The waters have been muddied here, not by Nagel, but by the so-called "theory" of Intelligent Design, some of whose supporters would like to promote a designer God as a scientific alternative to Darwinian evolution. But that seems radically misguided. Science necessarily operates within the natural world, investigating the structure of things and attempting to discover the hidden mechanisms of nature that account for how things behave. It searches, in one of Dennett's more helpful pieces of terminology, for "cranes"-solid workmanlike mechanisms that perform the laborious task of explanatory lifting. And it doesn't help to invoke "skyhooks"-futile attempts to short-circuit all the hard work of empirical scientific research by appealing to some miraculous solution from on high.

So are we back with the Darwinian "cranes" of random mutation and natural selection? Nagel thinks this won't do: he is sceptical about "the likelihood that [in the available geological time], as a result of physical accident, a sequence of viable genetic mutations should have occurred that was sufficient to permit natural selection to produce the organisms that actually exist." Well, the actual probabilities are a matter for the scientists to work out. But we may need to beware of words like "accidental", which are so often used in discussions of evolution. For if we suppose that the biological process is accidental in the sense of not consciously guided, it doesn't follow that it must therefore be inherently random and chaotic. On the contrary, most biologists (Darwin included) maintain that once the relevant combination of circumstances happens to arise, then, given the natural properties of the relevant structures, the resulting evolutionary processes can be expected to occur in an in principle perfectly predictable and lawlike fashion. The Astronomer Royal, Martin Rees, suggested some time ago that the universe may be "biophilic"-intrinsically apt to produce life (and we might add "noophilic"-apt for the eventual emergence of intelligence). As Professor Brian Cox put it in his recent television series The Wonders of Life, "far from being some chance event . . . the emergence of life might have been an inevitable consequence of the laws of physics". Nagel is perfectly entitled to express his doubts about this supposed "inevitability"; but again, the issue is one for scientists to investigate, not for philosophers to try to decide in advance.

Suppose, then, that it turns out that the neo-Darwinian picture survives the probabilistic objections raised by Nagel. Notice that this would still leave the door open for the theist, who accepts the processes of evolution as part of a natural order, but maintains that this natural order ultimately reflects divine purposes. If this is right, science, even modern biological science, does not necessarily have to be on a collision course with religion (despite what the redoubtable Dawkins would have us believe). Obviously science and religion have often locked horns in the past, and many religious fundamentalists today still see them as in conflict. But a more careful look at the available options tells a different story. Evolution, though in itself a "blind" or mechanical process, can be part of the natural order ultimately ordained by the creator.

On this picture, which seems to me the most attractive one, we look purely to science for a valid explanatory account of the mechanisms and processes by which the universe developed from its original state, and by which, over vast swathes of time, life and intelligence arose. The religious outlook does not offer a rival account to this scientific one, but instead interprets the entire natural world and all its beautiful and intricate physical processes as a manifestation of divine creativity.