Click for: CSSHS Archive Main Page
Vol. XII • 1990

Proofs for the Existence of God and Creation: A Catholic View
Paula Haigh

Saint Thomas Aquinas (1225-1274), Italian Dominican priest, has been honored by the Church more than any other theologian in history. Canonized in 1323, he has since been acknowledged as the Angelic Doctor, both for the purity of his life and for his incomparable writings on the angels. He has been named the Common or Universal Doctor and Patron of all Catholic schools. And yet, because the Church is catholic, that is, universal, there can and do co-exist within it many schools of thought, all faithful to the same dogmas of revealed Faith. And so, it would be untrue to say that Thomism is the only representative of Catholic theology and philosophy. However, it may and can be held that the systematic theology of Saint Thomas represents the best, the highest, and the most comprehensive Catholic theology that exists. And because of the organic nature of truth, it may be predicted that time will reveal the pre-eminence of the Thomistic synthesis over all others.

Most of the theologians of the Middle Ages held the existence of God to be self-evident. Now, self-evident facts can not be demonstrated. For example, I cannot demonstrate to anyone the fact of my own existence or the existence of that tree out there. Nor can it be demonstrated that a thing can not be and be at the same time. These facts must be accepted as given or else denied as given. But Saint Anselm and before him Saint Augustine claimed to demonstrate God's existence by reason, even though they held it to be self-evident.

How can this be? Well, it would seem that they did not recognize the existence of God as self-evident to the same degree as those other self-evident facts. Saint Thomas says that they were so accustomed to think of God that they found it to be self-evident to them even though it might not be to others. And for this reason they set out to demonstrate God's existence for those to whom it was not so self-evident. They did so, moreover, from a theology and philosophy of essence in the Platonic and neo-Platonic tradition. They did not begin with a theology and philosophy of existence as indicated by Exodus 3:14 wherein God gives His name to Moses as "I AM". It is not that Saint Augustine did not struggle with Exodus 3: 14, for he did, and he complained bitterly to God for not supplying at least one predicate nominative or adjective for that verb to be in the present tense first person singular (see Gilson, pp.86-87). In this case, Grammar is a far better servant of theology than Platonic philosophy.

Saint Thomas, on the other hand, took Exodus 3:14 just as it is and concluded that God's essence is His existence. In philosophical language, borrowed from Aristotle, this means that God is all actuality, for there is in Him no potency. Potency or potentiality is a principle of change and of limitation, of imperfection and need, and is found only in creatures. It is not in God. And so, by claiming for God just what Exodus 3:14 says, we can see clearly that God must exist as the source of all other existences understood as actualities.

But this is to take our cue from Holy Scripture, not from human reason alone, and it is from human reason alone that the theologians claim to prove, that is, to demonstrate the existence of God. How does Saint Thomas get around this? How does he maintain his five ways to be demonstrations from natural reason alone and not proofs taken directly from Holy Scripture and thus being truths of Faith and not of reason? Well, he does not apologize for citing Holy Scripture as his authority, nor does he cease to insist that he is demonstrating the existence of God from reason alone. It is because he uses the philosophical concepts of Aristotle that he is confident he is proceeding on the basis of reason only and not of Faith. It is only the five ways of Saint Thomas that succeed in truly demonstrating, by reason alone, that God exists and must exist to explain all other existences. The demonstrations are not facile, they are far from glib, and they are difficult. There are few men with the intellectual acumen, the perseverance, and the good will to really understand this cluster of proofs for God's existence. But Saint Thomas insists that this is, indeed, a series of proofs from reason alone that demonstrates, beyond possible refutation, the existence of God.

On the other hand, if one uses the Platonic philosophies of essence, one fails to transcend the point and sphere of the mental concept, the idea. One remains trapped within the mind. As Saint Thomas puts it, speaking of Saint Anselm's ontological argument, though without naming anyone, "Yet, granted that everyone understands that by this word 'God' is signified something than which nothing greater can be thought, nevertheless, it does not therefore follow that he understands that what the word signifies exists actually (i.e., outside the mind, in reality) but only that it exists mentally (i.e., in the mind, as a concept)." (ST,l,Q2,ad2)

