Reply Obj. 3: There are two reasons why the knowledge of the divine persons was necessary for us. It was necessary for the right idea of creation. The fact of saying that God made all things by His Word excludes the error of those who say that God produced things by necessity. When we say that in Him there is a procession of love, we show that God produced creatures not because He needed them, nor because of any other extrinsic reason, but on account of the love of His own goodness. So Moses, when he had said, "In the beginning God created heaven and earth," subjoined, "God said, Let there be light," to manifest the divine Word; and then said, "God saw the light that it was good," to show proof of the divine love. The same is also found in the other works of creation. In another way, and chiefly, that we may think rightly concerning the salvation of the human race, accomplished by the Incarnate Son, and by the gift of the Holy Ghost. _______________________
SECOND ARTICLE [I, Q. 32, Art. 2]
Whether There Are Notions in God?
Objection 1: It would seem that in God there are no notions. For Dionysius says (Div. Nom. i): "We must not dare to say anything of God but what is taught to us by the Holy Scripture." But Holy Scripture does not say anything concerning notions. Therefore there are none in God.
Obj. 2: Further, all that exists in God concerns the unity of the essence or the trinity of the persons. But the notions do not concern the unity of the essence, nor the trinity of the persons; for neither can what belongs to the essence be predicated of the notions: for instance, we do not say that paternity is wise or creates; nor can what belongs to the persons be so predicated; for example, we do not say that paternity begets, nor that filiation is begotten. Therefore there do not exist notions in God.
Obj. 3: Further, we do not require to presuppose any abstract notions as principles of knowing things which are devoid of composition: for they are known of themselves. But the divine persons are supremely simple. Therefore we are not to suppose any notions in God.
On the contrary, Damascene says (De Fide Orth. iii, 5): "We recognize difference of hypostases [i.e. of persons], in the three properties; i.e. in the paternal, the filial, and the processional." Therefore we must admit properties and notions in God.
I answer that, Prepositivus, considering the simplicity of the persons, said that in God there were no properties or notions, and wherever there were mentioned, he propounded the abstract for the concrete. For as we are accustomed to say, "I beseech your kindness"—i.e. you who are kind—so when we speak of paternity in God, we mean God the Father.
But, as shown above (Q. 3, A. 3, ad 1), the use of concrete and abstract names in God is not in any way repugnant to the divine simplicity; forasmuch as we always name a thing as we understand it. Now, our intellect cannot attain to the absolute simplicity of the divine essence, considered in itself, and therefore, our human intellect apprehends and names divine things, according to its own mode, that is in so far as they are found in sensible objects, whence its knowledge is derived. In these things we use abstract terms to signify simple forms; and to signify subsistent things we use concrete terms. Hence also we signify divine things, as above stated, by abstract names, to express their simplicity; whereas, to express their subsistence and completeness, we use concrete names.
But not only must essential names be signified in the abstract and in the concrete, as when we say Deity and God; or wisdom and wise; but the same applies to the personal names, so that we may say paternity and Father.