"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)

2) The reason for the validity of the demonstration from the effect and the kind of demonstration required. It is valid in virtue of the principle of causality, for, as St. Thomas says in the body of the article, "since every effect depends upon its cause, if the effect exists, the cause must pre-exist."

But this principle of causality must be properly understood. The Positivists understand it as referring only to the phenomenal order, since every phenomenon presupposes an antecedent phenomenon. Thus if we have expansion of iron, this presupposes the phenomenon of a greater degree of heat, because heat expands iron. If such were the case, this principle would hold good only in the order of phenomena, and as an experimental law but not as an absolutely necessary law. But a miracle would be out of the question, because a miraculous phenomenon does not suppose an antecedent phenomenon, but proceeds from God's exceptional intervention as first Cause, operating beyond the ordinary course of nature. Nor does it suffice, as the Kantians say, that the principle of causality should be a subjectively necessary law of our mind for the necessary subjective classification of phenomena. To prove the existence of the transcendent Cause, this principle must have, moreover, ontological validity as regards extramental being; in fact it must have transcendent validity.

As a matter of fact, this principle is commonly formulated not only in the phenomenal but also in the ontological order, and not only does it state that "every phenomenon supposes an antecedent phenomenon," but it also says: "Everything that comes into being has a cause"; or rather, to express it more universally, every contingent being is efficiently caused by another. Even if de facto this contingent being eternally existed, it would still need a productive and conservative cause, because a contingent being is not its own reason for existence.

Nor need we be surprised that this principle is thus formulated with reference to extramental being and not only to phenomena, because the proper object of our intellect, as distinct from the object of either the external or internal senses, is not only color, sound, extension, hardness, and such like, but it is the intelligible being of sensible things. Whereas the object of sight is colored being considered as colored, the object of the intellect is colored being considered as being; and at once our intellect perceives the truth of the first principle of contradiction or of identity, that "being is being, not-being is not being," or "no being is not-being." This pertains to the ontological order, which is above the order of phenomena.

Moreover, one cannot deny the principle of causality without denying the principle of contradiction. This is evident from an analysis of the terms, for this principle of causality is immediately evident without any middle term of demonstration; but it can, moreover, be demonstrated indirectly by the method of reduction to absurdity, as all Scholastics admit.

In fact, uncaused contingent being is repugnant to reason. In other words, nothing is what results from nothing, without a cause nothing comes into being. Parmenides already expressed the same in the negative form (for it was the negative formula of the principle of causality, in which the efficient cause was not as yet sufficiently distinguished from the material cause). Why is an uncaused contingent being repugnant to reason? It is because a contingent being is that which can either exist or not exist (this being its definition). Therefore it is not self-existent, and must be dependent upon another for this; otherwise, if it were neither self-existent nor dependent upon another for existence, it would have no reason for existing, and so would be the same as nothing. "Nothing is what results from nothing." To say that from nothing, or that from no cause either efficient or material, something comes into being, is a contradiction.

It is not, indeed, so clearly and directly contradictory, as if one were to say, "the contingent is not contingent"; but to say, "something that is contingent is not caused," is to deny a property of the same that directly enters into its definition, and indirectly this means to nullify its definition .(47) Such would be the case if Lucifer were to say: "Therefore I came forth from nothing, not having been caused." To say, "Something contingent exists that is not caused," is to affirm a positive relation of agreement between two terms which are in no way related to each other. Most certainly nothing comes into being without a cause.

Hence the ontological validity of the notion of being and of the principle of contradiction or of identity being admitted, this means that the ontological and not only the phenomenal validity of the notion of cause and of the principle of efficient causality must be admitted. The experimental law that heat expands iron pertains to the order of phenomena, and is hypothetically necessary, which means that if heat exerts its influence, the expansion of iron is the result; but this does not exclude the possibility of this expansion being produced by a higher cause beyond the ordinary course of nature. On the contrary, the principle of efficient causality is a law of the ontological order and is of absolute necessity; we cannot conceive of even a miraculous exception, for nothing comes into being without a cause. This formula extends to every cause whatever, whether the proximate and lowest, or the supreme cause.