Arguments from essence or from thought may be logically valid, but they do not on that account demonstrate the actual, extra-mental existence of God. And thus it is that Saint Thomas parts company with his famous and holy predecessors on this point of proving God's existence from reason. How, then, does he set about it himself? He holds firmly that the existence of God can be demonstrated from reason alone, but we must begin on the right epistemological foot. As Saint Paul says, we must begin with "the things that are made" (Rom. 1:20), that is, with God's effects, with creatures, with the given, perceived objects of sense knowledge. These carry their own certitude and guarantee of existential fact. Unlike Plato, we must accept the objects of sensible experience as real, individual, concrete things out there, the plainly obvious realities of the world which, in turn, form a structure of things, of beings that manifest an order that is supremely intelligible and carries its own message of the Creator's existence. If we must become as little children in order to enter into the Kingdom of God, we must also, it seems, become as little children accepting the objects of the real world as real if we are to enter the kingdom of true philosophy and theology.

The first way is by motion. It is certain that there is motion in the world because our senses tell us so. We know by observation and reason that if any thing moves, it does so by means of some agent either within itself or outside of itself. This is so because motion is defined as the passage from potency to act. Pure potency will never move into act by itself. It can not. It is like an egg which requires the active power of the sperm in order for the egg to be "activated" and the gestation process to begin. The being or aspect in potency must be moved by an agent already in act in order for the motion of change to take place. Thus, also, it is actual heat, say, that of fire, which makes wood, which is only potentially hot, to burn and become actually hot.

As for the active agent being within, here is an example. As I sit here reading or writing, I am in potency to standing, walking, running, etc. I may be moved to a change of position by a bell ringing or by an interior act of my will. In any case, my will is the interior active agent that moves me to a change of posture. So we see that whatever is moved, is moved by some agent already in act.

If we consider motion in a temporal, horizontal order, we enter what Saint Thomas calls the order of generation. The series in this order is temporal and thereby potentially or virtually infinite, that is, the series may go on as long as time goes on, and so, an "infinite regress" is possible. It is only by considering the a-temporal, vertical, and hierarchical order of creation (reality or nature) that we can arrive demonstrably and irrefutably at God's existence. For, the hierarchical order is immutable itself. It is the unchanging order of the world, of nature, of reality (unless you are an evolutionist and insist upon perverting this given evidence). We see the elements acting and interacting according to this strict low of motion which is passage from potency to act by an agent in act. Ascending to the plant kingdom, we see the same principle at work, and so on up the scale of being to man and the angels above him. Aristotle recognized the reasonableness of spiritual intelligénces, and Saint Thomas, having Divine Revelation, realized that Aristotle had "discovered" the angels.

This vertical series or hierarchy of being obviously can not proceed to infinity as a series, not even to a temporal and/or virtual-potential infinitude simply because the order itself is a-temporal and therefore unchanging, metaphysical, absolute, being the very order of nature, of reality itself. Therefore, we must arrive at a Being Who is all act, the Source Himself of all other actuality, a Being Who has in Himself no potency, no change, no need for change. Furthermore, this actuality of God is absolutely necessary, for without it, without Him Who is the very source of all actuality, there would be no actuality in the world at all and thus no motion. We conclude, therefore, that God must exist. The proof is irrefutable.

The second way is by efficient causality. We note in the things o~ the world and of nature an order of efficient or agent causes, nor car we ever meet a being which is its own maker or efficient cause Nothing, it is self-evident, can make itself. We could perhaps prove this by stating that an efficient cause is necessarily anterior to that which it makes or causes, and since no being can exist before itself then no being can be its own efficient cause. Now, this order o1 efficient cause may be considered temporally, that is, in time and is the order of generation, in which case, there could possibly be at infinite regress, at least a potentially infinite regress, given the time. But this is by no means the case in the order of creation, of reality, in the hierarchical order where the efficient cause is anterior to its effect is a relation that makes it to be not just anterior but primary in the sense of superior. It is superior to its effect in an order of relation that we will find to be, in the case of the First Efficient Cause, the relation of creation, a strictly one-way relation which exists only in the effect, and not in the cause.

So, if we trace the order of efficient causes up through the hierarchy of being, we must of necessity arrive at the source of al efficiency, which is God. The relation of all other efficiency to Him, therefore, is that of the relation of creation, one of absolute dependence. Without God's efficient causality, there could not possibly be any efficient causality (as of secondary causes) in the world. And so, nothing would exist except God. This argument is irrefutable.

