On the Grace of Union & the Logos Assuming Flesh

“And the Word was made flesh…”

Jn. 1:14

“…and took upon Him the form of a servant, and was made in the likeness of men…”

Phil. 2:7

“For verily He took not on Him the nature of angels; but He took on Him the seed of Abraham.”

Heb. 2:16



Order of Contents

On the Grace of Union  4
On the Logos Assuming Flesh  8
On the Difference between the Assumption & the Hypostatic Union  3




It is sometimes argued that the Incarnation of Christ contradicts the unchangeability of God, for if a divine Person became a man in time, then some change must have occured in the divine Person.

Traditional Christianity, however, has held that God, by definition, is able to act on others without changing.  In the divine Logos taking to Himself a created, human nature, there is no change in his divine Person, but rather a human nature is brought into a new relation with Himself.  Hence by the Incarnation there is no change in the Divinity, but only a change in the creature.

As in every single point of theology, these things are far deeper than we realize, and in fact, are ultimately unsearchable in their depths.  Learn more about your glorious God here.



On the Grace of Union



Aquinas – Summa, pt. 3, question 2, ‘Of the Mode of Union of the Word Incarnate’

article 10, ‘Whether the union of the two natures in Christ was brought about by grace? [Yes]’

article 11, ‘Whether any merits preceded the union of the Incarnation? [No]’

This article is very much worth considering though Aquinas also speaks of Christians meriting, which part can be safely ignored.

article 12, ‘Whether the grace of union was natural to the man Christ? [in a sense, Yes]’



Owen, John

pp. 227-8  in ch. 18, ‘The Nature of the Person of Christ…’ in Christologia  in Works  (NY: Robert Carter, 1850), vol. 1

p. 28 (4.)-(5.)  in Exercitation 26  in An Exposition of the Epistle to the Hebrews…  vol. 2  ed. W.H. Goold  in Works  (Edinburgh: T&T Clark, 1862), vol. 19, Preliminary Exercitations

van Mastricht, Peter – section 11, ‘2. The grace of union in the human nature’  in Theoretical Practical Theology  (RHB), vol. 4, bk. 5, ch. 4, ‘The Person of the Mediator’



Zanchi, Jerome – On the Incarnation of the Son of God, in Two Books, in which the Whole of this Mystery is Solidly Explained...  (Heidelberg: Harnisch, 1593), bk. 2, ch. 3

Q. 11, What consequences follow from the union 332 opposite things are to be predicated of Christ 333 names of the person and natures 334 the man, not the humanity is properly called God 337 what the grace of union is 341 Chemnitz and the Book of Concord do not badly define the communication of properties 347 in that which they err 348 how and by what gifts the human nature is endowed or deified 351 by which supernatural things 353 the habits of grace and the gifts of the Spirit which are given to Christ 354 places of Scripture, so Isa. 11, ‘The Spirit of Jehovah rests upon Him…’ explained 355 Lk. 2, ‘The child increased…’ 356 in what way He advanced 357 the sayings of the Fathers are not able to be taken of the real communication of divine properties 359 whether in the soul of Christ there was faith or hope 360 or love 362 of the threefold knowledge of the soul of Christ  362 whether by uncreated wisdom He saw God 364 whether He saw the whole essence of God 366 whether He saw all that is in God 367 whether the soul of Christ maintained equality with the wisdom of the Logos, reasons for the negative 371 it is not properly omniscient 372 the objection of the Ubiquitarians 373 whether through infused knowledge He knew all things 373 whether the infused knowledge rose above the angels 375 why habitual knowledge is so-called 376 the habitual knowledge of Christ is multifold 377 the kind of the acquired knowledge of the soul of Christ 378 whether He advanced or learned from angels 379 whether and what from men he learned 380 all He learned pertains to the perfection of the human intellect 381 of the power of the human Christ 382 what power and omnipotence is 383 howsofar Christ the man is omnipotent 384 the testimony of Lombard 385 the arguments of Thomas Aquinas 387 his response to that place, ‘All power is given unto Me’ [Mt. 28:18] 390 how great is the power of Christ’s soul 391 habitual graces, so they differ from the grace of union 393 of those testimonies of the Fathers, the simile of a grain ignited, the simile of the body and soul 394 this union made Christ the perfect Mediator 399 the office of the Mediator 401 Christ is the one Head of the Church 402 of the actions of Christ 405 what are the completed effects (apotelesmata405 in the one movement [agente] there are two principles of action 407 John of Damascus contra the Monothelite arguments 408 what energy is 409 the differences of the actions 411 the completed effects (apotelesmata) are threefold 412 the soul is the principle agent 413 miracles were of the divine nature, not the human 414-16 reasons for the double actions of Christ 418 exception one, according to Apollinarius 421 Christ-incarnate worked up to this point with the Father 423 exception two of the Monophysites 425 the plurality of actions does not infer plural persons 426 the simile of an ignited sword works against the Ubiquitarians 429 other arguments for the plurality of actions in Christ 432 the cause of the error of the Monothelites 437 their arguments 441 what theandric actions are and why they are so-called 444 how the actions of one nature are common to the other nature 448,455 the words of Leo, ‘Each nature works with the other in common,’ this is rightly explained contra the Ubiquitarians 457 Christ is the natural Son as God and man 462 Mary is the God-Bearer 464 from what is the efficacy of the blood of Christ? 465

