"The good of the grace of one soul is greater than the good of the nature of the whole universe"
- St Thomas Aquinas Ia IIa, q.24, a. 3, ad 2

— A Commentary on the Third Part of St Thomas' Theological Summa

by Reginald Garrigou-Lagrange, O. P.


Second Article: Whether The Union Of The Incarnate Word Took Place In The Person

State of the question. The meaning is: whether this union took place in such manner that there is only one person.

In this article we have the refutation of Nestorianism, a heresy that denied there was only one person in Christ, and that admitted only a moral union such as found in saints united by love with God.

The first two difficulties posited at the beginning of this article, are arguments raised by the Nestorians.

First difficulty. In God there is no real distinction between person and nature. If, therefore, this union did not take place in the nature, as the Nestorians say, then it did not take place in the person.

Second difficulty. Personality is a dignity that belongs to us as human beings. Hence it is not attributed to irrational animals or to other beings of a lower order, for these have individuality, but not personality. But Christ's human nature has no less dignity than ours. Therefore it was much more reasonable that Christ's human nature should have its own personality.

This difficulty is still proposed in our days by many theologians who disagree with Cajetan's interpretation of St. Thomas' teaching. These theologians, as we shall see, in advancing this difficulty against Cajetan, seem to be unaware of the reply to the second objection of this present article.

Third difficulty. It is taken from the definition of person as given by Boethius, who says: "a person is an individual substance of a rational nature." But the Word of God assumed an individual human nature, namely, this humanity belonging to Christ. Therefore this humanity belonging to Christ has its own personality.

This difficulty of necessity calls for the making of a profound distinction between individuality, or individuation, and personality. St. Thomas most fittingly makes this kind of distinction in his reply to the third objection, which is thoroughly explained by Cajetan. Nevertheless, even many Scholastics seem to have only a superficial knowledge of this reply to the third objection, perhaps because they did not begin by examining with sufficient care the state and difficulty of the question, as St. Thomas did in his presentation of these difficulties, which constitute, so to speak, the very problem to be solved in this article.

The reply, in spite of these difficulties, is: The union of the Word incarnate took place in the person of the Word, such that there is only one person in Christ. This declaration is a dogma of our faith.

This reply was defined against the Nestorians in the Council of Ephesus, in which the union was declared to be hypostatic, or personal,[417] and it condemned the assertion of two persons morally united in Christ. It likewise condemned the Nestorian expression, Christ the man is theophoron, that is, God bearer.[418] Likewise it declared that, "if anyone does not confess that the Word of God suffered and died in the flesh, let him be anathema."[419] It also defined that the Blessed Virgin Mary is the Mother of God,[420] since she is the mother of this man Jesus who is God, constituting one person.[421]

These definitions are confirmed in the Council of Chalcedon, which says: "One and the same Christ... acknowledged to be in two natures, without confusion... and concurring in one person and one hypostasis, not in something that is parted or divided."[422]

Similarly the Apostles' Creed confesses that one and the same person is the Son of God and of man; particularly the Creed of St. Athanasius, which says of the union, "absolutely one, not in confusion of substance, but in unity of person."[423]

Sacred Scripture. This doctrine of the faith is already clearly expressed in the New Testament; for it attributes the properties of both the divine and the human natures to one and the same Christ, since it is the same Christ who is conceived, born, baptized in the Jordan, who fears, is sad, hungry and tired on His journey, who suffers and dies on the cross. This same person is called the Son of God, God above all, the Author of life, for He Himself says: "I am the truth and the life."[424] Hence we see that the properties of each nature are attributed in Sacred Scripture to the same intelligent and incommunicable subject, that is, to the same person. But this person is the eternal person of the Word, as expressed by the Evangelist in these words: "The Word was made flesh,"[425] that is, the Son of God became man. Therefore the Son of God and man are not two persons, but one person.

The common notion of person suffices for an understanding of the preceding statements, namely, that a person is an intelligent and sui juris[426] or free agent. This subject can be merely a man, an angel, God, or any divine person.

Nestorius objected that a moral union was sufficient.

