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Dear visitor: Summer is here, and you may be thinking about a well-deserved vacation, family get-togethers, BBQs with neighborhood friends. More than likely, making a donation to Catholic Answers is not on your radar right now. But this is exactly the time we most need your help. The “summer slowdown” in donations is upon us, but the work of spreading the gospel and explaining and defending the Faith never takes a break. Your gift today will change lives and save souls for Christ this summer! The reward is eternal. Thank you and God bless.

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Aquinas vs. Intelligent Design

One day I received a phone call from a professor of philosophy at a nearby private, religiously affiliated college. He had just returned from an international conference devoted to challenges to evolutionary biology from intelligent design (ID) theory. There was a bit of urgency in the professor’s tone, so I agreed to meet him. As it turned out, he had something of a complaint to make, for he opened our meeting by showering me with a series of questions: Where are the Thomists? Where are the Catholics? How come you are not out there defending us ID advocates? After all, we are on the same side, are we not? He explained that the conference organizers had invited several Thomists to participate, and he was dismayed that, far from expressing sympathy with the ID movement and its challenge to Darwinism, they were quite critical of it. Perhaps feeling a bit betrayed, he wanted to ask me, a Thomist, just what was going on.

Since the time of Charles Darwin there has been vigorous debate between Christian creationists and Darwinian evolutionists. Neither side has been especially interested in what Catholic Thomism—a minority position to be sure—might contribute to the discussion. To the extent that philosophers working in the Thomistic tradition are considered at all, both sides seem to have been dissatisfied. Secular Darwinians often view Thomists as just another species of literalists attempting to substitute the Book of Genesis for good biology. On the other hand, Protestant creationists often have viewed Thomists as already halfway to secularism and naturalism, depending too little on a literal reading of Scripture and too much on philosophical reasoning.

Now, the advocates of ID have revived the debate with evolutionary biology on scientific grounds. This new challenge to Darwinism attempts to show that the biological evidence supports gradual evolution of species less than it does direct creation by a divine Designer. Given the philosophical sophistication of their arguments, it is perhaps natural that ID theorists would assume that they had allies among traditional Thomists who are known for their systematic defense of the doctrine of Creation.

Yet, as my friend discovered, the ID movement has not been well-received overall in Thomistic circles. So, the question is: Why not? Why have Thomists, who share so many of the same concerns about the secularization of our society, not been more supportive? Why have so many Thomists hesitated to join ID theorists in their campaign against Darwinism? Why do some Thomists appear even a bit hostile to the ID project?

A bit of attention to the Thomistic philosophy of creation may help to answer these questions. More importantly, investigating the coolness of Thomism toward ID theory may help to move the debate away from its polarized Creation vs. evolution state toward a discussion that is more philosophically productive. A look at the Thomistic understanding of God’s relationship to nature may even suggest a third alternative to the already well-known positions of the Darwinians and ID theorists.

An Earlier Creation Crisis

During Thomas Aquinas’ life there was a scientific revolution that seriously challenged the traditional Christian doctrine of Creation. From the time of the early Church, orthodox Christians have held that the universe was created by a transcendent God who is wholly responsible for its existence and the existence of everything in it. This is a teaching that Christians inherited from the Jews and shared with those of the Islamic faith.

At the beginning of the 13th century, however, a great historical change came to Western Europe, as the works of the ancient Greek natural philosophers and mathematicians became available in the Latin language for the first time. Especially important were the works of Aristotle, who had worked out the basic principles of nature and developed a methodology for scientific research that promised, in time, to unlock the secrets of the universe.

This scientific revolution caused great excitement among the Latin-speaking scholars in the then-new universities of Europe. They avidly pursued research in many of the natural sciences and essentially founded the historical tradition of experimental science that continues today. It was not long before progress was being made in such fields as mathematical astronomy, optics, meteorology, botany, zoology, and other sciences.

At the same time, the new science was a cause for concern, for some theologians saw in it a challenge to the doctrine of Creation. Specifically, the Greek naturalists held that “something cannot come from nothing.” Indeed, the Greek philosophers used their fundamental principle as grounds for arguing that the universe is eternal: There can be neither a first nor a last motion. It appeared to Aquinas’ contemporaries that this was incompatible with the doctrine of Creation ex nihilo.

