Tractatus de Deo Trino secundum personas

«Since the essence of the three persons is one, therefore also all absolute attributes are common, and every attribute is one in the three persons not in species but in number. For the same reason no operation ad extra can be proper to one person, but every operation is necessarily common and numerically one and undivided in the three persons, just as the nature of the three is one and undivided».

I. The Father, the Son, and the Holy Spirit are one God. They are therefore distinguished in no way insofar as they are God; and so the Godhead or essence or absolute perfection, by which God is understood to be and which God is, is altogether one and undivided ¹. The three are distinguished, however, insofar as the Father is formally the one producing the Word or begetting the Son, and insofar as the Son is formally begotten by the Father, and insofar as He is formally spirated by the Father and the Son. And so the real distinction rests solely in the relations of origin of one from another: this one relative to the other relative, the principle to the principiate, are not one, but under this aspect of relative they are really distinct; he who is the Father of the Son is not the Son; and he who is the Son of the Father is not the Father, yet the Son is that absolute which the Father is, and conversely. Hence comes that truest axiom of the theologians, most convenient for readily explaining many not very useful quibbles: «in God all things are one, where the opposition of relation does not stand in the way» ². Surely what we call an absolute attribute is really nothing other than the most simple divine essence conceived by us under the formal aspect of this or that perfection, for example wisdom, justice, etc.; nor indeed does an attribute have a real origin either one from another or from the essence, otherwise it would no longer be absolute (loosed from relation), but as proceeding it would be relative to its principle of procession, and by this very fact there would be as many relatives really distinct among themselves, i.e. as many persons, as attributes were numbered. (Cf. Tract. de Deo th. XIII. XX. XXVI.)

Not therefore only because the attributes are really the divine essence itself, but because they have no real origin either from the essence or from one another, and so «no opposition of relation stands in the way», the same essence, just as it is one in itself, so also viewed under the formal aspect of any absolute attribute is necessarily one and not multipliable. Hence if some absolute attribute were conceived in one person, e.g. in the Father, and the same were denied in the other person, by that very fact the most simple divine essence and the Godhead would be denied to this one: and if an attribute only the same in species but distinct in number in the distinct persons were affirmed, by that very fact distinct essences and several Gods would be introduced. On the contrary, although the relations of origin, i.e. the formal aspect of the Father and of the Son and of the Spirated, are really the divine essence itself, and therefore do not proceed from the essence by a real origin nor are really distinguished from it, nevertheless these relations have (and, which amounts to the same, in the concrete signification of the relative) among themselves the aspect of principle and principiate, one really proceeds from the other, and therefore «the opposition of relation stands in the way», so that the Father of the Son is not the Son, the Son of the Father is not the Father, but under this formal aspect of the relatives and under this alone they are really distinguished among themselves.

To this numerical unity of the essence and of the attributes in the three distinct persons it is no obstacle that the essence in the Father is uncommunicated and communicable, in the Son communicated by the Father, in the Holy Spirit communicated by the Father and the Son, and so seems to be otherwise disposed in one person than in another. For this diverse mode does not affect the essence viewed absolutely, or the absolute Being itself, one altogether and undivided; but that mode is in reality the relation of paternity, of filiation, and of procession. For what does it mean that the essence in the Father is uncommunicated and communicable? Nothing other than that the absolute essence is at the same time a relative, and under this aspect of the relative it is not proceeding from another (ἀγέννητον) but a principle producing the Word or begetting the Son; further, under this aspect of the relative disposing itself as principle toward the Son, the essence is no longer formally the common absolute essence, but is the Father, a hypostasis. Likewise this: the essence in the Son is communicated, signifies nothing other than that the absolute essence is at the same time a relative proceeding through generation as the Word or as the Son from the other relative, which is the generating Father; then, moreover, again under this aspect of the relative proceeding as the Word, the essence is not formally the common absolute essence, but is the Son, a hypostasis; «each one of the three persons is that thing, namely the substance, essence or divine nature... and that thing is neither generating nor generated nor proceeding, but it is the Father who generates, and the Son who is generated, and the Holy Spirit who proceeds; so that the distinctions are in the persons and the unity in the nature» IV Lateran Council, ch. Damnamus. But these things will be better understood where we treat of the proper notion of the divine hypostasis.

The proof for this unity of the three persons in all absolute perfections is none other than that by which the Godhead of the Son and of the Holy Spirit and consequently the unity of essence in the three distinct persons has been demonstrated above in many ways. The communication of attributes is formally expressed in the passages of Scripture where the Son in relation to the Father professes: «My Father, what He has given me, is greater than all» Io. X. 29; «as the Father has life in Himself, so He has given to the Son also to have life in Himself» ibid. V. 26. «all things which You have given me are from You» ibid. XVII. 7, «all my things are Yours, and Your things are mine» ib. XVII. 10; «all things whatsoever the Father has are mine; therefore I said, because He will receive of mine» ib. XVI. 15.

II. In exactly the same way as the nature of the three persons with all its absolute perfections is one and undivided, so also the operation ad extra of the three persons is one and undivided. The truth is evident from the proper notion of divine operation. For it is nothing other than the divine essence itself under the formal aspect of absolute intellect and absolute omnipotent will, with the connotation of a term to be effected extrinsically. But the divine essence, under whatever absolute formal aspect it is viewed according to our mode of distinguishing, and therefore also under the formal aspect of absolute intellection and volition, is altogether one in number and the same in the three persons. Such, therefore, is the unity of operation in the three persons.

The same is made clear from the very notion of the divine person. The persons in God are distinguished only by the relations of origin, insofar as under the formal aspect of the relative one is a principle disposing itself toward the other as principiate; the Father is distinguished from the Son in no other way than by paternity and filiation alone; the Father and the Son are not distinguished from the Holy Spirit, except that by spiration they dispose themselves as principle toward the one proceeding; paternity therefore (which is at the same time ἀγεννησία, insofar as this is understood as something positive, or as the aspect of a principle without a principle), filiation, procession are substantive relations proper to the individual persons; spiration, common to the Father and the Son, can be called proper only in comparison of the spirating principle with the Holy Spirit proceeding, to whom it is not common. Besides these relations ad intra, therefore, and whatever hypostatic relation ad extra there may be, all the rest which can be conceived of God are absolute and therefore one undivided in the three, just as the three are one God. But the effective operation in God is neither generation nor nativity nor spiration nor procession, nor a hypostatic relation to an external term. Therefore every operation ad extra is one undivided in the three persons, just as the Godhead of the three is one, or just as God is one.

I have said: operation is not a hypostatic relation to an external term (i.e. distinct and diverse from God). A hypostatic relation, neither from faith nor, faith being supposed, from the light of reason, can be understood as other than either ad intra, of a person producing another person or proceeding from another person, or ad extra, of a person having a created nature hypostatically united. A hypostatic relation ad intra indeed cannot be efficient of an external term, but regards the divine person. But the external term, beside this internal relation, can be connoted as nothing other than (prescinding now from the hypostatic union) the manifestation of the person ad extra through some efficiency; generation and spiration with this connotation is the mission of the Son from the Father, and the mission of the Holy Spirit from the Father and the Son. What therefore in mission is proper to one person and not common to the three: on the part of the sending person it is not operation but the relation of the one generating and spirating; on the part of the person sent it is the relation of filiation or procession; but the efficiency ad extra which is connoted in mission is necessarily common to the three persons, as they are one God ³.

There remains therefore only the hypostatic union, which can be proper to one person and not common to the three. For the individual divine hypostases have only their own formal aspect of hypostasis, but whatever pertains to the nature is common and one to them; but the function of the hypostasis, formally as it is a hypostasis distinct in reason from the nature, is known neither by revelation nor by the light of reason as other than that it be a subject having the nature as its own. Hence a function ad extra proper to one hypostasis and not common to the three can be understood as nothing other than that it have an assumed created nature as its own, which we know from revelation both can be done and has been done. But this having of a nature is not an effective operation, but is a hypostatic termination, and a certain state to be understood according to the analogy of a formal cause, not of an efficient cause. Whatever efficiency, however, intervenes in that union, it is all of the one and triune God. In sum, the divine persons do not operate ad extra formally as they are three distinct relatives to one another, but as they are one God. For the principle, or rather the subject, which operates is indeed the hypostasis; but the principle by which the operation is brought about is the nature.

Hence among the holy Fathers and in the Councils there is an axiom of the greatest moment in the doctrine of the Most Holy Trinity and of Christ: operations are not hypostatic but natural, i.e. the distinction of operation according to species and number does not follow the number of hypostases but the species and number of natures. Where therefore the nature is one in number, even if there are several hypostases, the operation is one in number, as in the Most Holy Trinity; on the contrary, where the natures are several in number, and where the natures are not only several in number but also diverse, even if there is one hypostasis, as in Christ, there also the order of operations is manifold and diverse according to the multiplicity and diversity of the natures. This principle the Fathers assume as altogether evident and conceded by all, when the question concerns God, because the divine operation is the divine essence itself and therefore, another operation in the Father and another in the Son being admitted, by that very fact another and another essence would be asserted. From this indeed, against the Monothelites, they demonstrate that in Christ the twofold diverse order of divine and human operation cannot be denied, without by that very fact one nature alone being admitted and consequently the heresy of the Monophysites being introduced. Thus in the case of the Monothelites, from the unity of the operation of the three persons argues St. Agatho the Pontiff, in the epistle to the Emperors read in the VI Council (Harduin. T. III. p. 1083). «According to the rule of the holy catholic and apostolic Church of Christ, (the same Church) confesses and preaches that there are also two natural wills in Him and two natural operations. For if anyone understand a personal will (which would follow the number of persons), while three persons are said in the holy Trinity, it is necessary that three personal wills and three personal operations also be said, which is excessively absurd and profane. But if, as the truth of the Christian faith contains, the will is natural (from the nature as principle by which, and following the number of natures), where this one nature of the holy and inseparable Trinity is said, consequently also one natural will and one natural operation must be understood». (See Tract. de Incarnat. th. XL.)

