I. Definition of the Term. — What, is tech-

nically known as the Communication of Idioms may be defined as "a mutual exchange of divine and human properties in virtue of the Hypostatic Union." Though practically identical with Peri- choresis, the Communication of Idioms may more appropriately be regarded as an effect thereof. For if the Divine Person of the Logos is both God and man, it is inevitable that His Godhead and His manhood should interchange their respective properties, and this is precisely what is meant by eommunieatio proprietatum s.
idiontCttUfn (avriSoo-is twv iStw/tarwv ^ l8tOTr]Twv\ Wc
thus have a transfer of predicates or attributes from one nature to the other, as, e. g., "God has suffered," or *'The man is God." Since, however, "interchange" and "predication" are not synony- mous terms, it will be better, for the sake of clearness, to distinguish between the (ontolog- ical) interchange of idioms and the (logical) predication of the several kinds of attributes.
18 Serm. de Pass., 3, c. i.
COMMUNICATION OF IDIOMS 185
a) Communicatio idiomatum means the actual transfer of divine attributes to the man Jesus and of human attributes to the Divine Logos. The extent and mode of this transfer depend on the manner in which Godhead and manhood are united in Christ. After a fashion even Nestorian- ism and Monophysitism admitted a Communica- tion of Idioms, but their theory, made to conform with the heretical system of which it is a corollary, differs essentially from the approved Catholic doctrine. Communication of Idioms in the Cath- olic sense is based on this principle : "In Christ God is man and man is God; but Godhead and manhood are by no means identical." In the words of the Council of Ephesus: "Una per- sona composita Christus totus est Deiis et totus est homo; totus est Deus etiam cum humanifate, sed non secundum humanitatem Deus, et totus est homo cum divinitate, sed non secundum di- vinitatem homo — One composite person, Christ, is all God and all man; He is all God even with His manhood, but not according to His manhood ; and He is all man with His Godhead, but not according to His Godhead." ^
It is wrong to say, therefore, as some theologians do, that the doctrines of Perichoresis and Communication of Idioms represent a mere Scholastic logomachy. They constitute a touchstone of orthodoxy in all questions re-
1 Cfr. Hardouin, Condi., I, 1640.
i86 UNITY IN DUALITY
garding the union between the Godhead and human na- ture. Perichoresis is merely the reverse side of the Hy- postatic Union, while the diTiSoat? twv tStw/Aarwv represents a necessary and important corollary of that dogma. These two doctrines enable the theologian to conclude a posteriori from the one to the other, and from the effect to the cause, i. e., the Hypostatic Union itself. It is by means of this method that we have demonstrated the Hy- postatic Union from Sacred Scripture, Tradition, and the Creeds, and by this same method Nestorius was convicted of heresy in his teaching on the Communication of Idioms.
b) By Predication of Idioms we understand the communicatio idiomatum expressed in terms of thought or speech. Needless to say, a term must correspond to the thing which it is intended to designate. Formulated in logical terms the ontological law underlying the communicatio idio- matum gives us the following rule of predication : "Whatever is predicated of the Divine Person of Christ according to His Divine Nature, can and must be predicated of the same Divine Person also in His human nature, and vice versa; but the predicates proper to the Divine Nature must not be assigned to the human nature, and vice versa/'
The first part of this rule is based upon the unity of the one Divine Person in two natures; the second, upon the fact that the two natures co-exist separately and in- confused in one Person. " Christus est una persona et hypostasis in utraque natura, divina sell, et humana," says St. Thomas, " unde potest utriusque naturae nomine
PREDICATION OF IDIOMS 187
designari; et quocunque nomine significetur, potest prae- dicari de eo id quod est utriusque naturae, quia utrique non supponitur nisi una hypostasis. Et per hiinc modiim possumus dicere, quod "homo creavit stellas" et quod " Dominus gloriae est crucifi.uts "; et tamen non creavit Stellas secundum quod homo, sed secundum quod Deus: nee crucifixus est secundum quod Deus, sed inquantum homo." - This rule is merely an application of the gen- eral principles of logic. Of sugar, for instance, we can say in concrete terms : " The white is sweet " and " The sweet is white," because the unity of the under- lying suppositum produces an objective identity between its attributes. But we cannot say that " whiteness is sweetness," because the two qualities thus denoted are separate and distinct entities and their concepts cannot be interchanged. Reduced to its simplest terms, therefore, the Christological law of predication reads : " Mutua idiomatum praedicatio valet tantummodo in concreto, non valet in ahstracto." We can say of Christ, for instance, " God is man," or " Man is God," but we cannot say, " Divinity is humanity," or " Humanity is Divinity." For according to a general rule of logic, concrete terms alone demonstrate or " suppose " the hypostasis or per- son, while abstract terms always demonstrate or suppose the nature of a being.^