Into this medieval debate comes Aquinas, who reasoned thus: God is the author of all truth; the aim of scientific research is the truth; therefore, there can be no fundamental incompatibility between the two. Provided we understand Christian doctrine properly and do our science well, we will find the truth.

Yet, what about the apparent conflict between notion of creation from nothing and the scientific principle that for every natural motion or state there is an antecedent motion or state? Seeing a conflict here, Aquinas says, is a result of a confusion regarding the nature of creation and natural change. It is an error that might be called the Cosmogonical Fallacy.

Out of Nothing at All

Aquinas argued that their error was a failure to distinguish between cause in the sense of a natural change of some kind and cause in the sense of an ultimate bringing into being of something from no antecedent state whatsoever. Creatio non est mutatio says Aquinas: The act of creation is not some species of change.

The Greek natural philosophers were quite correct in saying that from nothing, nothing comes. But by “comes” they meant a change from one state to another, which requires some underlying material reality. It also requires some pre-existing possibility for that change, a possibility that resides in something.

Creation, on the other hand, is the radical causing of the whole existence of whatever exists. To be the complete cause of something’s existence is not the same as producing a change in something. It is not a matter of taking something and making it into something else, as if there were some primordial matter which God had to use to create the universe. Rather, Creation is the result of the divine agency being totally responsible for the production, all at once and completely, of the whole of the universe, with all it entities and all its operations, from absolutely nothing pre-existing.

Strictly speaking, points out Aquinas, the Creator does not create something out of nothing in the sense of taking some nothing and making something out of it. This is a conceptual mistake, for it treats nothing as a something. On the contrary, the Christian doctrine of Creation ex nihilo claims that God made the universe without making it out of anything. In other words, anything left entirely to itself, completely separated from the cause of its existence, would not exist—it would be absolutely nothing. The ultimate cause of the existence of anything and everything is God who creates—not out of some nothing, but from nothing at all.

Looking at it in this way, the new science of the 13th century, out of which our modern science developed, was not a threat to the traditional Christian doctrine of Creation. To come to know the natural causes of natural beings is a different matter from knowing that all natural beings and operations radically depend on the ultimate cause for the existence of everything: God the Creator. Creation is not a change. Creation is a cause, but of a very different, indeed unique, kind. Only if one avoids the Cosmogonical Fallacy is one able to correctly understand the Christian doctrine of Creation ex nihilo.

Take the Hippo, for Example

Two implications of this distinction between change and creation are worthy of note here. One is that God creates without taking any time to create: He creates eternally. Creation is not a process with a beginning, a middle, and an end. It is simply a reality: the reality of the complete dependence of the universe on God’s agency. The other implication is the radical otherness of God’s agency. God’s productive causality is unlike that of any natural cause, for God not only produces what he produces all at once without any process, but also without requiring anything pre-existing or any preconditions whatsoever. God does not act as part of a process, nor does God initiate a process where there was none before. There is no before for God; there is no pre-existing state from which God’s action proceeds. God is totally and immediately present as cause to any and all processes.

On the basis of these implications for the correct understanding of creation, Thomists distinguish between the existence of natural beings and their operations. God causes natural beings to exist in such a way that they are the agents of their own operations. Indeed, if this were not the case, then it would not have been that God created this natural being, but some other. Salmon swim upstream to spawn. In creating salmon, God created a fish that reproduces in this way. If God created salmon without their natural reproductive agency, then he did not create salmon, but something else.

Consider another example: A large quadrapedic mammal, such as a hippopotamus, gives live birth to its young. Why? Well, we could answer this by saying that “God does it.” Yet, this could only mean that God created the hippopotamus—indeed the mammalian order—with the morphology, genetic makeup, etc. that are the causes of its giving live birth. God does not “reach into” the normal operations of hippopotamuses to cause them to give live birth. Were one to think that “God does it” means that God intervenes in nature in this way, one would be guilty of the Cosmogonical Fallacy.

