"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.


Second article: whether it can be demonstrated that God exists (cont)

Thus the idea of cause, unlike the idea of being, is not absolute, but is relative to the thing caused. It therefore admits the possibility of our raising the mind to God and of actually attributing to Him the aforesaid perfections. But before doing so we see no repugnance in this kind of attribution, since these ideas, analogical as they are in the created order, imply no imperfection.

We must therefore stress especially the transcendent validity of the idea of cause, inasmuch as it is already analogically but properly predicated in the created order and implies no imperfection in what it formally denotes. For it is quite clear that the word "cause" is predicated analogically but properly of the four kinds of causes. The intrinsic causes (the material and the formal) of course denote imperfection, especially matter which is able to be actuated and perfected, and also the form, which is a component part, something that is participated and limited by the matter in which it is received. But extrinsic causes (efficient and final) imply no imperfection, and are de facto predicated analogically but properly in the created order. Thus the efficient cause is de facto predicated of the principal cause, which operates in virtue of its own power, as in the case of a writer, and the same applies to the instrumental cause, which acts in virtue of another power, as a pen is moved by the hand of a writer. Hence it is not repugnant to the idea of efficient causality that it should be attributed analogically but properly to the most perfect Being. And it must de facto be attributed to Him, if the world requires the presence of a most perfect Cause. But the proper or untreated mode of the divine causality will not be for us positively knowable in this life but only negatively (saying that it is the uncaused cause, not premoved), and relatively (as when we call it the supreme, most eminent, absolutely transcendent cause).

St. Thomas does not here take up professedly this question of analogy, but explains it at length later on.(83) Why is this? It is because he proceeds as a theologian, by the synthetic method, starting from the divine Being and His knowableness by us, and not by the analytical method of investigation, as the philosophers would, inquiring step by step into the foundations for the demonstrability of God's existence.

However, St. Thomas points out what is necessary for this in his reply to the second and third objections of this article. This difficulty is presented in the second objection, as follows: The middle term of demonstration is the essence, or what is called the definition; but we cannot know what constitutes God's essence; therefore we cannot demonstrate that God exists.

The reply may be expressed in scholastic form by saying: I distinguish the major. That the middle term of demonstration is the essence in a priori demonstrations, this I concede; thus the immortality of the soul is demonstrated from its spirtuality. But in a posteriori demonstrations, I subdistinguish: that the middle term is the real definition of the cause, this I deny; that it is the nominal definition, this I concede. Therefore it can be demonstrated a posteriori that God exists, taking as a prerequisite for this the nominal definition of God, which states that He is the supreme and most perfect Cause; of course this definition derives its force from its reference to God's effects, and it suffices, although God's nature or His intimate life is hidden from us.

The third objection may be expressed equivalently by the following syllogism: A cause can be demonstrated only by an effect that is proportionate to it; but God's effects are finite, and hence they are not proportionate to Him, since He is infinite; therefore God's existence cannot be demonstrated a posteriori from His effects.

The reply of St. Thomas is that from the effects we cannot have a perfect knowledge of the first Cause, but its existence is proved. There is also the possibility of a distinction as regards the word "proportionate" in its application; for God's effects are proportionate to Him, the proportion not being of perfection but of causality, and this suffices for an a posteriori demonstration. For there is a proportion of causality between the proper cause and its proper effect, although this latter is less perfect. Thus, just as we say that light illuminates, fire heats, so we say that the first Mover moves all things, the supreme Ordainer has ordained all things in the world, the most real Being "realizes" or produces and preserves all things in being. This proposition pertains to the fourth mode of direct predication between the effect and its proper, necessarily and immediately required, cause.
This a posteriori knowledge of God from finite effects will indeed be very imperfect, namely, analogical; but the knowledge acquired will apply properly and not merely metaphorically to God, as will be stated farther on.(81) For, whereas God is said metaphorically to be angry, inasmuch as anger is a passion and not an absolute perfection, it is without any use of metaphor that justice, and a fortiori the supreme Cause, the most perfect Being, and other such terms are predicated of God.

