BEFORE DARWIN:
Reconciling God and Nature.
By Keith Thomson. Yale Univ. Press. 314 pp. $27

Reviewed by David Lindley

Strict creationism may not have gone away altogether, but for now it’s mostly in abeyance. These days, school districts in Kansas, Pennsylvania, and elsewhere are treating us to a debate on the “intelligent design” theory of life. Whether for sincere or merely tactical reasons, proponents of this latest anti-Darwinian ruse are willing to allow that some evolution occurs. The increasing prevalence of antibiotic-resistant bacteria is an urgent example that’s hard to ignore. So, yes, change happens. But that’s as much ground as the intelligent design crowd is willing to cede. The complexity of life, they say, is too great to be explicable by the spontaneous and purposeless actions of nature. The marvelously fine-tuned architecture of living organisms indicates a design, and design implies a designer. Ask who or what this designer might be, and you tend to get an innocent smile and a soothing assurance that this is a question—a scientific question, mind you—that only continued research can answer.

If nothing else, this latest installment of a long-running saga illustrates the old saw that those who don’t know history are condemned to repeat it. The apparently irresistible proposition that the earth and all it carries must have been put together deliberately has ancient roots, but intelligent design in its modern form is most usually traced to William Paley, archdeacon of Carlisle, who in an 1802 book titled Natural Theology came up with a famous argument about a watch. If, Paley said, you were wandering across a heath, tripped on something, and looked down to discover a watch lying in the grass, you would hardly imagine it got there of its own accord. Nor would you think such a clever little machine had sprung into existence spontaneously. No: Complex mechanisms cannot arise unaided. They must be designed and constructed. And so it is with life itself, Paley asserted.

But as Keith Thomson, a professor emeritus of natural history at the University of Oxford, shows in this engrossing and rewarding book, vapid summaries of this sort do enormous injustice to Paley, and to the profound and tortured arguments over the origin of life that swirled about in the century and a half preceding the publication of Origin of Species in 1859. For Paley was not some narrow-minded defender of biblical literalism, but a man of reason, a creature of the Enlightenment. His aim was not to vanquish science by means of religion, but quite the opposite. The nascent ideas and principles of science, he thought, would serve to bolster faith by demonstrating the inescapability of God’s hand in our world. The great irony of Paley’s failure, Thomson makes clear, was that many of the crucial issues he wrestled with were precisely those that led Charles Darwin to a quite different conclusion.

In earlier times, faith in God rested on biblical authority, augmented by the occasional miracle to show that he was still paying attention. Creation happened all of a piece, on Sunday, October 23, 4004 b.c., as Bishop James Ussher had calculated in 1650. But in a world increasingly devoted to reason, such thinking began to seem ludicrously primitive. Naturalists (a term encompassing what we now call geologists, botanists, and zoologists) began first to classify the world around them, then to make sense of it. They discerned function and mechanism in what they saw; the cliché of the world as a great, interconnected machine took root. The argument for God’s existence changed: The very fact that the world worked in such beautiful harmony was proof of his creating and guiding power.

But the naturalists also saw that the world was changing. Rocks built up and eroded away. Fossils betrayed the former existence of creatures that were no longer to be seen. Change posed a problem, especially when coupled with the conviction that the world was designed for human happiness. Was the Creation, then, less than perfect?

This, in a nutshell, was the tension that Paley hoped to resolve. To get to this point, Thomson reaches back into history and delivers a rich narrative of observers and thinkers who, starting in the late 17th century, began to see how evidence of evolution—a word that means, neutrally, that the world is not constant—challenged theological dogma. Unusually for a writer on the side of the scientists, Thomson knows his religious history, and displays a warm sympathy for the efforts of those who sought strenuously and sincerely to adapt their faith to the growing body of scientific argument about the world’s origins. The early naturalists were pious men, but modernists too. They left biblical literalism quietly behind. The Flood, for example, became a metaphorical episode, standing in for all the disruption and geological upheaval that scientists now adduced as the explanation for the world’s present form.

Some skeptics saw which way the wind was blowing. In the 18th century, Da­vid Hume offered an argument against design, observing that organisms lacking some minimal aptitude for life in their environment wouldn’t be around for us to notice. This, as Thomson points out, foreshadowed Darwin’s essential idea of natural selection—fitness determines survival.

Paley’s Natural Theology, in Thomson’s fascinating and persuasive presentation, emerges as the last desperate effort of a man determined to keep religion, science, and reason together. Unlike many who repeat it today, Paley knew that his watch argument by itself proved nothing. For one thing, watches don’t usually shower forth litters of tiny new watches, whereas living creatures generate new versions of themselves. But if animals and plants, unlike watches, create their own offspring, what differentiates the original act of creation from all the subsequent ones that took place on their own?

By the time Paley composed his argument, the notion of a world generated through cumulative small change, both organic and inorganic, was already stirring. Erasmus Darwin (grandfather of Charles), Hume, the Comte de Buffon, and others had all made suggestions along these lines. The sticking point, as Paley shrewdly saw, was tied up with the evident suitability of life to the world in which it lived. It’s not simply that you have to produce lungs, for example. Those lungs have to work effectively in the atmosphere in which they have appeared—and it was this harmonization of internal function to external purpose that Paley seized on as proof of the necessity of design. How could blind processes of nature create such coherence?

That, of course, is precisely what Charles Darwin explained. Darwin’s theory has two ingredients. Organisms change a little from one generation to the next. Natural selection then weeds out harmful changes and promotes helpful ones. Evolution is not, as some of its critics even now insist on thinking, a process of pure chance, but an elaborate form of trial and error that creates harmony, yet does so without advance planning.

Most impressive in Thomson’s artfully told tale is his evenhanded respect for the losers as well as the winners. All wanted to get at the truth, but in the shift from religious to scientific understanding, the meaning of truth itself became the subject of contesting philosophies. The debate nowadays, with both sides lobbing slogans back and forth, seems paltry by comparison. Thomson’s spirited book brings to mind another adage about the repetition of history—how it comes first as tragedy, then as farce.