"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.


Third article: whether God exists (cont.)


The fact, which is the starting point of this proof, is expressed as follows: "In the world of sense we find that there is an order of efficient causes," for instance, of those things that are necessary not only for the production but also for the conservation of vegetative and sensitive life on the face of the earth. And from conditional causality the mind soars to the unconditioned first Cause, that is necessary not only for the production but also for the conservation of things in being. (126) Hence this proof is of somewhat deeper significance than the proof from motion, but the method of procedure is about the same. It is made clear from what St. Thomas says in the two subsequent articles,(127) about God's preservation of things in being. This same relation of dependence is considered in these articles, though the consideration is of the transcendent order, not by way of finding but of judgment, the descent being from God to creatures.

The minor of our proof, previously enunciated in the first way, is: We find that there are in the world essentially subordinated causes. For instance, there are all the cosmic causes, which are necessary not only for the production but also for the conservation of animal and plant life. Thus we have the chemical activity of the air, the atmospheric pressure according to its determinate degree, solar heat. But causes of this kind presuppose a first unconditioned cause. For, on the one hand, it is impossible for "anything to be the efficient cause of itself, for in this case it would be prior to itself." On the other hand, in actually and essentially subordinated causes, it is impossible to go on to infinity, as was already shown in the first way. Therefore, apart from and transcending the series of mundane and efficient causes, there is a first cause that is not caused, or an unconditioned cause that is absolutely independent of the others. But the unconditioned cause must be its own action, and even its own being, because operation follows being, and the mode of operation the mode of being. In fact, this cause is the self-subsisting Being, a point that will be more clearly established farther on. (128) Hence this cause merits the name God, since it corresponds to the nominal definition of God. Thus an absolutely unconditioned Cause is required, who transcends the physical energy of heat or of electricity or of magnetism, and of whom the liturgy says:

"God, powerful sustainer of all things,
Thou who dost remain permanently unmoved." (129)


This third proof, like the others, starts from a fact of experience, which serves as the minor in the demonstration, and is as follows: We find in nature certain things that manifestly are contingent, which means that it is possible for them to be and not to be. Daily indeed we see plants and animals being generated and perishing, or ceasing to exist. It is indeed a fact attested to by science, that there was a time when there were no plants, animals, or men on this earth, when the heavenly bodies did not exist as they now do, but only in a nebulous state. This fact of the contingency of corruptible things is illustrated by the following principle.

Contingent beings, however, since they have not in themselves the reason of their existence, of necessity presuppose the necessary self-existent Being. Otherwise nothing would have existed. If at any time the necessary Being had not existed, then nothing would exist. Therefore there must be something the existence of which is necessary.

Moreover, if something is only hypothetically or physically and not absolutely and metaphysically necessary (as cosmic matter is necessary for all changes), "it has its necessity caused by another." But it is impossible to go on to infinity in necessary things which have their necessity caused by another. Therefore there is required, as the cause of all other things, the existence of a being that is not hypothetically but absolutely necessary.(130)

The difficulty is that perhaps this necessary being is in the world as its immanent principle, and so is not God. We say in reply that this necessary being is not: (a) an aggregation of contingent beings, even though it were infinite in time and space, because to increase the number of contingent beings still leaves the series contingent, and no more constitutes a necessary being than a numberless series of idiots results in an intelligent man; (b) it is not the law governing contingent beings, since the existence of this law depends on the existence of contingent beings; (c) it is not the common substance of all the phenomena, for this substance would be the subject of motion (first proof), and susceptible to perfection. Thus at any moment it would be deprived of some contingent perfection, which it could not give itself, because its being and perfection can never be more than it previously had. The necessary being can indeed give, but not receive; it can determine, but not be determined; it must have, however, of and by itself, and eternally, whatever it can have.(131)

From this very fact that the necessary Being is self-existent, it follows that His essence is not only something capable of existing, of receiving and limiting existence, but that this necessary Being is the self-subsisting Being. This point will be made clearer in the next question.(132)


The perfection of the First Cause is what is particularly made manifest in this proof, which is as follows: Among beings there are some more and some less good, true, noble. This means that being and its transcendental and analogous properties (unity, truth, goodness, beauty) are susceptible of greater and less, which we do not find to be the case with specific and generic perfections. Thus goodness is predicated of the stone, the fruit, the horse, the professor, the saint, on various grounds and in varying degrees. In like manner the unity of the soul excels that of the body; there is a greater degree of truth in principles than in conclusions, and in necessary propositions than in those that are contingent. So also life is found in varying degrees according as it is vegetative, sensitive, intellective, moral; and the highest degree of the moral life is sanctity. This fact of the inequality of perfection in beings is illustrated by the following principle.

