The analogical design argument, because of its inadequacy in furthering the cause of theism, seems to be in some disrepute today among leading theologians. It is usually relegated, along with most of the other arguments in the repertoire of 18th century natural theology, to the history of philosophy. However, Dr. Geisler has given us a more contemporary formulation and, therefore, deserves a more contemporary answer.
It is important to keep in mind that an answer to his argument is not tantamount to a case for atheism. The best a good answer can do is show that, among proposed proofs for God, this argument won't cut the mustard. That is all that this response is intended to accomplish.
The first way in which Geisler modernizes the traditional analogical design argument is by basing it on the scientific principle of uniformity—that "the present is the key to the past." However, his use of that principle as a basis renders any success he achieves devastating to the claims of most of his fellow creationists. These people don't seem to share Geisler's apparent enthusiasm for uniformitarianism. The story of the worldwide flood and other alleged catastrophic creation events involves processes not observable today. Thus one cannot have both the creation "model" and Geisler's argument from design. Of course, Geisler may actually reject the creation "model" and merely desire to prove a designer. If so, he is not properly a part of the scientific creationist movement and we can cease this line of criticism.
Still, his use of the principle of uniformity is a problem. The principle of uniformity is a naturalistic premise. One uses this principle precisely because one is not admitting miraculous, mysterious, or other processes into the argument, processes that are commonly called up in support of supernatural powers. Yet Geisler uses this principle apparently to demonstrate a supernatural designer. This is contradictory: arguing from naturalism to prove supernaturalism. In logic, a conclusion is never allowed to refute its premise, yet this is precisely what Geisler seeks to accomplish.
Can we save Geisler's argument by dropping the appeals to uniformitarianism? No we can't. The whole argument is dependant on a very weak analogy which breaks down as soon as it is examined. Following the lead of Matson in The Existence of God (pp. 123-125), let's clarify the argument by condensing it down to a single syllogism and then look at it more closely. Geisler's modernized version of William Paley's argument can be summarized in the following way:
Life forms share with artifacts the common possession of a patterned information content.
Artifacts possess this patterned information content because they are products of intelligent design.
Therefore, life forms possess this patterned information content because they too are products of intelligent design.
That is really all Geisler has said. As a result, we are left with some questions. For example, is the intelligent design that is claimed to be evident in life forms the product of a supernatural being, or only of a human being? Since Geisler is following Paley, I would assume the intent is to prove that life forms were created by a supernatural being who, in addition, created the entire universe. But Geisler's argument doesn't actually say that. It only declares that the design evident in artifacts is also present in life forms. Who did the designing? Humans? "Ancient astronauts"? Some assembly line somewhere? There is really nothing in the argument to compel us to look outside nature for the designing intelligence. And there is nothing to compel us to imagine that the designer(s) is even still alive. The analogy will work in quite a number of ways. As a result, even if correct it would prove very little.
These issues aside, there is the greater problem that the analogy isn't very complete. Even if we agreed that Geisler had made a case for the supernatural intelligent design of life, we would still have to carry the analogy further. How was this life designed? We can find out by asking how Mt. Rushmore was designed. Our answer will be that the sculptor went through a learning process wherein he made many mistakes, then he made smaller and different works of sculpture, then he made various experimental models of Mt. Rushmore before choosing the one he liked, and finally he made, over a long period of time, Mt. Rushmore.
Seeing the full effects of the argument, let us now apply the same sort of analogy to another case. The result should be an argument that is equally as true or as false as the previous one.
Life forms share with artifacts the common usual characteristic of being colored.
Artifacts have color because often they are painted or dyed.
Therefore, life forms have color because often they too are painted or dyed.
To some, this argument might suggest a divine painter, artistic "ancient astronauts," or humans who go around dying animals. All the living things with color might be used to support such conclusions.
Of course this painter analogy is clearly silly. But since Geisler's argument follows the same pattern, it shares the same judgment. His is too weak an analogy to work or be useful and must therefore be rejected as unhelpful to the cause.
But let's not stop here. Let's look at different applications that Geisler makes of his analogy to see if he even applies it consistently.
