Comments?
I'd love to hear.
There have been anti-intellectual themes in Christian thought through much of its history -- thinkers and theologians who placed a heavy emphasis upon faith apart from or even against reasoned consideration of argument and evidence. That has not been the dominant view, however, and we cannot adequately understand either the importance of Darwin or the response of Christian thinkers without attending to an alternative and more reason-friendly tradition. The dominant Christian tradition was not a version of saying "I just believe"; it held instead that there were good reasons for believing. This didn't mean the theologians and philosophers thought they could prove every detail of their theology, just that there were good reasons for believing some of the basic propositions (like 'God exists') and that, once you did believe those, further reasons could be given for trusting revelation for more detail.
In particular, in the era just before Darwin, the design argument was in its heyday. At the turn of the 19th century came the publication of Paley's book-length version of the argument. Today, people read rarely more than a few paragraphs -- the story about finding a watch in walking across a heath and the question Paley urged as to whether it would be reasonable to think its intricate structure and functionality had been undesigned, combined with the comparison to the greater complexities of organs in animal life. But, though that is the most famous passage in Paley, he had far more to say than that. He was a smart man and fully up-to-date on the best science of his day. And he argued that that science, specifically what we knew about the living world, pointed inexorably towards a powerful and intelligent designer.
In fact, I believe that's a good argument. As long as you could assume with some of the ancients, such as Aristotle, that living species and the world were everlasting, a thinker could reasonably believe that questions about origins of complex living order were not pressing because species had not originated. But that assumption was collapsing under the weight of the evidence well before Darwin's time. (For some fascinating intellectual history of the period running from the 17th century through the time of Darwin, see John Greene's The Death of Adam.)
But with that assumption no longer available to reasonable and well-informed thinkers, the design argument as it took shape in the hands of Paley and a multitude of lesser thinkers began to take on overwhelming force. First, as they presented it, it was not an argument for the all-powerful (etc.) traditional God. Most of them hoped at a later stage of the argument to identify the Designer with the Christian God, but objections to the Christian God, even if they were correct, did not automatically defeat or weaken the case for a powerful and intelligent designer. Second, the argument was inductive in the sense that it called upon many pieces of evidence. This is something that gets missed or overlooked when we just read a handful of paragraphs from Paley -- "I can see how that might have come about by chance or ...." carries less conviction the more cases it is applied to. And Paley gives us lots of cases. In the end, in the light of the best scientific evidence available, the chance that there wasn't an intelligent and powerful designer looked vanishingly small.
I turn now to a couple of pieces of corroborating evidence that the design argument was powerful. First is the case of John Stuart Mill. Most of his life was lived before the publication of Darwin's theory. He had no religious training of the usual type and, throughout his adult life, never professed anything like orthodox religious faith. He was enormously erudite with a broad familiarity with the history of philosophical discussion of arguments for and against the existence of a God. Nonetheless, when he discussed the design argument, in Three Essays on Theism, he concluded that though (given other considerations) it wasn't enough to give strong support to belief in the traditional God, it did establish that it was more likely than not that there was an intelligent designer: A reasonable man would believe it, or at least could not be faulted for believing it.
Second, many people think Hume, nearly three-quarters of a century before Darwin published, buried the design argument in his Dialogues Concerning Natural Religion. And it is true that he offers remarkably ingenious criticism of the argument. But there are three problems that have gotten less attention than they deserve. The first is that some of his criticisms are of the design argument as support for the traditional God, loaded down with "omni-" attributes. They are weaker or not even relevant against the claim for some intelligent designer.
The second is that there is an interesting tension between the premises he uses in the Dialogues to discredit the design argument and those he relied upon elsewhere to discredit arguments from testimony about miracles. The anti-design arguments depend on a significant degree of skepticism about induction to make it plausible that some of the alternatives to design that Hume suggests (maybe the universe is really a vegetable, casting off seeds that grow into new worlds ....) are just as good at explaining the complexity and order of the living world as the hypothesis that there's a designer. But the arguments against accepting testimony for the occurrence of miracles rest on significant optimism about induction -- that we know the world and its laws well enough that we would almost always be better justified in rejecting testimony about a miracle than in believing that there has been an exception to the regularities that we think of as natural laws. To say the least, it's a delicate balancing act, to maintain just the right amount of inductive skepticism to keep the anti-design arguments working without being so skeptical that the anti-miracle arguments fall apart.
The third is that Hume himself seems to give in at the end. Hume, personally, was as tough-minded and doubtful about religious doctrine as anyone of his time. But at the end of the Dialogues, he has Cleanthes, the character representing his own view, admit that, after all that has been done to raise doubt about the design argument, there probably is something like an intelligent mind -- more like a mind than anything else we might use as a model -- behind the observed order of the universe.
What these considerations amount to, I think, is that the design argument really is powerful. Once you've given up the "everlasting species" doctrine, a complete world view has got to say something about how the complex -- and therefore unlikely -- order of the living world came about. The problem is that there are uncountably many more ways of not being alive than of being alive and, more specifically, uncountably maany more ways of arranging material components so as not to amount to a functioning organ, such as an eye, than of arranging components to form a functioning organ. It may -- barely -- be possible to maintain that the order of the living world is just an incredible run of strokes of luck, but it is hard to imagine anyone finding that an intellectually satisfying explanation. It's tantamount to saying your explanation is probably not true.
The importance of Darwin is that he showed how to defuse that argument without denying its premises or appealing to incredible runs of luck. In essence, the Darwinian solution is to explain how there can be design processes that don't involve a conscious designer. We need a bit of luck at the beginning to provide some kind of self-copying entities1 which, first, are not guaranteed to produce perfect copies and, second, for which some changes in structure can increase the likelihood that a given instance will produce further copies of itself. That provides the foundation for differential copying or, to put it in biological terms, differential reproduction. And differential reproduction can, over time, consistently sort designs into better and worse -- ultimately, better and worse at getting reproduced! -- and replace worse designs with better. Gradually and non-accidentally, the order of the living world emerges and the designs of creatures are slowly improved, without any foresight on the part of the processes responsible. The design argument is correct -- the complex order of the living world stands in need of an explanation, a designer capable of surmounting unimaginably large odds; what we now have in Darwin's theory is an empirically better-supported account of "the designer," namely, the processes of natural selection.
[1] How much luck is that? It's hard to say. On some accounts, like Cairns-Smith's (in Seven Clues to the Origin of Life), very little indeed. He thinks life began with something literally as common as dirt, clay crystals. Even if it's much harder than he thinks to get the right kind of self-copying entity to spawn an evolutionary process, it only needed to happen once in a very large universe.
