We are delighted to offer an excerpt from Father Martin Hilbert’s new book for Discovery Institute Press, A Catholic Case for Intelligent Design. This article is adapted from Chapter 4.

If this were a book of Catholic philosophy, space would be given to make a full-throated defense of Aquinas’ first four philosophical arguments for the existence of God. But it is clear that every one of these ways requires a fair bit of philosophical sophistication to plumb, and in any case, this is not primarily a book of philosophy. It’s a book about scientific evidence — which brings us to Aquinas’ fifth way. This argument is different from the first four, as is evident from Thomas’s formulation in the Summa Theologiae:

The fifth way is taken from the governance of the world. We see that things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that not fortuitously, but designedly, do they achieve their end. Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.

As it stands, the connection between Intelligent Design (ID) and the Fifth Way (FW) is not immediately obvious. And, in fact, the proponents of intelligent design rightly note that ID doesn’t get one all the way to a transcendent God. But there is a connection between ID and the FW.

A Preamble to the Preambles 

Dominican priest Michael Chaberek has an excellent discussion of the relationship between the two in his book Aquinas and Evolution. If the ways of coming to God are preambles to faith, then, as he explains, ID can be considered a preamble to the preambles of faith. This is because ID gives examples of specified complexity to illustrate why, as Thomas puts it, “philosophers call every work of nature the work of intelligence.”

The FW, Chaberek says, is based on the logical inference that a Mind is necessary to create the laws of nature, which account for the laws of natural bodies. A more updated version might invoke the fine-tuning of the laws of physics, which enable the universe to exist in an orderly form and, more than this, support life. ID, as it is commonly understood in biological circles, finds structures and processes in nature that can now persist through the laws of nature but which could only, because of their specified complexity, have arisen through the agency of a mind. For example, the laws of physics permit the existence of a DNA molecule and support its exact replication. But there is nothing in the laws of physics that would have led the elements in some primordial soup to coalesce spontaneously into information-bearing molecules capable of self-replication. ID shows this to be the case and then runs with it, making the argument for intelligent design as the preferred alternative, as the only causally adequate, and therefore best, explanation.

Would Saint Thomas Support ID?

Saint Thomas did not have readily available examples of specified complexity such as are revealed by modern molecular biology, but it is possible to find a text that strongly suggests that he would be in favor of ID. In the Summa Contra Gentiles, he writes:

That which results from the action of an agent, but apart from the intention of the agent, is said to happen by chance or by luck. But we observe that what happens in the working of nature is either always, or mostly, for the better. Thus, in the plant world, leaves are arranged so as to protect the fruit, and among animals the bodily organs are disposed in such a way that the animal can be protected. So if it came about apart from the intention of the natural agent, it would be by chance or by luck. But this is impossible, for things which occur always or for the most part are neither chance nor fortuitous events.

Thomas is giving a basic lesson on the detection of purpose. A true roulette wheel, for example, is designed to produce chance events; that is to say, each of the numbers should come up with more or less the same frequency. A roulette wheel that kept giving the same number consistently would clearly not work according to chance, but would be fixed by the unscrupulous casino owner. In Thomas’s view, it is clear that organic structures result from the intention of an agent, because they occur regularly and for a reason. And only intelligent agents can have intentions.

At this point, one can engage in learned arguments as to how the intelligent agent causes the highly specified information-rich elements of life. One can find theistic evolutionists singing the praise of providence that can use “chance” to do its work. But the problem is that these same people tend to look upon chance as something that escapes God’s foreknowledge. And it should be clear to the reader by now that there is not enough probabilistic potential in the universe for life to have assembled by chance. The grasping at the weak straw of infinite multiverses is a clear admission of that basic fact. As the physicist Bernard Carr said, “If you don’t want God, you’d better have a multiverse.” Once chance is eliminated, we are left with intimations of God’s personal involvement on the evolutionary path to the flora and fauna of today — or alternatively, of His particular intelligent fashioning of each such form.

The Power Is the Point

It is not essential that the design argument be as watertight as a proof in geometry. The point is that it is powerful. And it is based on a logic that the average person can follow. It stands as one of the “converging and convincing arguments” that allow us to attain the certain knowledge that God exists. If ID is dismissed, it is difficult to see what other way remains open as an argument for God’s existence from the physical world, certainly none that would be in continuity with Scripture and Tradition.

Saint John Paul II gave a talk in 1985 in which he warned of the dangers of rejecting the design argument. “The evolution of living things, of which science seeks to determine the stages and to discern the mechanism, presents an internal finality, which arouses admiration,” said the Pope. This finality “directs beings in a direction for which they are not responsible or in charge” and thus “obliges one to suppose a Mind, which is its inventor, its creator.” He continues:

To all these indications of the existence of God the Creator, some oppose the power of chance or of the proper mechanisms of matter. To speak of chance for a universe which presents such a complex organization in its elements and such marvelous finality in its life would be equivalent to giving up the search for an explanation of the world as it appears to us. In fact, this would be equivalent to admitting effects without a cause. It would be to abdicate human intelligence, which would thus refuse to think and to seek a solution for its problems.

It is not surprising that atheists should want to reject ID, but it is disconcerting that many Catholics do. Their motivations might be various, ranging from the desire to keep their scientific positions or prestige — human weakness — to a genuine worry that future progress in science might reveal that the basic laws of physics can account for the information packed into living beings — the “god of the gaps” worry. Or they might want to protect the creating intelligence from responsibility for designing what appears manifestly evil, such as the predatory mating tactics of the black widow or praying mantis. Or they might think that the argument is too crude, for they see it working by analogy, and when terms are applied to God by analogy, there is more unlike than like in them.

An Empirically Unsubstantiated Claim

Philosophically sophisticated Catholics, who know that they must in principle believe that natural reason can arrive at the God of the philosophers, are often willing to see a design argument in the fine-tuning of the laws of physics but not in the intricacies of the biological world. They see the latter as an aggressive evangelical Protestant creationism, whereas Catholics, in their opinion, have grown beyond that and have learned to see God in the big picture without linking Him directly to the wonders of biology. But in order to do that, and live in a world filled with life, they have to support the empirically unsubstantiated claim that natural selection and random genetic mutations can take care of all of life once the rules of physics and other initial conditions are properly set up. Their resultant idea of God tends to be deistic: God created the laws and now He is no longer involved, or at least very little involved. It is far from the picture of God presented by Jesus in the Gospels: “Are not two sparrows sold for a penny? And not one of them will fall to the ground without your Father’s will. But even the hairs of your head are all numbered” (Matthew 10:29–30). Knowingly or not, such Catholics are supporting efforts to keep the divine foot out of the door.

Editor’s note: All references may be found in the published work.