What does St. Thomas hold about the beginning, the operation, and the end of the universe?

First, concerning the origin of the universe, St. Thomas speaks about the possibility of an eternal world. He says, "That the world did not always exist is a doctrine held only by faith, and is not able to be proved by demonstration" (Aquinas Summa Theologiae 1. 46. 2; confer: Aquinas Summa Contra Gentiles 2. 38; Aquinas Scriptum in Liber Sententiarum 2. 1. 1. 5).

How did Aquinas get involved in this dispute about the eternity of the world? Aquinas had two sources, Augustine and Aristotle. St. Augustine, and the Bible, held the creation of the world, saying, "The Creator is the only one who could produce things as the first cause" (Augustine De Trinitate 1. 3. 9. 18).²² On the other hand, Aristotle held the doctrine of the eternity of the world.²³ Aristotle and the other early philosophers had the "common opinion" only of a "natural agent" and "motion," and not a "supernatural agent"who could act without "mutation" ("mutationis...non oportet") as Aquinas had proved elsewhere; St. Thomas explains Aristotle, noting, "From nothing, nothing comes, as the Philosopher (Aristotle) said was the common opinion of the naturalists, because the natural agent considered by them does not act except through motion, whence it is necessary for that there exist the same subject of motion or change, which is not necessary in a supernatural agent, as already proved."²⁴ Some philosophers today, such as Heidegger and Sartre, make a similar mistake.²⁵

Donat says the "possibility" of an eternal world is not settled today.²⁶ But our inquiry about the origin of the universe, does not concern the "possibility" of an eternal world, rather the "necessity"of an eternal world.²⁷ The non-necessary world has a beginning (creation) and an end (destruction). St. Bonaventure, in Paris in 1270, taught in his famous Collationes that "eternal time" was absurd.²⁸ Today, the Big Bang (even if not admitted by all) means that the world had a beginning, and also was finite.²⁹ There are also signs in the universe that it is not auto-sufficient, signs of composition, being finite, being contingent, having action, and having order.³⁰

Concerning origins, some hold that the universe had its origin by chance, but St. Thomas holds that nothing happens in the universe by mere chance alone without Divine Providence.³¹ All is the fruit of the power and wise actions of God (Aquinas Summa Contra Gentiles 3. 75). Chance and Divine Providence operate together in the universe. St. Thomas teaches that nothing happens in the universe by pure chance alone; all is the fruit of the power and wise action of God.

Creation is defined and confirmed by St. Thomas. He says, "Creation is the production of something in its entire substance without any part of this presupposed created or uncreated" (Aquinas Summa Theologiae 1. 63. 3).³² St. Thomas says, "God is the original font and primary font of all causality, especially of the existence of things" (Aquinas De Substantiis Separatis 14).³³ St. Thomas also says, "God is the principle and goal of every creature, and consequently has a double relation with creatures: that according to which all creatures arrive at existence because of God, and that according to which all creatures are directed to God as their ultimate goal" (Aquinas De Veritate 20. 4).³⁴

Second, concerning the present evolution of the universe, St. Thomas confirms: "Every creature is in service of its own perfection. Second, creatures less noble are in service of the more noble, as lower creatures to man are (in service) for man. Further, every creature is in service of the perfection of the universe. Finally, the totality of the universe with all its parts is ordered to God as its goal" (Aquinas Summa Theologiae 1. 65. 2).³⁵ Therefore, St. Thomas portrays a dynamic universe, in which "every creature is in service of the universe." St. Thomas repeats this dynamic orientation of things to the universe, saying, "Now if we observe that every single being is best disposed by its nature, we must admit that this is more verified in the whole universe" (Aquinas In Metaph. 12. 12).³⁶ This dynamic is visible and can be understood as natural laws: "A physical law can be defined as an intrinsic inclination by which natural causes are constantly determined to producing similar effects in similar circumstances" (Aquinas Summa Theologiae 1-2. 93. 3).³⁷ Clearly, there is dynamic order in the universe, as St. Thomas notes that "Some (philosophers) take this occasion to err, thinking that no creature had some action for production of natural effects" (Aquinas Summa Contra Gentiles 3. 69).³⁸

Concerning the present evolution of the universe, St. Thomas also teaches that divine efficient causality is the ground for cosmic evolution: "The same divine wisdom is the efficient cause (effectiva) of all things, and not only gives to things that existence but also in things existence with order, in so far as things are joined to one another in an order to the ultimate goal. And so God is the cause of the indissolubility of this order, which always remains, in whatever way things change" (Aquinas De Divinis Nominibus 8. 4).³⁹ St. Thomas confirms, "The entire irrational world is related to God as an instrument to a principle agent" (Aquinas Summa Theologiae 1-2. 1. 2).⁴⁰