Q. 12, Of what they [Ubiquitarians] call ‘real communication’ 466 what communication is and in what ways it occurs 467 properties, essentials, naturals or personals 472, which properties may be communicated: not personal but natural ones 472 the true state of the controversy 475 Ubiquitarians concede things out of which they are convicted 477 they are Monothelites 480 they contradict themselves grossly 480 a real communication is everted, the first argument: because it is not given in Scripture 483 by what sort of sayings they seek to confirm Ubiquity 484, they are examined, so Jn. 1, ‘the Word was made flesh’ 485 the hypostatic union does not infer such a communion 488 Jn. 17, ‘Glorify Me with that glory…’ 490 the interpretation of Augustine 492 of Cyril, to glorify through the glory to be revealed 495 a twofold glorification of Christ 495 Col. 2, ‘In whom dwells all the fulness of the Deity bodily’ 497 the simile of a glowing iron 500 ‘In whom are all the treasures of wisdom…’ 502 Mt. 28, ‘All power is given unto Me’ 506 2 Cor. 10, ‘the weapons of our warfare are mighty’ 512 a certain grace of union and certain habitual grace has been given to Christ 515 Jn. 5, ‘Has given Him power to execute judgment because He is the Son of Man’ 518 places on the anointing of Christ 520 Jn. 5, ‘and I work with the Father simultaneously’ 524 Jn. 5 on the resuscitation of the dead 527, the proper life of God is not communicated to the flesh of Christ 530 multifold-life is in Christ 532 vivification is attributed to each nature, but in a diverse respect 536 Jn. 6, ‘He who eats my flesh has life’ 540 1 Jn. 1, ‘The blood of Christ cleanseth us from sins’ 542 Mt. 9, ‘But that ye may know that the Son of Man hath power to forgive sins 544 places on the exaltation of Christ, so sitting at the right hand 546 the judgment of Chemnitz 546 that sitting is unto nothing according to the Ubiquitarians 549 what sitting (the session) is, is explained out of Heb. 1 and other places 553 the judgment of John of Damascus on the sitting (session) 558 the false consequences of the Ubiquitarians shown forth 560 the inconstancy of Chemnitz & others 563 of what sort the glory of Christ was in Mt. Tabor [the mount of Transfiguration] 567 places on the vision of God and Christ, so Jn. 14, ‘Who sees me sees the Father’ 568 of the worship of the man-Christ 571 the second argument against the Ubiquitarians from the testimonies of the Fathers 576 Chemnitz alleges Fathers for himself, but perversely 578 his scope, defects and frauds 582-87 predications of Christ proper or improper 589 communion is a unity, not a real communication 592 the testimony of Leo evidenced 594 whether all given to Christ in time are given to the humanity 597 the 6th [Ecumenical] Synod and the sayings of Justin, Cyril, Athanasius, Sophronius against the Ubiquitarians 606 the Ubiquitarians badly cite the 6th Synod and its fathers, Athanasius, Euphem., Sophronius 609 the 7th Synod 612 Justin 613 of the coming in of Christ with the closed doors 618,671,716,724,729,743 Tertullian 620 Origen 621 of the simile of the glowing iron 624 the judgment of Basil on it, and why it was used by him [pp. 626-39 are repeated after p. 629] 630 the judgment of John of Damascus on this simile 638 the judgments of Athanasius and Cyril on the same 640 the saying of Esuebius of Caesarea 647 a man so is said to have been deified 652,694 Athanasius to Arius (and in another place he condemns the Ubiquitarians) does not support 656663 Eustath. 668 Hippolytus 669 Amphiloch. 670 Cyprian 671 Hilary on the glory of Christ, Jn. 17 674 Emisen., Didymus, Gregroy of Nyssa 689 Basil 691 Gregory of Nazianzen 693 Epiphanius 698 is opposed to the Ubiquitarians [after p. 707, pp. 704-07 are repeated] 709 the heresies of the Dimaeritites on ubiquity 710 Ambrose is the enemy of ubiquity 710 Jerome 716 Augustine 719 Chrysostom and Theophylact 725,729 Ecumenius and Aretius 727 Cyril opposes the ubiquitarians and is explained [after p. 729, pp. 716-29 repeats] 730 Paul Emisen 766 Theodoret 768 Primas. 776 Leo the Great 778 Vigilius 786 Cassiodorus 787 Sedulius, Nicephorus 788 the Golden Chain 788 Severian. 788 the Agnoets which were 789 Gregory the Great 789 Bernard 790 John of Damascus is examined 791 the third argument: a real communication fights with the Scriptures, it is proved by multiple testimonies, so on the union 811 of the properties of the natures, of actions 819 of the passion 822 the fourth argument is from the consensus of the Fathers against a real communication 828 proofs out of the 6th Synod 828 by Justin, Tertullian, Origen, Basil, Cyril 829 Eusebius, Athanasius 830 Ambrose 834 Cyril 834 Theodoret 837 Leo 838 Vigil 842 John Damascus 844 Fulgentio 855 Ignatius 862 Irenaeus 863 Clement of Alexandria, Severian, Eustathio 864 Epiphanius 865-75 Gregory Nazianzen, Gregory Nyssa, Didymus of Alexandria, Jerome, Cassiodorus, Gregory, Niceta, Bede, Gelasius, Justin, Lombard, Thomas, Bonaventura



