The ultimate goal of civilization is, perhaps, maximizing the sum of human happiness. Most governments interpret this as raising the standard of living. In fact, happiness correlates fairly weakly with economic affluence. For most of us, it is pretty much set by our inherent temperament, sunny or gloomy, modified by the triumphs or disasters of the past six months or so. Even lottery winners and bankrupts relax back to their normal mental state in under a year.

So Daedalus wants to lift our spirits directly. ‘Cosmetic psychopharmacology’ mdash; the use of anti-depressant or narcotic drugs mdash; has serious social side-effects. But Daedalus recalls the story of a patient with a fairly non-invasive pancreatic tumour. Despite his unenviable plight, the man was permanently cheerful. It turned out that the tumour generated a steady stream of endorphins, the hormones that mediate our feelings of satisfaction. This suggests that our inherent personality differences merely reflect the different endorphin levels maintained by our bodies.

Few people would want to boost their happiness by means of an implanted tumour, however non-invasive. Gene therapy seems more promising. Some of the subject's own cells would be extracted, loaded with the genes for his own endorphins, and then re-implanted into him. Dermal cells would be a good choice. They are easy to get at, and can be reimplanted by simple tattoo technology. If the subject remained gloomy, more cells could be inserted; if he developed a dangerously manic optimism, some could be removed.

Gene therapy, of course, is in its infancy. It is tricky to insert the right genes into the chosen cells, and trickier still to switch them on. But resources put into developing Daedalus' scheme should bring far greater returns of happiness than any amount of economic growth. Governments should rush to fund the project and offer its benisons to the people, starting with the most disgruntled and resentful citizens: criminals and the underclass. Infused with calm self-satisfaction, they would cease to be so troublesome. Later, the long-term unemployed and the more clamorous political activists would be added; later still, the rest of us. As contentment spread through society, the drive and restless ambition that fuel, not only crime, but innovation and economic growth, would falter and fade. But that, of course, would no longer matter.