Now indeed both in Scripture and in the preaching of the Fathers the unity of action is proposed, as closer and better known to our understanding, as a principle from which the unity of nature of the three persons is deduced. Thus the Son of God adduces the unity of His power and action and that of the Father for keeping the faithful and for giving eternal life as a declaration, and in general that He Himself does the works of His Father, as a demonstration of the mystery announced: «I and the Father are one; the Father is in me, and I in the Father» Io. X. 28. seqq. (above p. 20. sq.). The unity of testimony is joined with the unity of essence, and the testimony of the three is the testimony of the one God: «there are three who give testimony in heaven, the Father, the Word, and the Holy Spirit, and these three are one... the testimony of God is greater» 1. Io. V. 7. 9. (above th. V.). Likewise the Son affirms that every operation of the Father from the beginning is His operation, and denies that His power is other than the Father's power: «My Father works until now, and I work... whatsoever He has done, these the Son also does in like manner (ταῦτα καὶ ὁ Υἱὸς ὁμοίως ποιεῖ).... As the Father raises the dead and gives life, so also the Son gives life to whom He will». «The Son cannot do anything of Himself, except what He has seen the Father doing» Io. V. 17. 19. 21. From this unity of action the Jews themselves understood that the proper filiation of God and equality with God were being asserted: «because He called God His own Father (πατέρα, ἴδιον), making Himself equal (ἴσον) to God» ib. v. 18.

To the same point pertains that in the Scriptures the divine operation is sometimes attributed to the one God viewed absolutely, besides whom there is no other, sometimes to the individual persons, sometimes to the persons jointly. «I am the Lord making all things, stretching out the heavens alone, establishing the earth and no one with me» Is. XLIV. 24. «I confess to You, Father, Lord of heaven and earth» Matth. XI. 25. «But to the Son (concerning the Son) He says: You, Lord, in the beginning founded the earth, and the works of Your hands are the heavens» Heb. 1. 8. 10. «You will send forth Your Spirit, and they will be created» Ps. CIII. 30. «The Spirit of the Lord has filled the whole world, and that which contains all things (Πνεῦμα Κυρίου τὸ συνέχον τὰ πάντα), has knowledge of the voice» Sap. I. 7: (cf. Ambros. de Spiritu Sancto l. II. c. 5; Cyrillus Alex. Dialog. VII. p. 649, and elsewhere). «God made the ages through the Son» Heb. I. 2. «For us there is one God the Father, from whom all things... and one Lord Jesus Christ, through whom all things» 1. Cor. VIII. 6.

When the Father is said to create and operate in the Holy Spirit, both the relation of origin of the persons is indicated and the unity of operation is preeminently expressed, namely that just as the nature is one, so also the same power and operation is communicated from the Father to the Son, and from the Father through the Son (from the Father and the Son) to the Holy Spirit. Therefore both in the Scriptures and most frequently among the Fathers, when the relation to the works is to be expressed together with the internal relations of the persons, the Son and the Holy Spirit are called the power of the Father, and the Father is said to operate through the Son and the Holy Spirit as through His power, through His arm, through His hands: at the same time, however, insofar as the power and operation is one, this same thing is declared, as if it were said that the Father operates through Himself (above p. 136. 163; see Petav. de Deo l. V. c. 8. and 9.).

Among the Fathers the demonstration of the one essence from the unity of operation, or conversely of the latter from the former, is everywhere to be met with. «The Father, the Son, the Holy Spirit are three hypostases, since the subsistence of each one is distinct; but when the persons do not each will and operate in a manner proper to themselves, nor by a choice proper to themselves, and singly and separately, but as they are one (ἀλλ' ἑνάς), not three Gods but one God is» Damasc. de duabus volunt. n. 7. See the luculent doctrine of the Fathers in Petav. Trin. l. IV. c. 15.

Hence it is clear that nothing other than the unity of nature is signified when the three persons are said to be one in will, counsel, power, etc. Not rarely, however, these absolute attributes are expressed by the Fathers in such a way that the distinction of the persons is at the same time signified. Thus when the Father, the Son, the Holy Spirit are said to consent among themselves, to take counsel, one person to cooperate with another, the consent, the counsel, the cooperation must be understood in the manner in which consubstantiality is understood. For, as Cyril of Alexandria says in another matter, «the particle with, when added, always signifies one with another» (Anathemat. VIII. contra Nestor. cf. Apolog. ibi contr. Orientales); namely, through that particle with the distinction of the persons is expressed, not however also by itself that of the nature, or, which amounts to the same, of the operation (ad extra).

Corollary 1. Not only must the common operation ad extra of the three persons be believed as a revealed fact, as if indeed absolutely speaking there could be an operation proper to one person, without its being the same for all three hypostases; but every operation ad extra must be understood as so necessarily one in the three persons without any distinction, as the nature of the three is necessarily one and the three are one God.

Corollary 2. Just as in the declared sense no one can confess one common operation of the three persons without by that very fact affirming the nature of the three to be one in number and undivided, so conversely the negation of this unity in operating is a certain argument of a unity of nature either denied or not rightly understood. The Güntherians, affirming that by the very fact that the divine hypostases are really distinguished, the operation ad extra also cannot be common to the three and one in number, but that there is one operation proper to one person, another proper to another, are convicted by this even alone, as the clearest indication, that by them three substances or divine essences really distinct in number are admitted no less than three distinct hypostases. But that Günther was in the error which we have mentioned with regard to the divine operations is most certain. «The question must be solved, says Günther, which one of the three divine and personal substances has brought the idea of God concerning the universe and concerning the creature to reality, if it has not been brought to reality by all three together. This last no one will surely affirm, who has understood the distinction between the real theogonic process in the life of the absolute (i.e. between the processions of the substantial persons) and the formal process of the individual hypostases in that life (i.e. between the mode in which the individual persons know themselves and understand themselves as distinct from others)... In the manifestation of God ad extra all things are personal, i.e. to be attributed as operation and completed work to one determinate person and to no other, and much less to all three together.» He then teaches that creation must be predicated «of no other person than of the second, of the Son»; but that the union of the creature with God is effected by the third person. Propaedeut. T. II. p. 369-372; Symposion Peregrini p. 388. 396. He acknowledges no other community of operation, except that in certain works one person performs one part, another another. Thus he says that in the incarnation of the Word the Holy Spirit produced the body, the Father created the soul of Christ, or at least effected the union of the soul with the body. Propaed. ib. p. 371; Sympos. p. 396. That the Catholic doctrine is altogether contrary to all these things abundantly appears from what has been demonstrated in the thesis.

«Although from what has been said the absolute attributes and the operations ad extra are, without distinction, one thing common to the three persons; nevertheless both in Sacred Scripture and in the other documents of the faith certain attributes and certain operations are appropriated to one person in preference to the others. The reason for this predication is that, with the community of the absolutes preserved, the properties of the individual persons may be manifested; wherefore the foundation of appropriation is the analogy and, as it were, affinity of the absolute attribute with the hypostatic character of the person to whom it is appropriated.»

I. For there to be appropriation it does not suffice that an absolute be explicitly predicated of some one person; but appropriation in the strict sense exists only then, when an absolute is predicated of one person in preference to another. Therefore it is not quite fittingly, or not in the strict sense, called appropriation in the passages where the Father is called «the only Potentate, King of kings... who alone has immortality» 1. Tim. VI. 15, or where the Son says: «I am the way, the truth and the life» Io. XIV. 5. ¹ or where it is promised to the Apostles: «you shall receive the power of the Holy Spirit coming upon you» Act. I. 8; all of which Didacus Ruiz disp. 82. sect. 2. numbers among the appropriations, cf. S. Th. I. q. 39. a. 8. For these are not predicated by a special and proper reason of one person in preference to the others, but it is simply the affirmation of an absolute of one person ² also considered in itself, as it is God, which surely seems not more to be called appropriation than when the individual persons separately, e. g., are predicated God.

Nor again is it appropriation in the strict sense when a name, which in itself signifies an absolute attribute having affinity with a personal property, is used in a relative sense to designate the person herself, as when the Word is called begotten Wisdom, or subsisting Wisdom; the Holy Spirit, proceeding or subsisting love or will. These are not appropriated but proper; for by these names a common attribute is not ascribed more specially to one person, but the relative personal property itself is expressed.

In the strict sense, therefore, appropriation is when attributes or operations ad extra common to the three persons are predicated specially of one person, so that from such an attribute or operation we may be led to some understanding of a personal property. For this is the scope of appropriation. «For this reason certain things are uttered whether under the appellation of the Father, or of the Son, or of the Holy Spirit; so that the confession of believers in the Trinity may not err. Since it is inseparable, the Trinity would never be understood, if it were always spoken of inseparably» s. Leo M. serm. 2. de Pentec. c. 3. St. Thomas declares the same scope: «As we use the likeness of the trace or of the image found in creatures for the manifestation of the divine persons, so also the essential attributes. And this manifestation of the persons through essential attributes is called appropriation» I. q. 39. a. 7.

Hence the law or foundation of appropriation is manifest. The foundation, namely, is the analogy or likeness of certain absolute attributes with the hypostatic property of one person in preference to the others ³ For unless there were some peculiar affinity between the property and these certain attributes, as they are conceived by us, the special predication of such attributes of one person would not help but rather hinder the understanding of the proper personal character. «If we speak of the appropriated things as to the order or origin which they connote, thus they are appropriated on the side of the thing on account of their fittingness with the proper attributes of the persons. Whence, because the Father is from no one, and the Son from the Father, and the Holy Spirit from both, and an order of this kind is attended to in power, wisdom and goodness; therefore the reason of appropriating is manifest. Whence those things which do not in some way connote order or origin are not appropriable» s. Bonavent. in I. dist. 34. q. 3.

But since the personal characters can be considered under several different respects, according to which different attributes correspond to them: hence it comes about that several attributes can be appropriated to one person, and in turn one attribute can be appropriated not only to one, but under a different consideration also to the other persons. Thus e. g. power is appropriated to the Father according to the personal character, inasmuch as He is the principle of all processions ad intra; to the Son, however, inasmuch as He is the Word through whom all things were made, and thence through appropriation the arm of God the Father; likewise to the Holy Spirit as proceeding through love is appropriated every effecting of sanctifying charisms, and therefore power.

Hence it is that that passage Luc. I. 35: «the power of the Most High shall overshadow thee» is interpreted by some Fathers of the Holy Spirit, by others of the Son, by others of the Father — a diversity which would have no place, if appropriation were always fixed and settled according to one single mode. Nevertheless the likeness or affinity of the absolute attributes and operations with the personal properties must be considered according to the mode in which it is exhibited in the Scriptures and according to the norm of Catholic understanding. For in Scripture, in the creeds, among the holy Fathers appropriation is frequent enough, so that from these the foundation and the mode of application may easily be understood. The things said thus far must be confirmed and further declared by some examples.

