Manifestations of Design

For British researchers such as Sedgwick, God’s goodness was visible not just in the way He created Earth, but in the way He brought life into existence. Each species had been created separately and had been unchanged ever since. Yet species could also be grouped together–into categories such as plants and animals, and within them, into smaller categories such as fishes and mammals. This pattern, British naturalists believed, reflected God’s benevolent plan for the world. It was organized as a gradation that started with inanimate objects and the slimy forms of life and reached up toward higher and higher forms–“higher” defined, of course, as being more like humans. Not a single link in this Great Chain of Being could have ever changed, for that would mean that God’s creation had been imperfect. As Alexander Pope once wrote, “From Nature’s chain whatever link you strike/Tenth, or ten thousandth, breaks the chain alike.”

Not only did the Great Chain of Being reveal God’s benevolent handiwork, but so did the exquisite designs of individual species–whether you considered a human’s eye or a bird’s wing. William Paley, an English parson, laid out this argument in books that were mandatory reading for Darwin and other aspiring naturalists and theologians at Cambridge.

Paley’s argument centered on a seductive analogy. “In crossing a heath,” he wrote, “suppose I pitched my foot against a stone and were asked how the stone came to be there.” It might, for all Paley knew, have lain there forever. “But suppose I had found a watch upon the ground, and it should be inquired how the watch happened to be in that place.” In that case, Paley argued, he would come to a very different conclusion. Unlike a stone, a watch is made of several parts that work together for a single purpose: to mark the passing of time. And these parts can work only if they work together; half a watch cannot tell time.

The watch therefore must have been created by a designer. Paley could say this even if he didn’t know how to make a watch, and even if the watch he found was broken. To say that it was just one of many different possible combinations of bits of metal would be absurd.

When we look at nature, Paley argued, we find countless creations far more intricate than a watch. Telescopes and eyes are built on the same principle, with lenses that bend light in order to create an image. In order to bend light in water, a lens has to be rounder than it would be in air. Lo and behold, the eyes of fishes have rounder lenses than those of land animals. “What plainer manifestation of a design can there be than this difference?” Paley asked.

An oyster, a spoonbill, a kidney: anything Paley examined showed him that nature had a designer. The laws of physics, which astronomers were using at the end of the 1700s to describe the orbits of the planets, may have taken away some of the glory of God. (“Astronomy,” Paley admitted, “is not the best medium with which to prove the agency of an intelligent creator.”) But life was still fertile theological ground.

From nature, Paley deduced not only the existence of a designer, but that He was benevolent. In the vast majority of cases, he argued, the contrivances of God were beneficial. What little harm there was in the world was just an unfortunate side effect. A person might use his teeth to bite someone, but they were actually designed so that he could eat. If God had wanted us to cause each other harm, He could have designed much better weapons to put in our mouths. These sorts of shadows couldn’t distract Paley from the sunshine of life: “It is a happy world after all. The air, the earth, the water teem with delighted existence.”