"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 9: The Immutability of God


State of the question. The purpose of this article is to distinguish between God's absolute immutability and that of the angel and the human soul, their substances being incorruptible. It is also the purpose of this article to distinguish between God's absolute im¬mutability and that of the blessed, who are in possession of eternal life.
Conclusion. God alone is altogether immutable.

Thus St. Augustine says: "God alone is immutable; and whatever things He has made, being from nothing, are mutable." (18) It is proved from reason by distinguishing between incorruptible and corruptible creatures.

I) All created things, even the incorruptible, are, as regards sub¬stantial being, mutable by an extrinsic power that is in God. For God, indeed, by a most free act of His power brought creatures into existence, and He freely preserves them in the same. He can, therefore, by His absolute power, annihilate all things, although He would never do so by His well-ordered power (whether ordinary or extraordinary). (19)

2) All created and corruptible things are mutable, as regards their substantial being by an intrinsic power that is in them; for these are composed of matter that can lose its present form and receive another.(20)

3) All creatures, as regards their accidental being, are mutable by an intrinsic power. Even in the angels there is mutability as regards their choice of either good or evil. All were created good and in grace, and some freely merited their eternal happiness, whereas others sinned. In fact, the blessed are capable of receiving new accidental illuminations and of acquiring accidental glory. Finally, there is mutability in the angels by way of virtual contact, inasmuch as they can act in this place or that, and do not always act in the same place.

On the contrary, God is absolutely immutable as regards substantial being, which is absolutely necessary and not contingent, nor is there any accident in God. Moreover He always preserves in being all existing things by His virtual contact. Hence it is only in those things external to God that there can be mutability, as when the blessed begin to see Him. God's free act is a difficulty which must be later examined.(21)

It must be noted that God can annihilate all created things by His absolute power, but not by His well-ordered power (whether ordinary or extraordinary), for no end can be assigned as reason why God should annihilate the angels, the blessed, and Christ's humanity. Yet it remains true to say that all created things can be annihilated by an extrinsic power.

On this point Cajetan remarks that the potentiality of created things does not refer primarily to non-existence, because potentiality refers essentially to actuality, and not to its opposite. Real potentiality by its very nature is directed to actuality, although it cannot directly reduce itself to actuality; hence a thing is said to be in potentiality to exist in a particular way and not to exist in a certain other, just as active potency of itself means that a thing is capable of acting and not acting. In other words, potentiality is really ordained for actuality, and is not really but logically ordained for its opposite.

Hence in created things there can be no real potency for non-existence except in a secondary sense, inasmuch as in anything there is a potency to exist in another way that is incompatible with the existence that it actually has. Thus in composites of matter and form there is a real potency to exist in another way, inasmuch as the matter can receive another form, which can give it a different existence. Hence for anything to have a real potency and not merely a logical potency for non-existence, it must have matter that is capable of receiving another form.

Therefore in the essence of the angel and of the soul there is a real potency for existence, and only a logical potency for non-existence; corresponding to this there is the real power of God, who can annihilate all things created and freely maintained in being by Him. For just as the power of creating presupposes only a logical potency or a possibility on the part of the thing creatable, so the power to annihilate presupposes only the possibility of annihilation. In incorruptible things there is therefore no real potency for non-existence.

Corollary. Therefore the instability in any being arises solely from the possibility of its desiring some other reality which it does not have, for nothingness is not desired by anyone. Hence instability comes from the imperfection of that which is possessed, inasmuch as this does not fully satisfy the capacity for desiring.

Therefore the more we approach to God, the more stability takes the place of instability. This is the immutability of perfect sanctity that exists in heaven.(22) The saints in heaven adhere immutably to God, so that sin is no longer possible.(23) This immutability is of a higher order and is by participation.

On the other hand, there is an inferior kind of immutability that proceeds not from the illimitation of being, but from the limitation of its capacity or desire, which is found in those, as St. Paul so vividly expresses it, who are already filled and have no higher aspirations. For he says: "You are now full, you are now become rich." (24) This is an inferior kind of immutability, a sort of inert egotism, fanaticism, or sectarianism, since such persons do not sufficiently aspire to the higher truth and goodness.

Intermediate between this inferior kind of immutability of those who are now filled and the higher immutability of the blessed, is the praiseworthy mutability of the holy wayfarer who is, like Daniel, "a man of desires" (25) and who always aspires to something higher. This praiseworthy mutability, which tends toward the higher immutability, differs entirely from the instability of the dilettante, who regards no truth as immutable, who does not tend toward God, but who is always of a fickle disposition.

Reply to second objection. The good angels have a participated immutability of the will for good.

And so this terminates the question of God's immutability compared with that of any created being whatever. This question perfects the teaching proposed by St. Augustine since it brings out clearly the distinction between mutability that is the result of intrinsic power, and mutability that is the result of extrinsic power. In this we have a wonderful application of the Aristotelian distinction between real potentiality and actuality.

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18. De natura boni, chap. 1.

19. Summa theol., Ia, q. 104, a.3 f.

20. St. Thomas, along with the ancient physicists, thought that the heavenly bodies are incorruptible, since there were no signs of corruptibility to be seen in them. This was explained inasmuch as the form of ether (quintessence) perfectly completed the capacity of matter. But nowadays spectral analysis has shown that the same chemical combinations are to be found in the stars and in terrestrial bodies. Heavenly bodies are therefore corruptible.

21. Summa theol., Ila, q, 19, a.3. We must say that God's free act is not an accident, for it is not the actuation of divine liberty that was prior to this simple potency. There is only one act of love in God, by which He necessarily loves His own goodness, and not necessarily creatable and created goodness. Thus the possibility of a free act in God does not posit mutability in Him. Moreover, this act is eternal and irrevocable. On this point consult what St. Thomas says about the incorruptibility of the angels (Ia, q.50, a.5), and of the soul (Ia, q.75, a.6).

22. Ibid., IIa IIae, q.81, a.8.

23. Ibid., Ia IIae, q.5, a.4.

24. I Cor. 4: 8.

25. Dan. 9: 23.



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

Thomas á Kempis

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"What good does it do to speak learnedly about the Trinity if, lacking humility, you displease the Trinity? Indeed it is not learning that makes a man holy and just, but a virtuous life makes him pleasing to God. "

Thomas á Kempis

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