What is the most important issue facing our species today?

That is a modern question, arguably the modern question. A hundred years ago, it would have been essentially meaningless, because the conditions of life of the roughly two billion people alive then varied so much that they could hardly be said, collectively, to face a single overwhelming problem. Many were starving, many were ill; a few were struggling with ethical dilemmas, some of which were related to the starving millions; and some were busily engaged in trying, in a sense, to ensure that their children had the leisure to address those timeless issues – what does it mean to be a person? – or at least the choice to think of them or to relax in relative comfort.

Suddenly, in 1945, this changed. Or seemed to. With the explosion of the first atomic bomb, and soon thereafter the development of far more powerful weapons, Homo Sapiens was presented with the first real issue that our species as a whole has ever consciously faced: the possibility of total destruction. Most people, of course, remained unaware of it for several years (a few probably still are), but for a large minority the threat of The Bomb became a constant backdrop to their daily actions, one they generally ignored but one whose existence was widely, and probably accurately, thought to affect the way they thought and acted, even if only subconsciously.

Human existence became an issue.

We have now survived more than half a century under the metaphorical shadow of nuclear war, and it hasn't happened. Indeed, the last couple of generations have seen an unprecedented spread of technology, growth of population, lengthening of average lifespan and, in overall economic terms, a remarkable generation of wealth. They have also seen, as everyone is aware, concomitant environmental degradation so bad that it might yet render this planet functionally uninhabitable, a mass extinction of species the like of which we have never witnessed (though the earth has seen at least one before), an increasing gulf between rich and poor within as well as between nations, and even a resurgence of diseases we once thought were on the decline. Clearly our social systems – political, economic, technological, moral, and even scientific – are imperfect, a very important point to remember, but equally clearly we have been muddling along.

Quite suddenly, however, human existence has become an issue again.

This time, the question is not whether our species can exist but what our species is. The oldest question – what does it mean to be a person? – has moved from the abstract, philosophical realm to the very immediate, practical world. Gene technologists are extremely close to being able to create children who are, paradoxical though it sounds, genetically unrelated to their parents; and are discussing, and in some cases eagerly anticipating, the prospect of creating children who will not be able to breed with normal people, that is people who have not been genetically modified. They are talking of creating a new species.

This is not cloning, though the techniques are related. This is not a question of in vitro fertilization, or surrogate motherhood, or fertility treatments, or of the morality of abortion, though all those matters are related. This is something new, and important, that we as a society – indeed, we as a species – need to discuss, debate and consider before it happens. Now.

There is as yet no generally accepted term to describe the process of creating genetically modified people, but techno-eugenics, which was coined by Rich Hayes a couple of years ago, seems as good a rubric as any. There is obvious theoretical potential for good in the technology; nobody wants to perpetuate unnecessary suffering. Equally obviously, there is potential for harm; nobody wants to create monsters whose lives are wracked with pain. Less obviously, there is a possibility of an outcome that some people relish and others dread, which is essentially the creation of a minority super-species, a genetic aristocracy destined to rule the earth. Let me emphasise here, I am not exaggerating – this is the conscious vision of a number of idealists. The technology exists, or is reasonably expected to exist by the time President Clinton's ban on human genetic experimentation expires in 2003, to begin to pursue this vision.

The simplistic question is: Should we? But this in itself is not very illuminating. Some of the supporters of techno-eugenics actually claim that the question is irrelevant, and that use of the technology is inevitable; this is a rather transparent attempt to win the argument by default. Some of the opponents claim that use of the technology is unthinkable under any circumstances, usually on moral grounds whether as part of an organised religion or out of a more personal kind of pantheism; this too is essentially an assertion rather than an argument. In between lie many different positions, from the Christians who support it as part of God's plan for mankind to perfect ourselves, to the scientists who oppose it on the cautious grounds that there may be consequences we do not yet know.

And then there are other questions. How would such a process be implemented? What kind of regulation is appropriate? Whose children, if any, should be the subject of these procedures? Does society have a right to intervene, and if so on whose behalf? The general good? (Defined by whom and for whom?) The unborn children? And what of the rights, if any, of those in our global society or even our national one who have insufficient access to medical care and nutrition at present – is it appropriate for us to spend, in the aggregate, millions on cosmetic surgery for the living, let alone on gene manipulation for the unborn, while millions of people die for lack of a few dollars-worth of medicines? Should we even consider that question?

There is also a related, and deeply principled, question of science. Gene technologies represent perhaps the extreme of the reductionist view of science; which, though powerful, is not necessarily correct. Before we take such a major step as altering our own species, should we perhaps examine their scientific credentials, in the light of the extraordinary theoretical constructs of modern physics and the equally extraordinary but more mundane anomalies that certain biologists have highlighted?

Likewise, the reductionist capitalism that is the basis of modern economic society is thrown into sharp relief by the social questions the prospect of a genetic oligarchy raises. Perhaps it is time to re-examine some of the assumptions under which we have become used to operating.

In fact, the issue of what it is to be human raises, directly or indirectly, most if not all of the major questions surrounding how a human should live.

None of this means, need I add, that the environmental, social, political, economic and other issues that we face should be ignored. After all, whether our descendants are genetically modified or not, they still need a world to live in. But up till now there has been little real question that when we as humans discuss the world, we are discussing a world in which humans live. (Certain Gaians would quibble with this – it is virtually impossible to make an absolutefly true generalization that sweeping.)

We have become hardened to the extinction of species. We have become used to the idea of modifying plants, and even animals, for food and for research, though this is, to say the least, still controversial. Now, we face a momentous step: Modifying ourselves.

Should we do this without thinking it through? Without even trying to think it through? To that question, I say unequivocally, No. These issues are too important to ignore. We need a thorough-going, widespread debate that covers all the associated territory, that takes into appropriate account both the technological details and the feelings of people. We may not get to the 'right' answer but at least we will have tried.