It has bean suggested by scholars that there are not, in Saint Thomas, five ways of proving God's existence, but really only one proof with five parts or aspects. We will see this similarity in the third way, too. But while each proof is sufficient unto itself and irrefutable, containing at least virtually all the others, still it must be said that each one casts a slightly different light on God's Existence as Actuality. The structure of each proof is, indeed, the same, and any one of the five ways is enough to establish the existence of God. But each proof begins from a different series of God's effects and brings out a different aspect of the divine actuality and causality.

The third way is from possibility and necessity. At first sight this may seem to be but different words for the same ideas used in the first way-- potency and act. But not so. Here are really different aspects of God's causality, at least as seen from our limited and piece-meal point of view.

It is possible for any being that now exists not to have made it into existence, and we observe that all things that do come into existence, are but a few of those that might have come into existence. Also, those that do come into existence, begin to corrupt and eventually pass away. Now, it is impossible for such utterly and radically contingent beings to have always existed. And they certainly could not exist at all by themselves. For that which is possible could at some time not have been and at some time most certainly was not. And so, reason tells us that if everything that exists at some time, at some other time was not, then at one time, and even now, there would be nothing. This is the crux of the proof. Let us be sure to grasp it. For, if there were not a Being Whose existence was necessary and containing no possibility of coming into being or of passing away, the nothing at all could be in existence at the present time. This is true whether the order be one of generation and temporal, or hierarchical and a-temporal.

And so, we see clearly that there would be nothing at all now or ever if there were not God, because that which comes into existence contingently does so only by means of some agent already in act. But if this agent is itself a being contingent upon some other being for its existence, then there must be in existence some Being that is absolutely necessary in Himself, containing no possibility of coming to be and passing away. And this Being we call God. And we see that His existence is absolutely necessary if anything at all is to exist.

This proof also emphasizes the radical contingency of creatures, that is, their absolute dependence upon God for their very existence. Saint Thomas calls this dependence the relation of creation, and it is a relation that is in the creature only, for God depends upon nothing. He has in Himself absolutely no contingency. Contingency, however, or radical and absolute dependence, is an essential note of the creature. It is, in a word, exactly what is means to be a creature: to depend upon God for one's very existence--and not just at the time of coming into being but at every moment of time one exists. And, also, of course, in eternity too.

The fourth way is taken from the gradation or degrees of being in things. This proof may seem to have more in common with the Platonic-Augustinian ways of arriving at God's existence because of its appeal to abstract concepts such as goodness, truth, and nobility. But a closer look shows us that Saint Thomas is not appealing directly to these ideas or to their existence in things but rather to the fact that they are graduated, that is, that we observe them to occur in degrees. In each genus of things, for example, there is a maximum ens, a highest form of that genus of quality, as fire is the hottest of all hot things. But our reason requires a Being that is supreme in every category and embraces the maximum of every perfection. Otherwise, how explain the presence of the maximum in each genus, for it cannot be its own explanation? So there is required an infinite cause of all the perfections existing in finite and imperfect ways in creatures. For the finite and the imperfect will never be able to give rise to the infinite and perfect. More cannot arise from less and the imperfect does not come of itself to perfection. The Being our reason requires is God.

Here we may say that the total hierarchical structure of reality itself manifests, even cries out and declares the existence of the Source of its manifold but always limited and imperfect degrees of being. And this is God.

The fifth way is taken from the governance of the world. We must interpret the word governance in its most active, dynamic sense, for this proof - famous as the proof from design or teleology - really points to the existence of a God far greater in magnificence and power than Paley's Watchmaker, the Masonic Architect, or the Newtonian Author of Nature.

Saint Thomas says that we see things which lack intelligence, such as natural bodies, acting for an end so that they always or nearly always obtain the best result. Thomas gives us no examples here, but he is clearly thinking not only of the movements of the sun, moon, and stars in their regular courses, but also of the instinctive, quasi-intelligent activities of animals. It is plain, he says, that these actions do not proceed by chance but assuredly by design. But whose design? What lacks intelligence, or the power to plan intelligent activity, cannot move towards an end unless it be directed by some being with intelligence. So the arrow is shot to its mark by the archer.