II. In the Scriptures, where two or all three persons are enumerated together, they are frequently distinguished by absolute predicates — not indeed as proper, since these are elsewhere shown to be common to the three persons, but to designate the personal character proper to each. Thus: «there are diversities of graces (χαρισμάτων), but the same Spirit: and there are diversities of ministrations (διακονιῶν), but the same Lord; and there are diversities of operations (ἐνεργημάτων), but the same God, who works (ὁ ἐνεργῶν) all in all» 1. Cor. XII. 4. sq. Here you see a twofold appropriation; the former is that well-known one, by which in the connumeration the Father is called God, the Son Lord (see above p. 155). By the other appropriation, to the Father, the principle without principle, are attributed the operations of powers, i. e. of miracles, just as elsewhere in the creeds and by the Fathers omnipotence is appropriated to Him; to the Son as incarnate and as head and Lord of the Church are attributed the ministries disposed in the Church; to the Holy Spirit proceeding through love are attributed the sanctifying charisms — which sanctification indeed has such a relation and affinity to the proper personal character of the Holy Spirit, and is so constantly derived in Scripture and by the Fathers peculiarly from the Holy Spirit, that to some theologians sanctification seemed to be enunciated not merely by appropriation, but as proper to the third person; certainly by the Fathers sometimes the sanctifying power (δύναμις ἁγιαστική) is called the proper character of the Holy Spirit (Petav. l. VII. c. 13. n. 21. sq.), and that the character of gift, or of the givable, under a certain peculiar respect is proper to the third person is the common doctrine. But there will be a place to speak of these elsewhere. Meanwhile this must be held as most certain, that the efficiency of created charisms is not proper to the Holy Spirit in preference to the other persons, but appropriated, on account of the special affinity of these effects with His personal character.

To appropriation pertains that most frequent, as it were, distribution of the operation ad extra through the particles indicating the relation of origin among the persons themselves operating with one operation. The Father is said to operate through the Son in the Holy Spirit (above p. 163), or all created things are said to be from the Father through the Son in the Holy Spirit. To that which is read Rom. XI. 36, Augustine draws attention: «since there is one God but nevertheless a Trinity, it is not to be taken confusedly: from whom are all things, through whom are all things, in whom are all things» Aug. Trin. VI. c. 10. n. 12. St. Thomas adds: «from him is said on account of the Father, through him on account of the Son, in him on account of the Holy Spirit» (cf. S. Hilar. Trin. l. II. n. 1).

But the Angelic Doctor expounds this distribution in such a way that it coincides with that solemn appropriation of power to the Father, of wisdom to the Son, of goodness to the Holy Spirit, I. q. 39. a. 8. ad 4. About this appropriation of power, wisdom, goodness Richard of St. Victor treats at length in c. 2. of the little book which he wrote to St. Bernard on the three appropriated attributes, and he repeats the same again in de Trin. l. VI. c. 15.

A more distinct elaboration, however, of that order, from whom, through whom, in whom are all things, is contained in an appropriation among the Fathers no less frequent, by which whether in creation in general or chiefly in the creation of angels and men, to the Father is attributed the counsel, the will (βουλή) or the command of the work, to the Son the execution (ἐνέργεια or ὑπουργία), to the Holy Spirit the perfection (τελείωσις, which is in sanctification). «In the creation of the angels think for me of the cause which is the principle without principle (τὴν προαιτίαν τῆς αἰτίας), the Father; the creative (τὴν δημιουργόν) the Son; the perfective (τὴν τελειωτικήν) the Spirit; so that by the will indeed of the Father they are ministering spirits, by the operation (ἐνεργείᾳ) of the Son they are brought to existence, by the coming of the Spirit they are perfected; moreover the perfection of the angels is sanctification» s. Basil. de Spiritu Sancto c. 16. The same, as is evident, is the reason of appropriation in the creation of man: «first of all it must be believed that there is one God who made all things out of nothing through His Word, and quickened them through the Holy Spirit» Ambros. in symbol. c. 6. ⁴ (cf. Petav. l. VII. c. 14. n. 21-23). Recall what we said above p. 163. sqq.

One may behold this appropriation strikingly expressed in the sarcophagus of the Lateran Museum, dug out from the crypt near the tomb of St. Paul, the Apostle of the Gentiles, on the Via Ostiensis. The sculpture is thought to be of the fourth century, but, as often happens in works of this kind, probably derived from an older exemplar. This appropriation of which we treat, together with the remaining carvings wrought on the same monument, the most learned men illustrated with their erudite commentaries: first the distinguished Fr. Ios. Marchi, then the distinguished I. B. De Rossi, finally the distinguished Fr. Raphael Garrucci, to whom, a most distinguished archaeologist, I owe the cast ⁵

Other appropriated attributes are related and explained, e. g., by Augustine: «eternity in the Father, form in the image, use in the gift» Trin. l. VI. c. 10., which he himself relates as from St. Hilary (cf. Ambros. in symbol. Apost. c. 1.), although Hilary, Trin. l. II. n. 1., has them disposed a little differently: «one God the Father, from whom are all things, and one only-begotten our Lord Jesus Christ, through whom are all things, and one Spirit, the gift in all.... one power from which are all things, one offspring through which are all things, one gift of perfect hope. Nor will anything be found wanting to so great a consummation, within which there is in the Father and the Son and the Holy Spirit, infinity in the eternal, form in the image, use in the gift». Augustine, however, interprets these things, l. c., and following him St. Thomas I. q. 39. a. 8., so that eternity corresponds to the property of the Father as principle without principle; form or beauty to the property of the Son, inasmuch as He is the perfect image of the Father from the very mode of procession by generation; use or «love, delight and felicity» to the property of the Holy Spirit proceeding through the love of the Father and of the Son.

You will now easily explain when by the same Augustine are predicated «in the Father unity, in the Son equality, in the Holy Spirit the concord of unity and equality; and these three are all one on account of the Father, equal on account of the Son, all connected on account of the Holy Spirit» Doctr. christ. l. I. c. 5. See s. Bonavent. 1. dist. 31. a. 2. q. 3. Likewise others: «the Father, therefore, is for the Son, the truth, a truthful origin, and the Son is the truth born of the truthful Father, and the Holy Spirit is the goodness poured forth from the good Father and the good Son» Ser. 71. n. 18. Likewise in the creeds there is the distinction of God the Father almighty, creator; then of the Son, the Lord; of the Holy Spirit, the life-giver, who spoke through the prophets. Finally, as to the mode of praying, Christ the Lord Himself according to His humanity directed explicitly to God the Father both obedience and satisfactions for us and prayers, although all these referred to the one and triune God; and besides others He taught us the same form of praying which the Church also most frequently follows in the sacred liturgy, where the Father is asked, almighty eternal God, through Jesus Christ our Lord His Son, who with Him reigns in the unity of the Holy Spirit, God. All these things, especially in conjunction with the other forms by which prayer is directed to the Son and to the Holy Spirit, pertain to expressing the unity of God in the distinction of the persons together with the order of the processions. Cf. s. Fulgentium fragm. 29. p. 626; see Didac. Ruiz disp. 82. sect. 4. et 7.

« What is wont to be called circuminsession (=περιχώρησις circumincessio) of the divine persons, as regards the thing itself is nothing other than the numerical unity of nature in three persons distinct through relations of origin; formally, however, circumincession is understood as the mutual, as it were, passage or immanence of the persons in one another, necessarily arising from this unity and distinction ».

I. The doctrine frequent among the holy Fathers and theologians concerning this relation, which the Greeks called περιχώρησιν, the older scholastics, such as s. Bonaventura (1. dist. 19. P. I. q. 4.), sometimes called circumincession, or, as Aureolus (1. dist. 19. P. II. a. 1. propos. 2.), circumcession, and the more recent ones circuminsession, is nothing other than the declaration of the truth expressed by Christ the Lord Himself in so many words. « I and the Father are one.... that you may know and believe, that the Father is in me and I in the Father » Io. X. 30. 38. « He who sees me, sees the Father also... do you not believe that I am in the Father and the Father in me? » ib. XIV. 9. 10. « That they all may be one, as you, Father, are in me and I in you, that they also may be one in us... And the glory which you gave me, I have given them, that they may be one, as we (καθὼς ἡμεῖς) also are one » ib. XVII. 21. 22. Although in these passages there is no explicit treatment of the Holy Spirit, yet, given the distinction of the third person and the unity of essence, as in the Father and the Son so in all three persons, the very same relation of mutual circumincession of the other persons in the Holy Spirit and conversely must necessarily be admitted. Yet there can be added to the preceding an explicit testimony of the Apostle concerning the Holy Spirit: « God has revealed to us through His Spirit... For who among men knows the things that are of a man, except the spirit of the man which is in him? So too the things that are of God no one has known except the Spirit of God » I. Cor. II. 11.

1°. In all these passages there is declared the distinction of the persons, formally as they are Father and Son and Holy Spirit, together with the unity of the nature or essence of the same. Then, whether as a further declaration of this unity and distinction or as the relation necessarily consequent therefrom, the mutual inexistence of one person in another is enunciated. Surely if three persons distinct among themselves are one God without any distinction according to essence, the Father, who is God through the divine essence and is identified with the divine essence, can neither be nor be conceived by a somewhat more adequate notion, without having in himself and being understood to have, just as the divine essence with which he is identified, so also the Son and the Holy Spirit, who are identified with the same numerically one essence of the Father. In like manner neither can the Son, the same one God, be or be conceived through the divine essence, without in the same way having in his essence, identified with it, the Father and the Holy Spirit, and conversely the Holy Spirit the Father and the Son. « I am in the Father and the Father in me. For the Son is in the Father, in so far as one may understand, since the whole Being of the Son is itself proper to the essence of the Father, just as from light the brightness and from the source the river ¹, so that he who sees the Son sees that which is proper to the Father (the essence of the Father), and understands the Son to be in the Father, since the Being of the Son is communicated by the Father (the same numerically one). But the Father also is in the Son, since that which is proper to the Father (the essence) and communicated by Him, this very thing is the Son's, as the sun in the brightness, and the mind in the (internal) word, and the source in the river. For thus he who contemplates the Son contemplates that which is proper to the essence of the Father, and acknowledges the Father to be in the Son. Since therefore that which is proper to the Father, namely the divinity, is the Being of the Son, it follows that the Son also is in the Father and the Father in the Son. For for this reason He rightly, when He had earlier said: I and the Father are one, subjoined that: I am in the Father and the Father in me, in order to show the identity of the divinity and the unity of the essence » Athan. contra Arianos or. III. n. 3. « He who shall have truly taken the Son will have Him bringing with Himself on both sides, on the one hand His Father, on the other the Holy Spirit... Likewise he who has admitted the Father admits the Son and the Holy Spirit at the same time in power. For no section or division can by any means be devised, so that either the Son could be understood without the Father or the Spirit be separated from the Son; but a certain ineffable and incomprehensible communion together with distinction is observed in these » Basil. ep. 38. al. 43. n. 4. With declarations of this kind of the mutual inexistence of the persons through the unity of nature all the writings of the Fathers against the Arians are full (see Ruiz disp. 107; Petav. l. IV. c. 17; Thomassin. c. 28; Bullum Fid. Nic. sect. 4. c. 4. n. 10. sq.).

