I could have written this book for Margaret Somerville. The Ethical Canary focuses on such controversial topics as euthanasia, human cloning, and xenotransplantation (transplanting animal organs and tissues into human beings). All these issues she and I have debated often — on radio and TV, in the press, and at scholarly conferences. So often in fact that, notwithstanding the fact that we have rarely agreed about anything, I feel I know what her position on any issue will be even before she herself does. It will be the opposite of mine.

The book is a collection of essays but it's not meant to be a mere collection. It's meant to be a primer on "how to do ethics." The reader is presented with a careful discussion of how Somerville got to her conclusions. As well as opinions (of which there are tons, as you would expect), there are also supporting reasons and arguments. Along the way, Somerville considers many arguments contrary to her own. Since this review will be largely critical, I want to say at the outset how fair-minded she is in presenting the kinds of arguments which her critics would put forward.

The chapter on euthanasia is especially noteworthy for the judicious manner in which Somerville canvasses a wide range of arguments, but this is also a virtue of the book as a whole. She strives to present both sides. Critics, of course, will find, as I do, that she seriously overestimates the cogency of the arguments in favour of her own views, which tend to be socially-conservative and quasi-religious, and underestimates the cogency of the arguments against. But they won't be able to complain that she ignores their best arguments.

Confronted with an ethical problem, especially one arising from modern science and technology, Somerville advises readers to ask, as their first question "whether what we plan to do is inherently wrong." Now, for most of human history, when people perceived an action/policy/practice to be "inherently wrong," what they meant by this phrase was "against the will of God" or forbidden by the Bible or the Koran or some other divinely inspired text or authority.

Somerville recognizes we live now in a pluralistic secular society, and she accepts that, in such a society, appeals to divine authority are simply not acceptable as the basis for social policy.

You may decide, for example, not to terminate your unwanted pregnancy and your justification may be that you believe that abortion is forbidden by the Bible, hence against God's will, hence a sin, hence morally wrong. But, in a secular society no one can legitimately offer this as a reason for using legal coercion against my decision to terminate my pregnancy, and you will not expect me to be persuaded that all abortions are wrong unless I happen to share your particular interpretation of your particular religious tradition.

Recognizing this, Somerville attempts to develop an approach that will enable us to adjudicate rightness or wrongness by appealing to what she calls "the secular sacred." She proposes we regard actions or practices, such as abortion, euthanasia, human cloning, or whatever, as inherently wrong if they breach either of two values: profound respect for human life and for the human spirit.

As to the meaning and scope of these key concepts, "respect for human life" and "spirit," which do heroic overtime work for Somerville, she is somewhat vague and woolly. They function as a kind of "black box ethics machine." One sticks an ethical query into one end, cranks a handle, and presto, the answer emerges from the other end.

The problem is these answers correspond with remarkable precision to the antecedent prejudices and preferences of the person cranking the handle.

Thus, according to the book, pulling the plug on a dying patient, at that patient's request, is ethically permissible, but in a Sue Rodriguez-type situation, where a competent adult patient who is suffering terribly from a terminal disease asks for assistance in dying, it would be ethically impermissible for a physician to comply. It would be inherently wrong because it would violate the values of respect for life and spirit.

It's not clear, at least not to this reader, why we shouldn't make the same ethical evaluation of both actions — that they're either both right, or both wrong.

Even after a careful reading of Somerville's attempt to distinguish sharply between "pulling the plug" and "assisting to die," it feels very much as if doing ethics à la Somerville is about not much more than consulting one's own gut feelings. Since one's gut feelings will sometimes arise from little more than ignorance or prejudice or both, it is difficult to accept that this is the most reliable ethical compass available to someone who wishes to be ethically thoughtful.

So, what's the alternative? As mentioned above, for those who see the universe as a cosmos (that is, a purposive entity created according to a blueprint designed by a benevolent being), the alternative is the teleological one recommended by Greek philosophers such as Aristotle, and later modified by Christian theologians.

One must first discover the purpose of the universe which will, in turn, reveal the meaning of life. Once one has discovered one's place in the natural order, one will then know how to act appropriately. To live ethically is to correspond one's life choices to the divine order. Any attempt to change the natural state of things is disparaged as "unnatural" or worse, as "playing God."

Those who take a more scientific view of the world generally stop asking "why" type questions (Why me, dear God, why am I dying of cancer when my unrighteous rival lives and flourishes?). If the universe consists merely of atoms bouncing around in the void, if there is no divine architect and no blueprint to be discovered, then our challenge is to create such meaning as we are able to generate ourselves. On this view, meaning arises from the attempt to make life a little less terrible each generation, to reduce pain and suffering, to promote dignity and human flourishing.

That is, we are likely to reach the conclusion that ethics is about minimizing the suffering of human beings and the pain of all sentient creatures. Margaret Somerville misleadingly labels this approach "situationalism." Philosophers refer to it as "consequentialism," the view that we should make moral decisions by weighing and balancing the good against the bad consequences likely to be produced by each of the available alternatives, and choose that which has the best overall consequences.

Since the new medical technologies — which may enable us to replace diseased organs, cure genetic diseases, reverse infertility — carry risk of harm as well as promise of benefit, prudence dictates that we go slowly until we can assess both the risks and the stakes, and can deliberate upon who will likely benefit and who may be harmed.

Xenotransplantation, for example, could drastically increase the supply of heart valves available for transplantation, but it could unwittingly cause the spread of deadly new viruses from animals to humans, a phenomenon known as xenozoonosis. The precautionary principle urges us to put the burden of proof on those who want to proceed with risky new technologies to show they are safe.

Thus, on the consequentialist view, which I happen to share, our goal should be to obtain for humanity the maximum benefit from these new medical technologies while minimizing the risks of serious harms. We should also seek to distribute the resulting benefits and harms equitably. This is likely to be the greatest challenge we face, and there is little to be gained from Somerville's quasi-religious appeals to "respect for the human spirit."

Instead, we would be well advised to create independent regulatory bodies and careful regulations which will enable us to resist both the powerful religious lobbies who would dismiss the new technologies as "unnatural" or "inherently wrong" and the greedy corporations which want to plunge full-steam ahead into risky territory.

Arthur Schafer is a professor of philosophy at the University of Manitoba, and director of the university's Centre for Professional and Applied Ethics.