Now, if this distinction between the being of something and its operation is correct, then nature and her operations are independent in the sense that nature operates according to the way she is, not because something outside of her is acting on her. God does not act on nature the way a human being might act on an artifact to change it. Rather, God causes natural beings to be in such a way that they work the way they do. Hippopotamuses give live birth because that is the sort of thing they are. Why are there such things as hippopotamuses? Well, nature produced them in some way. What way did nature produce them and why does nature produce things in this way? It is because God made the whole of nature to operate in this way and produce by her own agency what she produces. Thus, God remains completely responsible for the being and operation of everything, even though natural beings possess real agency according to the way they were created.

“God of the Gaps”

In light of this sketch of the Thomistic account of creation and natural cause, one can perhaps understand the reluctance of contemporary Thomists to rush to the defense of ID theorists. It would seem that ID theory is grounded on the Cosmogonical Fallacy. Many who oppose the standard Darwinian account of biological evolution identify creation with divine intervention into nature. This is why many are so concerned with discontinuities in nature, such as discontinuities in the fossil record. They see in them evidence of divine action in the world, on the grounds that such discontinuities could only be explained by direct divine action. This insistence that creation must mean that God has periodically produced new and distinct forms of life is to confuse the fact of creation with the manner or mode of the development of natural beings in the universe. This is the Cosmogonical Fallacy.

Among the most sophisticated attempts of ID theorists to counter the Darwinian account of the formation of organisms is the irreducible complexity argument of biochemist Michael Behe. He argues that there are specific life forms and biotic subsystems which are irreducibly complex and which could not possibly be brought about by means of natural selection. Irreducibly complex systems and forms reveal intelligent design in nature and, therefore, indicate the reality of an intelligent designer of the universe.

ID theorists are often perplexed—and even a bit put out—that Thomists do not acknowledge the cogency of Behe’s argument. After all, Thomists are quite open to the notion that Creation provides evidence for the existence of the Creator—cosmological arguments for the existence of God based on the order and operation of nature have long been the special preserve of Thomism.

Why, then, have Thomists not been among Behe’s most ardent supporters? First of all, Thomists would agree with many biologists who have pointed out that Behe’s claims of irreducible complexity fail to distinguish between the lack of a known natural explanation of the origin of certain complex systems and the judgment that such explanation is in principle impossible. Thomists, however, would go even further than most biologists by identifying the first claim as concerning human knowledge and the second as an ontological claim concerning what exists.

Now, a Thomist might agree with Behe’s knowledge claim that no current or foreseeable future attempt at explanation for certain biological complexities is satisfactory. Yet, a Thomist will reject Behe’s ontological claim that no such explanation can ever be given in terms of the operations of nature. This ontological claim depends on a “god of the gaps” view of divine agency. This is the view that nature, as God originally created it, contains gaps or omissions that require God to later fill or repair. Given the Thomistic understanding of divine agency, such a “god of the gaps” view is clearly inconsistent with a proper conception of the nature of creation and, therefore, is cosmogonically fallacious.

No Order, No Science

Beginning with the insights of Aquinas, Thomists can show that the order and design evident in nature is precisely that which makes natural science possible. If nature were not ordered, then there would not be a reason why natural things are the way we observe them to be. Discovering such reasons or causes is the purpose of natural science. Without order and design in nature, then, there cannot be natural science. So, the followers of Darwin who argue that evolutionary theory removes all need for positing a design in nature are inconsistent. Presumably, they make this claim on the basis of natural science which, if their claim is true, is impossible.

Moreover, as Aquinas argued in the Summa Theologiae many centuries ago, the presence of chance and contingency in nature shows that nature requires a divine Creator in order to exist (I:2:3). Again, the Darwinians, who place so much weight on the role of chance in nature, are inconsistent to deny the creation of nature. So, Thomism provides a cogent response to the secular challenge of an evolutionary theory intended to replace the doctrine of Creation. Observed species of plants and animals may or may not be descendent from common primordial ancestors. If they are, then it can only be because God created them to be so, and their common evolutionary ancestry is part of his divine design.

