Imagine the anguish caused by an oxyacetylene torch applied, if only to a few seconds, to your child's face. Unspeakably appalling? Yet each day we pay - by our choice in food purchases - to have other living creatures treated no less abominably.

        An over-statement? Surely factory-farming and the apparatus of mechanised killing, even in their worst excesses, are rarely that bad? No, in a sense the reality is worse. What it feels like for our victims is more terrible than we can typically imagine. In fact, on the few occasions in life when pain that's even relatively severe strikes us down personally, we are shocked. The casual use of the word "pain" evokes only a pale shadow of the frightfulness of the experience that lies behind it. Severe pain really is uniquely awful. Only the state-dependence of memory helps us forget just how bad pain can be. The problem is not that our everyday language is emotive. It's that we can't use it to be emotive enough.

         Jewish writer Hanna Arendt once wrote of the "banality of evil". For most of the Nazi bureaucrats who actually organised the human Holocaust were not sadistic psychopaths in the usual sense of the term. Many were devoted husbands, loving fathers and cultivated family men. They were motivated by a distorted sense of duty rather than a relish for bloodshed or suffering for its own sake. Somehow it seems the "dissociation of sensibility" between their feelings and the effects of their actions was complete. The same is true of most of our own vivisectors, abattoir managers and the bureaucrats in charge of the mass-killing apparatus. So they shouldn't be demonised. But they must still be stopped.

        Would global veganism ensure a cruelty-free world? No, not by itself. Life in a state of Nature is often little kinder than a life of barbarous abuse by Man. Should we respect the ways of Nature simply because they are "natural"? Or is homage to the pain-ridden products of selfish genes as harmful a superstition as any? In one sense, after all, animals no more need liberating than babies and toddlers need liberating: they need looking after. Thus The Hedonistic Imperative argues that there is only one long-term way to abolish the ghastliness of suffering on a planetary scale. Such a strategy entails eradicating its biological roots. This can be done only by using genetic-engineering and nanotechnology. This major transition in the evolution of life will replace the DNA-driven pain and malaise of our evolutionary past. The molecular architecture of the old Darwinian Era will be succeeded by modes of consciousness that are more beautiful than anything we can currently imagine. Counter-intuitively, the world's last unpleasant experience - probably some (relatively) minor pain in some (to us) obscure marine invertebrate - will be a well-defined event. It will be as precisely dateable as any other historical milestone; and far more important. For it will mark the end of the ugliest chapter in the history of life on earth.

       Some people who care deeply about animals are still shocked at the implications of such an ambitious species-project. Many animal-lovers would oppose the loss, for instance, of the symbolically-charged big predators in their traditional guise - in spite of the cruelty and suffering inflicted on the weak, the old and the vulnerable that their present carnivorous habits entail. Indeed to anyone of a humanistic or spirituo-religious disposition, the blueprint to put an end to the primeval DNA regime might seem the vision of a soulless technocrat. Yet there's nothing soulful about rampant, pointless and utterly out-of-control suffering. The much-advertised "Death of God" shouldn't spell the loss of paradise, too; and there is only one scientifically literate way its promise is ever going to be realised.