It must be noted that for our demonstration it is not absolutely necessary to prove that the notion of cause is not innate to us, but that it is abstracted from sensible things. Even if it were innate to us, it could and would have not only phenomenal but also transcendent and ontological validity; for it manifests to us something deeper than phenomena, namely, the dependence of contingent being upon another being, for that which is not self-existent is dependent upon another for its existence.(48)

St Thomas says: "From every effect the existence of its proper cause can be demonstrated." Why does he say "the proper cause"? It is because, if it is not a case of the proper cause, then the demonstration is invalid. Thus the following inference is valueless: this man exists, therefore his father exists, and yet the father is the cause of the son. Very often the father dies before the son. Likewise, very often the antecedent phenomenon disappears when the subsequent phenomenon makes its appearance, as in the case of the local motion of rubbing the hands together by which heat is produced. Hence the agnostics would merely say that "from every effect it can be demonstrated, not that its cause does exist, but that it did exist." Thus heat is produced by local motion, and this latter presupposes heat, and so on indefinitely. In like manner, rain comes from the clouds, the clouds from the evaporation of the water, the evaporation is caused by the heat of the sun, and so on indefinitely, so that there was never a first rain, or a first evaporation. The case is the same in the series of generations of plants, animals, and men. There was never a first oak or a first lion or a first man. In fact, even Aristotle admitted that the world and generations are eternal, yet according to a certain mysterious dependence on the pure Act.

St. Thomas would reply that we are concerned with the proper cause, whereas the proposed difficulty does not refer to the proper cause.(49) What is the proper cause? It is the cause on which the effect absolutely first of all, or necessarily and immediately, depends, as Aristotle said, just as the property depends on the specific difference, for instance, the faculty of reasoning on the ability to reason. The proper effect is like a property manifested ad extra in its relation the proper cause about which we are concerned in this article.

St. Thomas presupposes from the works of Aristotle (50) the philosophical and profound notion of the required proper or absolutely first cause. Of the four modes of per se predication, the fourth pertains to causality, as the killer kills, light illuminates, the sculptor is the cause of the statue.(51) St. Thomas also examines more closely this notion of cause in his discussion of creation.(52) The most universal effect (that is, being inasmuch as this term applies to all existing things) must be reduced to its most universal cause, as the proper effect of this cause. St. Thomas again refers to this causality when treating of the conservation of all things by God. (53) These articles constitute the most sublime comment on the doctrine of the present article, and this because they treat of the same relation of causality, but they do so by starting from above, from God already known, and not by ascending to Him as we do here by the way of finding out.

For a more profound understanding of the proper or proximately direct cause, that is, of the one that is necessarily and immediately required, we must recall the five evident propositions taken from the Metaphysics of Aristotle. In this we see the methodical transition from the natural reason or the common sense to the philosophical reason, in accordance with Aristotle's accustomed way, who thus gave metaphysics its elements as Euclid did to geometry.

1) The proper cause must be the direct or necessarily required cause, (54) and not the accidental cause. We have an example of a direct cause in the following: a man generates a man, or the man generating is the direct cause of the generation of the man. An accidental cause would be: Socrates generates a man; because for a man to be generated it is not necessary that the one generating be Socrates or Plato. A fortiori, it is accidental that the musician generates a man, because it is accidental for the one generating to be a musician. In like manner and with far greater reason, the grandfather is the accidental cause of the generation of the grandson, for he is not directly concerned in it, and often he is already dead. His son generates inasmuch as he is a man, and not inasmuch as he is the son of another man, as St. Thomas says.(55) Hence a series of past causes, as grandfather, great-grandfather, and so on, is a series of accidental causes and in Aristotle's opinion was infinite in the past, that is, there was no first generator; but, according to St. Thomas, this is not repugnant to reason, as we shall state farther on.(56) We maintain it to be of revelation, however, that the world had a beginning, and Adam the first man was able to generate because, as we have said, man generates inasmuch as he is of adult age, and not inasmuch as he is the son of another man.

