36. The Hypostatic Union
8. Jesus Christ: True God and True Man
Up to this point, we have been dealing with the two natures of Jesus Christ: the human and the divine. Let us see now how these two natures are united in the Person of the Word. The union of the human nature and the divine nature in the Person of the Word is called hypostatic union, which is the same as “union in the Person” because hypostasis means “person” in Greek. We will see how this union comes about in the Person of the Word, and how his human nature (body and soul) is substantially assumed in the Person of the Word.1
8a) The Doctrine of the Church
Christ’s human and divine natures are hypostatically united in the unity of the divine Person (de fide).
Church dogma states that in Jesus Christ, there is only one divine Person (that of the Son of God) and two natures (divine and human) subsisting in the one divine Person of the Son. The human nature is united to the divine nature in the Person of the Word.
In a.d. 431, the Council of Ephesus defined that the two natures of Christ (divine and human) are united in one divine Person: “Christ … is both God and man”2; “The Holy Virgin is, therefore, Mother of God, for she gave birth in the flesh to the Word of God made flesh.”3
In a.d. 451, the Council of Chalcedon defined, “We all with one accord teach the profession of faith in the one identical Son, our Lord Jesus Christ. We declare that he is perfect both in his divinity and in his humanity, truly God and truly man.… The one selfsame Christ, only-begotten Son and Lord, must be acknowledged in two natures without any commingling or change or division or separation; that the distinction between the natures is in no way removed by their union but rather that the specific character of each nature is preserved and they are united in one person and one hypostasis … not split or divided into two persons, but that there is one selfsame only-begotten Son, God the Word, the Lord Jesus Christ.”4 The hypostatic union defined by the Council of Chalcedon is real and subsistent, not accidental. It is physical, not moral.
Paul VI reaffirms this in the Creed of the People of God: “We believe in our Lord Jesus Christ, the Son of God. He is the eternal Word, born of the Father before all time, and consubstantial to the Father; through whom all things were made. And he took flesh of Mary the Virgin by the work of the Holy Spirit, and was made man. [He is] equal, therefore, to the Father in his divinity, less than the Father in his humanity; completely one, not by confusion of the substance (which cannot be done), but by the unity of the person.”
Sacred Scripture reveals the hypostatic union, that is, the union of Jesus Christ’s two natures (human and divine) in one and only one divine Person. The operations proper to human nature and the operations belonging to the divine nature are attributed to the same Person, Jesus Christ. What is human (cf. Jn 4:6) is found next to that which is divine: “Before Abraham was, I am” (Jn 8:58). When St. John says, “the Word became flesh” (Jn 1:14), he indicates that God, without ceasing to be God, was made man.
The Fathers of the Church have always attributed divine as well as human actions to the one Person of Christ and have rejected any doctrine that supposes the existence of two persons in Jesus Christ. If there were two persons in Christ, the Incarnation would not have taken place, but only an indwelling of God in a man.
Besides, if it were only a human person who had suffered and died on the cross, the Passion of Jesus would not have infinite value, and, if Christ were a mere man, his Real Presence in the Eucharist would not be a foretaste of eternal life.
The cause of many misunderstandings and disputes about the one Person of Christ was actually a matter of terminology, since some of the Greek words that the Fathers of the Church employed were interpreted in several ways.
Some early Fathers referred to “person” as physis, while others referred to it as hypostasis. “Nature,” on the other hand, was always called physis. In saying that there are two physeis in Jesus Christ, some mistakenly thought that there were two persons in Jesus instead of two natures. Use of these terms became better defined in the course of time; hypostasis came to refer always to person, and physis to nature.
8b) Errors Regarding the Hypostatic Union
The Church had to fight some heresies regarding the one divine Person of Jesus Christ. In a.d. 428, Nestorius wrongly claimed that there were two persons in Jesus Christ: the divine (the Son of God) and the human (the son of Mary). If this were true, the Virgin would not have been Mother of God, but only mother of Christ as man. These two persons would have been only morally united. Consequently, the Redemption (Passion and death of Jesus) would be proper only to the human person of Christ. These teachings were condemned by the Council of Ephesus in a.d. 431.
At the other extreme, Eutiches and his followers (who were named the monophysites) falsely taught that there was only one person and only one nature in Jesus Christ (monophysis means only one person and only one nature). They affirmed that the human nature of Christ was either transformed or absorbed by the divine nature. In the same vein, others believed in a certain fusion or confusion of the two natures that gave rise to a third nature. The monophysite error of Eutiches was condemned in the Council of Chalcedon in a.d. 451.5
9. The Hypostatic Union on the Part of the Assuming Person
9a) Only the Word Became Man
Only the Second Person of the Most Blessed Trinity was made man (de fide).
