Last week, Harry Brighouse of Crooked Timber sparked an interesting discussion when he reviewed Phillip Kitcher's new book on the theological implications of Darwin.
Harry says Kitcher shows that Darwinism - while consistent with a strictly "spiritual" belief in God - is a threat to "providentialism", the view that "the universe was created by a Being who has a great design, a Being who cares for his creatures, who observes the fall of every sparrow and is especially concerned for humanity. "
I haven't read Kitcher's new book (I found his 1980s attack on sociobiology convincing when I read it fifteen years ago, but it has not held up well. ) But my amateur take is that his argument is wrong. Darwinism wouldn't have bothered Augustine or Aquinas, who were clearly providentialists by the above definition.
Aquinas believed that the ultimate cause for everything that happened was divine will (the "universal cause"). But the divinity normally wills that events should follow each other in accordance with regular laws of nature (the "particular cause"_- laws subsequent scientific inquiry has shown have a startlingly simple and symmetrical mathematical structure: ST, Q.22, Art. 2
What Darwin and his successors showed is that biological "design" can be accounted for by the mechanistic process of natural selction acting on many generations of entities replicating with significant but not perfect fidelity and with differing success. The insect eye and the human brain are "designed" by this purely impersonal process.
Darwinism is critical to the reduction of biology to chemistry and physics. But natural selection relies on the fact that physical laws are reliable (if, perhaps, fundamentally statistical) and intelligible. Otherwise, DNA couldn't replicate, and no feature would provide a selection advantage over any other.
As Dawkins and Dennett both concede, what Darwin showed was that - under certain conditions - order generates design. He didn't explain the origin of order.
For Aquinas, this would be enough to get his proofs off the ground. If the world has an intelligible structure, then the principle ultimately responsible for it must, in some sense, be intelligent. Why else does math - which appears to be a product of intellect, although independent of any individual intellect - describe the universe?
There is obviously a gap between a principle that is "intelligent" (in a sense somehow analogous to the way in which we are intelligent) and a providential intelligence that cares about sparrows. After all, Darwin shows that the sparrow came to be because of the winnowing of lineages, not because a particular intellect thought through sparrow design.
But if Aquinas had been familiar with his Darwin, he wouldn't be fazed. Perhaps the standard model of particle physics (or whatever model Lee Smolin's students ultimately come up with) and appropriate initial conditions amount to a more economical way of making sparrows (and all other creatures great and small) than individualized special creation. Who are we to argue? Where wast thou when He laid the foundations of the earth?
Maybe Kitcher objects that, however economical, natural selection is a cruel way of meta-designing sparrows and people. Natural selection gave us pain. It gave us desires we cannot satisfy, or can only satisfy at other people's expense. It made us selfish unhappy bastards, and we are lucky among animals. Whether or not Aquinas has a good answer to this objection, he hardly needed Darwin to be aware of it. It is just the problem of evil, and it is an existential rather than intellectual problem. Shall he that contendeth with the Almighty instruct him?
What Darwin might help us see is that there is no way for creatures like us to exist (because we wouldn't be us if we weren't animals evolved through natural selection) without both natural and moral evil. Neither type of evil can exist without evolution - there is no pain and no deceit on Mars. Differential reproduction creates - even among bacteria - an entity with interests. At some point a niche develops in which a central nervous system with the possibility of pain becomes more helpful than not in defending these interests. At a later point, both the ability to appeal to moral norms and the propensity to violate them also pass the benefit/cost threshold. That's when we appear -- perhaps the moment the Standard Model was designed to bring about. Man is born to trouble, as the sparks fly upward.