More and less are predicated of different things according as they resemble in their different ways something which is the maximum and which is the cause of the others. To understand this principle, its terms must be explained.

1) It is a case of different things. But a multiplicity of things different in themselves does not explain the unity of similarity that is found in these things. To express this more briefly: multitude does not give the reason for the unity in which it participates. Elements that are different in themselves, do not of themselves coalesce to form some sort of unity. As St. Thomas says: "Multitude itself would not be contained under being, unless it were in some way contained under one." (133) Thus those things that are many numerically, are one specifically; and those that are many specifically are one generically; and there are many processes of reasoning that are one in principle. Our first conception is of being, then of non being, of division of being, of indivision or of unity of being, and finally of multitude, which last is logically and ontologically posterior to unity.(134)

2) We are concerned with the absolute perfections of being, truth, goodness predicated of different things in varying degrees, which means that they are predicated of finite beings in an imperfect manner. But the imperfect is a composite of perfection and of a limited capacity for perfection. Thus goodness is found in varying degrees in the stone, the fruit, the horse, the good professor, the saint; and in all of these it is found in a finite manner, although this goodness in itself is not limited, for what is formally denoted by the concept implies no imperfection.

But the composite of perfection and of a limited capacity for the same needs a cause, for, as St. Thomas says, "things in themselves different (perfection and limited capacity for this) cannot unite unless something causes them to unite." (135) The reason is that the union of several things presupposes unity. Multitude does not explain the reason for the unity that is imperfectly contained in it. Union that is effected according to either composition or similitude presupposes a unity of a higher order. It is a question of the exemplary cause and also of the efficient cause, because the exemplary cause without the efficient does not actually produce anything. "Consequently there is something that is truest, something best, something noblest, and something that is uttermost being; for those things that are greatest in truth are greatest in being." So says St. Thomas in this article. But why does he add: "Now the maximum in any genus is the cause of all in that genus"? He does so to show that the greatest in truth, in goodness, and in being is the true equivalent of the nominal definition of God, or of the supreme Being, and of the cause of all beings. Therefore he concludes by saying: "And this we call God." If this greatest in being were not the cause of all beings, it would not correspond to the nominal definition of God.

Some were of the opinion that, previous to the introduction of this causal element, this proof does not proceed by the way of causality. But there is no other way of proving God's existence, as was previously stated,(136) and we must not only come by this proof to the ideal conception of the supreme Good, conceived by us as the exemplar in this order, but also to the supreme Good as truly existing outside the mind, and as truly and actually the cause of other beings.

This interpretation is confirmed by what St. Thomas says in another of his works: "If one of some kind is found as a common note in several objects, this must be because some one cause has brought it about in them; for it cannot be that the common note of itself belongs to each thing, since each thing is by its very nature distinct from others, and a diversity of causes produces a diversity of effects. . . .

"(Moreover), if anything is found to be participated in various degrees by several objects, it must be that, starting with the one in which it is found in the highest degree, it is attributed to all the others in which it is found more imperfectly. For those things that are predicated according to more and less, this they have by reason of their greater or less approximation to one of some kind; for if any one of these were to possess this perfection in its own right, then there is no reason why it should be found in a higher degree in one than in the other." (137) St. Thomas also says: "What belongs to a being by its very nature, and not by reason of any cause, cannot be either partially or completely taken away." (138)

This argument differs entirely from St. Anselm's, for it does not start from the idea of perfect being, but from the real grades of perfection as found in the world. Therefore, by means of the proof based upon exemplary and efficient causality, the most perfect Being is established, since actually existing imperfect beings originate from the real fount of perfection.

We find the same argument in the Theological Summa, but the order is reversed. The descent is from God, since the same relation of dependence can be considered by starting from the lowest or from the highest in the grades of being. The passage from the above-mentioned work reads as follows: "Whatever is found in anything by participation must be caused in it by that to which it belongs essentially, as iron becomes ignited by fire. Now it has been shown above (q. 3, a. 4) that God is the essentially self-subsisting Being; and it was also shown (q.11, a. 3, 4) that subsisting being must be one; as, if Whiteness were self-subsisting, it would be one, since whiteness is multiplied by its recipients.... Therefore it must be that all things which are diversified by the diverse participation of being, so as to be more or less perfect, are caused by one first Being, who possesses being most perfectly. Hence Plato said that unity must come before multitude." (139)

Thus this fourth way proves the necessity of a maximum in being, unity, truth, and goodness: in fact, it proves the necessity of the most pure Being that is not a reality considered as distinct from the limited capacity in which it would be received. Thus the maximum in being must be to being as A is to A. It must be the self-subsisting Being.(140) And so it is quite clear that this supreme Being by reason of His absolute identity, which excludes composition, imperfection, and changeableness, completely transcends the world, which is essentially composite and imperfect.(141)

St. Thomas applies this proof to the intellect, truth, goodness, and the natural law.

