The design debate: why evolution succeeds where the teleological argument fails – Part 2
The Formalized Teleological Argument
The first true arguments from design (those that argue for the existence of an intelligent creator) originated during the scholastic period, shortly after the turn of the second millennium AD. Perhaps the most well known of these is Thomas Aquinas’ teleological argument, which he presented in the thirteenth century as part of his “Summa Theologica.” Aquinas, just like Aristotle, perceived an apparent purposiveness to living things, and believed that this proved the existence an intelligent creator. As a part of his argument, Aquinas compared life to an arrow in mid-flight. An arrow is mindless, he reasoned, but it flies towards a target because it has been directed by an intelligent archer. Similarly, he argued, living things – even those without minds or intelligence – continuously pursue ends, and must therefore have been directed by an intelligent being.
This latter part of Aquinas’ argument insists that, as with the arrow, the purpose and direction inherent in unintelligent life must be due to an intelligent force. Thus, his argument is predicated on the critical assumption that the purposiveness of living things cannot have arisen via mindless natural forces. This assumption, together with the direction in the natural world, necessitates the existence of an intelligent creator.
A similar presumption exists in the teleological argument proposed by William Paley in 1802. Adapting Cicero’s comparison of life to a timepiece, Paley argued for the existence of God using his own watchmaker analogy. This can be illustrated by comparing a watch to a stone. By looking at a watch, we can see that it is comprised of numerous intricate and detailed parts that have been precisely pieced together – it has order and complexity to it. What’s more, the parts of a watch function in such a way that it tells us the time. This utility is an indication that a watch acts towards an end. And of course, we know that any watch is the product of an intelligent human designer. Thus, our analysis of the watch suggests that order, complexity, and purpose are characteristics of designed objects. By contrast, if we look at a stone we notice that it does not possess the same degree of ordered complexity. A stone typically appears to be just a lump of earthen material. Moreover, there is no indication that a simple stone has any purpose to it. A stone itself does not perform any function or act towards any end; it is instead quite inanimate. And of course, we all know that a simple stone is the product of mindless, natural forces. Thus, we might conclude that lack of ordered complexity, and lack of purpose are characteristic of objects that have not been designed.
This comparison illustrates a crucial piece of logic in Paley’s teleological argument: that all objects can be divided into two categories. One of these categories is for designed objects, which have order, complexity, and purpose; the other is for un-designed objects, which lack each of these qualities. According to Paley’s teleological argument, since life can be seen to have order, complexity, and purposiveness, it fits into the first category, and therefore must have been designed. Consequently, an intelligent designer must exist.
This logic is presented in different ways in different versions of the teleological argument, but the underlying line of reasoning is the same in each instance. The arguments of Paley and of Aquinas, as well as the conjecture of both Cicero and Aristotle, all pre-suppose that order, complexity, and purpose – in short, the appearance of design – cannot have resulted from mindless natural forces, and are instead the product of an intelligent designer. This is the essence of the teleological argument, and underlies all of its forms.
Refutations of the Argument
Counter-arguments against the argument from design have come in three different varieties. The first two of these do not deal directly with the biology at hand, and so I will only touch on them briefly. The third, however, delves straight into how the teleological argument treats living things, and so it is this third objection that will be the primary basis of my criticism.
The first type of complaint lobbied against the argument from design is that it does not provide an adequate resolution to its own problem. According to the teleological argument, ordered complexity indicates design, which in turn necessitates the existence of a designer. This logic is applied to living things, and it is asserted that an intelligent designer must be responsible for life. However, a designer is nearly always more complex than the things that it designs (indeed, a human is exceedingly more complicated than any watch or other timepiece). It therefore stands to reason that whatever being designed life must be even more complex than a human or any other life form. If complexity indicates design, then this begs the question of who designed the designer. Of course, one could always argue that there is another designer behind the first, but this being would be yet more complex, and only magnify the issue further. Layer after layer, this solution leads to an infinite regression of ever more complicated designers and is therefore no solution at all. It is a problem that was noted in the eighteenth century by the philosopher David Hume, in “Dialogues concerning Natural Religion,” and it means that the teleological argument does not provide a viable explanation for the ordered complexity of the natural world.
A second flaw in the argument from design, and specifically concerning Paley’s watchmaker argument, is that it makes use of faulty analogy. It is perfectly possible to distinguish between the characteristics of objects of human design and those that are the result of mindless natural forces, because we can readily find examples of both in the world around us. The case of comparing a watch to a stone is a perfect example of this. We cannot, however, distinguish in the same way between the properties of a designed universe and one that is not designed. The problem lies in the fact that all human experience is confined to the single universe that we inhabit. We have no basis with which to judge our universe against other types of universes, and thus cannot reason if ours is a designed one or not. This, too, was described by Hume, in “An Enquiry concerning Human Understanding,” and it means that the watchmaker analogy cannot be applied to our universe, nor the living things that it contains.
The final objection to the teleological argument, and the one that I am most interested in espousing, is that the argument from design presents a false dichotomy. The teleological argument depends upon the assumption that all objects can be placed into one of the two categories described above. In doing so, it ignores the fact that a third category of objects exists. Taking the example of crystals, these objects have rigorous order to their chemical composition, and can often grow into elaborate and somewhat complex structures. The same can be said about snowflakes. But both of these objects are the products of natural causes. As these examples go to show, the properties of order and complexity can result from mindless natural processes, and thus are not necessarily an indication of a designer. This demonstrates that there is a third type of category into which objects can be placed: one for those that are ordered and complex, but not designed. I believe that the teleological argument fails because living things belong in this third category.