2. Special Rules for the Predication of Idioms. — The communicatio idiomatum is not always accurately predicated.
a) The only correct predicates are those based upon the orthodox doctrine that there is in Christ
2 Lect. in I Cor., 2, II.
3 Cfr. St. Thomas, 5. Theol., 3a, qu. 16, art 4.
13
i88 UNITY IN DUALITY
but one Person, and that this one (Divine) Per- son possesses two inconfused natures.
a) Human predicates can be applied to the Divine Hy- postasis only in concreto. It is only by concrete terms that a subject is designated as the bearer of its predicates, and the rules of logic permit us to afifirm the objective identity of subject and predicate. We may, therefore, say : " God is man," " The Logos is the Son of Mary," " Christ was weary " ; for in making these statements we simply assert that one and the same person exercises two distinct natural functions.
y8) If, however, the Aoyos h(TapKo designated according to either one of His two natures, the respective predicates, even if concrete, must in each case be in accord with their proper subject. The reason is quite obvious. The subject in every such case is not taken formally as a person, but as a person constituted in this or that determined nature. It is correct, therefore, to say : " Jesus as God is the creator of the universe," " The Logos as man suffered and died ; " but it is false to say : " Christ as man created the world," or " Christ as God was crucified." The two last-mentioned proposi- tions require a negative particle to make them true (" Christ as God was not crucified," " Christ as man did not create the world "), though in this negative form they again become false if the apposition is removed, e. g., " The Son of God was not crucified."
y) Of abstract predicates those only can be applied to the Divine Hypostasis which connote a divine attri- bute, e. g., " Christ is the Godhead," " The man Jesus is omnipotence itself." The reason is that the Hypostasis of the Logos is really identical with the Divine Nature and all its attributes. This rule does not, however, apply to
PREDICATION OF IDIOMS 189
abstract terms that express a purely human quahty, be- cause the Godhead is not and cannot be identical with manhood. Hence it would be false to say that '' The Logos is the human nature/' or *' Christ is mortality."'
b) Predicates which deny the unity of Per- son or involve a confusion of the two natures in Christ ^ are necessarily false.
o) Any predicate which would either formally exclude the Divine Person or include a (non-existing) human person, would give rise to false and heretical inferences ; for example : '' The Son of ^Slary is not the same as the Son of the Father," or " Christ is a mere man." To this category belongs the Adoptionist thesis : " The man Jesus is not the natural, but an adopted son of God."
P) Whenever divine and human attributes are ex- pressed by means of abstract terms, these terms may not, under pain of heresy, be interchanged (e. g., " The God- head is the manhood," " Mortality is omnipotence "), be- cause abstract terms logically " suppose " the nature of a being, and the two natures in Christ are distinct and in- confused.
y) Purely human abstract terms must not be predi- cated of the Godhead,^ because the Divine Person and the human nature of Christ are in no wise identical. Hence it would be wrong to say : " The Logos is man- hood " (instead of: "The Logos is man"). This rule also applies to those concrete himian attributes which by their very nature cannot be predicated of the Divine Hypostasis, e. g., body and soul as essential components
4 The first-mentioned error is 5 The case is, of course, different
that of Nestorius, the second that with such abstract terms as denote of the Monophysites. divine attributes.
