Natural Theology

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    This may seem an inappropriate choice to begin a series of essays on the theory of evolution. But the book that Reverend William Paley (1743 Jul _ – 1805 May 25) titled "Natural Theology or Evidence of the Existence and Attributes of the Deity, collected from the appearances of nature" stands as one of the more important texts pertaining to the theory. First, it gives us the best possible exposition of the Argument from Design for the existence of God, the foundation of the original creationism whence the theory of evolution sprang. And second, it shows us one of the primary influences that inspired Charles Darwin, who read it when he studied for the ministry at Christ’s College in Cambridge (where he resided in the same room that Reverend Paley had occupied when he had studied at Cambridge).

    First published in 1802, "Natural Theology" quickly became, for its time, a best seller, as had Reverend Paley’s other books (along with "Natural Theology", "The Principles of Moral and Political Philosophy" (1785), "Horae Paulinae" (1790), and "Evidences of Christianity" (1794) constituted Paley’s vision of a comprehensive overview of the Christian religion). Oxford University Press republished the original 1802 text in 2006 as part of its Oxford World Classics collection so that modern readers can see for themselves that, while he was not much of an original thinker, Reverend Paley was an excellent writer. Even though he still used the inflected verbs that we associate with Shakespearean English, Paley had such an easy-to-read style that I forgot as I read the book that Paley had written it over two hundred years before. So much did I forget that fact that I felt considerable astonishment when I read (in Chapter XIX), "Europe has lately been surprised by the elevation of bodies in the air by means of a balloon." It actually took me a few moments of thought to recall to mind the fact that the Montgolfier brothers had lofted the world’s first hot-air balloon about fifteen years before Paley began writing in "Natural Theology".

    Paley opened his argument with a now-famous image:

    "In crossing a heath, suppose I pitched by foot against a stone, and were asked how the stone came to be there, I might possibly answer, that, for any thing I knew to the contrary, it had lain there for ever: nor would it perhaps be very easy to shew the absurdity of this answer. But suppose I had found a watch upon the ground, and it should be enquired how the watch happened to be in that place, I should hardly think of the answer which I had before given, that, for any thing I knew the watch might have always been there, yet why should not this answer serve for the watch, as well as for the stone?"

    Paley answered that question by pointing out that the watch differs from the stone in possessing the clearly evident properties of mechanism and contrivance. Unlike the stone, the watch consists of elaborately crafted parts put together in such a way that a pair of pointers move across a dial and thereby show the elapse of time. Parts moving together as a unit give us the epitome of mechanism and if that mechanism moves in accordance with a purpose, we can infer contrivance. The heart of Paley’s argument, then, consisted of the assertion that contrivance proves and verifies design.

    Having established the foundation of his argument, Paley devoted the rest of the book to piling up example on example drawn from nature and explaining how he conceived each example as evidence of contrivance. He reasoned by analogy, beginning by comparing the eye to a telescope, examining each of its parts, and describing how each part contributes to the function of the eye/telescope as a whole. In Chapter VI he stated, "The proof is not a conclusion, which lies at the end of a chain of reasoning, of which chain each instance of contrivance is only a link, and of which, if one link fail, the whole falls; but it is an argument separately supplied by every separate example. An error in stating an example affects only that example. The argument is cumulative in the fullest sense of that term." When his own turn came to interpret the natural world, Charles Darwin used a similar plan of cumulative examples.

    Paley’s reference to the complexity of the eye may look familiar to his modern readers. Many of the arguments used by Creationists appear in "Natural Theology". Consider the comment that Paley put into Chapter V: "What should we think of a man, who, because we had never ourselves seen watches, telescopes, stocking-mills, steam-engines, etc. made; knew not how they were made; or could prove by testimony when they were made, or by whom; – would have us believe that these machines, instead of deriving their curious structures from the thought and design of their inventors and contrivers, in truth derive them from no other origin than this; that, a mass of metals and other materials having run when melted into all possible figures, and combined themselves in all possible forms and shapes and proportions, these things which we see, are what were left from the accident, as best worth preserving; and, as such, are become the remaining stock of a magazine, which, at one time or other, has, by this means, contained every mechanism, useful and useless, convenient and inconvenient, into which such like materials could be thrown?" Compare that image in your mind with one of the Creationists’ favorite criticisms, which criticism tells us that a tornado blowing through a junkyard will not produce a Boeing 747 (which statement certainly stands true to Reality, but has no relevance whatsoever to the theory of evolution).

