1 Objection 1: It would seem that this word person, as applied to God, does not signify relation, but substance. For Augustine says De Trin. vii, 6): When we speak of the person of the Father, we mean nothing else but the substance of the Father, for person is said in regard to Himself, and not in regard to the Son.
1 Ad quartum sic proceditur. Videtur quod hoc nomen persona non significet relationem, sed substantiam, in divinis. Dicit enim Augustinus, in VII de Trin., cum dicimus personam patris, non aliud dicimus quam substantiam patris; ad se quippe dicitur persona, non ad filium.
2 Objection 2: Further, the interrogation What? refers to essence. But, as Augustine says: When we say there are three who bear witness in heaven, the Father, the Word, and the Holy Ghost, and it is asked, Three what? the answer is, Three persons. Therefore person signifies essence.
2 Praeterea, quid quaerit de essentia. Sed, sicut dicit Augustinus in eodem loco, cum dicitur, tres sunt qui testimonium dant in caelo, pater, verbum et spiritus sanctus; et quaeritur, quid tres? Respondetur, tres personae. Ergo hoc nomen persona significat essentiam.
3 Objection 3: According to the Philosopher Metaph. iv), the meaning of a word is its definition. But the definition of person is this: The individual substance of the rational nature, as above stated. Therefore person signifies substance.
3 Praeterea, secundum philosophum, IV Metaphys., id quod significatur per nomen, est eius definitio. Sed definitio personae est rationalis naturae individua substantia, ut dictum est. Ergo hoc nomen persona significat substantiam.
4 Objection 4: Further, person in men and angels does not signify relation, but something absolute. Therefore, if in God it signified relation, it would bear an equivocal meaning in God, in man, and in angels.
4 Praeterea, persona in hominibus et Angelis non significat relationem, sed aliquid absolutum. Si igitur in Deo significaret relationem, diceretur aequivoce de Deo et hominibus et Angelis.
5 On the contrary, Boethius says De Trin.) that every word that refers to the persons signifies relation. But no word belongs to person more strictly than the very word person itself. Therefore this word person signifies relation.
5 Sed contra est quod dicit Boetius, in libro de Trin., quod omne nomen ad personas pertinens, relationem significat. Sed nullum nomen magis pertinet ad personas, quam hoc nomen persona. Ergo hoc nomen persona relationem significat.
6 I answer that, A difficulty arises concerning the meaning of this word person in God, from the fact that it is predicated plurally of the Three in contrast to the nature of the names belonging to the essence; nor does it in itself refer to another, as do the words which express relation. Hence some have thought that this word person of itself expresses absolutely the divine essence; as this name God and this word Wise; but that to meet heretical attack, it was ordained by conciliar decree that it was to be taken in a relative sense, and especially in the plural, or with the addition of a distinguishing adjective; as when we say, Three persons, or, one is the person of the Father, another of the Son, etc.
Used, however, in the singular, it may be either absolute or relative. But this does not seem to be a satisfactory explanation; for, if this word person, by force of its own signification, expresses the divine essence only, it follows that forasmuch as we speak of three persons, so far from the heretics being silenced, they had still more reason to argue. Seeing this, others maintained that this word person in God signifies both the essence and the relation. Some of these said that it signifies directly the essence, and relation indirectly, forasmuch as person means as it were by itself one per se una); and unity belongs to the essence.
And what is by itself implies relation indirectly; for the Father is understood to exist by Himself, as relatively distinct from the Son. Others, however, said, on the contrary, that it signifies relation directly; and essence indirectly; forasmuch as in the definition of person the term nature is mentioned indirectly; and these come nearer to the truth. To determine the question, we must consider that something may be included in the meaning of a less common term, which is not included in the more common term; as rational is included in the meaning of man, and not in the meaning of animal.
