God Is Unique

Fr. Albert, O.P.

Hear, O Israel, the Lord our God is one Lord! (Deut. 6:4)

In our knowledge of what God is not, there remains one last thing to deny of Him: multiplicity. St. Thomas gives three proofs of the unity of God.1

Firstly, it follows from His simplicity, the fact that there is no composition in Him at all. Thus we say that God is His own nature, and so there can be no difference between Him and the Divinity. He is not like a man, who is distinguished from his nature and whose nature, therefore, can be found in other beings. God is Divinity: therefore there cannot be more than one God.2

Infinity of Perfection

Secondly, the unity of God is proven by the infinity of His perfection. If there were two Gods they would have to differ in some way (otherwise they wouldn’t be “two”). Therefore something would have to belong to one that didn’t belong to the other. Now if this “something” was just a privation, then the one to whom it belonged would not be infinitely perfect, and therefore would not be God. But if it was a perfection, then the one to whom it didn’t belong would be lacking that perfection and so wouldn’t be infinitely perfect and therefore would not be God. Therefore there can only be one God.

Finally, the oneness of God is shown by the unity of the world, which requires some cause that is one at least in some way, for otherwise it could not cause the world to be one. If this cause, however, was only one “in some way” (that is, in so far as many things came together to produce one effect) and not in itself, it would be a cause of unity not by itself but by a sort of chance.3 Furthermore, many are reduced to one order in a more perfect way by what is one in itself than by what is multiple in itself and one only “in some way” or accidentally. Now God, who is the ultimate cause of the order of the universe, is absolutely perfect, as has already been shown previously. Therefore He causes this order in the most perfect way, that is, as a cause that is one in itself and not just “in some way.”

God is not a Lowest Common Denominator

The uniqueness of God has very important consequences, especially with regard to religion. Thus it is absolutely false to say, as is often said today, and even by the highest officials in the Church, that we have “the same God as the Muslims” or “the same God as the Jews.” For, to start with the most basic thing, our God is Triune, whereas the God of the Muslims and the God of the Jews is not. Now there is only one God: so if He is Triune, then any God which is not Triune isn’t God. God is not a lowest common denominator obtained by abstracting from the different Gods of the different religions everything in which they differ: He is unique. He is what He is and whatever is not that isn’t Him.

Cajetan seems to have anticipated and refuted in advance this modern error that claims that all religions have the same God in his commentary on an article in St. Thomas’s treatise in the Summa on faith.4 The article asks whether the sin against faith is the greatest of sins. St. Thomas answers that yes, it is, because it distances man from God more than any other sin, and he explains: “For thus (that is by his false faith) man does not possess a true knowledge of God; rather by a false knowledge of Him he does not approach Him but is distanced from Him. Nor is it possible for one who has a false opinion of God to know Him in any way at all, because the object of his opinion is not God.”5

Cajetan comments: “This seems to be false because an infidel, for example a Jew or a philosopher, who refuses faith in the Incarnation, still knows something about God: he knows that God is pure act, for example, that He is above all things, that He is the best of all things, the first cause, etc. And the being that he thinks has not assumed flesh is God...”

But he responds to his own objection: “It is one thing to speak of the infidel as such; and another of the infidel man who has other knowledge. For St. Thomas does not say that the man who is an infidel does not have any knowledge of God, which is what the objection attacks; rather he says that God is not known through infidelity, neither simply nor even in some way. Not simply, because the false knowledge of something is not knowledge of it but an error about it: and thus it does not approach one to it but rather distances one from it....Neither even in some way, because a false proposition, as such, enounces the opposite of its subject....For when it is said : ‘Socrates is not capable of laughter,’ by this proposition is enounced what is not Socrates; for what is not capable of laughter implies what is not Socrates.6 And when it is said: ‘Socrates is running,’ when in fact he is seated, there is enounced what Socrates is not right now: for there is presented a running Socrates, who is not to be found. And thus in all matters it is evident that a false proposition, as such, gives no knowledge about the subject, because it enounces the opposite of the subject.

“And if it is said that it gives at least the simple knowledge of the terms of the proposition it must be said that that knowledge does not belong to the false proposition but is rather presupposed by it. And in our case it does not regard unbelief. Thus St. Thomas does not say that what is meant by the term of the proposition is not God: but that what it affirms is not God. For what an infidel, as such, affirms, is not God, as was said.”

