory examining the nature of altruism in human groups.

Here are some things I am reasonably sure about, because the scientific evidence is pretty conclusive:

First, our remote ancestors evolved from primates who banded together in simple, kin-based tribes. They were social animals long before they developed the physical features of modern humans. For millions of years they depended on other members of their small bands for survival. Altruism toward other members of the group became part of everybody’s genetic inheritance. It was based on blood relationships. Scientists have shown that kinship is the basis for altruistic behavior in other animals, from bees to wolves. Willingness to sacrifice one’s selfish interest, even one’s life, for the good of the hive or the pack will add to the survival prospects of the group as a whole, and over a long period of time natural selection will favor that kind of behavior.

In other words our consciences evolved even before we evolved into human beings. The Golden Rule is as much a part of our mental equipment as the ability to learn and use language. Indeed, it goes back even farther.

About fifty thousand years ago people began to band together in larger groups, which increased their ability to cope with a harsh environment. But they faced a problem: how could they learn to be loyal to other individuals in the group, even if they were not kin? Actually, the answer was relatively simple: as long as they all knew each other, people were decent to each other because everyone knew when somebody cheated and peer group disapproval was enough to keep people in line. It’s much the same today, in a village community where everyone knows everyone else. There were generally accepted rules of behavior, based foursquare on the Golden Rule, and they were mostly self-enforcing.

Let’s look a bit closer at this important transition from kin-based bands to somewhat larger tribal-type organizations. The instinct for altruistic behavior remained, and furnished the basis for interpersonal behavior, but it became reinforced by a modest superstructure of learned behavior, do’s and don’ts, that were drummed into each small child. These do’s and don’ts became possible because people now could think, and talk to each other, in abstract concepts. Such concepts were the seeds out of which all our later moral and legal codes have evolved. In all the primitive hunter-gatherer societies that have survived to modern times, this kind of code operates to maintain equilibrium and ensure cooperation.

About ten thousand years ago the population exploded, as people learned about farming and animal husbandry. Commerce developed, and new arrangements like granaries. There were many such things that required people to organize larger cooperating units. Social bonds based on small tribes simply didn’t measure up to the new needs, as towns grew into cities, and the cities grew into kingdoms and empires.

When the size of the cooperating social unit increased, each individual had to be able to identify other members of his group on sight, even if they were complete strangers. Elaborate rules of behavior evolved both to identify friend from outsider, and to regulate relations between categories of people inside the larger polity. This is when culture emerged as a defining difference between groups. By providing symbolic markers like clothes and accents and religious beliefs, culture made possible a great expansion in the numbers of individuals who would willingly cooperate with each other. Civilization as we know it became possible.

But culture had a downside. By emphasizing togetherness and loyalty within the group, it accentuated the human propensity to regard outsiders with suspicion and even hostility. It meant that when groups competed, outright conflict often followed. War between kingdoms, and later between nations, happened all too often. Look back in history, and whatever period you pick, someone was always fighting and killing in the name of his religion or his king or his nation. Patriotism trumped the Golden Rule when it came to outsiders.

For nearly ten thousand years, war has been the ultimate arbiter of issues between groups, whether they were called kingdoms or empires or whether they are called by the more modern term, nation states. The need to win has always been the top priorioty. Loyalty, the willingness to die in combat if necessary, has long been part of the cultural heritage of each individual. Patriotism became the highest ethical principle.

With that kind of selection process going on for thousands and thousands of years, is it any wonder that people have a strongly ingrained “us versus them” complex? That they treat “us” one way and “them” another? And what does this mean in terms of our conscience, that ancient instinct that tells us to treat other people decently?

Let’s move to the present and talk about our own nation. Most of us sympathize when we see other people suffering, even if they are foreigners. The media bring their condition right into our homes and our consciences tell us that this is a bad thing we’re seeing. But that empathy is quickly suppressed when the aliens belong to a group we see as a threat. As soon as that happens, our sense of the national interest trumps our innate altruism. This is particularly the case when we believe our nation is at war.

What about war? For thousands of years it has been the ultimate way of settling disputes between groups, whether they happen to be kingdoms or nations or whatever. Is it an inevitable part of human nature, sort of the flip side of our consciences? Or is it something our consciences can rise above and control? Or are there other factors at play here?

Well, there is at least one very important additional factor to take into account here. During the last half of the twentieth century, it gradually became clear that war between the major nuclear powers had become unacceptable because its costs had become prohibitive. And as time goes by and nuclear weaponry becomes more sophisticated, the costs keep on going up. So I am reasonably hopeful that a major nuclear war just will not happen. Of course, there are still many regional and local conflicts in various parts of the world, and they will probably continue in one form or another for another generation or two. However, there’s at least a good chance that over time, the major nuclear powers, and an increasingly strong United Nations, will manage to impose non-nuclear solutions on these conflicts and gradually dry up their sources.

What does all this mean in terms of the circumstances we find ourselves in today? People, as always, prefer to behave decently toward other people, as a matter of conscience. The current revolution in communications shows us that we are all basically one global community. There really is no more “them.” We are all “us.” But we cannot act according to our consciences because of all the strife and turmoil raging in the world. Here in America we are constantly being reminded that we are engaged in a “war” on terrorism. And in many other places, people’s consciences continue to be overruled by the perception that they are being threatened by some mortal enemy next door.

My conclusion—and this is the main conclusion in my new book—is that we’ve reached a stage in the evolution of our species where we need to internalize the fact that there is no more “them” left, and we are all “us”. And we have reached a stage where we can—in fact we must—abolish war as a means of settling disputes between nations.

To the extent we succeed, we face a very bright future. A world at peace. Global cooperation. A world in which our descendants can enjoy a world order that still contains and even rejoices in diversity, but where human rights will be respected everywhere, where the worst inequalities between rich and poor will be removed, and where everybody will cooperate in meeting environmental concerns.

The problem, of course, is that people aren’t entirely logical. Our behavior is more often determined by our emotions than by rational calculation. But here is something we can start doing right now that can make a difference.

We can stop thinking of ourselves as a nation at war. We are not. We are engaged in a police action against a gang of international criminals who wish us harm. We need to cooperate energetically with other governments to root these terrorists out and destroy their ability to harm us. But this is not war. Calling it war stifles our consciences and allows us to condone actions that we would find intolerable if we were a nation at peace. Actions like torture, and targeted political assassinations, and active efforts to subvert foreign governments. We can start insisting that our government try harder to act like a responsible member of a peaceful world community, and observe the common human decencies in the way it deals with the rest of the world.

A world at peace. Can we get there? We have the knowledge, and we have the means. Now we need to change our attitude toward people we’ve always considered foreigners or aliens. No more “them.” Only “us.” Then we can always let our conscience be the guide. And the world will be a better place.