2) The proper cause must be not only direct, but proximately or immediately required for its proper effect, as the specific difference is the cause of the property that is derived from it. Thus to say that an animal generates a man, is to assign the direct cause, but not the proximately direct cause, not the proper cause. We must say that a man generates a man.

3) Hence a most particular or singular cause is the proper cause of a most particular effect. Thus Socrates is the proper cause of the generation, not of a man, but of this man, his son. St. Thomas says: "Of two things in the same species (as a father and son), one cannot directly cause the other's form as such, since it would then be the cause of its own form, which is essentially the same as the form of the other; but it can be the cause of this form for as much as it is in matter, in other words, it may be the cause that this matter receives this form." (57) Thus Socrates is said to be the proper cause of the generation not of a man but of this man.

4) The most universal cause is the proper cause of the most universal effect. As St. Thomas says: "For the more universal effects must be reduced to the more universal and prior causes. Now among all effects, the most universal is being itself. Hence it must be the proper effect of the first and most universal cause, and that is God." (58) Thus only God can create or "produce being absolutely, not as this being (for instance, this wood), or such being (for instance, wood rather than stone)." (59) In like manner, "this movement is produced by this mover," (60) for example, the movement of the carriage by the horse; but if motion taken in the absolute sense is not its own reason for existence and needs a cause, we must reduce motion taken in the absolute sense and hence all motions to a higher universal cause, namely, to the first mover, who will be the proper or proximately direct cause, not of this particular motion, but of motion itself taken in the absolute sense (as it is a universal effect); and hence this first mover, the cause of all motions, will be immobile, at least as regards local motion. In fact, if immobility is a requisite for the mover not only of bodies but also of spirits, whatever kind of motion this may be, then our soul is mobile, not by way of local motion, but because of the discursive and deliberative process of its reasoning faculty.

5) Finally, we must distinguish between the proper cause of the beginning of the effect and the proper cause of the being of the effect.(6l) Thus the builder is the proper cause of the building of the house, and when the actual construction of the house ceases, then its construction in the passive sense also ceases; but the builder is not the proximately direct cause of the being of the house, for its being does not depend on the being of the builder; in fact, when the builder dies the house continues in its being. Likewise, Socrates is the cause of his son as to his becoming, or as to his passive generation, but not as to his being; for the son's being is independent of the father's being; in fact, whereas the father dies, the son continues to exist.

On the other hand, the illumination by the sun is the cause of the air being illuminated, and when the sun ceases to illuminate, then the air is no longer illuminated. In like manner, the object seen is the objective cause of the seeing, so that the seeing ceases with the removal of the object. Likewise the evidence of the principles is the cause of the evidence of the conclusion, not only as to its becoming, but also as to its being. Also the attraction of the good that is desired is the cause of the desire not only as to its becoming, but also as to its being and continuance in being.

These five subordinate propositions not only give us a more profound insight into the meaning of the proper or proximately direct cause as understood by Aristotle and St. Thomas, but they also explain the following words of this article: "From every effect the existence of its proper cause can be demonstrated," and not only that it did exist.

This is the same as saying with Aristotle,(62) that the positing of the cause (as it is the cause) means the positing of the effect, and, on the other hand, the removal of the cause means the removal of the effect. Thus the positing of a potential cause means the positing of a potential effect; for instance, the builder can build, and the house can be built. The positing of the cause in the act of causing the becoming of the effect means the positing of this becoming (the one who builds, is building); the positing of the cause in the act of producing the being of its effect means the production of this being. Thus, as long as the sun illuminates the atmosphere by its presence, this latter remains illuminated.

It is now easy to explain the end of the argumentative part of this article, which is but the application of the preceding to the proof of God's existence. This means that, if there are in the world effects proper to God, the supreme Cause, then God's existence can be demonstrated a posteriori from them, and, indeed, by an absolutely necessary metaphysical demonstration, if these effects pertain to being, inasmuch as it is the being of created things. But these effects proper to God are investigated in the following article.

Already from the aforesaid it is clear that these effects must be universal, since the most universal effects are the proper effects of the most universal cause, as being by participation is the proper effect of Him who is essential being. Thus our conclusion will be that this motion is caused by this previous motion; but if motion taken absolutely in its generic sense is not its own reason for existence, then we must seek for the proper cause of motion in the generic sense, and of all motions.

