Aquinas and Evolution

To show the substantial incompatibility (contradiction) between Thomas Aquinas’s teachings and theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species. we need to refer to the two levels of his intellectual enterprise. One is the level of philosophy (metaphysics); the other is the level of theology. Whereas philosophy is based entirely on the principles of natural reason and being (reality) without the help of revelation, theology is a rational reflection on the supernatural revelation given by God. These two levels can hardly be separated in Aquinas. Aquinas’s philosophy excludes the three grand claims of theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species.. Additionally, his theology contains a positive doctrine of creation Creation is a direct act of God emanating something out of nothing, either the entirety of being (as in the first creation), or a particular being (as in the creation of a species).which is quite different from theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species..

Philosophical Objections to Theistic EvolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species.

There are at least five reasons why Aquinas’s philosophy excludes theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species..

Reason 1

Every material being (i.e., composite being) is in between act and potency; it has some act and some potency. The more potency is actualized in a being, the more perfect it is. Granting for the sake of argument the existence of macroevolutionary change, we see that the older species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.would have less act and more potency, whereas the newer ones would be more actualized, that is, more perfect. Therefore, much potency in matter would have been actualized in the course of life’s history on earth. But no potency can actualize itself into act. To actualize potency something actual is needed. Further, it is supposed that in the macroevolutionary process lower (that is less perfect) organisms generate higher (that is more perfect) organisms. And this is contrary to the principle of sufficient reason which says that a lesser cause cannot bring about a greater effect. To achieve the perfection present in higher animals a higher cause is needed than the power of generation in the lower animals or plants. Thus, macroevolution Macroevolution refers to the supposed biological process of diversification of life from a single ancestor to all living beings.contradicts the metaphysical principle of potency and act as well as the principle of sufficient reason. MacroevolutionMacroevolution refers to the supposed biological process of diversification of life from a single ancestor to all living beings. is therefore impossible.  And if macroevolution Macroevolution refers to the supposed biological process of diversification of life from a single ancestor to all living beings.cannot have occurred, then theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species. is ruled out.

Reason 2

Any and all changes observed in the process of evolution Evolution, depending on the context, may mean microevolution, macroevolution or just any biological change. In the hot debate over evolution the word refers to the idea that all species descended from one or a few organisms via natural generation combined with random change and selection.are merely accidental, which means they affect only the accidental form. But the emergence of a new species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.entails the production of a new substantial form. Therefore, it doesn’t matter how long evolution Evolution, depending on the context, may mean microevolution, macroevolution or just any biological change. In the hot debate over evolution the word refers to the idea that all species descended from one or a few organisms via natural generation combined with random change and selection.works and how many accidental changes it accumulates over time; it will never produce a new species. It doesn’t even matter whether the accidental changes are random or guided by an intellect, they will never produce the substantial change. The grand claim of transformation of species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.due to the accumulation of accidental changes contradicts the fundamental metaphysical division of being into substance and accidents. 

Reason 3

Every material being has the four causes. But in theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species. the efficient cause of the production of species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.is variation and selection which are merely material changes. Thus in theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species. the efficient cause is reduced to the material cause. According to Thomistic metaphysics, every being tends to preserve its form. But in theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species. every being tends to be something else and so tends to exceed its form in order to follow the final cause which drives the evolutionary process. In effect, the formal cause is reduced to the final cause. Therefore in theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species. there are only two causes out of four. Consequently, theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species. lacks the metaphysical understanding of causality. It cannot explain the material being and contradicts Thomistic philosophy.

Reason 4

According to Thomas Aquinas, a thing can begin to exist in either of two ways: by creation Creation is a direct act of God emanating something out of nothing, either the entirety of being (as in the first creation), or a particular being (as in the creation of a species).or by change. There are different types of changes, such as mutation, alteration, generation, or any type of movement. Evolution is also a type of change. Aquinas says that there are four things that cannot start to exist by a change but need to be created instead. These are: angels, souls, the matter of the elements, and the first hypostases in each species, such as the first man, the first lion, etc. The reason first hypostases must be created directly by God is that they require an agent (a parent) in their generation—if there is no parent they cannot be generated (i.e. start to exist by a change). In case of the first man Aquinas explains:

 

The first formation of the human body could not be by the instrumentality of any created power, but was immediately from God.… [A] form which is in matter should be the cause of another form that is in matter, because composite is made by composite. Now God, though He is absolutely immaterial, can alone by His own power produce matter by creation: wherefore He alone can produce a form in matter, without the aid of any preceding material form.… Therefore as no pre-existing body has been formed whereby another body of the same species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.could be generated, the first human body was of necessity made immediately by God. (S.Th. I,91,2 co).