The insights of Aquinas also provide an answer to the recent challenge to Darwinian evolution from ID theory. God’s Creation of the world from nothing is not the same as a natural cause. Unlike the causes at work within nature, God’s act of Creation is a completely non-temporal and non-progressive reality. God does not intervene into nature nor does he adjust or “fix up” natural things. God is the divine reality without which no other reality could exist. Thus, the evidence of nature’s ultimate dependency on God as Creator cannot be the absence of a natural causal explanation for some particular natural structure. Our current science may or may not be able to explain any given feature of living organisms, yet there must exist some explanatory cause in nature. The most complex of organisms have a natural explanation, even if it is one that we do not now, or perhaps never will, know.

The Ultimate Cause of Everything

Yet, the evidence for God’s Creation of the natural universe is the known fact—a fact that we know on the basis of our scientific research—that natural things are intelligible. If they are intelligible, they are so as the products of nature—that is, they are intelligible in terms of their natural causes. If this is true of the totality of natural things, then there must be some ultimate source of this intelligibility—there must be some ultimate cause for the being of any and all natural things.

This ultimate source for the being and intelligibility of nature cannot be yet another natural thing. It must be something outside of nature that has the power to produce the totality of nature and does not itself require a cause. Both the existence and intelligible order of the natural universe, therefore, show that it exists because of an ultimate cause: God the Creator.

But to show that nature’s contingency and dependency requires God as its ultimate cause is not to argue for the existence of yet another natural cause within nature. In contrast, articulating the details of how the nature that God has created works is the task of natural science. So, Thomism provides a corrective to the ID theorists who claim that the lack of certain kinds of explanation in natural science shows the necessity of divine intervention into nature as a substitute for natural cause. According to Thomism, God is indeed the Author of nature, but as its transcendent ultimate cause, not as another natural cause alongside the other natural causes.

Aquinas’ Corrective Power

Both Darwinism, with its secular challenge to the unity of faith and reason, as well as the attempt of ID theorists to disprove evolutionary theory vindicate Pope Leo’s selection of Aquinas as the model for Catholic intellectuals (see “Catholic Faith and Modern Science,” below). Thomism has something useful and corrective to say on both sides of the debate. At the same time, Thomism does not replace the natural sciences, or perhaps to put it better, a Thomistic intellectual synthesis includes precisely the sort of research found in the modern natural sciences that have produced so much understanding of nature. In the Thomistic view, the teachings of the faith are fully compatible with what we learn of nature through scientific research, provided we both understand those divine teachings correctly and we do our scientific research consistently and rigorously. The truth or falsity of the claim that the diversity of living species is due to some sort of evolutionary process is a matter to be settled through biological research. Whatever the outcome of this research, it can never replace the need to explain the existence of the natural world in terms of a creation ex nihilo according to God’s divine design.

Clearly, the secular claims associated with modern Darwinism require the sort of corrective provided by Thomism. Does this mean, then, that Catholics should make common cause with ID advocates? Insofar as ID theory represents a “god of the gaps” view, then it is inconsistent with the Catholic intellectual tradition. Thanks to the insights of Aquinas and his many followers throughout the ages, Catholics have available to them a clearer and more consistent understanding of Creation. If Catholics avail themselves of this Thomistic tradition, they will have no need to resort to “god of the gaps” arguments to defend the teachings of the faith. They will also have a more complete and harmonious understanding of the relationship of the Catholic faith to scientific reason.


What Is “Intelligent Design”?

The intelligent design movement has gained adherents throughout the Christian world, especially among Evangelical Protestants. What is distinctive about it is that it does not simply reject evolutionary theory on religious grounds, but attempts a scientific critique. ID theorists hold that empirical evidence shows that there are biological forms in nature that cannot be explained in terms of any evolutionary process. Rather, they argue that such forms can only be explained by positing a divine designer who directly causes the form to exist. For many Christians, ID theory seems like a potent challenge to the secular and materialist worldview that dominates modern science.

Further Reading

There is a growing body of literature on ID theory. Consult the bibliographies available on the Web site of the Discovery Institute ( for a list of titles.