This truth is affirmed by all the symbols and definitions of the faith of the Church.
Reason enlightened by faith can explain why it was appropriate for the Second Person of the Trinity, the Word of God, to be the only one incarnated. We know that God created the world through his Word, which is the model (exemplary cause) of the entire universe. The sin of Adam and Eve introduced disorder into the world that God had created. God, in turn, promised a Redeemer. Now, an artist, when a work of his is destroyed, will restore it according to the model he used to make it. Therefore, it was quite fitting for the Word, the Second Person of the Trinity and model of creation, to be the Redeemer who would restore the human race to the original harmony that was destroyed by the sin of Adam.
9b) The Whole Trinity Caused the Incarnation
The hypostatic union was a common work of the three divine Persons (de fide).
In the Incarnation, one has to distinguish between the act of the Incarnation (or active Incarnation, which is an action originating in the divine nature and is therefore common to the three Persons of the Trinity) and the terminus of the Incarnation (or passive Incarnation, which is exclusive to the Second Person of the Trinity). In short, all three Persons took part in the Incarnation, but only the Second Person was incarnated.
The faith of the Church, as defined in the Fourth Lateran Council, states, “The Only-Begotten Son of God, Jesus Christ, [was] made incarnate by a common action of the Holy Trinity.”6
Divine revelation testifies to the fact that the act of Incarnation is proper to the three divine Persons, attributing it sometimes to the Father, at other times to the Son himself, and sometimes to the Holy Spirit (cf. Phil 2:7; Lk 1:35).
Sacred Tradition attests to the same teaching. St. Augustine wrote, “The fact that Mary conceives and gives birth is the work of the Trinity, by whose creative ability are all things made.”7
The reason behind this truth is that all operations ad extra (i.e., outward) of God are necessarily common to the three divine Persons.
10. The Hypostatic Union on the Part of the Assumed Human Nature
The Son of God assumed all and each of the parts that belong to the essence and integrity of human nature (sent. comm.).
The Son of God not only entirely assumed human nature, he also directly assumed each of its components. He directly assumed a rational soul. If this were not the case, he would not have been true man, as we have established. With his soul, he also assumed a body. He assumed blood, a part of the body. Thus, its shedding brings about our Redemption. Precisely because the Son of God assumed each of the parts of human nature, the Council of Trent taught that the body, blood, soul, and divinity of Jesus Christ is contained under each of the sacramental species of the Eucharist.8
11. Beginning and Duration of the Hypostatic Union
11a) The Beginning of the Hypostatic Union
The hypostatic union of the human nature of Christ with the Person of the divine Word took place at the instant of Christ’s conception (de fide).
The symbols of the faith teach us that “[Christ] was conceived by the Holy Spirit, and born of the Virgin Mary.”
Holy Scripture testifies, “God sent forth his Son, born of a woman” (Gal 4:4).
St. Augustine wrote, “From the moment in which he began to be a man, he is also God.”9
11b) The Continuity of the Hypostatic Union
The hypostatic union was never interrupted (sent. fidei prox.).
The definition of the Council of Chalcedon states that “Christ, only-begotten Son and Lord, must be acknowledged in two natures without any commingling or change or division or separation.”10 The symbols of the faith teach that the Son of God suffered, died, was buried, descended into hell, and resurrected. That is to say, Jesus Christ is always God and man, never losing the hypostatic union.
The text, “My God, my God, why hast thou forsaken me?” (Mt 27:46) should not be understood as an interruption of the hypostatic union, but as a lack of external protection against those who persecuted Jesus. The question could also have been a way of showing that, at that time, the Messianic prophecies of Psalm 22 were being fulfilled. The psalm starts with the same words and continues with a detailed description of the Passion: “They have pierced my hands and feet … They divide my garments among them, and for my raiment they cast lots” (Ps 22:16, 18).
11c) The Eternity of the Hypostatic Union
The hypostatic union will never cease (de fide).
In a.d. 381, the Council of Constantinople taught, “His Reign will have no end.”11
Sacred Scripture attests to the same truth: “[Jesus Christ] will reign over the house of Jacob for ever, and of his kingdom there will be no end” (Lk 1:33). “He holds his priesthood permanently” (Heb 7:24).
