I think there's an asymmetry. There's this fable of Ursula Le Guin, short story, Ones Who Walk Away From Omelas. We're invited to imagine this city o… - David Pearce

Human intuitions are systematically biased. Evolutionary psychology explains how our moral intuitions and the rationalisations they spawn have been shaped by millennia of natural selection to maximise the inclusive fitness of our genes, not to track the welfare of other sentient beings impartially conceived. Many human cultures have found nothing intuitively wrong with aggressive warfare, slavery, wife-beating, infanticide or female genital mutilation. Ultimately, folk morality is a doomed enterprise as hopeless as folk physics. A mature posthuman ethics, I'd argue, must be committed to the well-being of all sentient life; and mature posthuman technology offers the means to deliver that commitment.

More controversially, technology can accelerate the transition from harming to helping free-living sentient beings: mankind's fitfully expanding "circle of compassion". The civilising process needn't be species-specific but instead extend to free-living dwellers in tomorrow's wildlife parks. Every cubic metre of the biosphere will soon be computationally accessible to surveillance, micro-management and control. Fertility regulation via immunocontraception can replace Darwinian ecosystems governed by starvation and predation. Any species of obligate carnivore we choose to preserve can be genetically and behaviourally tweaked into harmlessness. Asphyxiation, disembowelling, and agonies of being eaten alive can pass into the dustbin of history.

Here the question comes down to an analysis of risk-reward ratios - and our basic ethical values, themselves shaped by our evolutionary past. Lest extension of the new reproductive medicine seem too rashly experimental even to contemplate, it's worth recalling that each act of old-fashioned sexual reproduction is itself an untested genetic experiment, the outcome of random mutations and meiotic shuffling of the genetic deck, and with no happy ending to date. So just who are we to accuse of reckless gambling? As it stands, all of us are genetically predestined to grow old and die; and in the course of a lifetime, the great majority of humans will experience periods of intense psychological distress, for instance loneliness and heartache after an unhappy love affair. Our social primate biology ensures that most of us sometimes experience, to a greater or lesser degree, all manner of nasty states that were genetically adaptive in the ancestral environment e.g. jealousy, resentment, anger, and so forth. Hundreds of millions of people in the world today suffer bouts of depression; others live with chronic anxiety. One might say these phenotypes are part of what it means to be human. Worse, we pass a heritable predisposition to these horrible states on to our children.