and the Son are one principle of the Holy Ghost," because, they declare, since the word "principle" in the singular number does not signify "person," but "property," it must be taken as an adjective; and forasmuch as an adjective cannot be modified by another adjective, it cannot properly be said that the Father and the Son are one principle of the Holy Ghost unless one be taken as an adverb, so that the meaning should be: They are one principle--that is, in one and the same way. But then it might be equally right to say that the Father is two principles of the Son and of the Holy Ghost--namely, in two ways. Therefore, we must say that, although this word "principle" signifies a property, it does so after the manner of a substantive, as do the words "father" and "son" even in things created. Hence it takes its number from the form it signifies, like other substantives.
Therefore, as the Father and the Son are one God, by reason of the unity of the form that is signified by this word "God"; so they are one principle of the Holy Ghost by reason of the unity of the property that is signified in this word "principle."
Reply Obj. 1: If we consider the spirative power, the Holy Ghost proceeds from the Father and the Son as they are one in the spirative power, which in a certain way signifies the nature with the property, as we shall see later (ad 7). Nor is there any reason against one property being in two _supposita_ that possess one common nature. But if we consider the _supposita_ of the spiration, then we may say that the Holy Ghost proceeds from the Father and the Son, as distinct; for He proceeds from them as the unitive love of both.
Reply Obj. 2: In the proposition "the Father and the Son are one principle of the Holy Ghost," one property is designated which is the form signified by the term. It does not thence follow that by reason of the several properties the Father can be called several principles, for this would imply in Him a plurality of subjects.
Reply Obj. 3: It is not by reason of relative properties that we speak of similitude or dissimilitude in God, but by reason of the essence. Hence, as the Father is not more like to Himself than He is to the Son; so likewise neither is the Son more like to the Father than is the Holy Ghost.
Reply Obj. 4: These two propositions, "The Father and the Son are one principle which is the Father," or, "one principle which is not the Father," are not mutually contradictory; and hence it is not necessary to assert one or other of them. For when we say the Father and the Son are one principle, this word "principle" has not determinate supposition but rather it stands indeterminately for two persons together. Hence there is a fallacy of "figure of speech" as the argument concludes from the indeterminate to the determinate.
Reply Obj. 5: This proposition is also true:--The one principle of the Holy Ghost is the Father and the Son; because the word "principle" does not stand for one person only, but indistinctly for the two persons as above explained.
Reply Obj. 6: There is no reason against saying that the Father and the Son are the same principle, because the word "principle" stands confusedly and indistinctly for the two Persons together.
Reply Obj. 7: Some say that although the Father and the Son are one principle of the Holy Ghost, there are two spirators, by reason of the distinction of _supposita,_ as also there are two spirating, because acts refer to subjects. Yet this does not hold good as to the name "Creator"; because the Holy Ghost proceeds from the Father and the Son as from two distinct persons, as above explained; whereas the creature proceeds from the three persons not as distinct persons, but as united in essence. It seems, however, better to say that because spirating is an adjective, and spirator a substantive, we can say that the Father and the Son are two spirating, by reason of the plurality of the _supposita_ but not two spirators by reason of the one spiration. For adjectival words derive their number from the _supposita_ but substantives from themselves, according to the form signified. As to what Hilary says, that "the Holy Ghost is from the Father and the Son as His authors," this is to be explained in the sense that the substantive here stands for the adjective.
QUESTION 37 OF THE NAME OF THE HOLY GHOST--LOVE (In Two Articles) We now inquire concerning the name "Love," on which arise two points of inquiry: (1) Whether it is the proper name of the Holy Ghost?
(2) Whether the Father and the Son love each other by the Holy Ghost?
Whether "Love" Is the Proper Name of the Holy Ghost?
Objection 1: It would seem that "Love" is not the proper name of the Holy Ghost. For Augustine says (De Trin. xv, 17): "As the Father, Son and Holy Ghost are called Wisdom, and are not three Wisdoms, but one; I know not why the Father, Son and Holy Ghost should not be called Charity, and all together one Charity." But no name which is predicated in the singular of each person and of all together, is a proper name of a person. Therefore this name, "Love," is not the proper name of the Holy Ghost.