If we start with the example of crystals in a cave, we actually see that he rejects his analogy outright. He agrees that crystals show apparent design, but he accepts that such design occurs through purely natural causes because he agrees with scientists who say that natural causes are known to "regularly produce such redundant order." Why, then, does he have trouble believing that life can form or change by natural causes? There are no lack of scientists who say that it can and who refer to known natural causes. So if he can depart from his analogy when it comes to crystals, why not when it comes to life? Does one idea bother him more than the other?
The rationale that Geisler provides for his inconsistent position is that life possesses a code that crystals are without and hence crystals display only "redundant order." Are these facts significant? Crystals, particularly snow crystals, possess an intricate symmetry that eroded stones are without, but did that stop Geisler from, in effect, putting crystals on a par with stones? Not at all. Yet it would seem that if it takes intelligence to make a design, even a design with "redundant order," by analogy it must take intelligence to make a snow crystal. The redundancy in the pattern of the crystal is no more an argument against its being designed than is the redundancy in the pattern of mass-produced models of Mt. Rushmore sold in South Dakota souvenir shops. One can't selectively use the analogy for sculpture and life but not snow crystals just because sculpture and life have different characteristics from snow crystals. They have characteristics different from each other as well!
Of course, Geisler goes on to argue that the human brain is incredibly complex, possessing information sufficient to fill the world's largest libraries. Is this argument grounds for giving the brain special consideration over snow crystals? Not if you consider that snow crystals, though individually less complex than the human brain, often appear in great abundance, with no two designs being alike. These designs, if translated into sculpture, would exceed the capacity of the world's largest art galleries. So why doesn't Geisler reject, "without further reflection," any suggestion that this vast art gallery of the skies might have emerged naturally from simple rain drops frozen around dust particles. His mind should reel at the improbability of such massive amounts of original artwork arising spontaneously by purely natural means! Yet he actually has no trouble accepting the natural origin of crystals.
Now let's go to the analogy of the watchmaker and see if his use of that is consistent.
In the watchmaker analogy, William Paley compared finding a watch to finding a well-organized life form. Now, I will grant that if I have experienced seeing watches made by watchmakers, and then I later see a watch on the ground, my common sense will tell me that this artifact was made by a watchmaker. Even if I see an unfamiliar manufactured object, I will most likely immediately recognize it as an artifact. But if the unfamiliar object I see doesn't look like anything I have ever seen produced by human hands, I have no analogy to draw upon. For example, I've never seen life created or a creator of life. Thus I can't claim that uniform experience leads me to the idea of intelligent design in life forms.
Geisler says, however, that coming to his conclusion is as scientific as the conclusions arrived at by archaeologists. This is clearly false. Archaeologists have uniform experience to draw upon; Geisler does not. Chemists are having some trouble showing how life could come from non-life for precisely the same reason. There is only a small amount of uniform experience to draw upon. Uniform experience comes more abundantly, however, in the matter of the evolutionary changing of one life form into another. There the scientist draws upon observed small changes in life forms today and an observed fossil record that shows systematic variation. He observes that the present is analogous to the past and so he draws the commonsense conclusion that evolution is the cause behind present life forms being the way they are. Geisler seems unwilling to apply this analogy.
In the Mt. Rushmore example, Geisler doesn't think that any person in his senses would attempt to account for the faces in the rock by arguing that these are just among the forms rocks may naturally take, that there might be a mechanism operating in the rocks causing them to form what only appear to be sculptured faces. By analogy, he clearly implies that if we see apparent design in life forms, we should not attempt to account for it with similar arguments (though it is seemingly all right to account for apparent design in crystals this way).
This analogy might fit if we really had no knowledge or idea of processes or laws that could bring about life forms so organized that some people would think they were designed. But we do have such knowledge. In the case of Mt. Rushmore, then, if we had actual evidence to support the existence of some natural face-forming mechanism operating in the rocks, we would not be foolish to accept this evidence. Looking at the body of knowledge in science today, however, we learn of no mechanism like Geisler described operating within rocks, but we do learn of a mechanism affecting life forms. This mechanism is natural selection. Analogies become less important once one has evidence of the existence of the mechanism at issue.
