The Fittingness of Evolutionary Creation

As a priest-scientist who supervises an NIH-funded research laboratory investigating the molecular regulation of cell death, I get a lot of science and religion questions from believers and non-believers alike. The second most common question I get – after the most common truth question: Do you believe in evolution? – is the purpose question: Why did God choose to work via an evolutionary process rather than create complex living species directly via special creation?

Many answers to this purpose question are possible, of course, but I have found that the most illuminating, and often the most surprising, response that I can give, is an argument based on the thought of the great medieval and scholastic thinker, St. Thomas Aquinas. It is a theological argument for the fittingness of evolutionary creation.

In his project of faith seeking understanding, St. Thomas frequently uses theological arguments of fittingness to reveal the meaning, beauty, and wisdom of God’s actions in the world. Arguing from fittingness involves understanding why an end is attained better and more conveniently with the choice of one particular means rather than another. In this sense, and as St. Thomas himself explains, choosing to ride a horse is more fitting than walking if one seeks to quickly reach one’s destination on a journey (see Summa theologiae, III.1.2). Theological arguments from fittingness try to explain how God’s choice of a particular means allowed him to most appropriately attain the end of his actions.

It is important to acknowledge at the outset that theological arguments from fittingness are not demonstrative. In other words, they cannot prove that a certain conclusion necessarily. They cannot prove that things have to be the way they in fact are. It may be fitting for someone to ride a horse to get from Rome to Naples (140 miles) in two days, but someone could in fact walk all day and all night instead. Theological arguments from fittingness do not prove doctrine. They attempt to reveal the inner coherence and the wisdom of the divine design, the theo-drama that has been revealed by a God who is true, good, and beautiful.

These arguments have been deployed by Christian theologians throughout the history of the Church to illustrate the coherence, the intelligibility, and the beauty of the Christian faith. For example, the author of the Letter of the Hebrews argues that it was “fitting [eprepen] that God, for whom and through whom all things exist, in bringing many children to glory, should make the pioneer of their salvation perfect through suffering” (Heb 2:10; NRSV).

Returning to our purpose-of-creation question in light of the Christian theological tradition, we can reword it as follows: Why was it fitting for God to work via evolution rather than will a special creation?

To answer this question, let us recall that for St. Thomas, theological arguments from fittingness attempt to explain how God’s choice of a particular means allowed him to most appropriately attain the end of his actions. Therefore, to grasp the argument for the fittingness of God’s creating via evolution, we need to begin by identifying the end of creation. Why did God create?

For the Catholic theological tradition, the answer to the purpose-of-creation question is clear: God chose to create because He wanted to manifest and to communicate His glory. The Catechism of the Catholic Church, the authoritative summary of Catholic doctrine, proclaims that “Scripture and Tradition never cease to teach and celebrate this fundamental truth: ‘The world was made for the glory of God’” (no. 293).

How does God communicate His glory to His creatures? According to St. Thomas, God communicates His glory to His creatures by giving them a participation in His existence. Creatures exist because God, whose essence is existence itself, gives them a share in His existence. This is the fundamental metaphysical distinction separating the Creator from His creatures: He is existence by nature, while they have existence by participation.

However, St. Thomas also explains that God shares His perfections with His creatures by inviting them to participate in His causality, which in the world manifests itself in His governance of His creation:

But since things which are governed should be brought to perfection by government, this government will be so much the better to the degree that the things governed are brought to perfection. Now, it is a greater perfection for a thing to be good in itself and also the cause of goodness in others, than only to be good in itself. Therefore God so governs things, that He makes some of them to be causes of others in government, like a master, who not only imparts knowledge to his pupils, but gives also the faculty of teaching others (Summa theologiae, I.103.6).

To put it another way, according to St. Thomas, it is a greater perfection, and therefore, more fitting, for God to share His causality with His creatures, making them authentic causes that can cause by their own natures, than for God to remain the sole cause acting within the universe.

As I have explained to my students at Providence College, it is easy for human beings to write a book, but it is impossible for them to make a book that writes itself. On the other hand, God not only causes, but also creates creatures who are in themselves true causes. In so doing, He manifests His power in a singular manner that signals His omnipotence.