Reply. A moral union is established by means of affection. But, however intimate is the friendship between two persons, one friend is not said to have become the other friend, neither is a saint who is united with God by a bond of most fervent love said to have become God, nor is God said to have become either Peter or Paul, although there is a moral union between them and God.

In fact, Christ could not have said truthfully: "I am the way, the truth, and the life."[427] In other words, speaking of Himself, He could not have attributed truly to Himself divine attributes and also those that belong to the human nature. The pronoun "I" denotes the person speaking, and there is only one person; for if there are two persons? it cannot be said that one is the other. In affirmative judgments, the verb "is" expresses real identity between subject and predicate. Thus: I am the truth, signifies: I, who by my mouth, am speaking, am the same person who am the truth. Otherwise the judgment is absolutely false, and it is as if Paul were to say: I, who am Paul, am Peter.

Testimony of the Fathers.[428] Tertullian, Origen, St. Ephrem, St. Athanasius, St. Gregory Nazianzen, St. Jerome, St. Cyril of Alexandria, St. Leo I, and St. John Damascene quoted by St. Thomas in the counter-argument of this third article have all affirmed clearly and most explicitly that there is one person in Christ.

It must be noted that in the liturgy of the Church the termination of the orations frequently is, "Through our Lord Jesus Christ who liveth and reigneth with Thee in the unity of the Holy Ghost, forever and ever."

Body of the article. It contains two parts. In the first part a distinction is made between person and nature. The second part proves that the union of the Word incarnate took place in the person.

First of all the article must be explained, and then we shall consider the erroneous system of several modern philosophers concerning personality, and also the systems freely discussed among Catholic theologians.

In the first part of this article, as regards the distinction that is made between person and nature, by a gradual process the argument proceeds from common sense or natural reasoning, to the establishment of a philosophical proof that acknowledges and defends the real validity of natural reasoning against either empiric or idealistic phenomenalism.

The first part of this article must be read. It is divided into three parts: 1. the conclusion; 2. definition of suppositum; 3. definition of person, which is completed in the reply to the third objection.

First conclusion. It may be expressed briefly as follows: There is a real difference between suppositum and nature in every creature, just as there is a real difference between the whole and its parts.

The reason is that the nominal definition of suppositum or the subject of predication signifies the whole, and in every creature existence and accidents are not included in its essence. Such is the case in the angels, for Michael is not his existence nor his action.[429] Moreover, in corporeal things, in addition to the essence of the species, each has individuating principles that are derived from quantified matter, such as these bones, this flesh.

Hence this real distinction between the created nature and the suppositum that contains it, is not a distinction between two separate things, but it is a distinction that prevails between a real and actual whole, and its real, formal, and perfective part.

Contrary to what has been said, there is, a real distinction in God between suppositum and nature.

The real definition of suppositum is given in the following words. The suppositum is taken to be a whole which has the nature as its formal part to perfect it; and as stated in the reply to the third objection, the suppositum is the whole that exists and acts separately by itself. This point must be carefully considered, because it constitutes the philosophical foundation of the whole treatise.

Thus the suppositum is that which is, namely, the real subject of attribution, so that the suppositum is not attributed to any other subject; whereas nature is that by which a thing is such as it is, in such a species. Similarly, existence is that by which a thing is placed outside of nothing and its causes; a faculty is that by which the subject can operate, and operation is that by which it actually operates.

All the above-mentioned are attributed to the suppositum, and this latter is not attributed to any other subject. Moreover, it must be noted that the following divers affirmative judgments: Peter is a man, Peter exists, Peter can act, Peter does act, all these affirmative judgments assert real identity between subject and predicate by the word "is." They are equivalent in meaning to: Peter is the same real subject that is the man that exists, that can act, that does act. For these judgments to be true, this real identity between subject and predicate must be verified outside the soul, although Peter's essence is not his existence, nor the faculty by which he acts, nor his action. Hence there must be something by which the subject is the same real subject, or that by which something is "that which by itself (separately) exists and acts,"[430] as stated in the reply to the third objection.

Farther on we shall see how that by which a thing is a quod (or subject of attribution)[431] is subsistence, for which reason the suppositum is that which is competent to exist by itself separately. This truth constitutes the philosophical foundation of this entire treatise.[432]

Person is defined as an intelligent and sui juris or free subject, namely, a suppositum having a rational, or intellectual, nature.