Although the reason for this mutual inexistence so far explained is the unity of nature, yet far different is that which inheres in one person, e. g. in the Father — the essence, with which the Son is identified — from that which inexists in the Father according to περιχώρησιν, namely the Son under the formal reason of a person distinct from the Father Himself. The former is not an inexistence of one in another; but only in our manner of understanding, according to the analogy of creatures, do we conceive the person as a subject and in it the nature, as it were, a metaphysical form; really, however, it is altogether an identity of person and nature, i. e. the same most simple thing, under one reason, inasmuch as it is absolute, is called and is the divine nature, and under another reason, inasmuch as it is relative, is called and is the divine person. But where there is no real distinction, certainly one thing cannot inexist in another. But person is really distinguished from person, and all three persons are identified with the nature; whence by reason of the distinction one can rightly be said to inexist in another; by reason of the identification of all three with the one common nature, all three necessarily inexist mutually in one another, as has been declared.

Circumincession, therefore, just as it has, as it were, as its form and containing bond the one numerically common nature, so it supposes and includes, as it were, as its terms the really distinct persons. In commending the unity of nature as the reason of περιχωρήσεως, the holy Fathers declare this distinction of the persons no less solicitously. « He who has received all things from him who has all things, God from God, spirit from spirit, light from light, says with more confidence: the Father in me and I in the Father; because as the Father is spirit, so also the Son is spirit; as the Father is God, so also the Son is God... What is in the Father, this also is in the Son... the one from the other and both one, not two one, but the one in the other, because there is not another thing in each » s. Hilar. Trin. l. III. n. 4. cf. l. VI. n. 19. Damascenus embraces the whole reason. « We know that the hypostases do not go out beyond one another, and are inseparable from one another and are a unity, and pass into one another without confusion; a unity indeed without confusion, for they are three even if they are united, but distinct without separation (1). For although each one subsists by itself, that is, is a perfect hypostasis, and has its own property, that is, a distinct manner of subsisting; yet they are united by essence and essential attributes, and so are not separated nor do they go out beyond the paternal hypostasis, and they are and are called one God » Damasc. Fid. orthod. l. III. c. 5.

The predication, therefore, of τῆς περιχωρήσεως, as it is contained in the Scriptures and in the doctrine of the Fathers, is a compendious refutation and exclusion of almost all the heresies concerning the mystery of the Most Holy Trinity. While the unity of nature is understood as the foundation of the mutual inexistence of the persons, the Arians are excluded, and whoever, by admitting natures of the three that are either diverse or distinct, separate the persons from one another. While, conversely, the inexistence of one in another is understood, the Sabellians and other heretics are refuted, who, denying the real distinction of the divine persons, by that very fact also take away the circumincession of one person in another.

Cf. S. Th. ² contr. gent. IV. c. 9.

In almost the same way in which, in the mystery of the Incarnation — though in an inverted order — the circumincession of the one nature in the other, predicated by reason of the unity of the person to which each nature is proper, excludes both the separation of the Nestorians into two hypostases and the confusion of the Monophysites into one nature ³. As long as we consider περιχώρησιν only in the way now declared, inasmuch as its proper reason is the unity of the nature identified with all and each of the persons, in exactly the same way the Father is understood to be in the Son and the Son in the Father, each of the two in the Holy Spirit and the Holy Spirit in each of the two. But the thing itself and the frequent doctrine of the Fathers admonish us that this consideration is not complete, unless the persons themselves, who are in one another, be regarded according to their distinct properties and origins. « In the Father and the Son there are three things to consider, namely the essence and the relation and the origin, and according to each of these the Son is in the Father and conversely » S. Th. I. q. 42. a. 5.; 1. dist. 19. q. 3. a. 2. Thus, however, with some distinction « the Son is in the Father as the originated in the originating, and conversely the Father in the Son as the originating in the originated » S. Th. 1. dist. 1. c. ad i. et 3.

2°. Therefore, even when the mode of procession of person from person in the divine is regarded, the mutual περιχώρησις of the persons and, as it were, immeation cannot but be. « The reason is always from the mind and in the mind (εἰς νοῦν), and the mind in the reason (ἐν λόγῳ). Or if they should deny these things to be true, the mind therefore will be without reason, and the reason without mind (νοῦς μὲν ἄνευ λόγου οὐδέποτε, λόγος δὲ ἄνευ νοῦ), and thus that will be empty which makes manifest what each (namely the mind and the reason) is, and it will be reduced to nothing. For the mind is always the root and origin of the reason, the reason in turn the fruit and offspring of the mind... But since the mind exists because it has reason, and the reason in turn because it is full of mind, how could the mind ever be thought without reason, and the reason bereft of mind?... How now does the force of this image fit the Father and the Son? The demonstration, I say, is most apt and very clear, that the procession of the Word is from the mind and a generation without passion, and certainly the begotten is not divided; but rather remains in the begetting mind, and altogether has in himself the begetting mind; and moreover it is shown that the Word has consubstantial subsistence immediately, and also simultaneous even in our consideration » (for neither can we think the mind without the reason, nor the Father without the Son, and conversely) Cyrill. Alex. dialog. II. de Trin. T. V. P. I. p. 450-452. « For the Word is also called Wisdom, because it is from the mind and in the mind proximately and inseparably, and on account of the mutual insertion of each in the other, so to speak (τὴν εἰς ἄλληλα ἀντιβολήν). For the mind is in the Word (ἐν λόγῳ); Wisdom and the Word in turn are understood to be in the mind (εἰς νοῦν) » Id. in Io. T. IV. p. 47. Most similar is the explanation of S. Fulgentii. « Thus the Word is with God, as the word is in the mind, as the counsel is in the heart... As the word is born of the whole mind, so the born word remains within the whole. And because, while the mind thinks, there is nothing of it where the word is not in it; therefore the word is only as great as the mind itself is, from which it is; and when it is with it, it is in it » Fulg. ad Monim. l. III. c. 7.

The same altogether, which holds of the Word proceeding through the intellect and immanent in His own hypostasis, holds also of the Holy Spirit in His own hypostasis, proceeding through the love of the Father and of the Son, with a procession, to be sure, immanent. « The Holy Spirit as a natural and essential act (ἐνέργεια), subsisting in itself, proceeding from God and remaining in God » Cyrill. Thesaur. T. V. P. I. pag. 341. Therefore of the three persons, by reason of the immanent processions, that holds which s. Anselmus says: « the whole Father is in the Son and in the common Spirit, and the Son in the Father and in the same Spirit, and the same Spirit in the Father and in the Son; because the memory ⁴ of the highest essence is wholly in its intelligence and love, and the intelligence in the memory and in the love, and the love in the memory and in the intelligence » Monolog. c. 57. To this pertain all those considerations of the Fathers described by us above, by which they exhibit the Word and the Holy Spirit as the subsisting Wisdom and Power of the Father, through which and in which God works ad extra.

From all things that have so far been brought forward from the holy Fathers, it seems to me that it can not without reason be observed, that if the unity of essence be precisely regarded, it will perhaps be better to say circuminsession, that is, the mutual immanence of the persons; but if the procession ad intra be regarded, and, as it were, the notional divine vital act, we shall express the matter more fully by calling it mutual circumincession, that is, mutual immeation. To this also can perhaps be referred the manner of signifying the act of procession in s. Ioannem (I. 18.), where in Greek it is said « the only-begotten Son to be in the bosom of the Father » εἰς τὸν κόλπον τοῦ Πατρός. Whence Cyril Alex., both in dialog. II and in Io. ll. cc., studiously preserves the diverse manner of speaking of the producing mind, which is in its Word (ἐν λόγῳ), and of the proceeding Word, which is into the mind (εἰς νοῦν).

3°. As for what s. Thomas I. q. 42. a. 5., besides the origin of person from person, also distinguishes the relation, under this reason he considers circumincession rather logically than ontologically, « that one of the relative opposites is in the other according to the intellect ». That is, one relative, e. g. the Father, cannot be understood without the other correlative, the Son, being understood at the same time; for they are relative to each other. This manner the Fathers often indicate, as s. Basilius in the cited epistle 38., and most excellently s. Dionysius Alex. in Damascenus (Eclog. c. 1). « Each of those names is inseparable, nor can it be divided from its neighbor: I said Father, and before I should subjoin the Son, I signified him in the Father; I subjoined the Son, and even if I had not named the Father beforehand, nevertheless he would already have been preconceived in the Son; I added the Holy Spirit, and at the same time (by the very name of the Spirated) I included both from whom and through whom (from the Father through the Son) He proceeds » Vide Ruiz disp. 9. sect. 4.

Although relatives universally and in themselves do not have a real immanence, yet in God they have it necessarily, on account of the mode of the internal origins or immanent processions, from which the relations arise in our manner of conceiving, or rather, with which the relations are really altogether identical. Whence a) if the ontological immanence of the persons is regarded, this reason, according to origins and according to relations, is not twofold but one and the same, as in another place also s. Thomas regarded it, I. dist. 19. q. 3. a. 2. b) From the origins themselves, however, the mutual immanence of the persons holds on account of the mode of the processions, inasmuch as they are through the communication of the one numerically one nature; and so the proper real reason of circumincession remains the unity of nature in distinct persons. « For God is not in a dwelling of a nature diverse from and alien to Himself, but He remains in His own and in that begotten of Himself: God in God, because He is God from God » Hilar. Trin. l. IV. n. 40.; Ambros. de Spiritu Sancto l. III. c. I.

II. After having set forth, as much as the matter required, the doctrine of Scripture and of the Fathers, it remains that we deduce from that very doctrine the proper reason and notion of that mutual inexistence of the persons — what it properly is, or what is the formal concept of circumincession. For concerning this the theologians dispute among themselves, although all agree that the reason from which it necessarily follows is the unity of nature in distinct persons, concerning which matter we have so far spoken.