Thus we can respond to the modern error by saying that the God of the Muslims or the Jews is not God, because even though when they use the term “God” they mean the God that everyone can know by reason, the propositions they form about Him are absolutely false and do not give any real knowledge of God but rather induce those who believe them into error about Him. Thus when the Muslims say: “Allah is one and Mohammed is His prophet!” they are not referring to our God, the true God, but to a false God, for Mohammed is not the prophet of God. And when the Jews say: “Jesus Christ is not God” they confess a false God because of the real God it is true to say that Jesus Christ is He.

The Truth is Unique

The ardent missionary zeal of the saints was founded on this fundamental truth of the uniqueness of God, and consequently of the uniqueness of the true religion. This was the case, for example, with St. Maximilian Kolbe, who had to fight against the modern ecumenical spirit that was present already at his time. He writes in some private notes: “Write in every issue of The Knight [the review he published]: the truth is unique....The truth is unique—also in religion.”7

In his contacts with non-Catholics he was always very charitable and prudent, but he didn’t hide the truth from them, precisely because of his charity for them. We see this, for example, in his relations with a certain Japanese philosopher, Nishida Tenko, who invited Father Kolbe to visit him. He recounts the story in an article:

“I was received very cordially. On one point, however, we did not manage to agree because of the fact that I obstinately maintained that the truth cannot be anything but unique and, consequently, that there can be only one true religion.…

“Some months ago on the train [I met] one of the collaborators of Nishida Tenko. We exchanged mutual questions and responses about health, our activities and so on and at the end we touched again on the question of religion.

“ ‘You must certainly look down on us, considering us to be inferior beings,’ he said to me.

“ ‘No, absolutely not, I appreciate and respect all those who seek the truth but…the truth is always and only one.’

“ ‘On the little table of Mr. Nishida Tenko there is always the little statue of the Immaculate that you sent us.’

“We had by this time arrived at the station where he had to get off, so we interrupted our conversation and said goodbye.

“Nonetheless, the news that the Immaculate, from Her little statue, turns Her look upon the founder of that village consoled me very much.”8

The firmness of Father Kolbe—and the intercession of the Immaculate—bore fruit. In a note, the editor of his writings informs us that Mr. Tenko died February 29, 1968, at the age of 96 and that before dying he was baptized by a Conventual Franciscan priest.9



1 By unity here, as Cajetan points out in his commentary, we are not referring to the inner cohesion of God but rather simply to the fact that there is only one of Him, what we could call His “uniqueness.” God is unique.

2 In fact the same principle applies to all beings that have no matter, that is, the angels, who, like God, are pure spirits. The nature of Gabriel (his “form”) is all there is of Gabriel because he has no matter. Consequently, there cannot be another being that has Gabrielness because it would have to be Gabriel to have it, since Gabriel is not distinct from his Gabrielness. Thus all angels are specifically different: it is as if there were only one specimen of each species of animal. In animals there can be more than one specimen of each species because in each animal, along with their species, there is matter, and so each individual animal is not identified with its species, but in the angels—and in God—this is not the case.

3 Thus, as John of St. Thomas remarks: “That which is most perfect in the whole universe, namely the ordering of things, would be the product of an accident, that is, the result of several causes that by chance come together to produce one effect.”

4 II-II, q. 10, a. 3.

5 “Id quod ipse opinatur non est Deus,” which literally translated would be: “That which he opines is not God.”

6 Being capable of laughter (being “risiblis”) is something that belongs to every man, because it follows necessarily from the fact that he has an intellectual nature that knows by discursive reasoning. Thus what is not capable of laughter cannot be Socrates.

7 Scritti Kolbiani (SK) 1270. He often comes back to this theme. He writes, for example, in an article in his review: “Truth is one....It is true, for example, that in this moment I am writing these words and you, dear reader, are reading them. Against this the contrary statement cannot be true, that is, that I did not write these words, or that you are not reading them. Indeed, about this question both ‘yes’ and ‘no’ cannot both be true. The truth stands either in “yes” or “no.” Truth, in fact, is one.
 Truth is also powerful. If someone wanted to lie and affirm that neither did I write nor did you read, the truth would not change, while he who denied it would be mistaken, he would delude himself. And even if these deniers were numerous, the force of the truth would not be affected in the least. More, even if all the men on the earth were to affirm, publish, film, and swear for their whole lives that I did not write these lines and that you did not read them, all that wouldn’t be able to take away even a little crumb from the granite of the truth, namely, that I wrote, that you read. And not even God cancels nor can He cancel the truth by a miracle, because He is essentially Truth itself.” (SK 1246, Rycerz Niepokalanej, XIII, 1940)

8 SK 1206, Rycerz Niepokalanej, April, 1936.

9 SK 357, Aug. 4, 1931, n. 2.