Concerning the present evolution of the universe, does St. Thomas think that there is alien life on other worlds? Yes, he seems to endorse alien life, although St. Thomas does not phrase the question in quite the same way. St. Thomas maintains that it is hard to believe that inorganic matter, not reason, dominates the universe: "The order of the universe seems to demand that what is in more noble things should exceed in quantity or number the more ignoble, because the ignoble seem to exist in service of the more noble. Whence it is necessary (oportet) that the more noble as if due to their own noble nature would be multiplied in existence as far as possible" (Aquinas Summa Contra Gentiles 3. 92).⁴¹ What are these "more noble" that St. Thomas believes should be "multiplied in existence as far as possible"? St. Thomas maintains, "That it is necessary for the best (optimam) perfection of the universe (universi) that there exist some intellectual creatures" (Aquinas Summa Contra Gentiles 2. 46).⁴² St. Thomas asserts that these intellectual creatures which are to be "multiplied in existence as far as possible" are not only more noble, but at the apex (summo rerum vertice) of creation: "And first we show that from the divine plan in assigning perfection to created things in the best way for each, it followed that there were some intellectual creatures, constituted at the highest level of things" (Aquinas Summa Contra Gentiles 2. 46).⁴³ Therefore, St. Thomas seems to hold that the intellectual creatures, the apex of creation, should be multiplied "as necessary for the best perfection of the universe."

Third, concerning the end or destruction of the universe, the richness of the teaching of St. Thomas needs to be examined in more detail, although he notes that "...the corruption and deterioration of (material) things are natural..." (Aquinas Summa Theologiae 1-2. 85. 6).

Concerning the end of the universe, the dispute on the eternity of the world also touches the end or the destruction of the world. If the world is eternal, then it will never be destroyed; however, there are some differences between the eternal creation of the world and the necessary (not just possible) eternal existence of the world. The contemporary world could end either by annihilation by God,⁴⁴ or by the corruption due to the finite nature of the world itself. The world will not end by annihilation, says St. Thomas, "In so far as the status in which the world now exists, it lacks the state of perpetual rest and death...whence it must simply be said that absolutely nothing will be annihilated" (Aquinas Summa Theologiae 1. 104. 4).⁴⁵ Our observation finds signs in the universe that it is not auto-sufficient, signs of composition, being finite, being contingent, having action, and having order.⁴⁶ While St. Thomas does not explicitly deal with the death of the universe, he does explain the material destruction of one of the material creatures of the universe when he treats the death of man, saying: "From this point of view the corruption and deterioration of (material) things are natural, not already by the inclination of the form, which is the principle of their being and of their perfection; but by the inclination of the material which the universal agent (God) distributes proportionally to each form. And it would be astonishing for every form to perpetuate its own being, since no form of corruptible things is able to attain this perpetuity, except for the rational soul of man...And from this point of view man is naturally corruptible, according to the nature of matter left to itself, but not in a prior way due to the nature of the form" (Aquinas Summa Theologiae 1-2. 85. 6).⁴⁷ Therefore, if the "corruption and deterioration of (material) things are natural" in the death of man, the same should be true about the natural corruption and deterioration of material things in the universe.

Concerning the end of the universe, St. Thomas teaches that the destiny of the universe has to do with knowing and loving, rather than something material. St. Thomas says, "Something close is joined to God if the thing can touch the very substance of God in some way, which can happen when someone knows the divine substance, which is the attainment of some likeness to God. It follows that the ultimate goal of the universe is God, which only an intellectual nature can receive in itself, by way of knowing and loving" (Aquinas Summa Contra Gentiles 3. 25).⁴⁸ This view of St. Thomas explains why he appears rather unconcerned about any physical destruction of the universe, since St. Thomas views the destiny of the universe as man’s joy in knowing and loving God.

Fourth, concerning the equivocal use of the word "evolution" in regard to cosmic evolution, St. Thomas makes no direct comment. However, St. Thomas is very careful about the use of terms in the description of the origin of the cosmos. St. Thomas notes, that even if the world were eternal, it is not univocally the same as the eternity of God.⁴⁹ Boethius teaches that God is the total and simultaneous presence of unending life. On the other hand, the universe includes potential act, contingent, continuously developing in eternal successive duration" (Aquinas De Aeternitate Mundi 11).