Petavius Trin. l. IV. c. 16.; Incarn. l. IV. c. 14. seems to have advanced much from this, that περιχώρησις according to the Greek Fathers is not to be understood as an embracing and comprehending of one in the other, and so is not a circuminsession, as the later Scholastics commonly handed down, but is a passage or circumincession of one into the other, since both the persons in the Trinity and the two natures in Christ are said not περιχωρεῖν ἀλλήλας (to embrace one another) but περιχωρεῖν εἰς ἀλλήλας (to pass into one another). But no one can deny — nor surely does Petavius deny — that περιχώρησιν is that which Christ the Lord expressed in those words: « I am in the Father and the Father in me, » and which afterwards all the holy Doctors understood as the immanence of the persons in one another. Now, for constituting the formal concept of this immanence, it seems to matter little whether you say mutual immeation or circuminsession or mutual embracing. A subtler concept, therefore, in so far as it is sought among Catholics, can be constituted neither from the name, nor from anywhere else, than from a more diligent consideration of the thing itself as handed down in Scripture and by the Fathers.

1°. Many of the later Scholastics think that the circuminsession of the persons (given, of course, the unity of nature) is, according to its formal concept, «the intimate presence of the persons among themselves, which is founded in the immensity of the same persons,» as Suarez teaches, l. IV. c. 16. n. 11., 12; or as Ruiz speaks: «circuminsession quidditatively and formally consists in the intimate and inseparable and perpetual presence according to an immense where, by reason of which it involves a contradiction for one person to be somewhere unless another person exists in the same place and is consequently present there» disp. 107. sect. 7. n. 9. 14.

In this matter we agree with all our heart with Petavius, l. c., that immensity, as it is understood by these theologians, does not enter at all into the formal concept of circuminsession; indeed, we judge that by this lighter way of considering περιχωρήσεως, which, as we noted a little earlier, is the most splendid outline of the whole mystery of the Trinity, set against all heresies, it is lowered in its majesty to a notion at least little worthy of so great a mystery.

In the first place, the very immensity of God is understood very improperly when it is conceived according to an «immense where» as some sort of diffusion, since it is nothing other than the eminent perfection of the divine existence above all relations of place and space, by force of which perfection it is indeed repugnant that a creature existing or possible be conceived somewhere where God is not; and St. Augustine splendidly illustrated the concept of this perfection from the analogy with the nature of truth freed from all relations of place and space (see Tract. de Deo, thesis XXXIII). When, therefore, a creature exists, it is necessarily intimately present to God, and this presence certainly adds nothing to God beyond the perfection of immensity. Hence the presence of God is said in the proper sense in reference to creatures, and is a relation of reason ad extra; that is, the presence of God is the immensity of God (in the sense declared) with the co-signification of the existing creature. Whence the divine persons, because they are really distinguished among themselves and at the same time, all identified with the divine essence, are one God, are indeed properly said to be one in another; but the name of presence in this sense can be employed not in a proper but only in an analogical signification, and it certainly expresses less clearly the mode of that divine in-being through identity of essence.

All the faithful indeed say: where one person is present, all three persons are present; but I do not know whether they would patiently bear it, if someone said, e.g., that the Holy Spirit is present to God the Father and the Son.

Nor, therefore, is it without reason, although it is rejected by those more recent Scholastics, what Aureolus, an exceedingly subtle theologian, says: «Presentiality, he says, seems to be a relation importing a distinction of the things that assist in presence; for the same thing is not present to itself; but the whole person is not distinguished from a person according to essence; therefore according to essence one will not be intimately present to the other but altogether the same, nor can such intimate presentiality be attended to except according to the relations that are really distinguished; and yet it is certain according to Hilary and Augustine that the circumcession of the persons is attended to in terms of the identity of the essence, which whole and perfect subsists in the three.... The whole personality of the Son in the personality of the Holy Spirit must so be understood that neither flows into the other or is intimately made present to it, lest through this they be conceived as essentially distinct, or as not united by identity in some simply one thing; for this seems to be what the respects of presentiality involve» in I. dist. 19. aa. 1. et 3.

But even with all these things set aside, that concept of circumincession through presence according to immensity, or the immense where, is shown to be altogether false on other grounds. For a) such an intimate presence of God is in all creatures; and yet the concept of this presence has nothing in common with the concept of περιχωρήσεως; but the sense of inexistence is plainly other when the Son says: I am in the Father and the Father is in me, and when Paul says: in God we live and move and have our being. And lest it be said that therefore there is no περιχώρησιν there, because the creature is not everywhere where God is, let another consideration be added. b) In the humanity of Christ the Father and the Holy Spirit are present no less than the Word, and yet the holy Fathers acknowledge, and the very reason of the incarnation proves, that περιχώρησιν is only between the divine nature insofar as it is the Word's and the human nature, although not everywhere present, of the same Word, but in no way between the human nature and the two other persons. The sole reason is that περιχώρησις can in no way be conceived from intimate presence but only from the substantial union or unity of distinct terms in one substance (i.e., either in nature or in hypostasis).

c) In the heretical opinion of the tritheists — i.e., if each distinct person had its own numerically distinct divine nature, as three men have three distinct natures — there would nonetheless be an intimate and necessary and inseparable presence according to the immensity of one person in all and of all in each; and yet there would be no περιχώρησις there, such as is taught in the Scriptures and declared by the Fathers.

For this is the mutual inexistence of distinct persons through identity of nature. For this reason, as we have already said above, circuminsession is so solicitously commended and declared both in Scripture and by the holy Fathers, because once this one doctrine is seen, all heresies denying either the singularity of the nature or the distinction of the persons are excluded. But this profundity of the mystery and gravity of the doctrine is no longer preserved in that concept of presence according to the immense where.

Hence you may see what is to be thought of the note of Johannes Clericus, an Arminian man (under the name of Theophilus Alethinus), on Petavius, l. IV. c. 16. de Trinitate. There that lying Alethinus says: «if the ancients had pondered one numerically single substance, they would never have thought of circuminsession; for no one would have said that one substance circuminsides itself... But if we understand three eternal spirits most perfectly equal, there can be room for τῇ περιχωρήσει.» Certainly the ancients would not have thought of it, nor would Christ have spoken of mutual inexistence, if, just as there is one substance, so there were one person; but distinct persons are taught to be in one another by circuminsession on account of the very numerical unity of nature or substance. In a completely inverted order, therefore, Alethinus should have said: if three equal spirits are understood, but in distinct natures, there can be no room for the τῇ περιχωρήσει such as is handed down in Scripture and by the Fathers; but because the ancients believed in one numerically single substance in three distinct persons, therefore they not only thought of circuminsession but vindicated it most amply and in manifold ways.

2°. In order that we may at last finish what we have begun, the proper concept of the mutual inexistence of the persons seems to be constituted in this way. What we say about God ad intra and ad extra does not signify an order and relation of presence; for thus nothing outside God could be or be conceived without absurdity. But we call ad intra that which really is the divine Being itself, the essence itself, God himself; ad extra, however, we call whatever is diverse from the divine essence, and so whatever is or can be created. Whence, if those things which are ad extra are said to remain in God, this is understood insofar as God, the first being and the first cause, by force of immensity is in all things through essence, presence, and power (see Tract. de Deo, thesis XXXIV).

But as for those things which are ad intra, of their immanence the discourse can be twofold. If in the first place we consider the absolutes which are conceived by us either as attributes or as actions, their immanence supposes a distinction of reason (i.e., according to our mode of conceiving), and formally is the very identity with God or with the divine essence, or of the attributes among themselves; for the attributes can be said to be immanent to God, or to the divine essence, or to one another. Thus, e.g., we can say that wisdom, the creative act, etc., is immanent to God. But this could not be said unless there were some distinction of reason; for we do not say that what we conceive without any distinction is the same thing immanent to itself; formally, however, in these absolutes, through immanence we signify that inexistence (by an analogy drawn from the attributes of creatures) which in God is the identity of the attribute with the divine Being or with the divine essence.

In another way, which properly pertains to the present matter, the divine persons must be considered, which are indeed really identified with the divine essence and consequently with the absolute attributes, but among themselves are really distinguished. Whence when one person is said to be immanent to or to inexist in another, it is supposed not a distinction of reason but a real distinction, and for that reason in another sense and more properly the persons are said to inexist in one another than the attributes in the essence or in one another ⁵. Formally, through this mutual inexistence of the persons there is signified not the identity of the persons among themselves insofar as they are persons, since indeed a real distinction is supposed; but there is signified the identity of the persons, who are said to inexist in one another, with one numerically one essence, and on account of this identity the comprehension of one person in another.

If we wish to signify the mode of distinction and identity more expressly, we can say: the persons are mutually immanent to one another insofar as one proceeds from another ad intra, i.e., in the identity of one numerically one essence. Just as, therefore, the immanence of the attributes, which are distinguished by reason, is their real identity with the essence, so here circuminsession is the mutual comprehension of one in another of the persons proceeding ad intra and really distinct, on account of the identification of them all with one numerically one nature or essence.

According to what has been said, it could seem to someone that circuminsession differs in nothing from the consubstantiality of the persons. We answer: without doubt, just as by the words of Christ, Io. X, «I and the Father are one,» and «the Father is in me and I in the Father,» so by consubstantiality and circuminsession the same thing is grasped, the same twofold truth of the unity of nature and the distinction of the persons; but the same thing and the same truth is conceived under two different notions.

While we say that the persons are consubstantial, we conceive that there is one nature of the distinct persons, in direct opposition to the heresy positing diverse natures in the three persons, and consequently also in opposition to tritheism on account of the singularity of the divine nature, which cannot be multiplied. When, however, we say circuminsession, we conceive that one person is mutually in another, insofar as all the persons subsist in one numerically one nature, so that the opposition is direct against the heresy by which one person would be said to subsist separated from another — not indeed according to where and through the negation of presence (for such an error, once divinity is admitted, could be conceived by no one), but one apart from another and outside another, insofar as it would have a distinct nature, in the way that, e.g., three spirits subsist. Wherefore circuminsession is in direct opposition against tritheism and consequently and a fortiori against Arianism.

« From the notion of circuminsession is declared the unity of perfection of the divine persons, that 1° the fullness of perfection of each one, insofar as they are referred to one another by a relation of origin, requires that each have the others immanent to itself; whence 2° each one has the whole of perfection, even relative, of the three persons, not indeed as constituting but through necessary immanence; which unity of perfection is 3° declared from the real identity both of all and of each of the persons with the infinite divine essence ».

I. After the proper notion of the mutual inexistence of the individual persons in all, and of all in the individuals, has been declared, we can explain how this very mutual immanence belongs to the perfection of the individuals and of all.

