"The good of the grace of one soul is greater than the good of the nature of the whole universe"
- St Thomas Aquinas Ia IIa, q.24, a. 3, ad 2

— A Commentary on the First Part of St Thomas' Theological Summa

by Reginald Garrigou-Lagrange, O. P.


Question 2: Prologue

The prologue to this question is concerned with the orderly arrangement of the whole Theological Summa. The definition of sacred theology, however, is the foundation for this division; for it is the knowledge of God as such, as acquired by the light of revelation. Hence it follows that theology must treat: (I) of God in Himself, and as He is the principle of creatures, especially of rational creatures; (2) of the rational creature's advance toward God as its end; (3) of Christ, who as man, is our way to God. Thus there are three parts to the Theological Summa.

It must be noted that the order is not philosophical but strictly theological. St. Thomas says: "For in the teaching of philosophy, which considers creatures in themselves and leads us from them to the knowledge of God, the first consideration is about creatures, and the last about God; whereas in the teaching of faith, which considers creatures only in their relation to God, the consideration about God takes the first place, and that about creatures the last. And thus it is more perfect as being more like God's knowledge; for He beholds other things by knowing Himself." (2)

This theological order is known as the synthetic order. It begins by considering the higher and more universal things in causation, and it descends to the lower and less universal; and this is in accordance with the very order of nature and causality.

Moreover, in this order, those things that are necessary receive first consideration, which, in the first and second parts of the Summa, are God and created natures, especially human nature. These are considered before the great contingent fact of the Incarnation of the divine Word for the redemption of the human race in accordance with the following statement in the Apostle's Creed: "Who for us men and for our salvation came down from heaven."

Finally, this order is of the nature of a complete revolution, in that its starting-point is God, the beginning of all things; and in the treatise on the last things it returns to this same starting-point, which is God, the ultimate end of all things. Thus it embraces everything, and for this reason the work is truly a Summa in which the dogmatic and moral parts of sacred theology are united under one formal aspect.

It is not exactly the same order that is observed in the Summa Contra Gentes, because in that work St. Thomas proceeds by the apologetic method. Yet it is not a philosophical summa that begins with a consideration of creatures, for it begins with a consideration of God Himself. In the first three books, however, God and creatures are considered according to what can be known of these by reason alone, whereas in the fourth book strictly supernatural mysteries are discussed, such as the Trinity and the Incarnation.

Although St. Thomas proceeds by the synthetic method in these two theological works, nevertheless, in beginning the treatise by considering the question of the demonstration of God's existence, he brings together arguments which had been given by Aristotle.(3) Thus he makes use of them, as was said, "not because of the defect or insufficiency of sacred theology, but because of the defect of our intelligence, which is more easily led by what is known through natural reason (from which proceed the other sciences), to that which is above reason, such as are the teachings of this science."(4) It is, indeed, under the guidance of a higher light that this assembly of philosophical arguments concerning God's existence is effected, and by this means certitude rests on more solid grounds.

There is a threefold division in the first part of the Summa. Here are considered: i)whatever pertains to the divine essence, or de Deo uno; (2) whatever pertains to the distinction of Person or de Deo trino; (3) whatever pertains to the procession of creatures from God, or de Deo creante et elevante.

The treatise on the one God is likewise divided into three parts. First, whether God exists (q. 2). Secondly, the manner of His existence, or rather, what is not the manner of His existence. This is discussed from the third question to the end of the thirteenth, in which the metaphysical attributes of God are considered, many them expressed in the negative form, such as the simplicity, the perfection, the infinity, the immutability, and the unity of God. These pertain to God as He is in Himself, and are considered from the third question to the end of the eleventh. Then in the twelfth and thirteenth questions God is discussed in His relation to us, how He is known and named by us. The analogical method is employed here, namely, the method of speculative theology. Thirdly, whatever concerns God's operation is discussed from the fourteenth question to the end of the twenty-sixth. In these questions the knowledge, life, will, love, justice, mercy, providence, predestination, power, and beatitude of God are considered.

It must be pointed out that this order proposed by St. Thomas is a great improvement upon the order established by Peter Lombard in the Books of the Sentences. This theologian, as we remarked, divides the subject matter not as it refers to God (the subject of sacred theology), but as it refers to the human will, the two acts of which are enjoyment and use. Thus his treatise is concerned first of all with those things in which we must find our delight, with those things that bring us happiness, namely, with the Father, thc Son, and the Holy Ghost, or, with the triune God. Then he discusses the knowledge, power, and will of God. He afterward comes to a consideration of those things which we must make use of, namely, creatures; in other words, angels, man, and grace. Original sin and actual sin are here discussed. Afterward he takes up the consideration of those things that must be the object both of our enjoyment and of our use, namely, Christ as man, and the virtues. Finally he discusses the sacraments and our last end.

In this division a discussion of the moral part of theology is not directly intended, but only as the occasion requires, as in the third hook of the Sentences, although the division of the entire treatise gives one the impression that it is concerned more with moral questions, namely, with those things that can be the object of our enjoyment and use.

Several modern authors, such as Scheeben, after the treatises on the one and triune God, and on creation, begin at once with the treatise on Christ before discussing grace and the infused virtues. Thus grace is presented more in its Christian aspect; but, on the other hand, grace must be considered as it existed even in the state of innocence and in the angels, who were not redeemed by Christ.

The existence of God

There are three articles to this question: (1) whether the existence of God is self-evident; (2) whether it can be demonstrated that God exists; (3) whether God exists. Thus three possible standpoints are considered. (1) There is the standpoint of those who, like St. Anselm, say that God's existence is self-evident; (2) then there are those who, like the agnostics, hold that God's existence is neither self-evident, nor possible of demonstration; (3) and we have the stand taken by St. Thomas, who shows that God's existence can be and is demonstrated by a consideration of existing effects.

John of St. Thomas asks why St. Thomas treats in theology of God's existence. He replies that the reasons given by sacred theology in proof of the existence of God as the Author of nature, are not its own but are taken from metaphysics. These reasons, however, are corrected and perfected by theology guided by the light of revelation, which says those men are inexcusable (5) who, from the orderly arrangement of all things in the world, did not know that there is a supreme Ordainer. This constitutes the preamble to the faith. It is also of faith that God exists as the Author of grace and salvation; and this is not proved but supposed by sacred theology, and is afterward explained and defended by it.

This question begins by taking for granted what is meant by the name God or the nominal definition, namely, that by this name men generally understand the intelligent and supreme Cause of the universe, which he has designed. Hence the question is, whether the highest and most perfect cause truly exists as really and essentially different from the world. Thus any demonstration of God's existence begins by some nominal definition of God, and the existence is proved of the first Mover, the first Cause, the first necessary Being, and the supreme Ordainer.


Index Top


1. The prologue says: "God, as He is in Himself," that is, as He is the principle and end of creatures. This expression, however, does not mean "just as He is," because it is only in the beatific vision that God is known "just as He is."

2. Cf. Contra Gentes, Bk. II, chap. 4, § 3.

3. Physics, Bk. VIII: Metaph., Bk. XII.

4. Summa theol., Ia, q. 1, a.5 ad 2um.

5. Rom. 1: 20.


"The one thing necessary which Jesus spoke of to Martha and Mary consists in hearing the word of God and living by it."

R. Garrigou-Lagrange, OP

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"The greatest glory we can give to God is to do his will in everything."

St Alphonsus de Liguori

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"Spiritual persons ought to be equally ready to experience sweetness and consolation in the things of God, or to suffer and keep their ground in drynesses of spirit and devotion, and for as long as God pleases, without their making any complaint about it."

St Philip Neri

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