Sometimes, even the most bitter moral debates evaporate overnight. In what might be thought of as a sudden, large exhalation of ideological hot air, scientists announced last week that they had solved the quandary of how to exploit the extraordinary potential of human stem cell research without using – and destroying – live human embryos.

In America, where concern about ethical manipulation of human life is mercifully greater than in Britain or Asia, the debate was transformed overnight. Or more to the point, the debate ended.

You can see why. Few of those opposed to embryonic stem cell research actively wanted to prevent aggressive investigation of the pathogenesis of human disease as such; with very few exceptions, they’re not Luddites or heartless Dickensian characters revelling in others’ sickness. They’re just rightly squeamish about crossing a line in the utilitarian abuse of human life.

Equally, it’s fair to say, almost nobody on the pro-stem-cell research divide actually enjoys the prospect of using and then discarding human life-forms in their earliest manifestation. The vast majority are thrilled to continue with fascinating and potentially transformative research without incurring moral backlash.

What struck me was how common this phenomenon is becoming. Increasingly science seems both to plunge us into irresolvable ethical quandaries only to rescue us shortly thereafter. Trade-offs of all sorts – moral, ethical and economic – that were once hard to fudge are increasingly rendered moot by technological or scientific advance.

It seems to me, for example, that the inherent trade-off between economic growth and environmental protection may not ultimately be solved by a successor to Kyoto, or any of the palliatives now on offer. The sacrifices required to halt or even reverse climatic damage are, alas, simply not politically feasible in the time period necessary. But what may save the planet instead is a now unheard of technological breakthrough in energy technology: some new biofuel perhaps, or some new wrinkle in bioengineering to manage the climate, or maybe some conservation technology that can help us ratchet down or reuse our energy demand in ways now unimaginable. What politics cannot accomplish, technology might. Or rather, technology may have to.

We’ve seen this happen already in other areas. The eternal human trade-off between sexual pleasure and sexual morality was transformed by contraceptive technology in the 1960s. The biggest restraint on female sexual freedom for millenniums, after all, was always the risk of pregnancy, combined with the risk of childbirth.

Dramatically lowering those risks with the pill and medical science did not abolish the moral debate about when sex is legit; but it rendered it practically moot for vast numbers of women. Technology saved them from a debate that had defined them for ever.

On the other side of the procreative cycle, science’s advance keeps changing the debate over abortion. On the one hand, the increasing technological sophistication of methods of keeping foetuses alive outside the womb has intensified awareness of the preciousness of human life at all stages. Ditto the emotional power of seeing your child in early development on a blurry printout.

On the other hand, new technologies such as RU-486 and other emergency postcoital contraceptives have rendered legislative and collective responses to abortion increasingly irrele-vant. Passing laws to criminalise abortion doctors becomes much less salient when very early embryonic and foetal development can be halted within the privacy of your own bathroom without any doctor intervening at all.

In RU486’s case, the technology actually restored a more traditional notion of morality. The oldest Christian case against abortion – before the pro-life absolutism of the late 20th century – long allowed for blurred moral lines in the very first weeks of pregnancy, before what Aquinas described as “quickening” took place. For centuries, Christians made a distinction between human life and human “personhood” in the early stages of pregnancy. New technology helped make such an argument more vivid and more persuasive – and so shifted the moral debate back to more traditional grounds.

Technology resolved our long-standing moral debates about sex in other ways too. A century ago, an adventurous sexual life generally led to countless people dying miserable early deaths from syphilis and other brutal, degenerative diseases. Now, even a virus as devious, sophisticated and deadly as HIV has been effectively stymied as an indiscriminate killer in advanced societies. Already, you see a completely predictable uptick in risky or “immoral” sexual behaviour – because the actual risk has declined.

People respond to shifting costs and benefits of any given behaviour – and technology is the biggest factor in those shifts. In many ways, sexual liberation of the past half-century should be seen less as a function of a changed moral climate than the simple consequence of humans responding to a technological revolution, allowing moral choices that were once fatal to become close to banal.

Science is not always our rescuer, of course. Medical advance has made the question of when and how to end human life much more excruciating. People who, a decade ago, would have died with no need for their loved ones to agonise over when to pull the plug will now be able to survive indefinitely at some atrophied level of existence. What to do then becomes a brutal decision.

Genetics and neuroscience will also transform our worlds in complicating ways by making what is currently deniable all too transparent. And so we will soon find out for a fact whether there are measurable, genetic differences in IQ between different ethnic groups or how exactly men differ from women; health insurance companies will discover if their customers are predisposed to particular illnesses; we may live in the knowledge of diseases likely to kill us that affect the moral choices we make in life. All these lovely things await us.

But increasingly, the pace of expansion in human knowledge also provides unexpected technological palliatives to seemingly intractable dilemmas. As we wrestle with moral and political arguments, scientists increasingly hover around us, constantly poised to make some discovery that renders our frenzied debates suddenly moot. It just happened last week. May it happen again and again.

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