The divine intellect, from its inmost necessary perfection, produces the consubstantial Word by understanding. The intellect thus considered is relative to its Word as a mind producing, and the Word is relative to the producer as proceeding from it: the former is the Father, the latter the Son. Hence the Father is indeed constituted formally, insofar as He is the intellect producing the Word (which is said abstractly: the Father is constituted by the relation of paternity identified with the essence); but by the same inmost necessity by which He produces the Word by understanding, He has His Word as the produced term immanent to His intellection; nor would He be producing by understanding, and so would not be the Father, without the Word immanent to Himself.

Most truly, therefore, the holy Fathers say that without His Word the Father would be without intelligence, without wisdom (ἄσοφον καὶ ἄλογον), not as if the Word were formally the intelligence and wisdom by which the Father is wise; for in that way wisdom is absolute, common to the Father and to the Son and to the Holy Spirit, and insofar as it is in the Father it is the principle by which He produces the Word; but the most true sense of the Fathers is that intelligence and wisdom, as it is in the Father, necessarily has the Word produced as its term, and, this necessary immanent product being removed, there would not be intelligence either. (See the Fathers in Ruiz disp. 29. sect. 3; Petav. l. VI. c. 9. cf. s. Thom. opusc. contra Graecos c. 7.).

It belongs, therefore, without doubt to the perfection of the Father, not indeed as a constituting form but as the necessary term of His paternal intellection, that He have in Himself the Word, produced by Himself and immanent.

« For since this Word is placed in God by this, that God understands Himself by conceiving His intelligible Word, it must be that if at some time the Word of God was not, then God did not understand Himself. But always, when God was, He understood Himself, because His understanding is His being. Therefore His Word always was » S. Th. Compend. theol. c. 43. This matter, of great moment for some understanding of ours of the divine persons, we shall express in the words of the distinguished theologian Didacus Ruiz. « The Father has in Himself, he says, the whole Son and His filiation as the perfect term of the vital operation (by which He produces the Word by understanding), i.e., as the Word of altogether the same substance; and hence the Father has filiation within Himself as a perfection due to Him and His own, without which He would be defective (better: without which He would not be at all, because He would not be perfect)... For even a tree is perfected by the fruit united to it and remaining in it; the created intellect is perfected by the word of the mind produced through intellection and remaining in the intellect itself. Therefore a fortiori the Father is perfected by the Son, since He is the fruit vitally produced and quidditatively demanding to be united with His root or principle, and is the Word produced by the immanent action of the paternal intellect. Therefore the Father, for His own perfection, quidditatively demands within Himself and in Himself to contain the perfection of filiation, not as constitutive of His person but as the glory and ornament of His person » (better: as the term of His producing, that is, notional intellection) Ruiz disp. 30. sect. 6. n. 13. 14.

Conversely, the Word, the splendor of glory and the perfect expression of the paternal substance and the consubstantial image, proceeding without beginning and without end by internal necessity and always begotten as the term of the paternal intellection, in this very perfection of His comprehends and has immanent to Himself the speaking mind, that is, the Father, His principle; nor would He be the perfect Word without the immanence of His principle.

But it is evident that in the same way we must think and speak about the perfection of the will, that is, of the love in the Father and in the Son, whose necessary produced term is the subsisting love, the Holy Spirit. That love (as it is in the Father and in the Son), from its very inmost necessary perfection, expresses the subsisting love as its immanent term. Hence the holy Doctors, just as they say that the Father without the Word would be without wisdom, in the same sense say that without the Spirit

God would not be Holy. « What Deity, if imperfect? But how will it be perfect, to which something is lacking for perfection? For it is lacking, if it does not have holiness. But how will it have this, if it does not have the Holy Spirit? » Gregor. Naz. or. 31. al. 37. n. 4. Holiness, namely, of love (see Tract. de Deo th. XXIX), as it is in the Father and in the Son, has the Holy Spirit as its produced internal term ¹, and the divine love of the Father and of the Son without this term, i.e., unless the love is a spiration, is not in its perfection. It belongs, therefore, to the perfection of the Father and of the Son to have their Spirit immanent as the necessary term of their notional love, that is, of their spiration.

Conversely, by the same reason by which the Word has in Himself the Father immanent as His principle, and this immanence is required for the very perfection of the Word, in like manner the perfection of the subsisting love is that it have immanent to itself its principle, the Father, I say, and the Son.

II. Anyone can easily see how, from the principles handed down, there can be conceived and declared in the mystery of the most holy Trinity that most certain truth which Augustine, with the other Fathers, often proclaims, as in the conclusion of book VI. de Trin. « Here in corporeal things (from which Augustine there scrutinizes the vestige of the Trinity) one thing is not as much as three together, and two are something more than one thing: but in that supreme Trinity one is as much as three together, nor are two something more than one; but they are infinite in themselves » Aug. Trin. VI. n. 12. He himself declares the reason, continuing in the same place: « so the individual things are in the individuals, and all things in the individuals, and the individual things in all, and all things in all, and all are one. Whoever sees this, whether in part or through a mirror and in an enigma, let him rejoice in knowing God, and honor Him as God and give thanks; but whoever does not see it, let him strive through piety to see, not through blindness to calumniate ».

Those individual things and all things, which are said to be in the individuals and in all three mutually distinct persons, and all are said to be one, are understood by Augustine not only of the essence and the absolute attributes but also of the relative ones, i.e., also of the personal characters and hence of the persons themselves; for about these distinguishing characters, distinct among themselves, he had spoken in the immediately preceding context. The supreme reason, even in the relative things, why « all things are in the individuals and all are one, » is at last their real identity with the infinite and absolute essence. And so not only are « the individual things in the individuals, » and accordingly (speaking of the relative things) the individual constituting characters in the individual persons, that is, the individual persons in themselves (e.g., the Father a hypostasis by Himself and in Himself), but also « all things in the individuals »; and hence in the Father there are not only the constituting paternity but also the Son and the Holy Spirit, although not as formally constituting the Father but as the necessary internal terms of the paternal intellection and love; and likewise in the Son the Father and the Holy Spirit, in the Holy Spirit the Father and the Son. By this very fact they are « the individual things in all and all things in the individuals, » the individual persons in themselves and in the two other persons, and all in each one. Finally « all are one, » three persons, not indeed one person, not three as one; but three are one, one essence and one God.

This mutual immanence and identification, however, Augustine connects, as a declaratory reason, with that dogma, that « in that supreme Trinity one is as much as the three together ». Granted the truth of faith, that of the three, distinguished only by relations of origin, the essence, that is, the divine nature, is one in number, it is easily understood that there is one and the same absolute perfection, whether one person be considered, who is the one God, or the three be considered, who are one and the same God; for the essence, and hence the absolute perfection, is neither increased nor multiplied in the several persons nor diminished in each one: « one supreme thing, which is truly Father and Son and Holy Spirit, the three persons together and any one of them » Conc. Later. IV.

But a difficulty and a great diversity of opinions among theologians arises, when it must be declared how the three persons, formally according to the relative things by which they are really distinguished from one another, are not more of relative perfection than one person. Since the three are real persons, although distinct only insofar as they are three relatives to one another, and hence are three relative things, three relative beings (as most concede), how does it come about that the three relative things considered together are not more of relative perfection than one of the three?

In questions of this kind, before all things the greatest reverence must be preserved, which is owed to the mystery that is adored, and so the matter is to be conceived in such a way that the consideration, without importunate curiosity, modestly tends toward some more distinct understanding of God, who in His infinity is eminent above all created things and especially above all sensible and material things.

Then, indeed, the proposed difficulty can be declared from the principles about circuminsession in this way. The divine intellect in act, that is, the substantial divine understanding under the formal notion as producing the immanent consubstantial Word, is God the Father; and so the perfect Father is not, except as He simultaneously includes the Word immanent to Himself as the term of the notional intellection.

By the same reason the Father and the Son are not in their full relative perfection, except insofar as they include the Holy Spirit as the term of the notional willing or love ².

Conversely, to the relative perfection of the Word belongs the immanence of the Father as principle, and to the relative perfection of the Holy Spirit in the same way the immanence of the Father and of the Son. Hence the full relative perfection of the Father comprehends in itself whatever of relative perfection is in the two other persons; and so in turn it must be said of the individual persons that in the fullness of relative perfection they comprehend the relative perfection of the other persons. But the mode of comprehension corresponds to the property of the individual persons; for in each one one relative perfection is constituting, the others are present for the fullness of perfection as the internal terms of vital production or as the producing principle.

This very point we can reduce to this formula: the individual persons have formally the perfection by which they are constituted; the relative perfections of the other persons they have not formally, i.e., as constituting, but through immanence or correlatively. Therefore each person is not only the same whole absolute perfection which the three persons together are, because the divine essence is one; but also each person in the fullness of its relative perfection has the relative perfections of all persons in a manner fitting each person ³.

III. Although these things are so and the proposed consideration can be instituted not without fruit; nevertheless, just as circuminsession is ultimately reduced to the numerical unity of the essence in three distinct persons, so also this truth — that the individual persons are the whole infinite perfection, which can neither be increased nor diminished, of as much perfection as the three persons together are — this truth too, I say, is finally to be explained from the unity of the essence as from its own proper foundation, to which in this chapter the holy Fathers also appeal more frequently (cf. the Fathers in Ruiz disp. 30. sect. 2.; in Petav. de Deo l. VI. c. 7. n. 12. sqq.; de Trin. l. VIII. c. 9. n. 16.).

But the manner of declaring this very point among the various theologians is very diverse. Our explanation is deduced from the principles set forth in the Tractatus de Deo. One infinite Being, one thing (as the Fourth Lateran Council speaks) is at once absolute and relative. As it is absolute, it is and is called one infinite essence; insofar as it is relative, it is not nor can it be one relative (since there the relation is ad intra of one to another), but from the internal necessity of that essence and nature there are three relatives, Father, Son, Holy Spirit, distinct from one another under the formal ratio of relatives, who under the formal ratio of the absolute, as has been said, are both singly and all together one essence; « the same essence which in the Father is paternity, in the Son is filiation » S. Th. I. q. 42. a. 6. ad 3.

Therefore the same thing, existing at once as one absolute essence and as a threefold substantial relation, or as three relatives to one another, cannot be understood by us in one concept; but there is one concept, to which that thing responds as absolute (and this is and is called the formality or formal ratio of the absolute or of the essence), and there is another concept, to which the same thing responds as relative, whether confusedly or distinctly, as Father or Son or Holy Spirit or Trinity (under which concept it is and is called the formality or formal ratio of the relative or of the person). Hence there is a distinction of reason with a foundation in the thing between the absolute and the relative, between essence and person.