Let's pursue this further. Paley argued that intelligently designed objects show "marks of contrivance" whereas objects that are not designed don't. Geisler follows this line by arguing that the DNA code is such a "mark of contrivance" and hence life forms were designed. What he fails to consider is that a so-called "mark of contrivance" can be caused by a mechanism other than intelligent design. As the evidence now stands, there are two known sources of these marks, human intelligence and natural selection. The "marks of contrivance" on Mt. Rushmore and in a library can be explained by human intelligence. The "marks of contrivance" of the DNA code can be explained by the process of natural selection. Therefore, there is no essential reason why a person must be limited to seeking an intelligent designer, particularly a supernatural one, for the complexity found in life.
It is curious that Geisler makes no mention of this mechanism except in his second footnote. And when he does mention it there, he shows that he misunderstands it by his improper limiting of its scope. No doubt, if scientists were as unaware of the power of natural selection as Geisler seems to be, they too, being stuck with purely random natural events as the only alternative, might be tempted to imagine an intelligence behind the DNA code.
Apparently Geisler believes that natural selection only weeds out misfits and maintains the purity, as it were, of the original life form. But for him to take this position, he has to hold that life forms are never known to change, a position that runs directly contrary to the evidence. Beneficial mutations are frequently observed in animals, there are new strains of virus and bacterium that arise, and animals are sometimes observed to adapt in small ways to their environment, occasionally in ways that make it difficult or impossible for them to interbreed with the original life forms from which they evolved.
For Geisler to suggest that these changes don't represent the production of "an entirely new form of life" is for him to get caught up in the largely semantic issue of species definition. Categories like species, family, order, and so forth are pretty much arbitrary divisions developed (and constantly revised) by scientists for the sake of convenience. Different specialists, in fact, divide life forms differently. So the supposed difficulty in observing the formation of "an entirely new form of life" has no significance. Given the small changes we see, sufficient time, and the absence of any force to prevent the accumulation of these small changes, evolution on larger and larger scales becomes inevitable. This is due mostly to the combination of mutation and natural selection.
A good part of Geisler's analogical argument depends on the supposed easiness of separating artifacts from natural objects. But it isn't always that easy. A person could conceivably smooth a stone in such a way that it was indistinguishable from one smoothed by a stream. How could anyone judge which was which? If a stone face in the side of a mountain were carved crudely enough, it might be impossible to distinguish it from natural features. By the same token, some natural features bear an uncanny resemblance to human-made objects, often to the point that they have been mistaken for such. One of the most recent examples is the creationist mistaking of random erosional features along the Paluxy River for human footprints. In the Smithsonian natural history museum there is an exhibit on "false fossils," and one item is a fossil "horseshoe print" that, in reality, is a random feature of the rock. Because of these facts, Geisler's criterion is unsuitable and unreliable. The appearance of "marks of contrivance" can be deceptive and their absence proves nothing.
Sitting back and looking at the broad outlines of Geisler's argument, it becomes clear that he is using analogy to show that life forms resemble artifacts in the possession of the features of "intelligent design." Then he is using the principle of uniformity to show that intelligent design is always the result of an intelligent being. Nowhere does he specify the nature of the intelligent being responsible for life, making his whole case appear, on the face of it, to be an argument supporting the human creation of all life. But, were we to raise that possibility seriously, Geisler would no doubt repeat his point about "the intelligence it takes to create computers which can also create." He would ask us what intelligence created the human intelligence that supposedly created life.
This would take us where his paper by itself does not, into the realm of the supernatural. But when we got there, and he told us that the buck stops with the supernatural creator, would we not be justified in repeating his own question about the intelligence necessary to create intelligence that can create? After all, he established it in the beginning that complex information content implies design and that design requires a designer. Well, the supernatural creator would certainly show evidence of complex information content, hence design. So, by Geisler's own rules, the supernatural creator would require its own creator, ad infinitum.
Geisler's point about the infinite regress not being acceptable does not save him from the consequences of having his conclusion defeat his premises. It merely shows that, while he finds an infinite regress unacceptable, he perhaps has no difficulty with self-contradiction. And the infinite regress doesn't even have to be there. This is a problem of Geisler's own making. He adopted as a basic principle that design requires a designer. This has the infinite regress already built in! The solution seems to require that Geisler get off of the "intelligent designer" bandwagon and opt for a natural, non-intelligent source of human creativity. But that would lead him straight to naturalistic evolution, a predictable conclusion for an argument beginning with naturalistic premises.