Playing God ... A Thousand Years by Damien Hirst, 1990, at the Saatchi Gallery.

Despite a religious upbringing, I quickly found Charles Darwin - and his influence on Damien Hirst - far more compelling

It was fascinating to read Damien Hirst's Guardian comment on Charles Darwin the other day. It was not a shock to find that Hirst has read Darwin and finds the great naturalist inspiring. I suppose there is no more Darwinian work of modern art than Hirst's grisly masterpiece, A Thousand Years (1990), in which a race of flies are born in a white cube inside one half of a long glass tank; in the other half of the tank rests a rotting cow head. To feed on it, the flies have to find their way through specially created openings into that part of their sealed world - which is also where Hirst has placed an insect-o-cutor. In the rush to feed, they are massacred; to live is to die. The Brownian motion of black flies swarming inside their glass universe, as the cow's head decays and the glass gets progressively dirtier, makes this organic machine a compelling vision of existence and Hirst's greatest work of art.

The artist who created it resembles the God you would have to believe in to square religion with the discoveries of modern science, or indeed with simple observation of the natural world. The passion to survive, the competition to exist is what lures the flies to their destruction. You can see how Hirst's reading of Darwin would have helped him to think that.

Reading Darwin definitely made me stop even half-believing in God as a teenager. I grew up in religious north Wales, my Taid was a churchwarden in a small village and I was confirmed in the church - despite telling the vicar I didn't believe in any of it. By that time I'd discovered Darwin (not that he was taught or even mentioned in school). A BBC series called The Voyage of the Beagle fascinated me. Buying The Origin of Species, I found Darwin's prose beautiful. What's so amazing is the way Darwin builds his case through one fascinating case study after another. It is the triumph of empiricism. This is one reason why creationists are so wide of the mark when they insist evolution is "just a theory". Darwin never actually presents anything as abstract as pure "theory" - he argues from observation.

But do you need Darwin to doubt God? Surely, the biblical view of the world became unsustainable as soon as early 19th-century geologists started to realise the vast antiquity of the earth and as soon as fossils began to be understood. Why would God bother to create all those species that became extinct long before humanity appeared? What is a trilobite in God's plan? You are forced back on the image of a cruel scientist god that Hirst creates in A Thousand Years, creating and destroying for his own psychotic fun.