For the Thomistic reaction to ID theory:

  • Aquinas on Creation, tr. Steven E. Baldner and William E. Carroll (Pontifical Institute of Medieval Studies, 1997)
  • William E. Carroll, “Creation, Evolution, and Thomas Aquinas,” Revue des Questions Scientifiques 171 (2000): 319-47
  • Marie I. George, “On Attempts to Salvage Paley’s Argument from Design,” in Science, Philosophy, and Theology, ed. John O’Callaghan (St. Augustine’s Press, 2008)

Catholic Faith and Modern Science

In 1879 the Catholic Church was facing an intellectual crisis. For centuries, Catholic higher education and intellectual life was centered in the great universities of Europe. During the French Revolution, however, many of these universities were closed. In the decades that followed, new universities were established, mostly under direct state sponsorship. These new institutions of learning were generally secular in their orientation and presented a serious challenge to the old intellectual and moral order. An especially important.aspect of this challenge was the notion that the great scientific advancement of the age was made possible precisely because intellectual activity had been disassociated from the Church. To many in the new universities, science and human progress seemed to be at war with the older Christian view of reality.

Among the new scientific views of the time that was thought to seriously challenge Christianity was Charles Darwin’s theory of the evolutionary descent of species through natural selection. His conception of how the elementary forces of nature generated the complex organic wholes that we observe in the world of living things seemed to many to stand in opposition to the Christian teaching that God created the universe according to his divine design. Darwin seemed to have uncovered the mechanism—natural selection—whereby environmental pressures allow certain organic forms, which arise by chance, to survive better than their competitors and to proliferate. What appears to be designed and made necessary by God is really the outcome of random occurrences joined with environmental opportunities. Whereas once the traditional doctrine of Creation by a benevolent God seemed reasonable, now such a view seemed unscientific.

Darwin’s theory of evolution suggested that the highest good of the living thing is not the perfection of the individual within its species according to God’s design, but simple survival. As the lowest common denominator of nature, survival came to represent the good toward which evolution progressed—a good that was merely material and without any divine origin. Later, some advocates of evolution came to consider that even this material good was too much like design and held that evolution has no goal at all—that it is simply constant directionless change. Atheist Richard Dawkins, for example, argues that modern evolutionary biology proves that the universe “has precisely the properties we should expect if there is, at bottom, no design, no purpose, no evil and no good, nothing but blind, pitiless indifference” (River Out of Eden, ch. 4). If the general secularization of learning made the separation of faith and science seem possible, Darwin’s theory of biological evolution made it seem necessary.

In the face of this challenge, Pope Leo XIII realized that something needed to be done to restore Catholic intellectual life and its witness to the truths of the faith. Thus, in 1879, he issued the encyclical Aeterni Patris, in which he reaffirmed a central principle of the Catholic intellectual tradition: the harmony of faith and reason. The teachings of the faith are God’s revelation of the truth; science, the product of human reason, is the search for truth. The true faith, therefore, cannot be opposed to good science because truth is the object of both. The secular view that had come to dominate modern intellectual life was mistaken: Faith is not opposed to reason, and modern secular science is not the replacement for the ancient faith taught by the Church. Faith and reason can, of course, seem to be opposed. Yet this can only happen if either we misunderstand what God reveals to us or if we make mistakes in our scientific research. If, on the other hand, we clearly understand divine revelation and we are careful and rigorous in our science, then we will know the truth—not one religious truth and another scientific truth, but the truth—the way reality actually is.

Realizing that the exhortation to unifying faith and reason would be best supported by an example, Pope Leo provided one: the medieval theologian St. Thomas Aquinas. Were we to take St. Thomas as our model and inspiration, we would have a good foundation upon which we could rebuild Catholic intellectual life in the face of the new secular challenge. In the nearly 130 years since the release of Aeterni Patris, a modern Catholic intellectual movement has indeed been established and, following Pope Leo’s lead, its prominent character has been that of a Thomism that seeks to apply the perennial insights of Aquinas to the problems of modern science and culture.

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