This distinction is with formal abstraction, by which we conceive the essence explicitly without the express notion of the person, although the ratio of the person is included implicitly in that conceived thing ⁴. But the distinction is not with objective precision (as we said in the Tract. de Deo Th. XIII. XXVI.); i.e., neither can the formal ratio of the person be so conceived that it does not include the ratio of the essence (in which most theologians agree); nor is the formal ratio of the essence to be so conceived that it does not include the ratio of the person. Concerning this latter point several theologians speak otherwise; we, however, convinced by arguments, follow many others, among whom are Gregory of Valencia in I. disp. 2. q. 13. punct. 1. and the one who declared these things more fully, Card. de Aguirre Theol. S. Anselm. T. I. disp. 26; disp. 31. sect. 4. seqq. cf. T. II. disp. 73. I do not say that the notion of the person is necessarily included in the notion of the essence; but I say that that objective ratio which is conceived by the notion of the divine essence (or of any absolute attribute) is such that it really includes, and, given revelation and faith, must be judged to include, the relative ratio and the persons, Father, Son, Holy Spirit. But if one judged that the reality which is offered to the concept of the divine essence (or of an absolute attribute) were abstracted with objective precision, so that it does not include the persons, that would not be the concept of the divine essence, and this judgment would be altogether false.

From these principles follows the solution of the proposed question. If the ratio of the person, or the substantial relations, or the personal properties (which all signify the same) were really distinct from the essence just as they are mutually distinct from one another, and accordingly there would be a quaternity (as Abbot Joachim thought followed from the numerical unity of the essence and the Trinity of persons); then indeed the essence together with the personality, and a fortiori the essence together with the three persons, would comprehend more perfection than the essence alone by itself or the individual persons separately; but by this very fact neither the essence nor the individual persons, and consequently not all the persons together, would be the infinite Being comprehending the whole fullness of the divine Being ⁵, and therefore the very concept of God would be perverted.

But the divine essence, one and the same, is both the absolute and — without the addition of another perfection (for nothing of divine perfection can be or be conceived outside it) — is at once the relative Father, the relative Son, and the relative Holy Spirit: « one supreme thing, which is the Father, the Son and the Holy Spirit, the three persons together and each one of them ». Therefore, while I conceive the formal ratio of the essence or of the absolute, I do not indeed explicitly conceive the relative, yet I conceive that which from its inmost ratio is necessarily at once relative with a threefold substantial relation, and therefore is every perfection, both that which is explicitly conceived under the ratio of the absolute and that which is explicitly conceived under the ratio of the relative; which two ratios are distinguished only by our concept, one and the other, but in reality are one thing, as has already been said.

Therefore, conversely too, under the notion of the person, e.g., of the Father, I indeed conceive explicitly the relative, which in the notion of the essence was only implicit; but surely neither more nor less perfection is comprehended under this notion of the Father than under the notion of the essence, which holds equally of the notion of the Son or of the Holy Spirit, and hence holds as much of each singly as of all three together. Wherefore in the individual persons the absolute viewed together with the relative, or the essence together with the relation, is not something greater or more perfect than the absolute essence viewed by itself; nor is the essence viewed together with the three relations, which are really one with it, something greater or more perfect than the essence viewed by itself. Therefore, since the individual persons are really the divine essence, the three persons are not something greater than one viewed by itself.

Namely, the divine essence is the fullness of the divine being, incapable as of diminution so of increase, one and the same, identified both with each single and with all three substantial relations or persons, although the persons are not explicitly conceived under the notion of the essence but are comprehended implicitly. Hence the three persons are the same fullness with the explicit expression of the substantial relations; each person likewise is the same fullness with the explicit expression of one relative and with the comprehension of the two remaining persons, insofar as they are identified with the essence, and insofar as on that account by their formal ratio of relatives they pertain — not indeed as constituting but as immanent termini — to the perfection of each person. In which last ratio, as is evident, one returns to circuminsession.

All this was excellently expressed by St. Cyril of Alexandria. « That nature which is above all is simple and incomposite, dilated indeed by the properties of the hypostases and by the differences of persons and names (διαπεφυκυῖα, i.e., common to several persons) and tending into the holy Trinity (εἰς ἁγίαν τεταμένην τριάδα); yet by natural unity and all-embracing identity concurring into one something, namely into the name and thing of God: so that in each one the whole nature is understood, together with its property, namely the hypostatic one. For each one remains what it is in natural union with the others, also possessing that same thing in its own nature (ἔχουσα ταὐτὸν ἐν ἰδίᾳ φύσει); for the Father is in the Son and the Holy Spirit, and likewise also the Son and the Spirit are in the Father, and in one another » Cyrill. dialog. VII. T. V. P. 1. p. 641.

Now from what has been said answer is made in form to the difficulty proposed at the beginning, in which it was said: three relative perfections are really distinct from one another; but three perfections together are something better and more perfect than one of them. Therefore, etc. Resp. I distinguish the major: they are really distinct from one another as opposed relations, so that in one common essence, with which they are identified, they are one (i.e., so that the distinction is inadequate), I concede the M.; they are distinct without unity in a common essence (i.e., so that the distinction is adequate), I deny the M. Likewise I distinguish the minor: three relative perfections distinct both from one another and from the essence would be something greater (a quaternity being introduced and the infinity of the divine Being subverted), I concede the m.; three relative perfections distinct from one another through mutual opposition but identified both singly and all together with one and the same infinite essence are something greater and more perfect than one, I deny the m.

If it is further urged: the Father does not have the relative perfection which is the property of the Son, etc.; therefore, etc. I distinguish the antecedent: the Father does not have that thing, or rather is not that supreme thing which identically is the Father, the Son and the Holy Spirit, I deny the A. The Father does not have that thing under the formal relation of filiation, I subdistinguish the A.: he does not have it as constituting the Father himself, I concede the A.; he does not have it as it befits the Father, namely as his Word, as the immanent terminus necessary to his vital intellection, I deny the A. To this pertains what St. Bonaventure says: « there is unity of nature and plurality of persons, and there is as much in the unity as in the plurality, but not in so many ways » I. dist. 19. P. II. q. 1. ad 3.

Scholion. Some theologians, among them Suarez l. III. c. 10., distinguish in God absolute perfections and relative perfections in such a way that the former are indeed simply simple and in their formal ratio common to all persons, like the one numerically divine essence; the latter, however, they say are not simply simple perfections, and that they are contained in the divine essence itself not formally but only eminently, and therefore further that the individual relative perfections are in the individual persons formally, but all are in all eminently; and thus they think it is sufficiently explained how one person, no less than three together, is all perfection.

This manner of considering and speaking will perhaps be necessary, if objective precision of the divine essence from the personal properties is admitted, and these are conceived as a perfection superadded to the essence; but we can follow neither that precision nor this manner of considering.

« The perfect, outside of which there is nothing, » as the Scholastics are wont to define from Aristotle; namely, the perfect is that to which nothing of what befits it is lacking: perfection, therefore, is the fullness of what befits (see on these things Tract. de Deo th. XXIX.). All those things which, distinct in reality or in reason, constitute this fullness are called perfections, in creatures indeed as perfecting forms; but in God those individual things are really the fullness itself. For in creatures both all and each of the perfections are only an entity of some degree with the negation of further possible reality, i.e., they are limited in perfection, and to that extent, in comparison with the unlimited and (in this sense absolute) entity, they are perfections secundum quid. Therefore, because there no perfection includes the whole ratio of unlimited being, those perfections can be really distinct; and those which are not even really distinct can be conceived with objective precision from the others. Although, e.g., the intellect and the will in a created spirit, this nature connaturally subsisting and the hypostasis, this real essence and existence, are supposed to be really one thing and one perfection, yet the intellect, the nature, the essence are conceived without the will, subsistence, existence being included in the formal ratio and perfection so conceived, i.e., they are conceived with objective precision. But if the ratio or reality conceived were a reality in itself unlimited, including the whole perfection of being and hence also the perfection of will, subsistence, existence, such objective precision would be repugnant. Now indeed in God it is altogether so. Whatever of divine reality is conceived, it is entirely the fullness of infinite reality including the whole perfection and fullness of unlimited being, to which nothing can be added; for nothing is outside, i.e., nothing of perfection without imperfection, or (as they say) of simply simple perfection or of infinite perfection, can be conceived outside and beyond the ratio of that most full Being. Therefore nothing there can be abstracted with objective precision. For I ask, that which is said to be abstracted by a precisive concept, e.g., the formal ratio of paternity, does it have the ratio of divine being or does it not? and that formal ratio from which such precision is made, e.g., the essence (not only in the thing itself, but as it is in the concept), does it remain a divine being? If paternity so precised does not have the ratio of divine being, this is not divine paternity; for that is God, nor can it be conceived with such precision that it itself is not God, without the concept ceasing to be the concept of divine paternity. « We believe and confess that only God the Father, the Son, and the Holy Spirit is eternal, and that there are absolutely no things — whether they be called relations or properties or singularities or unities, or other things of this kind — present to God, which are from eternity and are not God » (Creed delivered to Eugene III in the Council of Rheims and approved by the Pontiff against Gilbert Porretanus. Harduin. VI. P. II. p. 1299.). Therefore, just as the essence cannot be precised from the relations, as even Suarez concedes, so we say that neither can the internal relations be abstracted with objective precision from the essence, insofar as it is known by faith. That which we conceive by express notion as the divine essence is at once the threefold substantial relation, the Father and the Son and the Holy Spirit, no less necessarily from its inmost ratio than immutable eternity, wisdom, goodness and the other absolute attributes are. Wherefore just as the divine essence, as we know it even by the light of reason alone, cannot be conceived with the absolute attributes precised, without the notion of the divine essence being perverted; so the same essence, as we know it by faith, cannot be conceived with the substantial relations precised, without equally departing from the notion of the essence, such as it objectively really exists and is knowable to us through faith. Whence, just as the absolute attributes, so also the substantive relations or personal properties add nothing to the essence, as if they completed it toward the fullness of perfection; but they are the divine essence itself under one and another ratio or function. (See Tract. de Deo th. XIII.). Hence also, conversely, each personal property or substantive relation or person (which all signify the same, although in a different manner), for the reason that it really is the divine essence itself, is also the fullness of the divine being and infinite perfection; and because the individual persons are the same essence and fullness of being, under the ratio of perfection (in this proper sense of the word) they are not opposed to one another, but « the three are one. » Thus, therefore, « that supreme thing, » which God is, whether under the express ratio of the essence, or under the express ratio of one person, or under the express ratio of the Trinity, is one and the same fullness of infinite Being, and therefore one and the same perfection in the proper sense of this name.