Obj. 2: Further, the Holy Ghost is a subsisting person, but love is not used to signify a subsisting person, but rather an action passing from the lover to the beloved. Therefore Love is not the proper name of the Holy Ghost.
Obj. 3: Further, Love is the bond between lovers, for as Dionysius says (Div. Nom. iv): "Love is a unitive force." But a bond is a medium between what it joins together, not something proceeding from them. Therefore, since the Holy Ghost proceeds from the Father and the Son, as was shown above (Q. 36, A. 2), it seems that He is not the Love or bond of the Father and the Son.
Obj. 4: Further, Love belongs to every lover. But the Holy Ghost is a lover: therefore He has love. So if the Holy Ghost is Love, He must be love of love, and spirit from spirit; which is not admissible.
_On the contrary,_ Gregory says (Hom. xxx, in Pentecost.): "The Holy Ghost Himself is Love."
_I answer that,_ The name Love in God can be taken essentially and personally. If taken personally it is the proper name of the Holy Ghost; as Word is the proper name of the Son.
To see this we must know that since as shown above (Q. 27, AA. 2, 3, 4, 5), there are two processions in God, one by way of the intellect, which is the procession of the Word, and another by way of the will, which is the procession of Love; forasmuch as the former is the more known to us, we have been able to apply more suitable names to express our various considerations as regards that procession, but not as regards the procession of the will. Hence, we are obliged to employ circumlocution as regards the person Who proceeds, and the relations following from this procession which are called "procession" and "spiration," as stated above (Q. 27, A. 4, ad 3), and yet express the origin rather than the relation in the strict sense of the term. Nevertheless we must consider them in respect of each procession simply. For as when a thing is understood by anyone, there results in the one who understands a conception of the object understood, which conception we call word; so when anyone loves an object, a certain impression results, so to speak, of the thing loved in the affection of the lover; by reason of which the object loved is said to be in the lover; as also the thing understood is in the one who understands; so that when anyone understands and loves himself he is in himself, not only by real identity, but also as the object understood is in the one who understands, and the thing loved is in the lover. As regards the intellect, however, words have been found to describe the mutual relation of the one who understands the object understood, as appears in the word "to understand"; and other words are used to express the procession of the intellectual conception--namely, "to speak," and "word." Hence in God, "to understand" is applied only to the essence; because it does not import relation to the Word that proceeds; whereas "Word" is said personally, because it signifies what proceeds; and the term "to speak" is a notional term as importing the relation of the principle of the Word to the Word Himself. On the other hand, on the part of the will, with the exception of the words "dilection" and "love," which express the relation of the lover to the object loved, there are no other terms in use, which express the relation of the impression or affection of the object loved, produced in the lover by fact that he loves--to the principle of that impression, or "vice versa." And therefore, on account of the poverty of our vocabulary, we express these relations by the words "love" and "dilection": just as if we were to call the Word "intelligence conceived," or "wisdom begotten."
It follows that so far as love means only the relation of the lover to the object loved, "love" and "to love" are said of the essence, as "understanding" and "to understand"; but, on the other hand, so far as these words are used to express the relation to its principle, of what proceeds by way of love, and "vice versa," so that by "love" is understood the "love proceeding," and by "to love" is understood "the spiration of the love proceeding," in that sense "love" is the name of the person and "to love" is a notional term, as "to speak" and "to beget."
Reply Obj. 1: Augustine is there speaking of charity as it means the divine essence, as was said above (here and Q. 24, A. 2, ad 4).
Reply Obj. 2: Although to understand, and to will, and to love signify actions passing on to their objects, nevertheless they are actions that remain in the agents, as stated above (Q. 14, A. 4), yet in such a way that in the agent itself they import a certain relation to their object. Hence, love also in ourselves is something that abides in the lover, and the word of the heart is something abiding in the speaker; yet with a relation to the thing expressed by word, or loved. But in God, in whom there is nothing accidental, there is more than this; because both Word and Love are subsistent.
Therefore, when we say that the Holy Ghost is the Love of the Father for the Son, or for something else; we do not mean anything that passes into another, but only the relation of love to the beloved; as also in the Word is imported the relation of the Word to the thing expressed by the Word.
