For St. Thomas (following Aristotle), the formal and final causes of artifcats, like desks, computers, and iPods, are imposed from outside the collection of parts by an intelligent agent. On the other hand, the formal and final causes of natural objects are intrinsic to those objects. This is why, as Aristotle points out, if you own a bed made out of wood and then plant a piece of the bed in the ground, “it would not be a bed that would come up, but wood.” This “shows that the arrangement in accordance with the rules of the art is merely an incidental attribute, whereas the real nature is the other, which, further, persists continuously through the process of making.” In other words, the form and finality of the bed is imposed from without (an “arrangement in accordance with the rules of art”) while the form and finality of the wood is intrinsic to the nature of the tree from which it was taken (“the real nature” that “persists continuously through the process of making”). In the words of Etienne Gilson, “The artist is external to his work; the work of art is consequently external to the art which produces it. The end of living nature is, on the contrary, cosubstantial with it. The embryo is the law of its own development. It is already of its nature to be what will be later on an adult capable of reproducing itself.”
Consequently, for example, a medical scientist may provide an exhaustive account of the mechanics of respiration without any reference to final and formal causes. But it does not follow that final and formal causes play no part in our rational deliberations about the world. In fact, some critics of ID simply cannot resist helping themselves to those causes in their assessments of ID and its advocates, even though many of these critics believe that Darwinian evolution has forever banished these causes from our study of nature. And there is a reason for this: formal and final causes are so much the woof and warp of our lives that we, like the water-skeptic fish submerged in H2O, are blissfully unaware of the role they play in our ontological and normative pronouncements.
As Stephen M. Barr, a physicist at the University of Delaware (and a critic of ID), puts it:
Contrary to what is often claimed, even by some scientists, modern science has not eliminated final and formal causes. It uses them all the time, even if unaware that it is doing so. For example, a liver and a muscle are made up of the same material constituents—hydrogen, carbon, oxygen, and so on—acting on each other by the same basic forces. It is precisely their forms, their organic structures, that differ and enable them to play different roles in the body.
The same is true in physics. The very same carbon atoms can form a diamond (transparent, hard, and electrically insulating) or a piece of graphite (opaque, soft, and electrically conducting). What explains their different properties is the difference in form, in intelligible structure. Indeed, as one goes deeper into fundamental physics, one finds that matter itself seems almost to dissolve into the pure forms of advanced mathematics.
Some people think that the Darwinian mechanism eliminates final causes in biology. It doesn't; the finality comes in but in a different way. Why does natural selection favor this mutation but not that one? Because this one makes the eye see better in some way, which serves the purpose of helping the creature find food or mates or avoid predators, which in turn serves the purpose of helping the animal to live and reproduce. Why do species that take up residence in caves gradually lose the ability to see? Because seeing serves no purpose for them, and so mutations that harm the faculty of sight are not selected against. (Even a Dawkins would not deny purpose in this sense; he would deny only that these purposes were in the mind of God.) Darwinian explanations can account for very little indeed without bringing intrinsic finality into the explanation.
So, the problem with Darwinism in relation to belief in God is not the Darwinian claim that natural processes, including scientific laws, are sufficient to account for the variety of life forms that now populate the world. After all, for the Thomist, Darwinian mechanisms and algorithms, as well as scientific laws and other natural processes, no more count against the existence and necessity of God (or even final or formal causality) than does the account of my conception by the natural processes of human reproduction count againt the claim that God is Creator of the universe.
For ID advocates Michael Behe and William A. Dembski no design inference about nature is warranted short of achieving that threshold of irreducible or specified complexity. But that means that the person who believes he has good grounds for final and formal causes—while rejecting Behe’s and Dembski’s criteria—has no warrant for believing that the final and formal causes he claims to “see” in living organisms. In other words, Behe and Dembski are implicitly accepting the assumption of the materialists—the opponents of final and formal causes--that God’s role in nature may only be exhibited in properly arranged bits of matter so as to signify an agent cause of the arrangement. But this means that design in nature is more like Aristotle’s bed than the tree from which the bed was made.
Suppose that in the next few years biologists discover another force in nature, similar to natural selection, that has the power to produce in living organisms organs and systems that appear to be irreducibly or specifically complex. According to the ID advocate, the rational person would have to abandon the idea that these organs and systems are intelligently designed, since his criterion would no longer be a reliable detector of “design.” Consequently, the rational person would have to conclude that these organs and systems are probably the product of necessity and/or chance (to employ Dembski’s categories). Thomistic Design (TD), on the other hand, is not threatened by such discoveries, since the TD advocate actually expects to find such laws in nature, since she believes that God created ex nihilo a universe teeming with ends or purposes that depend on laws and principles that cry out for explanation. By rejecting the mechanistic assumptions of both the Darwinian materialists and the ID advocates, TD does not have the burden of waiting with bated breath for the latest scientific argument or discovery in order to remain confident that the universe, or at least a small sliver of it, is designed. It has something better: rigorous philosophical arguments that challenge the philosophical assumptions of both the Darwinian materialists and the ID advocates who unconsciously (though sometimes purposely) offer their assumptions as undisputed premises under the guise of “science.”
It would be one thing if the ID advocates were only offering their point of view as a mere hypothesis subjected to the usual give and take in scientific and philosophical discourse. (In fact, my earlier work on ID assumed as much). But that in fact is not the case. It has over the years morphed into a movement that treats the soundness of its arguments as virtually essential to sustaining the rationality of theism itself. Steve Meyer, for example, suggests that before the 20th century’s advances in biochemistry and microbiology, immaterialism and teleology were down for the count. But now ID stands ready, Meyer contends, to triumphantly procure these advances to help restore “some of the intellectual underpinning of traditional Western metaphysics and theistic belief.” Who knew?
This embellished sense of ID’s importance in the march of history is not a virture. It is an unattractive enthusiasm that clouds rather than showcases ID’s important, though modest, publishing successes and the legitimate questions these writings bring to bear on many issues that overlap science, theology, and philosophy. Combine this lack of academic modesty with the ubiquitous propagation of ID within Evangelical Protestantism and its churches, seminaries, and parachurch groups (and even among some Catholics) as a new and improved way to topple the materialist critics of Christianity, and you have a recipe for widespread disappointment (and perhaps disillusionment with Christianity) if the ID ship takes on too much water in the sea of philosophical and scientific criticism. For this reason, other non-materialist Christian academics, such as Thomists and some Cosmic Fine Tuning supporters, who would ordinarily find ID’s project intriguing and worth interacting with (as I do), are hesitant to cooperate with a movement that implies to church goers and popular audiences that the very foundations of theism and Western civilization rise or fall on the soundness of Behe’s and Dembski’s inferences.
(The above is excerpted from my forthcoming 16,000-word article, "How To Be An Anti-Intelligent Design Advocate," University of St. Thomas Journal of Law and Public Policy 4.1 (2010))