 

Thus, for Aquinas, there is no way in which a new species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.can start to exist except by creation. This is based not just on the interpretation of Genesis but on a metaphysical necessity. Creation Creation is a direct act of God emanating something out of nothing, either the entirety of being (as in the first creation), or a particular being (as in the creation of a species).of first hypostases is required by metaphysics, independently from revelation. As such it is a matter of natural reason. This is confirmed in Aristotle, who did not know Genesis but maintained that species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.were eternal along with the universe. Philosophically, species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.are either eternal or created directly by God as first representatives. Thanks to the Christian revelation, Aquinas can reject the eternity of species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.and embrace their creation.

Reason 5

In another place Aquinas explicitly contradicts the core tenet of theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species. that the universe and all species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.were formed by natural laws and properties endowed by God in the first creation:

The institution of the natural things may be considered in two ways: either regarding the mode of becoming or regarding the properties following the instituted things. The mode of becoming cannot be natural, because there were no natural principles existing beforehand whose actions and passions would suffice to produce the effect naturally. So it was necessary that the first principles in nature were constituted by supernatural power (virtus supernaturalis). This refers to the formation of the human body from earth and the body of the woman from the rib, and so on (Super Sent. Lib. 2 d.18 q.1 a.1 ad 5).

Theological Objections to Theistic EvolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species.

Aquinas’s theology excludes theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species. because Thomas has a quite clear explanation of the origin of species In the debate over evolution the relevant notion of species refers to the idea of natural species - a category broader than biological species.which is very different from that of theistic evolutionTE is the idea that God used secondary causes, such as evolution, to produce all animal and plant species..

Thomas Aquinas, following the Catholic tradition, says that the universe was not only created in the beginning out of nothing (creatio ex nihilo) but also formed supernaturally over a period of time described in Genesis as the six days. But the supernatural formation has been completed once for all with the creation Creation is a direct act of God emanating something out of nothing, either the entirety of being (as in the first creation), or a particular being (as in the creation of a species).of man and nothing entirely new can begin to exist afterwards. Aquinas speaks about two stages of formation – the work of distinction (opus distinctionis) and the work of adornment (opus ornatus) (S.Th. I,66-74). At the first of these stages God divided matter into basic forms, such as the heavens and the Earth, and on Earth things that are bound to the earth, like plants. At the second stage, God created moving things —sun and moon and stars, animals, and man—to adorn the basic divisions.

It is important to notice that Aquinas follows the literal understanding of the Bible. Contrary to St. Thomas, Thomistic evolutionists opt for a highly figurative reading of Genesis. They also either try to prove that Aquinas’s reading was also figurative or that he would follow modern exegesis supporting figurative reading if he had known modern science. But creation Creation is a direct act of God emanating something out of nothing, either the entirety of being (as in the first creation), or a particular being (as in the creation of a species).is supernatural and by definition cannot be an object of natural science. Therefore, as much as science can modify our understanding of how things operate and change over time, it cannot establish that things that need to be created were not created. Aquinas was aware of the progress of natural knowledge and theories of nature. For example, he believed that the explanation of the planetary movements, which in his time was geocentrism, could change in the future, if a better theory were invented. In a way he anticipated the Copernican revolution. Yet, regarding the origin of species, Thomas believes that both the Bible and metaphysics exclude their natural emergence. This is clear in fragments like this:

In the first production of corporeal creatures no transmutation from potentiality to act can have taken place, and accordingly, the corporeal forms that bodies had when first produced came immediately from God, whose bidding alone matter obeys, as its own proper cause. To signify this, Moses prefaces each work with the words, “God said, Let this thing be,” or “that,” to denote the formation of all things by the Word of God (S.Th. I, 65,4 co).