Reply Obj. 3: The Holy Ghost is said to be the bond of the Father and Son, inasmuch as He is Love; because, since the Father loves Himself and the Son with one Love, and conversely, there is expressed in the Holy Ghost, as Love, the relation of the Father to the Son, and conversely, as that of the lover to the beloved. But from the fact that the Father and the Son mutually love one another, it necessarily follows that this mutual Love, the Holy Ghost, proceeds from both. As regards origin, therefore, the Holy Ghost is not the medium, but the third person in the Trinity; whereas as regards the aforesaid relation He is the bond between the two persons, as proceeding from both.
Reply Obj. 4: As it does not belong to the Son, though He understands, to produce a word, for it belongs to Him to understand as the word proceeding; so in like manner, although the Holy Ghost loves, taking Love as an essential term, still it does not belong to Him to spirate love, which is to take love as a notional term; because He loves essentially as love proceeding; but not as the one whence love proceeds.
Whether the Father and the Son Love Each Other by the Holy Ghost?
Objection 1: It would seem that the Father and the Son do not love each other by the Holy Ghost. For Augustine (De Trin. vii, 1) proves that the Father is not wise by the Wisdom begotten. But as the Son is Wisdom begotten, so the Holy Ghost is the Love proceeding, as explained above (Q. 27, A. 3). Therefore the Father and the Son do not love Themselves by the Love proceeding, which is the Holy Ghost.
Obj. 2: Further, in the proposition, "The Father and the Son love each other by the Holy Ghost," this word "love" is to be taken either essentially or notionally. But it cannot be true if taken essentially, because in the same way we might say that "the Father understands by the Son"; nor, again, if it is taken notionally, for then, in like manner, it might be said that "the Father and the Son spirate by the Holy Ghost," or that "the Father generates by the Son." Therefore in no way is this proposition true: "The Father and the Son love each other by the Holy Ghost."
Obj. 3: Further, by the same love the Father loves the Son, and Himself, and us. But the Father does not love Himself by the Holy Ghost; for no notional act is reflected back on the principle of the act; since it cannot be said that the "Father begets Himself," or that "He spirates Himself." Therefore, neither can it be said that "He loves Himself by the Holy Ghost," if "to love" is taken in a notional sense. Again, the love wherewith He loves us is not the Holy Ghost; because it imports a relation to creatures, and this belongs to the essence. Therefore this also is false: "The Father loves the Son by the Holy Ghost."
_On the contrary,_ Augustine says (De Trin. vi, 5): "The Holy Ghost is He whereby the Begotten is loved by the one begetting and loves His Begetter."
_I answer that,_ A difficulty about this question is objected to the effect that when we say, "the Father loves the Son by the Holy Ghost," since the ablative is construed as denoting a cause, it seems to mean that the Holy Ghost is the principle of love to the Father and the Son; which cannot be admitted.
In view of this difficulty some have held that it is false, that "the Father and the Son love each other by the Holy Ghost"; and they add that it was retracted by Augustine when he retracted its equivalent to the effect that "the Father is wise by the Wisdom begotten." Others say that the proposition is inaccurate and ought to be expounded, as that "the Father loves the Son by the Holy Ghost"--that is, "by His essential Love," which is appropriated to the Holy Ghost. Others further say that this ablative should be construed as importing a sign, so that it means, "the Holy Ghost is the sign that the Father loves the Son"; inasmuch as the Holy Ghost proceeds from them both, as Love. Others, again, say that this ablative must be construed as importing the relation of formal cause, because the Holy Ghost is the love whereby the Father and the Son formally love each other. Others, again, say that it should be construed as importing the relation of a formal effect; and these approach nearer to the truth.
To make the matter clear, we must consider that since a thing is commonly denominated from its forms, as "white" from whiteness, and "man" from humanity; everything whence anything is denominated, in this particular respect stands to that thing in the relation of form.