I90 UNITY IN DUALITY
of human nature. Not even during the triduum mortis would it have been correct to say : " The Son of God is a corpse," or " The Logos is a soul," because, though concrete, the terms body and soul apply solely to the human nature in its essential constituents.
8) No human concretum, and a fortiori no human abstractum, can be predicated of a divine abstractum. Hence it would be inaccurate to say : " The Godhead is the Son of Mary," or " Omnipotence was crucified," or, still worse, " Divine wisdom is passibility." There is but one exception to this rule, namely if the abstract term is employed by the speaker or writer — as it was sometimes employed by the Fathers — in lieu of a con- crete, e. g., " Deitas [=w qui habet deitatem] nata est ex Virgine." In the famous hymn attributed to St. Ambrose a concrete is substituted for an abstract term: " Tu ad liberandum suscepturus hominem [= naturam humanam s. humanitatem] non horruisti Virginis uterum."
c) Lastly, such attributes as are based on the supposi- tion that the Incarnation has not yet taken place, may be predicated of the Logos, but not of Christ. Hence it is incorrect to say : " Christ was made man," instead of : " The Son of God (or Logos) was made man." This is a rule which is often violated by catechists and preachers ; fortunately, however, disregard of it does not involve heresy.
c) Ambiguous predicates are those which, be- ing couched in indefinite terms, admit of both an orthodox and a heretical interpretation. Predi- cates of this sort have always been popular with heretics, because they afiford a comfortable hiding
SOME FAMOUS AMPHIBOLO'GIES 191
place to those who covertly attack the Catholic faith.
When such ambiguous predicates occur in the writ- ings of the Fathers the presumption is ahvays in favor of orthodoxy. Preachers, catechists, and all who write on theological subjects should, however, bear in mind that they are bound to express the Catholic doctrine in correct, unmistakable, and unequivocal terms. Thus, instead of saying : " Christ is a creature," it is pref- erable to use the phrase : " Christ according to His manhood is a creature," thus positively excluding Arian- ism. In view of Nestorianism certain expressions which were employed by the Fathers before the rise of that heresy have been officially proscribed and must now be avoided; e. g., homo deifer (av6pwTro diznnus s. dominicus (dv6pwn-o Augustine in his Retractationes recanted the phrase " homo dominicus " which he had employed in his earlier writings.^ The Council of Ephesus decreed: "Si qiiis attdeat dicere hominem Christum Theophorum, id est Deum ferentem ^ ac non potius Deum esse veraciter * dix- erit . . . anathema sit." ^
3. Some Famous Amphibologies. — In the history of Christology three phrases have become famous: (a) "Christus est servus Dei" {^vXo-i ©eov) ; (2) " Units de SS. Trinitate crucifixus est;" and (c) ^'Christus secundum hiimanitatem est omnipraesens." The first two of these locu- tions admit of an orthodox interpretation, but the
^" Nunc mallem me non dixisse." 9 Cone. Ephesin., can. 5; cfr.
1 d€o
8 Geoj' elvai Karh, aK-tiOeiav, n. 117.
192 UNITY IN DUALITY
last is inadmissible because based on the Lutheran error of Ubiquitarianism.