This definition is given at the end of the first part of this article in the following equivalent words: "And what is said of a suppositum is to be applied to a person in rational, or intelligent, creatures; for a person is nothing else than an individual substance of a rational nature, according to Boethius."

In addition to this it must be said that a person is an intelligent sui juris subject by itself separately existing and by itself operating, such as Peter, Paul. St. Thomas says similarly: "Person is a subsistent individual of a rational nature."[433]

This definition is explained at the end of the third objection. The objection states that according to Boethius, person is an individual substance of a rational nature; but Christ assumed an individual human nature; therefore He assumed a human person, and so there are two persons in Christ, namely, the person assuming and the person assumed.

In the solution of this objection, St. Thomas in his reply most splendidly illustrates the definition of Boethius, by distinguishing accurately between individuality, or individuation, and personality.

This reply to the third objection must be read.

Not every individual in the genus of substance, even in rational nature, is a person, but that alone which exists by itself, and not that which exists in some more perfect thing. Hence the hand of Socrates, although it is a kind of individual, is not a person, but the part of a person, the part of a person and the part of a substance.

On the other hand, we know that according to St. Thomas[434] quantified matter is the principle of individuation, that is, as Cajetan explains: "Matter capable of this particular quantity so that it is not susceptible of that other quantity; for it is in this way that we distinguish between two drops of water that are most alike: not having the same quantified matter, they are thus in different parts of space. Hence individuation, which is derived from matter, is of the lowest order in man, whereas personality, as stated in the reply to the second objection, pertains to the dignity of a thing and to its perfection, so far as it pertains to the dignity and perfection of that thing to exist by itself."[435]

In Christ, as we shall see, individuation, as in our case, is effected by matter, whereas His personality is uncreated and thus there is an infinite difference between the two. St. Thomas discusses this point in his reply to the third objection, and elsewhere he says: "Person signifies what is most perfect in all nature, that is, a subsistent individual of a rational nature."[436]

Therefore we must not confuse the individual nature, individuated or singular, with suppositum and person. For even the individuated nature is not that which is, but that by which anything is constituted in a certain species that is limited or contracted to an individual grade of being, for example, an individuated nature is this humanity. Similarly matter is that by which anything is material.[437] On the contrary, by suppositum or person is meant this person separately existing by himself and acting, to whom this humanity is attributed, as constituting a part of him; hence we do not say that this man is his humanity, for the verb "is" expresses by a logical distinction real identity between the whole and its parts. We truly say that this man is not his humanity, but has humanity, or has his nature. Thus the common sense or natural reason of all men, by so speaking, distinguishes in a confused manner between person and nature, or between that which is, and that by which something is constituted in a certain species.

Hence St. Thomas[438] and the Thomists, in explaining the definition of person as given by Boethius, make some addition and say that a person is an entirely incommunicable individual substance of a rational nature, inasmuch as a person is the first subject of attribution, which is predicated of no other subject, and to whom is attributed whatever pertains to person, such as nature, existence, properties and actions. But communicability is threefold.[439]


COMMUNICABILITY [diagram page 126]

  • of the part to the whole
    • to this whole that is the suppositum: e.g., of the humanity to the Word
    • to this essential or quantitative whole: e.g., of the soul to man; e.g. of the arm to the body
  • of the universal to the inferior
    • e.g., of the humanity to all individuals of the species

Hence, when it is said that a person is incommunicable, what is especially meant is that such person is incommunicable to another suppositum, although even both to inferiors and to the quantitative whole.

St. Thomas discusses this incommunicability of person in various parts of his works.[440]

Thus the transition is made gradually from the common or popular notion of person to the philosophical notion of the term. It is not necessary here by way of conclusion to this article to explain the various systems freely disputed among Catholic theologians concerning personality, or what formally constitutes a person.[441]

Second conclusion. Toward the end of the argumentative part of this article, what St. Thomas intends to prove concerning the formal constituent of person may be expressed by the following syllogism.