On the Logos Assuming Flesh, or on the Assumption



Aquinas – Summa, pt. 3

question 2, ‘Of the Mode of Union of the Word Incarnate’

article 7, ‘Whether the union itself is something created? [Yes]’

question 7, ‘Of the Grace of Christ as an Individual Man’

article 13, ‘Whether the habitual grace of Christ followed after the union? [Yes]’



Owen, John – pp. 224-26  in ch. 18, ‘The Nature of the Person of Christ…’  in Christologia  in Works  (NY: Robert Carter, 1850), vol. 1

Turretin, Francis – Question 6, ‘Did the Son of God assume human nature into the unity of his person?  We affirm against the Socinians’  in Institutes of Elenctic Theology  ed. James Dennison, Jr.  (P&R), vol. 2, 13th Topic, pp. 310-17

van Mastricht, Peter – Theoretical Practical Theology  (RHB), vol. 4, bk. 5

ch. 4, ‘The Person of the Mediator’

Exegetical Part, section 2, C

Dogmatic Part

section 3, ‘There are two natures in the one person of the Mediator’
section 7, ‘Regarding the hypostatic union, these are explained: 1. Its nature’
section 8, ‘The uniting is explained, with respect to:’, ‘Assumption’
section 9, ‘This uniting does not argue:’, ‘2. Nor does this assumption imply any change in the one assuming.’

Practical Part

section 32, ‘5. It excites in us a just concern’, ‘Signs’
section 33, ‘6. It dissuades from various abuses. What they are’

ch. 9, ‘The Humiliation of the Mediator’

Exegetical Part, section 2, 2.a



Dolezal, James – ’Neither Subtraction, Nor Addition: The Word’s Terminative Assumption of a Human Nature’  Nova et Vetera, vol. 20, no. 1  (Winter, 2022)  23 pp.

Dolezal has written numerous works on divine simplicity, and has been a reformed baptist pastor as well as a professor of Church history, Trinitarian theology and philosophy.

“This accusation [of incoherency against classical theism] is plausible so long as one is compelled to hold either that the divine Word subtracted something from Himself in assuming a human nature or added something to Himself.  But contrary to widespread recent opinion, subtraction and addition are not the only options.

Thomas Aquinas, among others, repudiates both these approaches, expounding instead a doctrine of terminative assumption.  Termination eludes the liabilities of subtraction and addition by requiring neither privation of being nor passive potency in the divine Word in order to account for his becoming man.”