In this emphasis upon the final cause or teleological and therefore intelligible activity of all things, Thomas is proving that the very reason for which the efficient cause of the second way moves or causes all things to act and endows them with secondary causality according to their specific nature--this reason is beyond the immediate activity. In the words of Etienne Gilson (p.75), this fifth way "arrives ... not only nor first of all at the reason for what order there is in the universe, but also and pre-eminently at the reason for nature itself. In brief, beyond the intelligible manner of existing, the final cause attains the supreme reason for which beings exist."

Not only does God exist, but He is the destiny, the end of everything that He has caused to be, the reason for all existence. He is that for which and by which all things act, even when they are not so aware. Here, as perhaps nowhere else in the natural order of things, based on reason alone, we arrive at that predicate nominative supplied by Saint John the Evangelist when he tells us that "God is Love" (I John 4:8). It is certainly why, as Saint Augustine exclaims so poignantly in his Confessions, "Thou hast made us for Thyself, O God, and our hearts are ever restless until they rest in Thee." For all creation does God's will, ordered by Him to Himself, but only man, being free, can resist the attraction of God as his destiny and end, the object of compelling love.

We may sum up the five ways of proving God's existence in this way: God is infinite dynamism in Himself though without change or motion; He is infinite efficiency and power being the First Cause of all other causality: He is absolute necessity without Whom nothing would or could exist; He is infinite perfection; and He is infinite Wisdom and Love, being the final end and destiny of all things--a fitting gloss upon the "invisible power and divinity" of Saint Paul in Romans 1:20.

Saint Thomas differed yet again from the other great theologians of his time, notably Saint Bonaventure, in holding that creation of the universe from nothing (ex nibilo) is a truth of divine Faith and cannot be arrived at by unaided natural reason. Perhaps it is because Saint Thomas saw Aristotle as the embodiment of the highest that natural reason could attain without the gift of Divine Revelation that he held this. Aristotle believed in the eternity of the world, or, at least, he did not see how it could be otherwise, and indeed, his logic is irrefutable. Saint Thomas appreciated this fact.

The efficient cause of the five ways of Saint Thomas is not, therefore, the God of Genesis Who creates all things at the beginning of time from nothing by His Word alone. This God must be revealed to men by Himself in order for man to know it. This is the view of Saint Thomas. The most that natural reason can attain is the necessity for a first uncaused cause of all things. The reason for the mind's ability to reach this far is that the notion of causality is a first principle immediately known by the natural light of reason as soon as it awakens in contact with experience. And Saint Thomas saw this power of natural reason best exemplified in Aristotle. But the inadequacy of this same natural reason to proceed further is demonstrated by the propensity of the pagan philosophers to fall into such errors as the eternity of the world and of matter, not to mention the worse errors exhibited by those other than Aristotle. It must be said that he is the best--and invaluable for us in so many areas. His metaphysics of substance is far superior to Plato's metaphysics of ideas and to the crude materialism of the pre-Socratics.

Therefore, Saint Thomas rightly concludes that in order to possess the true idea of God as Creator, we need Divine Revelation and the light of divine Faith.

At this precise juncture, at this dividing line between reason and Faith, there comes the necessity for good will on the part of man (Luke 2:14), that is, a submission or docility of mind and a willingness to receive and to accept God's gift of the revelation of Himself. We witness the immense benefits that flow from this loving submission of reason to Faith in the work of the Creationists today and in the flowering of theology during the Middle Ages. Contrariwise, we also see only too clearly today that the most pernicious and degrading errors dominate men as they refuse to submit their reason to God's Word.

Divine Faith is like the light of the sun that illumines all things, and when human reason, which in comparison is like a puny light bulb, loses its light in the divine radiance of Faith, then truth reigns, for "in Thy Light we see light" (Psalm 36:9~.

Allow me to conclude with a quotation from Etienne Gilson (pp.5758):


Saint Thomas Aquinas. Summa Theologica. 3 vols. Literally trans. by the Fathers of the English Dominican Province. New York: Benziger Brothers. Inc. 1947.
Gilson. Etienne. The Christian Philosophy of St. Thomas Aquinas. New York: Random House 1956.

"Proofs for the Existence of God and Creation: A Catholic View"
CSSHS • Creation Social Science & Humanities Society • Quarterly Journal

Main Page:  CSSHS Archives