St. Cyril of Jerusalem wrote, “If at any time you hear that the kingdom of God has an end, abhor this heresy.”12
Footnotes:
1. Cf. CCC, 470–474.
2. DS 253, 257.
3. DS 252.
4. DS 301.
5. Cf. CCC, 466–468.
6. DS 801.
7. St. Augustine, De Trin., 2.5.9.
8. Cf. DS 1640–1641.
9. St. Augustine, De Trin., 12.17.22.
10. DS 301.
11. DS 86.
12. St. Cyril of Jerusalem, Cat. 15.25.
Up to this point, we have been dealing with the two natures of Jesus Christ: the human and the divine. Let us see now how these two natures are united in the Person of the Word. The union of the human nature and the divine nature in the Person of the Word is called hypostatic union, which is the same as “union in the Person” because hypostasis means “person” in Greek. We will see how this union comes about in the Person of the Word, and how his human nature (body and soul) is substantially assumed in the Person of the Word.1
8a) The Doctrine of the Church
Christ’s human and divine natures are hypostatically united in the unity of the divine Person (de fide).
Church dogma states that in Jesus Christ, there is only one divine Person (that of the Son of God) and two natures (divine and human) subsisting in the one divine Person of the Son. The human nature is united to the divine nature in the Person of the Word.
In a.d. 431, the Council of Ephesus defined that the two natures of Christ (divine and human) are united in one divine Person: “Christ … is both God and man”2; “The Holy Virgin is, therefore, Mother of God, for she gave birth in the flesh to the Word of God made flesh.”3
In a.d. 451, the Council of Chalcedon defined, “We all with one accord teach the profession of faith in the one identical Son, our Lord Jesus Christ. We declare that he is perfect both in his divinity and in his humanity, truly God and truly man.… The one selfsame Christ, only-begotten Son and Lord, must be acknowledged in two natures without any commingling or change or division or separation; that the distinction between the natures is in no way removed by their union but rather that the specific character of each nature is preserved and they are united in one person and one hypostasis … not split or divided into two persons, but that there is one selfsame only-begotten Son, God the Word, the Lord Jesus Christ.”4 The hypostatic union defined by the Council of Chalcedon is real and subsistent, not accidental. It is physical, not moral.
Paul VI reaffirms this in the Creed of the People of God: “We believe in our Lord Jesus Christ, the Son of God. He is the eternal Word, born of the Father before all time, and consubstantial to the Father; through whom all things were made. And he took flesh of Mary the Virgin by the work of the Holy Spirit, and was made man. [He is] equal, therefore, to the Father in his divinity, less than the Father in his humanity; completely one, not by confusion of the substance (which cannot be done), but by the unity of the person.”
Sacred Scripture reveals the hypostatic union, that is, the union of Jesus Christ’s two natures (human and divine) in one and only one divine Person. The operations proper to human nature and the operations belonging to the divine nature are attributed to the same Person, Jesus Christ. What is human (cf. Jn 4:6) is found next to that which is divine: “Before Abraham was, I am” (Jn 8:58). When St. John says, “the Word became flesh” (Jn 1:14), he indicates that God, without ceasing to be God, was made man.
The Fathers of the Church have always attributed divine as well as human actions to the one Person of Christ and have rejected any doctrine that supposes the existence of two persons in Jesus Christ. If there were two persons in Christ, the Incarnation would not have taken place, but only an indwelling of God in a man.
Besides, if it were only a human person who had suffered and died on the cross, the Passion of Jesus would not have infinite value, and, if Christ were a mere man, his Real Presence in the Eucharist would not be a foretaste of eternal life.
The cause of many misunderstandings and disputes about the one Person of Christ was actually a matter of terminology, since some of the Greek words that the Fathers of the Church employed were interpreted in several ways.
Some early Fathers referred to “person” as physis, while others referred to it as hypostasis. “Nature,” on the other hand, was always called physis. In saying that there are two physeis in Jesus Christ, some mistakenly thought that there were two persons in Jesus instead of two natures. Use of these terms became better defined in the course of time; hypostasis came to refer always to person, and physis to nature.
8b) Errors Regarding the Hypostatic Union
The Church had to fight some heresies regarding the one divine Person of Jesus Christ. In a.d. 428, Nestorius wrongly claimed that there were two persons in Jesus Christ: the divine (the Son of God) and the human (the son of Mary). If this were true, the Virgin would not have been Mother of God, but only mother of Christ as man. These two persons would have been only morally united. Consequently, the Redemption (Passion and death of Jesus) would be proper only to the human person of Christ. These teachings were condemned by the Council of Ephesus in a.d. 431.
At the other extreme, Eutiches and his followers (who were named the monophysites) falsely taught that there was only one person and only one nature in Jesus Christ (monophysis means only one person and only one nature). They affirmed that the human nature of Christ was either transformed or absorbed by the divine nature. In the same vein, others believed in a certain fusion or confusion of the two natures that gave rise to a third nature. The monophysite error of Eutiches was condemned in the Council of Chalcedon in a.d. 451.5
9. The Hypostatic Union on the Part of the Assuming Person
9a) Only the Word Became Man
Only the Second Person of the Most Blessed Trinity was made man (de fide).
This truth is affirmed by all the symbols and definitions of the faith of the Church.