    Although I regard this as an important text in the history of the theory of evolution, I point out that Reverend Paley did not intend his book as an explanation of how life came to have the forms that we see in nature. Indeed, Paley assumed, as most of the scientists of the time did, that life on Earth had not changed since the Creation, in 4004 BC. That assumption supported Paley’s argument: if life forms don’t change, then the closeness of the fit between an organism and its environment can only bespeak contrivance. For Paley contrivance provided the evidence that he needed to prove and verify the existence of God, the master contriver of Reality. It simply did not occur to anyone at the time, or to Charles Darwin in his time, to think that the close fit between an organism and its environment needed any explanation.

    Paley put a great amount of effort into crafting the argument for his case, because he intended "Natural Theology" to stand as the foundation of what, with his other books, would present to the world what we might call the Unified Theory of Christianity (at least the Anglican version of it). But Paley’s argument falls before one question, which no one seems to have asked at the time: how can we certify contrivance in nature? How can we know for certain that what Paley presents to us actually displays mechanism and contrivance?

    We can’t. Reverend Paley ran afoul of the human tendency to see patterns where none truly exist. As the Ancients looked at the sky and conceived the stars as making patterns, constellations, to which images and stories accrued, as Michael Faraday looked at the patterns that appeared in iron filings sprinkled on a sheet of paper when a magnet came near and conceived lines of force comprising a forcefield, so Paley looked to the natural world and conceived biology as an elaborate Newtonian clockwork mechanism. In Chapter XIX he provided an excellent example of such an analogy:

    "Some years ago, a plan was suggested, of producing propulsion by reaction in this way. By the force of a steam engine, a stream of water was to be shot out of the stern of a boat; the impulse of which stream upon the water in the river, was to push the boat itself forward: it is, in truth, the principle by which sky-rockets ascend in the air. Of the use or the practicability of the plan I am not speaking; nor is it my concern to praise its ingenuity; but it is certainly a contrivance. Now, if naturalists are to be believed, it is exactly the device, which nature has made use of, for the motion of some species of aquatic insects. The larva of the dragon fly, according to Adams, swims by ejecting water from its tail; is driven forward by the reaction of the water in the pool upon the current issuing in a direction backward from its body." He might also have mentioned the octopus, which uses its siphon to propel itself through the water.

    If we focus our attention upon the principle of jet propulsion (and ignore the fact that Paley did not describe it quite right: few people do), then we see a clear analogy between the boat and the octopus or the dragonfly larva, as Paley intended. But if we instead focus our attention on the facts that the boat’s engine comes from craftsmen shaping and assembling its parts while the octopus’s siphon grows as part of the animal, then the analogy seems less clear: on the one hand we have a clearly contrived mechanism, but in the cephalopod’s siphon we have a fleshy tube that doesn’t conform to our usual notions of machinery. Paley could only make his analogy work by virtue of the fact that no one at the time had an alternative explanation for the origin of jet propulsion in molluscs or in insect larvae.

    To put it bluntly, "Natural Theology" stands before us as a work founded on ignorance. It was not the willful and contemptible ignorance of the present-day Creationist, but was rather the necessary ignorance of a man whose society did not possess the knowledge that he needed. In the book Paley mentioned "chymistry" several times, but at the beginning of the Nineteenth Century chemistry as we understand it did not yet exist. Natural philosophers had only just begun to develop a true science of the composition of matter out of the gibberish and ætherial treasure maps in the bizarro-realm of alchemy. Likewise, the science of biology consisted of little more than naturalists compiling catalogues of organisms along with descriptions of their habits and habitats in accordance with the Linnaean system of classification (and Paley did make good use of those). Nobody knew that living matter consists of cells. Heredity remained a complete mystery. Paley had no possibility, then, of giving a correct accounting for life on Earth to support his argument.

    But every science must begin in some speculation about its topic and, almost inevitably, that speculation gives us an error. Somebody must make an initial guess so that someone else can see that it doesn’t match Reality and thereby begin the process of cumulative correction that constitutes science. In astronomy Claudius Ptolemy gathered up all of the knowledge that the Greeks possessed and organized it into The Almagest, using as his organizing principle the assumption that Earth exists motionless at the center of the world system. In 1608, while studying at the University of Bologna, Niklas Koppernigk noticed, and wrote in the margins of his own copy of The Almagest, that Mars and Saturn did not occupy the locations on the sky that he had calculated from Ptolemy’s theory. Ptolemy made Copernicus possible. In like manner Paley made Darwin and Wallace possible.

    This does not mean that we toss "Natural Theology" into the trash. It merely means that we must read it as we would read a work of science fiction or fantasy, employing the willing suspension of disbelief in order to enjoy the story. The book is worth reading for the pleasure of Paley’s style and its view into the world as it existed in 1802. And it does give us a nice-and-easy prelude to the hard trudge (and it is a hard trudge) through "The Origin of Species".


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