So when I say, "this man is clothed with a garment," the ablative is to be construed as having relation to the formal cause, although the garment is not the form. Now it may happen that a thing may be denominated from that which proceeds from it, not only as an agent is from its action, but also as from the term itself of the action--that is, the effect, when the effect itself is included in the idea of the action. For we say that fire warms by heating, although heating is not the heat which is the form of the fire, but is an action proceeding from the fire; and we say that a tree flowers with the flower, although the flower is not the tree's form, but is the effect proceeding from the form. In this way, therefore, we must say that since in God "to love" is taken in two ways, essentially and notionally, when it is taken essentially, it means that the Father and the Son love each other not by the Holy Ghost, but by their essence.
Hence Augustine says (De Trin. xv, 7): "Who dares to say that the Father loves neither Himself, nor the Son, nor the Holy Ghost, except by the Holy Ghost?" The opinions first quoted are to be taken in this sense. But when the term Love is taken in a notional sense it means nothing else than "to spirate love"; just as to speak is to produce a word, and to flower is to produce flowers. As therefore we say that a tree flowers by its flower, so do we say that the Father, by the Word or the Son, speaks Himself, and His creatures; and that the Father and the Son love each other and us, by the Holy Ghost, or by Love proceeding.
Reply Obj. 1: To be wise or intelligent is taken only essentially in God; therefore we cannot say that "the Father is wise or intelligent by the Son." But to love is taken not only essentially, but also in a notional sense; and in this way, we can say that the Father and the Son love each other by the Holy Ghost, as was above explained.
Reply Obj. 2: When the idea of an action includes a determined effect, the principle of the action may be denominated both from the action, and from the effect; so we can say, for instance, that a tree flowers by its flowering and by its flower. When, however, the idea of an action does not include a determined effect, then in that case, the principle of the action cannot be denominated from the effect, but only from the action. For we do not say that the tree produces the flower by the flower, but by the production of the flower. So when we say, "spirates" or "begets," this imports only a notional act. Hence we cannot say that the Father spirates by the Holy Ghost, or begets by the Son. But we can say that the Father speaks by the Word, as by the Person proceeding, "and speaks by the speaking," as by a notional act; forasmuch as "to speak" imports a determinate person proceeding; since "to speak" means to produce a word. Likewise to love, taken in a notional sense, means to produce love; and so it can be said that the Father loves the Son by the Holy Ghost, as by the person proceeding, and by Love itself as a notional act.
Reply Obj. 3: The Father loves not only the Son, but also Himself and us, by the Holy Ghost; because, as above explained, to love, taken in a notional sense, not only imports the production of a divine person, but also the person produced, by way of love, which has relation to the object loved. Hence, as the Father speaks Himself and every creature by His begotten Word, inasmuch as the Word "begotten" adequately represents the Father and every creature; so He loves Himself and every creature by the Holy Ghost, inasmuch as the Holy Ghost proceeds as the love of the primal goodness whereby the Father loves Himself and every creature. Thus it is evident that relation to the creature is implied both in the Word and in the proceeding Love, as it were in a secondary way, inasmuch as the divine truth and goodness are a principle of understanding and loving all creatures.
QUESTION 38 OF THE NAME OF THE HOLY GHOST, AS GIFT (In Two Articles) There now follows the consideration of the Gift; concerning which there are two points of inquiry: (1) Whether "Gift" can be a personal name?
(2) Whether it is the proper name of the Holy Ghost?
Whether "Gift" Is a Personal Name?
Objection 1: It would seem that "Gift" is not a personal name. For every personal name imports a distinction in God. But the name of "Gift" does not import a distinction in God; for Augustine says (De Trin. xv, 19): that "the Holy Ghost is so given as God's Gift, that He also gives Himself as God." Therefore "Gift" is not a personal name.
Obj. 2: Further, no personal name belongs to the divine essence. But the divine essence is the Gift which the Father gives to the Son, as Hilary says (De Trin. ix). Therefore "Gift" is not a personal name.
Obj. 3: Further, according to Damascene (De Fide Orth. iv, 19) there is no subjection nor service in the divine persons. But gift implies a subjection both as regards him to whom it is given, and as regards him by whom it is given. Therefore "Gift" is not a personal name.