Those who have held to the incarnation of Christ by way of subtraction of certain attributes of his deity, are known at kenotists, holding to kenosis, which is heresy.  Those seeking to uphold orthodoxy have often upheld an incarnation by way of addition.  Dolezal, with some reformed orthodox support, argues against, at least, a certain form of metaphysical addition.  However, in appearing to exclude and disaprove of all language of addition, we do not believe he is wise.

He follows Aquinas in particular in arguing for another option, that of a terminative assumption:

Since drawing to oneself, and thereby supplying subsistence to that which is drawn, necessitates neither divestment nor augmentation, the Word does not subtract or add anything to himself in his assumption of a human nature and so requires no privation of being or passive potency in order to become flesh.  Such are the fundamental claims of terminative assumption.”

Towards the end of the article, in making his concluding arguments, he follows, explicitly and only, Neo-Thomists.  The most helpful illustrations he provides (borrowed from Garrigou-Lagrange, a Neo-Thomist) are in that section, of a point terminating a line segment, and of an object terminating a line of sight.

Two criticisms are able to made of this article:

1. Dolezal defines “addition” very specifically according to one, and only one, metaphysical meaning, namely the divine essence being added to, as an essence, in the assumption.  This he (rightly) denies, but in doing so he seemingly, therefore, considers all language of addition with regard to the assumption to be illicit.

Peter van Mastricht is only one example of a major reformed orthodox theologian who was comfortable using the language of addition in a different sense with respect to the assumption (TPT, vol. 4, ch. 4, section 16).  What possibly could be a strict, metaphysical, definition for “addition” being appropriate to the assumption?  David Tamisiea explains from Thomas Aquinas in this article: ‘St. Thomas Aquinas on the One ‘Esse’ of Christ’  Angelicum, vol. 88, no. 2 (2011), pp. 383-402.

2. Near the end of Dolezal’s article, in support of his thesis, he quotes the Romanist, Neo-Thomist, Garrigou-Lagrange approvingly, saying that:

“Assumption is properly an action by which the human nature is drawn into the subsistence of the Son, so that it may subsist by his subsistence.  Hence this action not only produces in the human nature of Christ a relation of dependence on the Word, but communicates to it the personality of the

It is no accident that Dolezal only quotes a Romanist to support this view of his, because the dominant view of the reformed orthodox, contra the Romanists and Lutherans, was that, while the Assumption is terminative in nature in a certain sense, yet the personality, or subsistence (or hypostasis), of the Word is not properly communicated to the human nature.  See this documented on these sections on our page, ‘On the Person & Human & Divine Natures of Christ’:

‘On the Son of God Assuming an Impersonal Human Nature, & on Subsisting’

‘That Christ’s Personality was Not Properly Communicated to the Human Nature’




Zanchi, Jerome – in On the Incarnation of the Son of God…  (Heidelberg: Harnisch, 1593), bk. 2, ‘Heresies on the Incarnation of Christ are Refuted’, ch. 3

Q. 7, Of the order of the assumption 181 the conception was made in the virgin with consent [or knowingly] 182 Christ assumed to Himself a soul and a body simultaneously, but a soul immediately 184

Q. 8, Of the perfection of assuming the living body 188 it was not formed gradually 189 a twofold union of the Word and of the human nature (soul and body) was in Christ 191 the union of the soul and body proved 193

