In the longer-run, however, irrespective of how clever our pharmacological interventions may one day be, wed arguably be better off taking no drugs at all. For if there were nothing fundamentally wrong with our default-state of consciousness, then we wouldnt now try so hard to change it. Thus our sophisticated descendants may opt instead to rewrite the vertebrate genome and allow themselves life-long genetically pre-programmed bliss. They may "naturally" be animated by gradients of well-being beyond the bounds of normal human experience as an everyday part of mental health.

        Wouldnt lifelong happiness make us stagnate? No. In our genetically-enhanced post-human successors, the functional analogues of aversive experience can potentially perform an analogous functional role to mental and physical pain in our Darwinian past, but without its textures of phenomenal nastiness. Our descendants enriched dopamine function will enhance drive, energy and will-power, not just hedonic capacity. Thus outright abolitionism is not technically infeasible - just ideologically problematic.

        Tomorrows bioscientists face another challenge. Taken in excess, opioid-based drugs of today tend to dull consciousness, inducing a dreamy warm contentment. The name "narcotic" derives from the Greek word for stupor. Indeed smacked-out bliss is typically used as the archetype of what any drug-or-gene-underwritten chemical utopia would be like. Most notably, soma in Aldous Huxleys Brave New World is depicted as a cross between a non-addictive opioid and a hangoverless tranquilliser. Thus Huxleys utopians enjoy only an empty imbecilic happiness, not life-enriching peak experiences. Unlike dopaminergics, soma doesnt increase incentive-motivation, nor does it heighten the felt intensity of experience. You can use soma to drift off to sleep.

        Yet this negative stereotype of synthetic bliss is profoundly misleading. Addictive tranquillity is only one option among many. It reflects a poverty in our conception of the range of options for paradise-engineering that biotechnology puts on offer. In reality, the quality of our consciousness can be intensified, sharpened and radically diversified by creative psychopharmacology. Intellect and empathy, and not just mood, can be prodigiously enhanced when the ideology of Better Living Through Chemistry finally enters mainstream culture.

        Better still, when a wholesale genomic rewrite - and not just piecemeal genetic tinkering - unfolds in the millennium ahead, then any chemical manipulation of our descendants emotionally- and intellectually-enriched superminds may be redundant. At most, lifestyle drugs will offer an optional fine-tuning for the parameters of their well-being - set against a backdrop of native-born bliss. In the wake of any such Post-Darwinian Transition, a wide variety of social interactions will "naturally" trigger a far richer endogenous opioid release than occurs today; and do so from a much higher baseline of emotional well-being.

        However, our present restrictive definitions of mental illness, and the technical challenges posed by large-scale genetic-rewrites, make germline gene-therapy seem a pipedream for now. In the present era, lifetime pure dysthymia afflicts far too many people; and periods of "mild" anxiety, malaise and depressive episodes blight the lives of hundreds of millions more. Thanks to biotechnology, the real obstacles to curing the nasty side of life are set to become doctrinal, not technical. Suffering is due to become optional. It remains to be seen how quickly the ideological baggage of the past can be overcome.