Reason enlightened by faith can explain why it was appropriate for the Second Person of the Trinity, the Word of God, to be the only one incarnated. We know that God created the world through his Word, which is the model (exemplary cause) of the entire universe. The sin of Adam and Eve introduced disorder into the world that God had created. God, in turn, promised a Redeemer. Now, an artist, when a work of his is destroyed, will restore it according to the model he used to make it. Therefore, it was quite fitting for the Word, the Second Person of the Trinity and model of creation, to be the Redeemer who would restore the human race to the original harmony that was destroyed by the sin of Adam.
9b) The Whole Trinity Caused the Incarnation
The hypostatic union was a common work of the three divine Persons (de fide).
In the Incarnation, one has to distinguish between the act of the Incarnation (or active Incarnation, which is an action originating in the divine nature and is therefore common to the three Persons of the Trinity) and the terminus of the Incarnation (or passive Incarnation, which is exclusive to the Second Person of the Trinity). In short, all three Persons took part in the Incarnation, but only the Second Person was incarnated.
The faith of the Church, as defined in the Fourth Lateran Council, states, “The Only-Begotten Son of God, Jesus Christ, [was] made incarnate by a common action of the Holy Trinity.”6
Divine revelation testifies to the fact that the act of Incarnation is proper to the three divine Persons, attributing it sometimes to the Father, at other times to the Son himself, and sometimes to the Holy Spirit (cf. Phil 2:7; Lk 1:35).
Sacred Tradition attests to the same teaching. St. Augustine wrote, “The fact that Mary conceives and gives birth is the work of the Trinity, by whose creative ability are all things made.”7
The reason behind this truth is that all operations ad extra (i.e., outward) of God are necessarily common to the three divine Persons.
10. The Hypostatic Union on the Part of the Assumed Human Nature
The Son of God assumed all and each of the parts that belong to the essence and integrity of human nature (sent. comm.).
The Son of God not only entirely assumed human nature, he also directly assumed each of its components. He directly assumed a rational soul. If this were not the case, he would not have been true man, as we have established. With his soul, he also assumed a body. He assumed blood, a part of the body. Thus, its shedding brings about our Redemption. Precisely because the Son of God assumed each of the parts of human nature, the Council of Trent taught that the body, blood, soul, and divinity of Jesus Christ is contained under each of the sacramental species of the Eucharist.8
11. Beginning and Duration of the Hypostatic Union
11a) The Beginning of the Hypostatic Union
The hypostatic union of the human nature of Christ with the Person of the divine Word took place at the instant of Christ’s conception (de fide).
The symbols of the faith teach us that “[Christ] was conceived by the Holy Spirit, and born of the Virgin Mary.”
Holy Scripture testifies, “God sent forth his Son, born of a woman” (Gal 4:4).
St. Augustine wrote, “From the moment in which he began to be a man, he is also God.”9
11b) The Continuity of the Hypostatic Union
The hypostatic union was never interrupted (sent. fidei prox.).
The definition of the Council of Chalcedon states that “Christ, only-begotten Son and Lord, must be acknowledged in two natures without any commingling or change or division or separation.”10 The symbols of the faith teach that the Son of God suffered, died, was buried, descended into hell, and resurrected. That is to say, Jesus Christ is always God and man, never losing the hypostatic union.
The text, “My God, my God, why hast thou forsaken me?” (Mt 27:46) should not be understood as an interruption of the hypostatic union, but as a lack of external protection against those who persecuted Jesus. The question could also have been a way of showing that, at that time, the Messianic prophecies of Psalm 22 were being fulfilled. The psalm starts with the same words and continues with a detailed description of the Passion: “They have pierced my hands and feet … They divide my garments among them, and for my raiment they cast lots” (Ps 22:16, 18).
11c) The Eternity of the Hypostatic Union
The hypostatic union will never cease (de fide).
In a.d. 381, the Council of Constantinople taught, “His Reign will have no end.”11
Sacred Scripture attests to the same truth: “[Jesus Christ] will reign over the house of Jacob for ever, and of his kingdom there will be no end” (Lk 1:33). “He holds his priesthood permanently” (Heb 7:24).
St. Cyril of Jerusalem wrote, “If at any time you hear that the kingdom of God has an end, abhor this heresy.”12
Footnotes:
1. Cf. CCC, 470–474.
2. DS 253, 257.
3. DS 252.
4. DS 301.
5. Cf. CCC, 466–468.
6. DS 801.
7. St. Augustine, De Trin., 2.5.9.
8. Cf. DS 1640–1641.
9. St. Augustine, De Trin., 12.17.22.
10. DS 301.
11. DS 86.
12. St. Cyril of Jerusalem, Cat. 15.25.