Leading Article: That's life

WHAT IS life? That's one of those questions we turn to philosophy to answer, and turn away again after hearing the cacophony of replies. It's the Form, says Plato. It's "thinking", says Descartes. No, it's just a complicated machine, says Hobbes. But that machine needs to be animated, says Bergson, and that's done by the elan vital. There's no need to invent ghosts in the machine, responds the hard-nosed analytic philosopher; all this special psychic stuff is just an illusion spun by the words we use to describe ourselves. Then along come the theoreticians of the computer world who think that life is really a matter of software, not hardware at all.

Well, if you're still with us, you will be happy to know that science has come to the rescue, with a "minimal definition of life". Life, we are now told, can be reduced to a set of 350 genes that describe, with no redundancy, an organism that can survive and replicate. No more messy abortion arguments about when life begins; it begins when those 350 genes are assembled, placed in a suitable environment and given a suitable charge to get them moving.

That's all, folks!