George Bush is confident he has crafted a complete solution to the stem cell controversy, one that faithfully reflects nature and the sanctity of human life. Advocates of stem cell research are appalled by the limits he has imposed. They are confident that this research offers the possibility not merely of progress against disease but even of quantum leaps in longevity.

Columnist George Will has suggested that these differences are symptomatic of the most basic divisions between our two parties. Will is correct in discerning philosophical implications in this debate, but his reading is open to challenge.

Republicans are beset by gaping divisions over medical research. In addition, many Democratic advocates of stem cell technologies share a subtle article of faith with their archenemies. Social conservatives may assume that nature offers a clear set of ethical guidelines, but many of their opponents are equally sure it can be endlessly reshaped to meet our needs and desires. Both sides are confident that nature is designed for human purposes.

Republicans are the party of business. They are also the party of social conservatism. On no issue have these agendas been more at odds than over stem cells. Despite entreaties even from such social conservatives as Orrin Hatch, the president opted for guidelines that will place severe limits on research.

The president argues that he has reaffirmed the sanctity of human life. Yet even accepting the debatable equation of human life with an embryo, I suspect there are major problems with Bush’s decision. Limiting research funding to already existing lines of stem cells puts us – and him – on the famous slippery slope so often lamented by social conservatives. If existing lines do yield major medical breakthroughs for some classes of patients but not others, the pressure to fashion new stem cell lines from discarded or newly cloned embryos will be immense.

What is the logic of funding research on lines already created from discarded embryos while forbidding work on others that will soon be discarded anyway? Will defends the president acceptance of existing stem cell lines on the grounds that we may ethically benefit from the immoral act of embryo murder as long as we do not cooperate with or abet it. Yet a decision to use the surplus embryos of fertility clinics, especially if those clinics were not compensated, would seem to me to meet the same criteria.

The staunchest social conservatives, who have always opposed any reproductive technology that kills embryos, would seem to have more logic going for them than the president. But even they miss a more profound possibility. It is the nature of human beings to seek to understand and alter nature. One could argue that as soon as human beings managed to understand the biology of conception, they were on a slippery slope toward choosing which embryos would live or die.

If opponents of this research are unduly confident that nature offers precise guidelines as to the appropriate sources of stem cells, some research advocates share an equally unbounded faith in future experimentation. Toronto’s Globe and Mail recently gushed: “Stem cells could one day cure everything from Alzheimer’s to heart disease. Aching joints? Damaged liver? Just grow a brand new replacement. These cellular magicians are the most seductive area of scientific research today. … The applications to treat and perhaps cure currently incurable diseases have some scientists discussing the regenerative powers of stem cells as though they could be the source of the fountain of youth.”

The editors’ choice of the adjective seductive may carry more significance than the paper recognized. However likely progress against disease through stem cells may be, human beings may well never be as simple and fixable as a broken alarm clocks needing new springs. That we may eat, drink, and be merry as we will on the assurance we can replace worn out parts without adverse side effects may be a dangerous fantasy. Every basic medical breakthrough I can think of, from antibiotics to x-rays, has carried significant downsides. And even with medical “success,” I wonder if we are ready for a world where all of us-or those of us who could afford new organs-are going to live 500 years? The hubris of the science warriors may be just as grave as the fundamentalists’ conceit that nature was designed so as to give us clear signals.

I’d like to see stem cell research go forward on an expanded base of currently surplus embryos. Nonetheless, clinics should be forbidden any compensation for such embryos. Just as important, however, is the broader ethos with which we approach future research. Every project and every discovery may open up both new possibilities yet occasion difficult dilemmas. Even some scientifically promising lines will have to be discouraged in the interests of our fragile values. Neither science nor nature is ever likely to trump the need for flexible and ongoing political adjustments.

John Buell is a political economist who lives in Southwest Harbor. Readers wishing to contact him may e-mail messages to jubell@acadia.net.