Final doubt. In the first objection of this article a difficulty of a different kind is presented, which may be expressed by the following syllogism: The articles of faith are not demonstrated; but that God exists is an article of faith, for we say, "I believe in one God"; therefore that God exists is not demonstrated.

In the reply to this first objection it is remarked that God's existence, so far as it is known by natural reason, is not an article of faith, but is a preamble to the faith. In other words, the major is conceded, and the minor is denied. But St. Thomas adds: "There is nothing to prevent a man, who cannot grasp a proof, accepting, as a matter of faith, something which in itself is capable of being scientifically known and demonstrated."

Two objections are raised against this reply. The first is as follows: No one can accept revelation as the motive for believing in the existence of God as the author of nature; for the act of faith presupposes the evidence of credibility, and this has its foundation in the principle that God's veracity is infallible and that He has confirmed this revelation by divine signs.

Reply. That the existence of God as the author of nature cannot begin to be known by revelation, in a rudimentary and confused manner, let this pass without comment; that we cannot have a more explicit and more certain knowledge of the same by revelation, this I deny. All men have, practically by natural instinct, a confused knowledge of God's existence as the Ordainer of the world and the Lawgiver; for when human beings come to the full use of reason, they have knowledge at least of the first precept of the natural law, which is that "we must do good and avoid evil"; the natural law, however, like the order prevailing in the world, presupposes clearly enough a supreme Ordainer. This truth not only is known as the result of a scientific or philosophic process of reasoning, but it also arises as it were spontaneously from the rational faculty, as when we say: "The heavens show forth the glory of God." (85)

But, if afterward men doubt God's existence, influenced by their unrestrained passions and the objections of materialists and skeptics, this truth can be manifestly made known to them by revelation and confirmed by some divine sign; for, as the Vatican Council declares: "the miracle is a clear indication of God's omnipotence and liberty." (86) Thus certain materialists, who believed in the absolute determinism of the laws of nature, when confronted by what was manifestly a miracle, acknowledged God's existence and liberty, and accepted the Christian revelation.

They had already given their assent to the hypothetical truth that, if there is a God, He cannot lie. This suffices in conjunction with some clearly enough divine sign for the evidence of credibility that is a prerequisite to the act of faith elicited on the authority of God revealing.

For this reason we said in the reply, let the major pass without comment, rather than conceding it; for God's existence as the Author of nature can be made known to one, if not by revelation itself, at least by some manifest and divine sign that confirms the revelation. This sign suffices in conjunction with the hypothetical truth that, if there is a God, then He cannot but say what is true. It was by this method that certain Positivists were converted. Certainly God can, if He so wills, clearly manifest Himself to unbelievers.

Second objection. The Vatican Council seems to infer that all the faithful, even philosophers and theologians, must believe in God's existence from a supernatural motive. Therefore this truth is "an indemonstrable article of faith" and not merely a demonstrable preamble to the faith. For the Vatican Council says: "The Holy ... Church believes that there is one God. ..."( 87) and the principal attributes of the true God are enumerated. Farther on we read: "All those things are to be believed with divine and Catholic faith which are contained in the word of God, written or handed down, and which the Church . . . proposes for belief as having been divinely revealed." (88) But St. Paul says: "He that cometh to God must believe that He is, and is a rewarder to them that seek Him." (89)

It is the common teaching of the theologians that at least these two primary truths can be the subject matter of belief, and that they always were necessary as means for attaining salvation.(90) Therefore all, even Christian philosophers, must believe God's existence and say, by reason of belief and not of knowledge, "I believe in one God."

We are confronted by two difficulties (1) the article of faith in itself, as it is distinct from the preamble to the faith, cannot be demonstrated; (2) for us, at least according to the teaching of St. Thomas,(91) one and the same thing cannot be both known (or evident) and believed (or obscure) by the same person. We do not believe what we already see, for the evident object is already sufficient of itself to move the intellect. I do not believe, but I see the presence of the pen which I hold in my hand.
Certain theologians, as Mazzella and Didiot, thought it impossible, after the declaration of the Vatican Council, for the Thomists to continue to defend the thesis that, one and the same thing cannot be the object of science and of belief for the same person.