Everything that adheres to a person, whether it does or does not pertain to the nature, is united to it in the person, which is the whole by itself separately existing.

But our Catholic faith teaches us that the humanity of Christ adheres to the person of the Son of God.

Therefore it is united to the person of Christ, but not to His nature.

The major follows from the definition of person, since it is the whole or the subject by itself separately existing and acting to whom are attributed as to the ultimate subject of attribution all those things that pertain to a person, such as nature, existence, accidents, and other notes.

The minor is evident from revelation, inasmuch as the human nature as also its parts and properties, such as the soul, the body, passibility, and other qualities are attributed to the Son of God.[442]

First confirmation. There are only two possible unions; either the union of the Word was with the nature, or with the person. For union by affection or by reason of the extraordinary grace bestowed upon the person loved, such as Nestorius imagined in the case of Christ, does not belong solely to the Word, but is common to the three persons of the Trinity operating together ad extra, and this union is already found in varying degrees in all the just.

Second confirmation. If there are two persons in Christ, then we are not redeemed; for neither of these two persons could have redeemed us from sin: not the divine person, because He could neither suffer nor satisfy for sin nor merit for us; not the human person, because he could not confer infinite value upon his satisfactory and meritorious works, such as was required for our redemption, so that the redemption be adequate.

It remains for us to reply to the first two difficulties proposed at the beginning of this article.

The first objection was: The person of God is not distinct from His nature. But the union of the Word incarnate did not take place in the nature. Therefore it did not take place in the person.

Reply to first objection. I distinguish the major: that there is no real distinction between nature and person in God, this I concede; that they do not differ in meaning, this I deny. I concede the minor.

I distinguish the conclusion. Therefore the union did not take place in the person, if by this is meant that the divine person is not even distinct in meaning from nature, then I concede the conclusion; otherwise I deny it. The reply to the first objection must be read.

Therefore this union of the humanity with God took place, not in the divine nature, but in the person of the Son.

Thus the mental distinction between God's mercy and justice is the foundation for the truth of these propositions: God punishes not by His mercy, but by His justice, although these two attributes are not distinct. Thus God understands by His intellect and not by His will. Likewise the Word is united to the humanity not in the nature but in the person.

As Cajetan says: "The reply is confirmed by reason of the fact... that the union of the human nature in the mystery of the Incarnation does not add anything to the meaning of nature, but it does indeed add something to the notion of person, because it adds the notion of subsisting in the human nature."[443]

Moreover, it must be noted that St. Thomas in this reply to the first objection and often afterward, says: "The Word subsists in the human nature." So does Cajetan,[444] whereas many modern theologians say less correctly: The humanity subsists in the Word. In truth, that which subsists is not the humanity, which is that by which the Word is man; that which subsists is the very Word incarnate.

Second objection. It is still proposed in these days by many theologians who object to Cajetan's interpretation of St. Thomas' teaching. It reads as follows: Christ's human nature has no less dignity than ours. But personality belongs to dignity. Hence, since our human nature has its proper personality, there is much more reason for Christ's to have its proper personality.

Several theologians in our times revive this argument against Cajetan, saying: Personality cannot be a substantial mode that terminates the nature, rendering it immediately capable of existence, as constituting it that which by itself separately exists.

The reply of St. Thomas is quoted by Pius XI in his encyclical commemorating the decrees of the Council of Ephesus against Nestorius. The following statement summarizes the reply of St. Thomas: Personality pertains to dignity inasmuch as it is that by reason of which a person exists separately by oneself. But it is a greater dignity to exist in something nobler than oneself than to exist by oneself. The complete reply to the second objection should be read.

Thus it is more perfect for the sensitive life to be united to the intellective, and for every inferior to be united to the superior. Just as it is more perfect for the deacon to be made a priest, so it is more perfect for the human nature to exist in the person of the Word, than to have its own personality; because whatever perfection there is in its own personality, is found infinitely and more eminently in the Word, so that there is intrinsic independence not only from inferior material things, as in the case of every rational soul, but from every creature, for Christ, indeed, is not a creature, but above every creature.

And what St. Thomas says in this reply concerning one's own personality can be said of the substantial mode by which, as Cajetan remarks, it is that by which it exists separately.