Obj. 4: Further, "Gift" imports relation to the creature, and it thus seems to be said of God in time. But personal names are said of God from eternity; as "Father," and "Son." Therefore "Gift" is not a personal name.
_On the contrary,_ Augustine says (De Trin. xv, 19): "As the body of flesh is nothing but flesh; so the gift of the Holy Ghost is nothing but the Holy Ghost." But the Holy Ghost is a personal name; so also therefore is "Gift."
_I answer that,_ The word "gift" imports an aptitude for being given.
And what is given has an aptitude or relation both to the giver and to that to which it is given. For it would not be given by anyone, unless it was his to give; and it is given to someone to be his. Now a divine person is said to belong to another, either by origin, as the Son belongs to the Father; or as possessed by another. But we are said to possess what we can freely use or enjoy as we please: and in this way a divine person cannot be possessed, except by a rational creature united to God. Other creatures can be moved by a divine person, not, however, in such a way as to be able to enjoy the divine person, and to use the effect thereof. The rational creature does sometimes attain thereto; as when it is made partaker of the divine Word and of the Love proceeding, so as freely to know God truly and to love God rightly. Hence the rational creature alone can possess the divine person. Nevertheless in order that it may possess Him in this manner, its own power avails nothing: hence this must be given it from above; for that is said to be given to us which we have from another source.
Thus a divine person can "be given," and can be a "gift."
Reply Obj. 1: The name "Gift" imports a personal distinction, in so far as gift imports something belonging to another through its origin. Nevertheless, the Holy Ghost gives Himself, inasmuch as He is His own, and can use or rather enjoy Himself; as also a free man belongs to himself. And as Augustine says (In Joan. Tract. xxix): "What is more yours than yourself?" Or we might say, and more fittingly, that a gift must belong in a way to the giver. But the phrase, "this is this one's," can be understood in several senses. In one way it means identity, as Augustine says (In Joan. Tract. xxix); and in that sense "gift" is the same as "the giver," but not the same as the one to whom it is given. The Holy Ghost gives Himself in that sense. In another sense, a thing is another's as a possession, or as a slave; and in that sense gift is essentially distinct from the giver; and the gift of God so taken is a created thing. In a third sense "this is this one's" through its origin only; and in this sense the Son is the Father's; and the Holy Ghost belongs to both.
Therefore, so far as gift in this way signifies the possession of the giver, it is personally distinguished from the giver, and is a personal name.
Reply Obj. 2: The divine essence is the Father's gift in the first sense, as being the Father's by way of identity.
Reply Obj. 3: Gift as a personal name in God does not imply subjection, but only origin, as regards the giver; but as regards the one to whom it is given, it implies a free use, or enjoyment, as above explained.
Reply Obj. 4: Gift is not so called from being actually given, but from its aptitude to be given. Hence the divine person is called Gift from eternity, although He is given in time. Nor does it follow that it is an essential name because it imports relation to the creature; but that it includes something essential in its meaning; as the essence is included in the idea of person, as stated above (Q. 34, A.
3).
Whether "Gift" Is the Proper Name of the Holy Ghost?
Objection 1: It would seem that Gift is not the proper name of the Holy Ghost. For the name Gift comes from being given. But, as Isaiah says (9:16): "A Son is given to us." Therefore to be Gift belongs to the Son, as well as to the Holy Ghost.
Obj. 2: Further, every proper name of a person signifies a property.
But this word Gift does not signify a property of the Holy Ghost.
Therefore Gift is not a proper name of the Holy Ghost.
Obj. 3: Further, the Holy Ghost can be called the spirit of a man, whereas He cannot be called the gift of any man, but "God's Gift" only. Therefore Gift is not the proper name of the Holy Ghost.
_On the contrary,_ Augustine says (De Trin. iv, 20): "As 'to be born' is, for the Son, to be from the Father, so, for the Holy Ghost, 'to be the Gift of God' is to proceed from Father and Son." But the Holy Ghost receives His proper name from the fact that He proceeds from Father and Son. Therefore Gift is the proper name of the Holy Ghost.
_I answer that,_ Gift, taken personally in God, is the proper name of the Holy Ghost.
