Article 6 — Whether, when we speak of God, we may rightly use the word “person” in the plural

The sixth point of inquiry is whether, when we speak of God, we may rightly use the word “person” in the plural. (Parallel texts: ST I.30.4; In I Sent. 25.3.)

Obj. 1: And it seems that we may not. For a person is a substance, as is clear from the definition of Boethius. (Boethius, On the Person and the Two Natures 3 (PL 64:1345).) But “substance” in God is not predicated in the plural. Neither therefore is “person.”

Obj. 2: Other absolute names in God are only predicated in the singular, like wise, good, and so forth. Now the word “person” is an absolute term. Therefore, in God it should not be predicated in the plural.

Obj. 3: The word “person” apparently is taken from subsistence, inasmuch as it denotes an individual in the genus substance, and is, so to speak, one through itself (per se una). Now subsistence would seem to pertain to the essence, and this is not multiplied in God. Therefore, the word “person” should not be predicated in the plural.

Obj. 4: To this it will be replied that even if “subsistence” is taken from essence, we can still say that there are three subsistences in God, and likewise three persons.

On the contrary, terms that signify the divine essence cannot be predicated in the plural unless they be adjectives, which do not take their number from the form signified but from the supposits, whereas the contrary obtains in substantives. Hence, we may say that in God the three are eternal, if “eternal” be an adjective, whereas if it be a substantive, then the words of Athanasius in the Creed are true: there are not three eternals but one eternal. (Athanasius, Athanasian Creed 11 (PG 28:1582); cf. above, q. 2, a. 5, obj. 1.) Now this term “person” is a substantive and not an adjective. Therefore, it should not be predicated in the plural.

Obj. 5: Although essential adjectives are predicated of God in the plural, the forms signified by them are not predicated in the plural but only in the singular. Thus, although in a certain sense we may use the plural in predicating “eternal” of God, in no way do we speak of three eternities. Therefore, although in a sense we may speak of three persons in God, by no means may we say that there are three personhoods.

Obj. 6: Just as “God” signifies one who has divinity, so “divine person” signifies one who subsists in the divinity. Now just as we speak of three subsisting in divinity, so do we speak of three having divinity. If, then, for this reason one can say that there are three persons in God, likewise one can say that there are three Gods, which is heretical.

Obj. 7: Boethius says that there are not three Gods because God does not differ from God in the divine nature. (Boethius, On the Trinity 1, 3 (PL 64:1249, 1251).) But in like manner, seemingly, one divine person does not differ from another by a personal difference, since it is common to them to be a person. Therefore, “person” cannot be predicated of God in the plural.

On the contrary (1), Augustine says that when we ask, “what are these three, Father, Son, and Holy Spirit?” the reply is: “three persons.” (Augustine, On the Trinity 7.4 (PL 42:939–42).) Therefore, “person” is predicated of God in the plural.

Furthermore (2), Athanasius says that one is the person of the Father, another that of the Son, another of the Holy Spirit. (Athanasius, Athanasian Creed 5 (PG 28:1582).) Now, distinction is the cause of number. Therefore “person” must be predicated of God in the plural.

I answer that substantive names, as stated above, draw their number from the form signified, and adjectival names from the supposits. And the reason of this is that substantive names signify through the mode of a substance, whereas adjectives signify through the mode of an accident, which is individuated and multiplied through its subject, whereas a substance is so through itself.

Accordingly, seeing that “person” is a substantive, the possibility of its being predicated in the plural depends on the form signified thereby. Now the form signified by the word person is not the nature absolutely, for in that case “man” and “human person” would mean the same thing, which is clearly false, but “person” formally signifies incommunicability or individuality of one subsisting in a nature, as we have clearly explained.

Since, then, the properties make the being distinct and incommunicable in the divine, it follows that the term “person” would be predicated of God in the plural, just as the term “person” is predicated of men in the plural on account of the plurality of the individuating principles.

Reply Obj. 1: A person is an individual substance, which is a hypostasis: and this is predicated in the plural, as is evident from its use in Greek.

Reply Obj. 2: “Person” is an absolute term from its mode of signification: and yet it signifies a relation, as stated above.

Reply Obj. 3: The word “person” designates not only what is subsisting, which seems to pertain to the essence, but also that which is a distinct and incommunicable existence, which is on account of the relative properties in the divine.

Reply Obj. 4: The form signified by the word “person” is not the essence taken absolutely but that which is the principle of incommunicability or individuation. For this reason is it predicated in the plural, although it is a substantive term. And for this reason also, since there are several distinctive properties in the divine, there are said to be several personhoods.

Reply Obj. 5: Wherefore, the reply to the fifth objection is clear.

Reply Obj. 6: The word “person” signifies one subsisting in the divine nature along with distinction and incommunicability, whereas the word “God” signifies one possessing the divine nature, indicating nothing of distinction or incommunicability: hence the comparison fails.

Reply Obj. 7: Although God differs not from God by any difference in divinity, for there is not but numerically one divinity, yet divine person differs from divine person by a difference of personhood, since in God even the property that distinguishes the persons pertains to the personhood.