Q. 9, Of the mode of union 194 the collation of the union of the three persons of the Deity and of the two natures of Christ 195 the explication of the apostles of the mode 196 the Fathers are brought to more accurately explain from the heretics 199 what the union is, and how it is twofold, out of Nyssa, Bernard and Thomas 199 the dogma of Nestorius is refuted, that the union made was by inhabiting, assisting, affection, dignity, grace 203 the union made was not by conversion or comixture, contra Apollinarus, Eutyches, Dioscorus 208 the 6 reasons of John Damascus 211 the cause of the errors of Nestorius, Eutyches and the Ubiquitarians, that He is a quasi-person with the same natures 215 the whole Christ and the whole of Christ are distinguished by the Fathers 216,223 5 other arguments against Eutyches 216-17 the objections of Eutyches 220 of the simile of the human body and soul and of the natures of Christ, how far it ought to be used 222 how far the person of Christ may be said to be composit 224 of the worship of the human Christ 226 of the double will and double operating faculty of Christ contra Macarius and the Monothelites 232 the Ubiquitists are Monothelites 233 the arguments of John of Damascus against the Monothelites 234,247 the distinction of actions & properties does not divide the union 240-44 the will and energy is taken for the power or for the act 244 autotheleton [self-willing] was in Christ 245 as well as a human will besides the divine will 247 nor was one will conflated from the divine and human 250 objections of the Monothelites 254 the Paulicians are refuted 256 two other false opinions on the union 257 Christ put on flesh, but not simply as clothes 261,265 the simile of flesh and clothes explained 262 the union was not made by the mode of an accident 268 objections to the contrary are solved 270 the error of Brentius [a Lutheran] 272 the true judgment of the mode of the union 273 to assume into the unity of the person, what it means 275 the union was made atreptos (unchangeably), adiairetos (indivisibly), asugkutosousiodos 277-78 this is proved out of Phil. 2 280 and other places of Scripture on the Incarnation, as John 1, Heb. 2 & Col. 2 286 in what way the whole fulness of Deity is in Christ bodily 293 Col. 2 is explicated out of the Greek scholastics 295 the saying of Ecumenius that He fills all with the flesh is in no way for the Ubiquitarians 296 the creed of Chalcedon proves this mode of union and refutes the Ubiquitarians 297 the testimony of John of Damascus 300 Adiastatos [without division] what it means, contra Chemnitz 302 the testimony of Justin 303 the simile of the union of the soul with the body explained and accommodated 305 how insofar it is dissimilar 307 the impudence of the Ubiquitarians 308 the simile of Justin and others of primal light, the same of Emperor Justinian, Boethius, Cassian, Gelasius, [Pope] Vigilius, Fulgentius, Rusticus, Maxentius, of the Roman Church, of Lombard and the testimony of the scholastics 310 of Thomas Aquinas 315



Polanus, Amandus – ch. 15, ‘On the Assumption of the Human Nature’  in A System of Theology  (Hanau, 1609; 1615), vol. 2, cols. 2366-2416

Voet, Gisbert – I. ‘Of the Person of Christ the Mediator’  in Tract 2, ‘Of the Person, Offices & States of Christ the Mediator’ in A Syllabus of Theological Problems…  (Utrecht, 1643)  no page numbers  Abbreviations

Table of Contents
I. Of the Person of Christ the Mediator

1. Of the Assumption & Union of the Human Nature

Of the Person Assuming
Of the Human Nature Assumed
Of the Mode of the Assumption, as far as the Order

Buxtorf, Johann – The First Theological Disputation, on the Form of the Personal Union of the Son of God with an Assumed Human Nature  (Basil, 1657)  12 pp.

Buxtorf (1599-1664).  Buxtorf defines the reformed view of personal sustentation on p. 11, with that of the Lutherans following.  At the end Buxtorf says he will treat the Lutheran view in another disputation shortly following, which is here.



On the Difference Between the Assumption & the Hypostatic Union


James Dolezal

’Neither Subtraction, Nor Addition: The Word’s Terminative Assumption of a Human Nature’  Nova et Vetera, vol. 20, no. 1  (Winter, 2022), fn. 10.

“It should be noted that assumption and hypostatic union are not the same thing.  Assumption speaks of the action in the agent assuming and the passion in the patient assumed.  Union implies the relationship that follows from this. To be united may be said equally of the divine and human natures in the incarnate Word; but to assume actively is said only of the Word’s divine nature, and to be assumed is said only of the human nature.  It cannot be said of the Word’s divinity that it is assumed, though it can be said that it is united.

Thus, assumption and hypostatic union do not have the same meaning.  Assumption, considered actively and passively, is what establishes the hypostatic union as a consequence.”



Aquinas – Summa, pt. 3, question 2, ‘Of the Mode of Union of the Word Incarnate’, article 8, ‘Whether Union is the Same as Assumption?’

Owen, John – pp. 225 (bot) – 226  in ch. 18, ‘The Nature of the Person of Christ…’  in Christologia  in Works  (NY: Robert Carter, 1850), vol. 1



Martinius, Matthew –  VII, ‘In what way to unite and to assume differ’, p. 578  in pt. 1, tract 1, ch. 11, The doctrine of the personal union of two natures in Christ, collected in 20 theses, is explained’  in A Theology on the Singular Person of our Lord Jesus Christ in Two Natures…  (Bremen, 1614)




Related Pages

On the Person & Human & Divine Natures of Christ

The Trinity

On Divine Simplicity


On the Communication of the Properties of Christ’s Natures

The Grounds of Christ the Mediator Receiving Divine Worship

On the Doctrine of Appropriations

Images of Christ