So we shall conclude: (1) that the proper cause of all motions is the first and immobile Mover (first way); but that it does not follow immediately from this that the first Mover is infinite and intelligent; (2) likewise that the proper cause of all caused causality is the first uncaused Cause (second way); (3) that the proper cause of all contingent being is the necessary Being (third way), and this necessary Being will manifest Himself to us as the cause not only of the becoming but also of the being of contingent beings; (4) that the proper cause of those things that admit of greater and less in being, in truth, and in goodness, is the greatest in being, in truth, and in goodness (fourth way); (5) finally that the supreme and intelligent Ordainer of all things is the proper cause of the ordaining of all things. This means that the supreme Ordainer is the absolutely first cause of the ordaining and preserving of all things in the world, just as the sculptor is the proximately direct cause of the formation of the statue as to its becoming (but not as to the being of the statue, for this continues in existence after the sculptor's death).

First doubt. The question is whether the aforesaid demonstration from effects ought to have its foundation in a series of accidentally connected causes, or in a series of actually existing and essentially, connected causes.(63)

This difficulty arises from another general principle that together with the principle of causality is included in all proofs of God's existence. The principle is that we cannot proceed to infinity in a series of subordinated causes. Therefore we must come to uncaused cause. What sort of subordination are we concerned with here?

Some, having failed to grasp the meaning of St. Thomas in the following article, think that he considers an infinite series of accidentally subordinated causes to be a contradiction in terms, so that this necessarily implies that creation was not eternal, which means that there must have been a first man, a first lion, and series of eternal generations of men, animals, and plants. But afterward, these same persons find St. Thomas, in the article in which he asks whether it is of faith that the world began, writing as follows: "But it is not impossible to proceed to accidental infinity, regards efficient causes," (64) in a series, for instance, of past generations. This shows that they misunderstood the proofs of God's existence.

We find the solution to the doubt precisely in the complete reply of St. Thomas from which the above-mentioned quotation is taken. He writes: "In efficient causes it is impossible to proceed to absolute infinity; for example, there cannot be an infinite number of causes that are absolutely required for a certain effect; for instance, that a stone be moved by a stick, the stick by the hand, and so on to infinity. But it is not impossible to proceed to accidental infinity as regards efficient causes; as for instance, if all the causes thus infinitely multiplied should have the order of only one cause their multiplication being accidental; as an artificer acts by means of many hammers accidentally, because one after the other may be taken. It is accidental, therefore, that one particular hammer acts after the action of another; and likewise it is accidental to this particular man as generator to be generated by another man; for he generates as a man, and not as the son of another man. For all men generating hold one grade in efficient causes, namely, the grade of a particular generator. Hence it is not impossible for a man to be generated by man to infinity; but such a thing would impossible if the generation of this man depended on this man and on an elementary body, and on the sun, and so on to infinity." (65)

Hence the ancients said that "man and the sun generate man", which means man acting in conjunction with the general agents actually existing; for, if there were a cessation of solar heat on the earth, this would mean the end of the generations of animal and plant life. But the influence of the sun directly depends on the actual influence of a higher cause, and we cannot proceed to infinity in a series of directly subordinated efficient causes; as Aristotle said: "anagke stenai (Ed: written in Greek)" or we must come to a first in this series. Otherwise all movers would be moved and no reason could be assigned for the being or cause of motion itself. We must therefore come to a first cause that is its own principle of action.(66)

In accordance with the modern physics of our times, we may express the series of directly subordinated efficient causes as follows: the ship supports the sailor, the sea enables the ship to float, the earth holds the sea in check, the sun keeps the earth fixed in its course, and some unknown center of attraction holds the sun in its place. But we cannot proceed to infinity in this series; otherwise all movers would be moved, and so we could not assign any cause for motion itself, which needs a cause, since it is not its own principle of motion. Hence we must come to the supreme Mover that is not of the past but is actually existing, who is His own action and His own being, because operation follows being, and the mode of operation the mode of being.