In proof of this we must know that a gift is properly an unreturnable giving, as Aristotle says (Topic. iv, 4)--i.e. a thing which is not given with the intention of a return--and it thus contains the idea of a gratuitous donation. Now, the reason of donation being gratuitous is love; since therefore do we give something to anyone gratuitously forasmuch as we wish him well. So what we first give him is the love whereby we wish him well. Hence it is manifest that love has the nature of a first gift, through which all free gifts are given. So since the Holy Ghost proceeds as love, as stated above (Q.
27, A. 4; Q. 37, A. 1), He proceeds as the first gift. Hence Augustine says (De Trin. xv, 24): "By the gift, which is the Holy Ghost, many particular gifts are portioned out to the members of Christ."
Reply Obj. 1: As the Son is properly called the Image because He proceeds by way of a word, whose nature it is to be the similitude of its principle, although the Holy Ghost also is like to the Father; so also, because the Holy Ghost proceeds from the Father as love, He is properly called Gift, although the Son, too, is given. For that the Son is given is from the Father's love, according to the words, "God so loved the world, as to give His only begotten Son" (John 3:16).
Reply Obj. 2: The name Gift involves the idea of belonging to the Giver through its origin; and thus it imports the property of the origin of the Holy Ghost--that is, His procession.
Reply Obj. 3: Before a gift is given, it belongs only to the giver; but when it is given, it is his to whom it is given. Therefore, because "Gift" does not import the actual giving, it cannot be called a gift of man, but the Gift of God giving. When, however, it has been given, then it is the spirit of man, or a gift bestowed on man.
QUESTION 39 OF THE PERSONS IN RELATION TO THE ESSENCE (In Eight Articles) Those things considered which belong to the divine persons absolutely, we next treat of what concerns the person in reference to the essence, to the properties, and to the notional acts; and of the comparison of these with each other.
As regards the first of these, there are eight points of inquiry: (1) Whether the essence in God is the same as the person?
(2) Whether we should say that the three persons are of one essence?
(3) Whether essential names should be predicated of the persons in the plural, or in the singular?
(4) Whether notional adjectives, or verbs, or participles, can be predicated of the essential names taken in a concrete sense?
(5) Whether the same can be predicated of essential names taken in the abstract?
(6) Whether the names of the persons can be predicated of concrete essential names?
(7) Whether essential attributes can be appropriated to the persons?
(8) Which attributes should be appropriated to each person?
Whether in God the Essence Is the Same As the Person?
Objection 1: It would seem that in God the essence is not the same as person. For whenever essence is the same as person or _suppositum,_ there can be only one _suppositum_ of one nature, as is clear in the case of all separate substances. For in those things which are really one and the same, one cannot be multiplied apart from the other. But in God there is one essence and three persons, as is clear from what not the same as person.
Obj. 2: Further, simultaneous affirmation and negation of the same things in the same respect cannot be true. But affirmation and negation are true of essence and of person. For person is distinct, whereas essence is not. Therefore person and essence are not the same.
Obj. 3: Further, nothing can be subject to itself. But person is subject to essence; whence it is called _suppositum_ or "hypostasis."
Therefore person is not the same as essence.
_On the contrary,_ Augustine says (De Trin. vi, 7): "When we say the person of the Father we mean nothing else but the substance of the Father."
_I answer that,_ The truth of this question is quite clear if we consider the divine simplicity. For it was shown above (Q. 3, A. 3) that the divine simplicity requires that in God essence is the same as _suppositum,_ which in intellectual substances is nothing else than person. But a difficulty seems to arise from the fact that while the divine persons are multiplied, the essence nevertheless retains its unity. And because, as Boethius says (De Trin. i), "relation multiplies the Trinity of persons," some have thought that in God essence and person differ, forasmuch as they held the relations to be "adjacent"; considering only in the relations the idea of "reference to another," and not the relations as realities. But as it was shown above (Q. 28, A. 2) in creatures relations are accidental, whereas in God they are the divine essence itself. Thence it follows that in God essence is not really distinct from person; and yet that the persons are really distinguished from each other. For person, as above stated (Q. 29, A. 4), signifies relation as subsisting in the divine nature.