a) While it is true that St. Paul speaks only of the " form of a servant," ^° and nowhere directly refers to our Saviour as " servant of God," ^^ the prophet Isaias expressly described the coming Messias as nin^ nay (= servus Dei). The Adoptionists seized upon this phrase to support their false theory that, side by side with the di- vine utoTj^s, there exists in Christ a creatural Bovkua, which ceases only in virtue of a gracious vloOema or adoption on the part of God, Against this heretical teaching Pope Hadrian wrote in his decree approving the Council of Frankfort (A. D. 793) : " Adoptivum eum F ilium, quasi purum hominem, calamitati humanae suhiectum, et quod pudet dicere, serv'um eum impii et ingrati tantis beneficiis liberatorem nostrum non pertimescitis venenosd fauce susurrare, . . . etsi in umbra prophetiae dictus est servus propter servilis formae conditionem, quam sumpsit ex Virgine." ^^ This dogmatic definition clearly states under what conditions it is permissible to speak of Christ as " servus Dei." The word " servus " may be taken hypo- statically in the sense of " Hypostasis Christi est serva," in contrary opposition to " Filius naturalis Dei," who, as such, cannot be a servant of His Father, with whom He is consubstantial. In this sense the use of the term is heretical. If, however, "servus Dei" be taken sub- stantively in the sense of " Christus est servus Dei ratione naturae servae," in so far as, in His human nature. He owes obedience to the Father, of whom He Himself says :
10 " Forma servi (^fioptpii Soi)- 12 Denzinger-Bannwart, Enchiri-
11 "Servus Dei (SovXos Oeov)."
SOME FAMOUS AMPHIBOLOGIES 193
" Tlie Father is greater than I," the term is Scriptural and thoroughly orthodox.^^
b) The formula : " Unus de SS. Trinitate cruciUxus est" is also quite orthodox in itself, but was used in a heretical sense in the fifth century by Peter the Fuller, Bishop of Antioch and leader of the Theopaschitae. Peter held that the Godhead as such was crucified. In this sense the phrase was condemned by Pope Felix III (483-492). A. D. 519 the so-called Scythian monks, headed by John Maxentius, in their intemperate zeal for the purity of the faith against the Nestorians and Monophysites, vehemently demanded that the propo- sition : " One of the Trinity suffered in the flesh," be made a shibboleth of orthodoxy and incorporated into the Creed of Chalcedon. Already at Constantinople the papal legates had declared that the Creed of Ephesus and Chalcedon was sufficiently explicit against the two here- sies. August 13, 520, Pope Hormisdas wrote to Posses- sor, an African bishop resident at Constantinople, se- verely rebuking the quarrelsome spirit of the Scythian monks.^* The hesitating attitude of Pope Hormisdas towards these fanatical monks did not mean that the Church condemned the formula in question, for not long after (A. D. 553) the Fifth General Council of Constan- tinople declared that " Wlioever does not profess that our Lord Jesus Christ, who was crucified in the flesh, is true God and the Lord of glory, and one of the Blessed Trinity, let him be anathema." ^^
13 Cfr. Suarez, De Incarn., disp. minum nostrum lesum Christum, qui 44; Petavius, De Incarn., VII, 7; crucifixus est came, Deum esse ve- De Lugo, De Mysterio Incarn., disp. rum, et Dominum gloriae, et unum 28, sect. 3. de Sancta Trinitate (icai lpa r^s
14 Cfr. Bardenhewer-Shahan, Pa- ayias Tpiados)> tolis a. s." (Can. 10. trology, p. 548. apud Denzinger-Bannwart, Enchiri-
15 " Si quis non confitetur. Do- dion, n, 222). On the affair of Pope
194 UNITY IN DUALITY
That the Theopaschitae interpreted the formula in a Monophysitic sense, is evident from the fact that they added " qui crucifixus es pro nobis " to the ancient dox- ology, thereby insinuating that they believed the thrice holy Trinity, i. e., the Godhead itself, to have been cruci- fied for us. The Church has ever abhorred this Theo- paschitic heresy, as appears from the Professio Fidei Orientalibus Praescripta drawn up by Urban VIII and Benedict XIV, which says : " Per quam definitionem [Concilii Chalcedonensis] damnatur impia haeresis illo- rum, qui Trisagio ah angelis tradito et in praefata Chalce- donensi synodo decantato: ' Sanctus Deus, sanctus fortis, sanctus immortalis, miserere nobis ' addebant: ' qui cruci- fixus es pro nobis/ atque adeo divinam naturam trium per- sonarum passibilem asserebant et mortalem." ^" Even thus illegitimately expanded, the doxology could still be interpreted in an orthodox sense, provided it were under- stood as relating to Christ alone and not to the whole Trinity ; for Christ, being true God, is " holy, strong, and immortal," and " was crucified for us " in the flesh. But the Church has always regarded this hymn as a profession of faith in the Blessed Trinity.^^
c) The Lutheran doctrine of Ubiquitarianism origi- nated in a wrong application of the communicatio idioma- tum. Luther wished to defend his teaching on the Holy Eucharist against Zwingli without having recourse to the Catholic dogma of transubstantiation. He was not sat- isfied with saying, in conformity with the rules govern- ing the Communication of Idioms, that " Christ is omni- present," but falsified this true proposition by making it
Hormisdas and the Scythian monks lo Denzinger-Bannwart, Enchiri-
see H. Grisar, S. J., History of dion, n. 1463.