So that it is one thing to ask the meaning of the word animal, and another to ask its meaning when the animal in question is man. Also, it is one thing to ask the meaning of this word person in general; and another to ask the meaning of person as applied to God. For person in general signifies the individual substance of a rational figure. The individual in itself is undivided, but is distinct from others. Therefore person in any nature signifies what is distinct in that nature: thus in human nature it signifies this flesh, these bones, and this soul, which are the individuating principles of a man, and which, though not belonging to person in general, nevertheless do belong to the meaning of a particular human person.
Now distinction in God is only by relation of origin, as stated above Question 28, Articles 2, 3), while relation in God is not as an accident in a subject, but is the divine essence itself; and so it is subsistent, for the divine essence subsists. Therefore, as the Godhead is God so the divine paternity is God the Father, Who is a divine person. Therefore a divine person signifies a relation as subsisting. And this is to signify relation by way of substance, and such a relation is a hypostasis subsisting in the divine nature, although in truth that which subsists in the divine nature is the divine nature itself.
Thus it is true to say that the name person signifies relation directly, and the essence indirectly; not, however, the relation as such, but as expressed by way of a hypostasis. So likewise it signifies directly the essence, and indirectly the relation, inasmuch as the essence is the same as the hypostasis: while in God the hypostasis is expressed as distinct by the relation: and thus relation, as such, enters into the notion of the person indirectly. Thus we can say that this signification of the word person was not clearly perceived before it was attacked by heretics.
Hence, this word person was used just as any other absolute term. But afterwards it was applied to express relation, as it lent itself to that signification, so that this word person means relation not only by use and custom, according to the first opinion, but also by force of its own proper signification.
6 Respondeo dicendum quod circa significationem huius nominis persona in divinis, difficultatem ingerit quod pluraliter de tribus praedicatur, praeter naturam essentialium nominum; neque etiam ad aliquid dicitur, sicut nomina quae relationem significant. Unde quibusdam visum est quod hoc nomen persona simpliciter, ex virtute vocabuli, essentiam significet in divinis, sicut hoc nomen Deus, et hoc nomen sapiens, sed propter instantiam haereticorum, est accommodatum, ex ordinatione Concilii, ut possit poni pro relativis; et praecipue in plurali, vel cum nomine partitivo, ut cum dicimus tres personas, vel alia est persona patris, alia filii.
In singulari vero potest sumi pro absoluto, et pro relativo. Sed haec non videtur sufficiens ratio. Quia si hoc nomen persona, ex vi suae significationis, non habet quod significet nisi essentiam in divinis; ex hoc quod dictum est tres personas, non fuisset haereticorum quietata calumnia, sed maioris calumniae data esset eis occasio. Et ideo alii dixerunt quod hoc nomen persona in divinis significat simul essentiam et relationem. Quorum quidam dixerunt quod significat essentiam in recto, et relationem in obliquo. Quia persona dicitur quasi per se una, unitas autem pertinet ad essentiam.
Quod autem dicitur per se, implicat relationem oblique, intelligitur enim pater per se esse, quasi relatione distinctus a filio. Quidam vero dixerunt e converso, quod significat relationem in recto, et essentiam in obliquo, quia in definitione personae, natura ponitur in obliquo. Et isti propinquius ad veritatem accesserunt. Ad evidentiam igitur huius quaestionis, considerandum est quod aliquid est de significatione minus communis, quod tamen non est de significatione magis communis, rationale enim includitur in significatione hominis, quod tamen non est de significatione animalis.
Unde aliud est quaerere de significatione animalis, et aliud est quaerere de significatione animalis quod est homo. Similiter aliud est quaerere de significatione huius nominis persona in communi, et aliud de significatione personae divinae. Persona enim in communi significat substantiam individuam rationalis naturae, ut dictum est. Individuum autem est quod est in se indistinctum, ab aliis vero distinctum. Persona igitur, in quacumque natura, significat id quod est distinctum in natura illa sicut in humana natura significat has carnes et haec ossa et hanc animam, quae sunt principia individuantia hominem; quae quidem, licet non sint de significatione personae, sunt tamen de significatione personae humanae.