1) The application to our intellect. "What is such by participation and what is mobile and imperfect, always requires the preexistence of something essentially such, immovable and perfect. Now the human soul is called intellectual by reason of a participation in intellectual power; a sign of which is that it is not wholly intellectual but only in part. Moreover, it reaches to the understanding of truth by arguing, with a certain amount of reasoning and movement. Again, it has an imperfect understanding. ... Therefore there must be some higher intellect by which the soul is helped to understand." (142) And this higher intellect must be the self-subsisting Being.(143)

2) Application to eternal truths. We perceive by the intellect truths that are at least negatively eternal, absolutely necessary and universal, such as the principle of contradiction. But the absolute necessity of these, which is the rule of every finite intellect and of every possible and actual contingent being, calls for an actually existing and necessary foundation. Therefore this necessary and eternal foundation exists, and it is the necessary and the eternal intellect.

St. Thomas says practically the same in the following passage: "From the fact that the truths understood are eternal as regards what is understood, it cannot be concluded that the soul is immortal, but that the truths understood have their foundation in something eternal. They have their foundation, indeed, in the first Truth as in the universal Cause that contains all truth." (144) This means that, in accordance with the fourth proof, they have their foundation in the maximum truth.

Obviously the absolute necessity of the principle of contradiction, which is the law governing every real being, whether possible or actual, has not its foundation in either contingent being or in the different natures of contingent beings; multitude does not explain the reason for unity. There is required a supreme truth. Likewise the first principle of ethics, good is to be done and evil to be avoided,(145) has its proximate foundation in the nature of virtuous good to which our will is ordained, and its ultimate foundation is in the supreme Good and in the maximum Truth.

Thus the natural law in the rational creature is "the participation of the eternal law." (146) This is confirmed by the fifth proof, since the passive ordination of our will to do what is virtuously good presupposes the active ordination of the supreme Ordainer or Lawmaker.

3) Application to the natural desire in us for universal good. More and less are predicated of different goods, according as these approximate in varying degrees to the highest goods. It follows psychologically from this that, in conceiving universal good, we naturally desire a non-finite good (in virtue of the principle of finality: every agent acts for an end). And this desire, being natural, cannot be to no purpose. We are not concerned here with the conditional and inefficacious desire for the beatific vision, but with the natural desire for natural happiness, which no finite good, but only the supreme Good naturally known and loved can satisfy. Hence St. Thomas says: "That good which is the last end, is the perfect good fulfilling the desire. Now man's appetite, otherwise the will, is for the universal good. And any good inherent to the soul is a participated good, and consequently a portioned good. Therefore none of them can be man's last end." (147) And farther on he says: "Hence it is evident than nothing can lull man's will except the universal good. This is to be found not in any creature, but in God alone, because every creature has good by participation." (148)

This may be expressed more briefly as follows: If there is a natural appetite for universal good in the things of nature, since good is not in the mind but in things, then it must be the universal or most perfect good. Otherwise the existence of this appetite or natural desire would be a psychological contradiction. In such a case the tendency of this natural desire would be and would not be for infinite good.

This is an apodictic argument at least for philosophers, and it must be most clear to the angels. It is an application of the fourth proof in conjunction with the principle of finality: that every agent acts for an end, and that a natural desire cannot be purposeless. The fifth proof confirms this argument, since the passive ordination of our will to non-finite good presupposes the supreme Ordainer.

Index Top


126. Summa theol., Ia, q. 104, a. 1 f.

127. Ibid.

128. Ibid., q.3, a.4.

129. See Roman Breviary, hymn assigned for None.

130. Summa theol., Ia, q.44, a. 1.

131. Ibid., q.3, a.6, where it is stated that in God, the necessary Being, there cannot be any accident.

132. Ibid., a.4.

133. Ibid., q.11, a. 1 ad 2um.

134. Consult St. Thomas' Com. on Metaph., Bk. IV, lect. 3.

135. Summa theol., Ia, q. 3, a. 7.

136. Ibid., q.2, a.2.

137. De Pot., q.3, a. 5.

138. Contra Gentes, Bk. II, chap. 15.

139. Summa theol., Ia, q.44, a.1.

140. Ibid., q.3, a.4.

141. Ibid., a.8.

142. Ibid., q 79, a.4.

143. Ibid., q. 14, a.4.

144. Contra Gentes, Bk. II, chap. 84.

145. Summa theol., Ia IIae, q.94, a.2.

146. Ibid., q.91, a.2.

147. Ibid., q.2, a.7.

148. Ibid., q.2, a.8.



"We must not be behind time in doing good; for death will not be behind his time. "

St Phillip Neri

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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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