When I reviewed Stephen Meyer’s Signature in the Cell I was a year late commenting on what others had said about it, and the book came out a year before that. Not wishing to sully my track record, I’m over two centuries late in reviewing William Paley’s Natural Theology. I read the book because it’s almost universally compared (unfavourably) with Origin of Species, and even opponents of Darwinian evolution speak mainly of its weaknesses.
I suspected that a book apparently so mistaken, which nevertheless was a bestseller throughout the nineteenth century, had probably been misrepresented. Having read Origin of Species recently, I thought it was an opportune time for comparison.
The first thing to say is that Natural Theology clearly suffers from having been written early in the modern scientific period and therefore makes some errors of fact, and in most cases can only deal with its subject matter at what, by today’s standards, is a superficial level. Neither is it able to interact with evolutionary theory in any real way, Darwin’s book being 60 years in the future. Lamarck’s unrefined ideas get a mention, and some justified criticism.
So it is true that, for the most part, Paley’s argument relies on a simplistic design hypothesis: “Look at these wonderful and obviously designed features of the world, especially of living things – the inference is that there is a wonderful designer.” It’s also true, as many modern critics point out, that the emphasis on mechanical analogies like watches is limited both scientifically and theologically.
But I think both these criticisms are unfair. In the first place, and most importantly, Paley was not trying to write a scientific proof of God, but a theology of nature, and the distinction is important. Towards the end of the book (and most criticisms don’t get beyond the first chapter or two) Paley says that his aim is not to provide “proof” for those who deny the existence of God (and there were many in his time), but to strengthen the convictions of those who do believe in God, but have not deeply considered the marks of his work in nature. It is also intended to lead the uncommitted to a frame of mind where they will investigate Paley’s other works, on the moral and Scriptural arguments for God. This remains a valid methodology. Even within an evolutionary framework, to look more closely at the big picture and see God’s hand in it is one foundation of, say, theistic evolution, and a valid impetus to worship for the believer. One could view Paley’s target readership as those who, in Alvin Plantinga’s terms, have an internally “warranted” belief in God.
The second criticism, that he takes too mechanical a view of nature, is surely forgiveable in the light of the “clockwork Universe” science of his time; but in any case at more than one point he is quick to point out the limitations of the design analogy. Indeed, he is very open to the possibility of secondary agents and causes, by which I suspect he mainly thought of angels but which he might easily have applied, in a later age, to material mechanisms. Like modern design theory, it was the undeniable signature of design within nature, rather than a recourse to God’s direct or miraculous activity, that underpinned his case.
I should note in passing that Paley even anticipated the modern argument from fine-tuning of the Universe, from within a very much less-developed physics. So he points out how the inverse-square law of gravity, which appears arbitrary, is absolutely necessary to the Universe’s operation as opposed to, say, an inverse-cube law. I saw that very example in a recent defence of fine-tuning.
My main impression, though, is of the great similarity between the book and Darwin’s Origin. I came away with the strong impression that the later work was largely intended as a rebuttal of Paley’s book. This close literary relationship would hardly be surprising, since Darwin always acknowledged his early dependence on Natural Theology. I’m not, however, so convinced that Darwin really had a “Damascus Road” conversion from Paleyism, as his writings might suggest. Paley expressly dismisses (from the viewpoint of his contemporary science) the mutability of species, and quietly criticises Darwin’s grandfather Erasmus for his evolutionary views. The young Charles was also surely from the start more sympathetic to his grandfather’s religious skepticism and radical sympathies than to Paley’s conservative (and Tory) approach. The scholars argue about when Darwin lost his faith, but it is known he had more or less abandoned his specifically Christian convictions, and any abiding interest in religion, well before he wrote the Origin. The pivotal loss of his daughter occurred whilst it was actually in progress. There is evidence that the “religious” references in various editions had more to do with placating his readers than sharing his faith.
The similarities between the two books have been noted elsewhere, but here I will mention the parallel use of “one long argument” to build a cumulative case even where individual elements might be weak; the stress in Darwin on fitness and apparent design, for which his theory provides a naturalistic cause over against Paley’s theological conclusion; and an emphasis in both on the generally harmonious economy of nature (despite a Malthusian struggle for existence). Darwin’s work on living organisms is more detailed, because of his background as a naturalist, but then Paley’s brief is wider, drawing also on anatomy and astronomy.
It has been said that Darwin’s drift away from God as Creator was a consequence of his discovery of natural selection, but given that most of Darwin’s arguments for “natural evil” are covered in depth in Paley, it seems to me that Darwin brought his skepticism to bear from the beginning, however much this was reinforced by the effect on his beliefs of his daughter’s untimely death. The younger man, in other words, always had a metaphysical intent: evolution by natural selection was presented from the start as an alternative to the work of the Creator, whereas it could very easily have been put forward as a secondary means of God’s designing activity.
I conclude that both works are books with comparable intent, but informed by, and concluding in, very different metaphysics. Since both have suffered in their factual accuracy from two centuries of new discoveries, in my view they now deserve to be read together for a full-orbed appreciation of the metaphysical issues facing nineteenth century science.