Similarly there may be many wheels in a clock, but we must come to that part of the mechanism whose elasticity, whether you call it tension or weight, is the cause of the local motion of the wheels and of the index hand of the hours. Thus local motion originates from some force, from some dynamic influence that must be explained by some higher cause.

In the opinion of St. Thomas, that creation was not eternal but took place in time, so that there was a first day, a first revolution of the sun, is dependent on God's most free will and is known only by revelation.(67)

So also Aristotle,(68) although he admits the eternity of motion, proves the existence of a supreme and immobile mover who does not need to be premoved so as to act. In fact, he says that the greatest motion must be infinitely powerful to move in an infinity of time (that is to say, eternally).(69) In like manner, from the fact that act is prior to potency, Aristotle seeks to prove the perpetuity of eternal generation. Hence he concludes that the first Mover is permanently unmoved.(70) Indeed he shows that there is no process to infinity in any genus of directly subordinate causes.(71)

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47. For a more complete explanation of this, consult, God, His Existence, I, 181-91.

48. In Adam, since he was created an adult in the state of innocence, with his ideas, the idea of cause was per accidens infused, or innate: in us it is acquired by abstraction as the notion of being is. Cf. Surnma, Ia, q.84, a.6.

49.This is explained more fully in God, His Existence, pp. 71-81.

50. Post. Anal., Bk. I, lect. 10; Metaph., Bk. V, chap. 2, 1ect. 3.

51. The first mode of per se predication is the definition of the thing; the second is the property that is necessarily connected with the essence of the thing; the third is the first substance, which exists in itself; the fourth is the necessarily required cause.

52. Cf. Summa, Ia, q-45, a.5.

53. Ibid., q. 104, a. 1.

54. It is said to be necessarily required, rather than necessary, because it can be a free cause. Thus we speak of God.

55. Summa theol. Ia, q.46, a.2 ad 7um.

56. Ibid.

57. Ibid., q. 104, a. 1.

58. Ibid., q.45, a.5.

59. Ibid.

60. Likewise my will is the proper cause not of the free choice, but of my free choice as being mine.

61. Summa theol., Ia, q. 104, a. 1.

62. Metaph., Bk. V, chap. 2, lect. 3 (end).

63. This has been more fully explained in God, His Existence, I, 77-84.

64. Summa theol., Ia, q.46, a.2 ad 7um.

65. Ibid.

66. Of course the Augustinians generally rejected, as St. Bonaventure did, the possibility of eternal creation, whereas, contrary to this, the Averroists held with Aristotle that the world actually is eternal, being somehow dependent, however, in the order of causality, on the pure Act. St. Thomas holds in all his writings that eternal creation is not repugnant to reason, and that temporal creation is an article of faith, which cannot be demonstrated.

67. Summa theol., Ia, q.46, a.2; Contra Gentes, Bk. II, chap. 38; De Potentia, q.3, a.14. Quodl., XII, q.6, a. 1; Opusc., 27, De aeternitate mundi.

68. Physics, Bk. VIII (lect. 9, 21, 23 of St. Thomas' commentary).

69. Ibid., lect. 21.

70. Metaph., Bk. XII, chap. 6 (lect. 6).

71. Ibid., Bk. II.


"To think of oneself as nothing, and always to think well and highly of others is the best and most perfect wisdom. Wherefore, if you see another sin openly or commit a serious crime, do not consider yourself better, for you do not know how long you can remain in good estate. All men are frail, but you must admit that none is more frail than yourself. "

Thomas á Kempis

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"If, devout soul, it is your will to please God and live a life of serenity in this world, unite yourself always and in all things to the divine will. Reflect that all the sins of your past wicked life happened because you wandered from the path of God's will. For the future, embrace God's good pleasure and say to him in every happening: "Yea, Father, for so it hath seemed good in thy sight." "

St Alphonsus de Liguori

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"The supreme perfection of man in this life is to be so united to God that all his soul with all its faculties and powers are so gathered into the Lord God that he becomes one spirit with him, and remembers nothing except God, is aware of and recognises nothing but God, but with all his desires unified by the joy of love, he rests contentedly in the enjoyment of his Maker alone."

St Albert the Great

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