I said: the persons are not opposed to one another under the ratio of perfection properly so called. For the notional intellection producing the Word is indeed a perfection, but not a perfection other than the absolute intellection, which is common to the three persons and is the essence itself; likewise the formal ratio of the Word, as it is the immanent terminus necessary to the paternal intellection, is surely a perfection, but not a perfection other than the absolute wisdom, which is common to the three; the same holds of the expressed terminus of the love of the Father and the Son, that is, of the Holy Spirit.

You will say: all these things only show that the absolute perfection is one, singular, and that of the three persons together; but they do not yet show how the relative perfections, which are three and distinct from one another, are not more perfection than one. I answer: a) all these things show that the three distinct relative perfections are called so improperly. For the individual relations or personal properties, insofar as they are themselves really the divine essence, are perfection in the proper sense of the fullness of the divine being; but this is not threefold but one of the three, and therefore one perfection in the proper sense. b) If the epithet relative restricts the name of perfection to signifying the relative property, then indeed in this sense there are three distinct relative perfections, and three are more than one, but they are not more perfection. For this phrase more perfection expresses an increase of perfection properly so called by the addition of one to another, which is absurd in divine things, since each one is the whole infinite perfection, because they are really the infinite essence itself. On the contrary, when several relative perfections are named in the said improper sense, not the addition of several to unity but the enumeration of distinct properties is expressed, which under the ratio of perfection taken in the proper sense are one, not by addition but by identity with the essence. c) The three relations, three relative things, three relative beings, three relative perfections, even if they are viewed in our inadequate concept, not insofar as they are one, and whence they properly have the whole ratio of perfection, but are viewed only formally under the express ratio of distinct things — still, thus one relation includes all the others, although in a different manner. For the notional intellection, formally as producing and relative to the Word, in this its relative perfection includes the Word, not indeed as constituting form but as immanent terminus: « the fullness of perfection is attended to in the speaker through the Word » (S. Th. contr. gent. IV. c. 45.). The same is the case in the relative perfection of the Word and of the Holy Spirit or the Spirated, as has been declared in the thesis.

« Since equality and similitude presuppose distinction and signify « some unity — the former, indeed, a unity of perfection without excess, « the latter either the same unity or an inferior agreement: the divine persons, just as « they are identical according to essence, so are they to be affirmed as simply equal; « as similar, however, they can be said in one sense, in another they cannot be said. « Whence the holy Fathers, once the Arian and Semiarian heresy had already arisen, not the profession « of similitude simply, but of similitude according to essence and according to « equality (κατὰ πάντα) were accustomed to admit ».

The theologians of the schools, with the Master (I. dist. 19.) and with St. Thomas (I. q. 42.), join to the doctrine of circuminsession, as a connected member, the question of the equality of the persons. And indeed, although the manner of considering the persons under each of those two aspects is distinct, the foundation of both is nevertheless the same. « Equality in things divine, says Aureolus (I. dist. 19. P. II. a. 1. propos. 2.), is nothing other than the indistinction of distinct things, namely of supposits, in a certain thing wholly indistinct (in the essence); but this indistinction is the same as identity, according to which one person is said to remain in another identically. According to this, circumincession and equality are the same, for which reason the Master in the present dist. 19., when he treated of equality, immediately transfers himself to circumincession. Whence he who conceives the undivided Trinity, or the Trinity distinct (in persons) indistinct in a certain indistinguishable (essence), has everything that all those habitudes import » (identity, equality, similitude, circumincession).

I. Identity, equality, and similitude generally denote a) some distinction of the terms; b) some unity or agreement of those same terms in a formal respect, according to which they are understood as identical, equal, similar. For many things « are the same whose substance is one; similar, however, whose quality is one; equal, moreover, whose quantity is one » (Aristotle, Metaphys. V. c. 15.).

Identity, therefore, simply so called, does not of itself include a real distinction but only a distinction of reason, just as something is said to be identical with itself, and a divine person identical with the essence; yet a real distinction of the terms can be presupposed, especially when the respect is added according to which the identity consists. But the formal ground of identity is the unity of essence. The divine persons, therefore, are one identical with another according to nature or essence.

Equality — the same holds of similitude — includes a real distinction of the terms, for nothing is equal or similar to itself. But the formal ground of equality is an agreement without excess of one over the other, that is, a unity in quantity; and equality is the more perfect, the greater (given the distinction of the terms) the unity of quantity is. Quantity is not only that of mass and extension, of which there can be no question in God, but also the nobler quantity of power or perfection: « in those things which are not great by mass, to be greater is to be better » Aug. Trin. VI. 8. In God the quantity of perfection is the infinite indivisible essence itself. Since this, in the really distinct persons, is one in number both in each one and in all together, the most perfect equality among the persons is evident, of each one to the other and to all together.

Similitude requires a somewhat greater consideration, because the signification of the name extends more widely and is more ambiguous. Given the real distinction of the terms, the formal ground of similitude is said to be an agreement or unity of quality. Quality in God cannot be understood as a perfection superadded to the essence, but is understood as the very quiddity of the essence (so that τὸ ποιόν is the same as τὸ τί ἦν εἶναι), or the essence considered according to its essential attributes. In this, indeed, no difficulty appears; but similitude is also sometimes taken more widely in the manner of speaking of Scripture and in relation to God. For similitude, unlike equality, does not of itself require an agreement without excess of one over the other, nay not even an agreement in the same order; whence even the adumbration of the perfection and spiritual nature of God in rational creatures, and especially in the elevation through the gifts of grace, is called similitude with God. Wherefore in the first place there must be distinguished natural similitude, and the similitude which, in comparison with the natural, is called analogical. Natural similitude — the only one with which we are now concerned — is not understood in this distinction as though one nature and another were the terms and one were similar to the other by some quality; but it is here called natural similitude because the unity of nature is the formal ground of the similitude of distinct things, just as the Apostle, from the assumed form or human nature, says the Son of God « was made in the likeness of men » (Phil. II. 7)¹. The divine persons, therefore, can in the catholic sense be said to be similar with a natural similitude, that is, according to essence or in essence. If ever, indeed, even the ancient catholic Doctors say that the nature of the Son is similar to the nature of the Father, it must be understood of the nature inasmuch as it is identified with the Son and inasmuch as it is identified with the Father, i.e., a hypostasis similar to a hypostasis according to nature; but nature is not said to be similar to nature except by the Arians and Semiarians. It is clear from what has been said that the similitude among the divine persons, as it is predicated in the catholic sense, coincides with equality, and that both are finally the identity of the persons according to essence (Aureol. l. c. a. 1.).

II. From the very diverse signification of the name it is understood how the Arians and Semiarians fraudulently substituted the one formula ὁμοιούσιος for the catholic tessera ὁμοούσιος, and how nevertheless several even of the holy Fathers were able to interpret this one in the catholic sense, especially with the added determination that the Son is similar to the Father in all things and without any discrepancy (ὅμοιον τῷ Πατρὶ κατὰ πάντα καὶ ἀπαραλλάκτως). For the heretics wished to signify that essence is similar to essence, and therefore distinct essences as the terms of comparison, whose formal ground of similitude (since the one term is the divine essence, which cannot be but one) had necessarily to be constituted in a certain adumbration and participation only; and so they understood an analogical similitude, which in comparison with natural similitude is rather a dissimilitude.

Those Arians perceived this very well, who with Aëtius and Eunomius professed impiety without disguise, and therefore, in place of that fraudulent similitude, said without circumlocution that the Son is dissimilar to the Father (ἀνόμοιον, whence they were called Anomoeans). Thus Eunomius argues (in s. Basil, contr. Eunom. l. I. n. 21. T. I. p. 233) with an argument certainly valid against those disguised Arians, who wished to profess that the Son is similar to the Father but not equal and consubstantial. Since in God, he says, there is neither quality nor mass nor quantity, the (perfect and proper) similitude of the Son to the Father could not be said except according to essence; « but the similitude or comparison or communion which is according to essence leaves no preeminence or difference, but manifestly effects equality ». Basil in his response (ib. p. 234) declares the true ground of the similitude between the Father and the Son to be the essence itself, namely that the essence of the Father and of the Son is one, just as the ground of equality is the identity not of mass (which in God is none) but of perfection; and therefore the Son is most truly similar to the Father with a true natural similitude, and by this very fact is equal to the Father. « I say that similitude is perceived not according to the identity of the external form (τοῦ εἴδους), but according to the essence itself. For those things which are encompassed by form and figure have similitude according to the identity of the form (τοῦ εἴδους); but that nature which is alien to form and figure (the Son of God) — it remains that it have similitude in the essence itself, and equality not in the dimension of mass but in the identity of power (ἐν τῇ ταυτότητι τῆς δυνάμεως). Scripture says: Christ, the power of God and the wisdom of God, the whole paternal power, namely, residing in him ».

The catholics, therefore, asserted against the Anomoeans indeed the similitude of the Son with the Father, but a natural similitude through the identity of nature; and, to determine this, they joined equality with similitude², and they added those epithets of similitude, in all things and without any discrepancy. « For my part, says Basil, as regards the similitude according to essence, provided it have joined to it that "without any discrepancy" (τὸ ἀπαραλλάκτως), I receive this word, as one which comes back to the same as consubstantiality, according, namely, to the sound sense of consubstantial... But if anyone should cut off from the name "similar" that other element "without discrepancy," as they did at Constantinople³, I hold the word suspect as diminishing the glory of the Only-begotten; for even in obscure assimilations which differ very much from their exemplars, we are not rarely wont to conceive something similar » Basil. ep. 9. (al. 41.) n. 3. See Petav. l. IV. c. 6.

Although this natural similitude, as is clear from what has been said, is reciprocal among all three persons, nevertheless similitude as image can still be taken more peculiarly as a hypostatic property; and in this peculiar sense the ground of similitude — and (as Aureolus adds, l. c. a. 6.) of equality — belongs to the Word alone in relation to the Father. Because in this way the identity of nature does not suffice for the ground of similitude, but there is further required an origin from a principle and exemplar, and that not any origin whatsoever but such that the mode of procession from its very own proper ground is directed to representing the archetype; and in this way only the Word proceeding through the paternal intellection is the image and similitude of the Father. On this elsewhere; in the meantime compare S. Th. I. q. 35.; Petav. l. VI. c. 5.; VII. c. 14.