Rome and tlie Popes, Vol. II, pp. 17 Cfr. Is. VI, 3; Apoc. IV, 8.
302 sqq., London 191a. See Franzelin, De Verba Incarnato,
p. 348, Rome 1910.
SOME FAMOUS AMPHIBOLOGIES 195
read : " Christ, as man, i. e., according to His human nature, is omnipresent ; " nay, he went so far as to assert that " the body of Christ is omnipresent." The early Lutheran divines treated this ludicrous theory as an arti- cle of faith and expounded it with a wealth of subtle distinctions; but in process of time its absurdity became so glaringly apparent that Ubiquitarianism was gradually dropped.^*
Belief in the omnipresence of Christ's human nature, particularly His material body, is repugnant to com- mon sense and to the teaching of Revelation. Holy Scripture treats the local circumscription (ubicatio lo- calis) of the body of Christ both during His earthly pilgrimage ^^ and after His glorious Resurrection,^** as a matter of course. The mysteries of our Saviour's life which are proposed to us as articles of faith in the Apos- tles' Creed (such as, e. g.. His conception, His birth, His death, His burial, His descent into hell, His resurrection, etc.), would be utterly meaningless in the Ubiquist hy- pothesis. " Unus idemque homo" says St. Fulgentius, " localis ex homine, qui est Deus immensus ex Patre." ^^ And the Second Council of Nicaea (A. D. 787) defines: "Si qiiis Christum Deiim nostrum circumscriptum— non confitetur secundum humanitatem/^ anathema sit." ^*
Readings : — * St. Thomas, S. Theol., 3a, qu. 16, art. 1-12. — Billuart, Summa S. Thomae, Tr. de Incarnatione, diss. 16. — L. Janssens, De Deo-Homine, Vol. I, pp. 570 sqq., Friburgi 1901. —
18 Cfr. G. Esser in the Kirchen- 22 irepi'ypairT6v lexikon, 2nd ed. Vol. XII, s. v. 23 Kara rb dvOpdirtvoy,
" Ubiquitatslehre." 24 Denzinger-Bannwart, n. 30.
19 Cfr. Matth. XXVI, 11; John For a detailed refutation of Ubiq- XI, 14-21, XVI, 28. uitarianism see Bellarmine, De
20 Cfr. Matth. XXVIII, 5 sq.; Christo, 1. Ill, c. 9-20; L. Jans- Mark XVI, 6; Luke XXIV, 51; sens, De Deo-Homine, Vol. I, pp. Acts I, II, III, 21; Heb. VIII, i. 6n sqq.; Tepe, Instit. Theol., Vol.
2-LAd Trasam., II, 17. Ill, pp. 551 sqq.
196 UNITY IN DUALITY
The teaching of the Fathers is fully expounded by Petavius, De Incarnatione, IV, 15-16, and * Stentrup, Christologia, thes. 37 sqq., Oeniponte 1882. — Cfr, also Wilhelm-Scannell, A Manual of Catholic Theology, Vol. 11, pp. 108 sqq., 2nd ed., London 1901.
ARTICLE 3
THE DIVINE SONSHIP OF CHRIST AS DEFINED AGAINST ADOPTIONISM