Distinctio autem in divinis non fit nisi per relationes originis, ut dictum est supra. Relatio autem in divinis non est sicut accidens inhaerens subiecto, sed est ipsa divina essentia, unde est subsistens, sicut essentia divina subsistit. Sicut ergo deitas est Deus, ita paternitas divina est Deus pater, qui est persona divina. Persona igitur divina significat relationem ut subsistentem. Et hoc est significare relationem per modum substantiae quae est hypostasis subsistens in natura divina; licet subsistens in natura divina non sit aliud quam natura divina.
Et secundum hoc, verum est quod hoc nomen persona significat relationem in recto, et essentiam in obliquo, non tamen relationem inquantum est relatio, sed inquantum significatur per modum hypostasis. Similiter etiam significat essentiam in recto, et relationem in obliquo, inquantum essentia idem est quod hypostasis; hypostasis autem significatur in divinis ut relatione distincta; et sic relatio, per modum relationis significata, cadit in ratione personae in obliquo. Et secundum hoc etiam dici potest, quod haec significatio huius nominis persona non erat percepta ante haereticorum calumniam, unde non erat in usu hoc nomen persona, nisi sicut unum aliorum absolutorum.
Sed postmodum accommodatum est hoc nomen persona ad standum pro relativo, ex congruentia suae significationis, ut scilicet hoc quod stat pro relativo, non solum habeat ex usu, ut prima opinio dicebat, sed etiam ex significatione sua.
7 Reply to Objection 1: This word person is said in respect to itself, not to another; forasmuch as it signifies relation not as such, but by way of a substance, which is a hypostasis. In that sense Augustine says that it signifies the essence, inasmuch as in God essence is the same as the hypostasis, because in God what He is, and whereby He is are the same.
7 Ad primum ergo dicendum quod hoc nomen persona dicitur ad se, non ad alterum, quia significat relationem, non per modum relationis, sed per modum substantiae quae est hypostasis. Et secundum hoc Augustinus dicit quod significat essentiam, prout in Deo essentia est idem cum hypostasi, quia in Deo non differt quod est et quo est.
8 Reply to Objection 2: The term what refers sometimes to the nature expressed by the definition, as when we ask; What is man? and we answer: A mortal rational animal. Sometimes it refers to the suppositum, as when we ask, What swims in the sea? and answer, A fish. So to those who ask, Three what? we answer, Three persons.
8 Ad secundum dicendum quod quid quandoque quaerit de natura quam significat definitio; ut cum quaeritur, quid est homo? Et respondetur, animal rationale mortale. Quandoque vero quaerit suppositum; ut cum quaeritur, quid natat in mari? Et respondetur, piscis. Et sic quaerentibus quid tres? Responsum est, tres personae.
9 Reply to Objection 3: In God the individual, that is, distinct and incommunicable substance, includes the idea of relation, as above explained.
9 Ad tertium dicendum quod in intellectu substantiae individuae, idest distinctae vel incommunicabilis, intelligitur in divinis relatio, ut dictum est.
10 Reply to Objection 4: The different sense of the less common term does not produce equivocation in the more common. Although a horse and an ass have their own proper definitions, nevertheless they agree univocally in animal, because the common definition of animal applies to both. So it does not follow that, although relation is contained in the signification of divine person, but not in that of an angelic or of a human person, the word person is used in an equivocal sense. Though neither is it applied univocally, since nothing can be said univocally of God and creatures Question 13, Article 5).
10 Ad quartum dicendum quod diversa ratio minus communium non facit aequivocationem in magis communi. Licet enim sit alia propria definitio equi et asini, tamen univocantur in nomine animalis, quia communis definitio animalis convenit utrique. Unde non sequitur quod, licet in significatione personae divinae contineatur relatio, non autem in significatione angelicae personae vel humanae, quod nomen personae aequivoce dicatur. Licet nec etiam dicatur univoce, cum nihil univoce de Deo dici possit et de creaturis, ut supra ostensum est.