But relation as referred to the essence does not differ therefrom really, but only in our way of thinking; while as referred to an opposite relation, it has a real distinction by virtue of that opposition. Thus there are one essence and three persons.
Reply Obj. 1: There cannot be a distinction of _suppositum_ in creatures by means of relations, but only by essential principles; because in creatures relations are not subsistent. But in God relations are subsistent, and so by reason of the opposition between them they distinguish the _supposita_; and yet the essence is not distinguished, because the relations themselves are not distinguished from each other so far as they are identified with the essence.
Reply Obj. 2: As essence and person in God differ in our way of thinking, it follows that something can be denied of the one and affirmed of the other; and therefore, when we suppose the one, we need not suppose the other.
Reply Obj. 3: Divine things are named by us after the way of created things, as above explained (Q. 13, AA. 1, 3). And since created natures are individualized by matter which is the subject of the specific nature, it follows that individuals are called "subjects," _supposita,_ or "hypostases." So the divine persons are named _supposita_ or "hypostases," but not as if there really existed any real "supposition" or "subjection."
Whether It Must Be Said That the Three Persons Are of One Essence?
Objection 1: It would seem not right to say that the three persons are of one essence. For Hilary says (De Synod.) that the Father, Son and Holy Ghost "are indeed three by substance, but one in harmony." But the substance of God is His essence. Therefore the three persons are not of one essence.
Obj. 2: Further, nothing is to be affirmed of God except what can be confirmed by the authority of Holy Writ, as appears from Dionysius (Div. Nom. i). Now Holy Writ never says that the Father, Son and Holy Ghost are of one essence. Therefore this should not be asserted.
Obj. 3: Further, the divine nature is the same as the divine essence.
It suffices therefore to say that the three persons are of one nature.
Obj. 4: Further, it is not usual to say that the person is of the essence; but rather that the essence is of the person. Therefore it does not seem fitting to say that the three persons are of one essence.
Obj. 5: Further, Augustine says (De Trin. vii, 6) that we do not say that the three persons are "from one essence [ex una essentia]," lest we should seem to indicate a distinction between the essence and the persons in God. But prepositions which imply transition, denote the oblique case. Therefore it is equally wrong to say that the three persons are "of one essence [unius essentiae]."
Obj. 6: Further, nothing should be said of God which can be occasion of error. Now, to say that the three persons are of one essence or substance, furnishes occasion of error. For, as Hilary says (De Synod.): "One substance predicated of the Father and the Son signifies either one subsistent, with two denominations; or one substance divided into two imperfect substances; or a third prior substance taken and assumed by the other two." Therefore it must not be said that the three persons are of one substance.
_On the contrary,_ Augustine says (Contra Maxim. iii) that the word _homoousion,_ which the Council of Nicaea adopted against the Arians, means that the three persons are of one essence.
_I answer that,_ As above explained (Q. 13, AA. 1, 2), divine things are named by our intellect, not as they really are in themselves, for in that way it knows them not; but in a way that belongs to things created. And as in the objects of the senses, whence the intellect derives its knowledge, the nature of the species is made individual by the matter, and thus the nature is as the form, and the individual is the _suppositum_ of the form; so also in God the essence is taken as the form of the three persons, according to our mode of signification.
Now in creatures we say that every form belongs to that whereof it is the form; as the health and beauty of a man belongs to the man. But we do not say of that which has a form, that it belongs to the form, unless some adjective qualifies the form; as when we say: "That woman is of a handsome figure," or: "This man is of perfect virtue." In like manner, as in God the persons are multiplied, and the essence is not multiplied, we speak of one essence of the three persons, and three persons of the one essence, provided that these genitives be understood as designating the form.
Reply Obj. 1: Substance is here taken for the "hypostasis," and not for the essence.
Reply Obj. 2: Although we may not find it declared in Holy Writ in so many words that the three persons are of one essence, nevertheless we find it so stated as regards the meaning; for instance, "I and the Father are one (John 10:30)," and "I am in the Father, and the Father in Me (John 10:38)"; and there are many other texts of the same import.
Reply Obj. 3: Because "nature" designates the principle of action