Cajetan gives a good explanation of St. Thomas' reply to the second objection, saying: "Just as it is nobler for the sensitive life to have its complete specific nature by a form of a nobler order, namely, by the rational soul, so a greater dignity was bestowed upon the human nature of Christ from the fact that it was assumed by the divine personality."[445]

Later Thomists, such as Billuart, make this additional comment: Subsistence or personality is the perfection and completion of the nature, perfecting it not in its notion of nature or essence, but in its notion of suppositum or person, inasmuch as it pertains to the dignity of a thing that it exist by itself; as St. Thomas says: "It is a greater dignity to exist in something nobler than oneself than to exist by oneself. Hence, from this very fact, Christ's human nature is not less noble but more noble than ours."[446]

It must be noted that the above definition of person, namely, an intelligent and free subject, easily finds its verification both in the human person, the angelic person, and the divine person. In all of them the subject is incommunicable, which cannot be attributed to another, and all of them enjoy intelligence and free will. But it is evident that person is not predicated univocally of God and man; it is predicated analogically, though not metaphorically, but properly; for the formal signification of person is properly retained in God proportionally, just as the proper signification of intelligence and liberty, of the real subject.[447]

Difficulty proposed by more modern critics. The final difficulty is thus proposed by many modern philosophers of the Guntherian and Rosminian trend of thought. They say that the mystery of the Incarnation is absolutely unintelligible from the mere abstract and metaphysical notion of either suppositum or subsistence or personality. For it is not only the metaphysical or ontological concept of personality that must be considered; it must be viewed in its psychological and moral aspects likewise, which come under experience. But psychologically, personality seems to consist in consciousness of oneself, and in personal judgment. Hence Locke, and after him Gunther, defined person as "a nature conscious of itself."[448] But in the moral order, personality seems to consist in this, that every one is sui juris, or is master of himself, or is free to act as he wishes, and Rosmini insists on this point.[449]

In the days of Modernism (1905) several students of dogmatic theology attending this course in a certain university did not even listen to the professor who was explaining the treatise on the Incarnation. They wrote letters or read books not pertaining to dogmatic theology, because, as they said, the conception of personality as proposed by scholastic theology is unintelligible.

I then said to one of these students: "Therefore, in your opinion in what does personality consist so as to give us a better understanding of the mystery of the Incarnation?" He replied: "Personality consists in a consciousness of oneself, and this is enough." I asked him how many consciousnesses and intelligences there are in Christ? This student had not even considered the fact that there are two intelligences and consequently two consciousnesses in Christ. Therefore there ought to be two personalities in Christ, if personality formally consisted in consciousness of oneself.

Another of these students replied to me: "Personality consists in freedom or dominion over oneself." But neither had he considered that in Christ there are two freedoms, and so there ought to be two personalities and hence two persons, which is the heresy of Nestorianism.

Hence it is manifest that, for assuming a more profound notion of personality, it must be considered in its ontological aspect, and not merely in its psychological and moral aspects.

For the solution of this difficulty, which is very widespread in these days, it will be useful at the beginning of this treatise, for its clarification, to start with a certain introduction or ascent from the psychological and moral notion of personality, especially as found in the saints, ending in the ontological notion of the most exalted personality of Christ. The notion of personality will thus be present in a less abstract, but more vivid and concrete manner, as befitting this mystery, when speaking not only with modern philosophers, but also with the faithful who are not accustomed to the language of philosophy, and who must, nevertheless, live by faith in the Incarnation, and who aspire to the contemplation of this mystery.

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"The essence of perfection is to embrace the will of God in all things, prosperous or adverse. In prosperity, even sinners find it easy to unite themselves to the divine will; but it takes saints to unite themselves to God's will when things go wrong and are painful to self-love. Our conduct in such instances is the measure of our love of God."

St Alphonsus de Liguori

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"God gives us some things, as the beginning of faith, even when we do not pray. Other things, such as perseverance, he has only provided for those who pray."

St Augustine

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"Many words do not satisfy the soul; but a good life eases the mind and a clean conscience inspires great trust in God."

Thomas Kempis

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