Building upon this Thomistic theological account, I propose that it was fitting for God to have worked via evolution rather than created all species at the beginning because in doing so, He was able to give His creation – the material universe and the individual creatures within it – a share in His causality. In this way, He more fully communicates His perfection to His creation more clearly manifesting His glory. As St. Thomas points out: “If God governed alone, things would be deprived of the perfection of causality” (Summa theologiae, I.103.6, ad 2).

Note that this is not the causality that allows one to create something from nothing, because that causality is solely the prerogative of God, who alone is creator. Rather, this is the causality that allows one to introduce novelty and diversity into pre-existing matter. This is also not the causality that philosophers call primary causality. Instead, it is the causality called instrumental causality where God, the primary cause, activates the instrumental causality of His creatures so that He and they can act together wholly and fully, , in the same way that an author and his pen work together wholly and fully to write a letter. This is the kind of causality that underlies biological evolution.

In my view, at least three further points follow from this theological argument for the fittingness of evolutionary creation. First, I propose that given that God chose to prepare fitting matter for the human body through His creatures, it was fitting that He should use evolution to achieve this end rather than another means, because evolution is a most efficient way for divine providence to use non-personal causes to generate novel and adaptive life forms on a dynamic and ever changing planet.

Take, for example, the Chicxulub asteroid that impacted what is now the Yucatan Peninsula in Mexico approximately 66 million years ago. There is significant evidence that suggests that this asteroid strike, which left a 110-mile wide crater now buried nearly a mile underground, triggered the mass extinction of dinosaurs at the Cretaceous-Paleogene boundary. This mass extinction emptied ecological niches throughout the planet that could now be filled with novel plant and animal life.

In my view, evolution was a most efficient and fruitful way for God to use non-personal causes to produce novel life forms after this planetary-wide extinction event, because a Darwinian evolutionary mechanism can shape and transform pre-existing life forms so that their surviving progeny can diversify and adapt to an increased number of available ecological niches.

Next, because of the fittingness of evolution, I also maintain that God did not “waste” life in the evolutionary process. This is a charge often levied against theistic evolution by creationists. For example, Henry Morris of the Institute for Creation Research argues that evolution cannot be reconciled with Christianity because “the standard concept of evolution involves the development of innumerable misfits and extinctions, useless and even harmful organisms. If this is God’s ‘method of creation’, it is strange that He would use such cruel, haphazard, inefficient, wasteful processes.”

In response, no one thinks that Michelangelo “wasted” marble because there were leftover marble pieces after he had completed sculpting his masterpiece David. There is no waste when the agent fittingly attains his end. Furthermore, I propose that extinct species are not pointless waste. Rather, in addition to revealing God’s glory while they existed, they were also the necessary “leftovers” from the creative evolutionary process that God used to generate the novel and diverse forms of life visible today in a manner most fitting to reveal His glory.

Finally, according to St. Thomas, God created the diversity of creatures because no single creature can adequately reflect the perfection of God:

We must say that the distinction and multitude of things come from the intention of the first agent, who is God. For He brought things into being in order that His goodness might be communicated to creatures, and be represented by them; and because His goodness could not be adequately represented by one creature alone, He produced many and diverse creatures, that what was wanting to one in the representation of the divine goodness might be supplied by another. For goodness, which in God is simple and uniform, in creatures is manifold and divided and hence the whole universe together participates the divine goodness more perfectly, and represents it better than any single creature whatever (Summa theologiae, I.47.1).

Therefore, in my view, it is also fitting that God worked via evolution rather than will a special creation because in doing so He was able to produce more species to reflect His glory: Four billion species created over a three billion year period is far more than the eight million extant species today. In fact, it would have been ecologically impossible for all four billion species to co-exist on our planet, because there are only a limited number of ecological niches on the planet at a given moment in time.

To put it another way, there is a limit to the number of species and individual organisms that can be sustained by the planet at any one moment in time. Some of them are even mutually exclusive: If they had been created together, the large carnivorous dinosaur, Tyrannosaurus rex, would have wiped out the Asian elephant, Elephas maximus. However, with evolutionary development – and not with special creation – these species were able to exist at separate moments in history to uniquely manifest the glory of their Creator. Again, they were not wasted.

To sum up, why did God choose to work via an evolutionary process rather than will a special creation? Because it better reveals His glory and His power. Because it reveals better that He is God.

— Rev. Nicanor Pier Giorgio Austriaco, O.P.

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