1. Having settled the most pressing logical considerations concerning unity, St. Thomas asks the expected question: whether God is one. He proposes two objections. The first is based on Scripture. He cites St. Paul’s first letter to the Corinthians, saying there are “many gods”.
2. The second objection is more complex: one cannot be attributed to God in either of the senses we have discussed: not as number, because quantity as an accident cannot be attributed to God; not as convertible with being, because in this notion one is defined by a privation (lack of division), and there are no privations in God.
3. Both of these objections are obviously lame, and we have seen variants of them over and over again. This is, unfortunately, because they are among the most common sorts of theological errors. The first is from a failure to distinguish the sense of scripture correctly (cf. Q.1 AA.9-10), and the second is from a failure to distinguish a logical privation from a real privation.
4. His Sed Contra is from the beautiful proclamation in Deuteronomy: Hear, O Israel, the Lord your God is one. (Audi, Israel, Dominus Deus tuus unus est.)
5. In the Corpus he gives three arguments for God’s unity: from his simplicity, from his infinite perfection, and from the unity of the world.
6. As regards simplicity, he observes first that the principle by which a thing is this particular thing (hoc aliquid), i.e. the principle of its individuation, is incommunicable. The substantial form of a thing may be communicable (e.g. humanity, by generation), and all of its accidental forms (heat, by radiation), but whatever makes an individual this individual must belong to it solely. Now, the principle of God’s identity as a hoc aliquid (a particular individual) is his own nature, because he is, in his utter simplicity, identical with his nature. Thus to be of the nature of God is to be this God, and no other. Therefore there can only be one God.
7. As regards perfection, Thomas offers a demonstration by supposing the contrary: God has in himself the totality of the perfection of being. Now, if there were many Gods, they would have to differ from each other somehow. But the difference between them would have to be either a privation or a perfection, and either way those lacking the perfection or suffering the privation would be less than absolutely perfect in their being. Thus there cannot be multiple Gods.
8. As regards the unity of the world, he argues from the order of the universe: The unity of a multitude as regards its order or operation must be reduced to a unitary principle, or it goes unexplained. (Cf. our discussion of the Fourth Way in Q.2 A.3) The principle is multitudo non reddit rationem unitatis suae: a multitude as such cannot supply the cause of its own unity. In essence this argument returns back to the fourth and fifth ways: what orders the multitude ought to be one, lest it too depend on some ordering principle.
9. His replies to the objections are straightforward: He explains the text of St. Paul by pointing out that “gods” spoken of are the gods of the pagans, who confused various planets and other things for true gods.
10. To the second objection he clarifies that “one” as number is not predicated of God, since quantity is an accident of material things. Numerical “one” is a mathematical concept which regards the quantity of matter, abstracted from any particular form. On the other hand, the “one” that is convertible with being is predicated of God, and the objection fails on this count because even though according to our idea “one” is defined by the lack of division, this is only a logical and not a real privation: to be one is more perfect than to be divided. And we have already shown that many such logical privations can be attributed to God (infinite, incorporeality, simplicity, immutability, eternity, etc.).
OUTLINE OF ARTICLE
- St. Paul speaks of “many Gods”.
- God cannot have quantity, nor can any privation be attributed to him.
- The principle of individuation is incommunicable: God is this God by his nature, therefore there can only be one God.
- If there were multiple Gods, they would have to differ, and some would be lacking in the perfection of others, but to be God is to be infinitely perfect.
- The unity of the world as regards order and operation must be reduced to the unity of its first cause.
- St. Paul refers to the false gods of the pagans.
- Unity of quantity is proper to material things and is not said of God. Unity of being includes privation only logically, since the removal of imperfection is itself a perfection.