On the contrary A. Vacant,(92) although he himself does not admit the Thomist thesis, shows that it was not condemned by the Vatican Council, and, in fact, that it is more easily reconciled with the declarations of the Council.

What is the more common opinion among the Thomists? They say that all the faithful, even philosophers, who know the demonstration of God's existence as the Author of nature, must believe God's existence as the Author of grace or salvation. This is what St. Paul has in mind in the following text: "He that cometh to God must believe that He is, and is a rewarder to them that seek Him." (93) The reference is certainly to a supernatural rewarder, otherwise the believer would not have a supernatural end in view, since he would not have even a confused knowledge of this. "There is also reference in this text, as in the parallel texts of the Council, to God's existence as the Author of salvation and grace. This truth is an indemonstrable article of the faith, and is something more than a preamble to the faith. God, the Author of salvation, is called the God of Abraham, Isaac, and Jacob in the Old Testament, and the heavenly Father in the New Testament.

On the other hand, God's existence as the Author of nature is a demonstrable preamble to the faith, as St. Thomas stated in his reply to the first objection. Thus it remains true that the same thing, taken in the same sense, is not for the same person both known (or evident) and believed (or obscure). God as the Author of nature is not called either the God of Abraham, Isaac, and Jacob, or the heavenly Father, but the first Mover and Ordainer of the world, pure Act.

Moreover, according to the teaching of the Thomists, when the Christian philosopher is not actually considering the demonstration of God's existence as the Author of nature, it is possible for him to believe the same, and he actually does, as included in the belief of God's existence as the Author of grace. Finally, infused faith confirms from on high the certitude resulting from a philosophical demonstration, since it is the same faculty and is concerned with the same object, considered not in its formal but in its material aspect.(94)

This view, which is the one more commonly held among the Thomists, is more in harmony with the Vatican Council, which says: "The Church believes that there is one God ..." (then His attributes are enumerated)." Certainly the whole of this previous declaration pertains directly to the faith, if the reference is to God as the Author of salvation and His supernatural providence. But from this it does not follow that God's existence as the Author of nature must be strictly believed by Christian philosophers. Likewise, when the Council says: "All those things are to be believed by faith which are contained in the word of God, written or handed down . . . , and which the Church proposes for belief," (96) this does not militate against the general principle that.some of the faithful are ignorant of certain dogmas that are necessary for salvation, and that Christian philosophers may hold it to be true that God exists as the Author of nature, and this solely for the reason that they have proved the same, and while they are actually considering this proof.

The foregoing suffices to establish the demonstrability of God's existence.

Index Top


83. Summa theol., Ia, q. 13.

84. Ibid., a.3

85. Ps. 18: 1.

86. Denz., no. 1790.

87. Ibid., no. 1782.

88. Ibid., no. 1792.

89. Heb. 11: 6.

90. Summa theol., IIa IIae, q.2, a.5.

91. Ibid., q. 1i, a.4 f.

92. Cf. Etudes sur le Concile du Vatican, 1, 169; II, 132, 200 f.

93. Heb.11: 6.

94. Summa theol., IIa IIae, q.1, a.4 ad 3um.

95. Denz., no. 1782.

96. Ibid., no. 1792.


"The Lord has always revealed to mortals the treasures of his wisdom and his spirit, but now that the face of evil bares itself more and more, so does the Lord bare his treasures more."

St John of the Cross, OCD - Doctor of the Church

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"It is vanity to love what passes quickly and not to look ahead where eternal joy abides. "

Thomas á Kempis

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"There is nothing which gives greater security to our actions, or more effectually cuts the snares the devil lays for us, than to follow another person’s will, rather than our own, in doing good."

St Philip Neri

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