Question 3. The mode of union on the part of the person assuming
Article 1. Whether it is befitting for a Divine Person to assume?
Objection 1. Now no addition can be made to what is perfect.
Objection 2. But it is of the nature of a person to be incommunicable.
Objection 3. A person is constituted by a nature, and should not take on “a nature.”
I answer that, We must remember that the assumed human nature is that which is perfected, not God Who is infinitely perfect.
Reply to Objection 1. No addition is being claimed in the manner of perfection.
Reply to Objection 2. The Person is not predicated of several things, but several things predicated of the Person.
Reply to Objection 3. A person is constituted by nature simply. The Divine Person is not assuming a Divine Nature, which it already has essentially, but assuming a human nature.
Article 2. Whether it is befitting to the Divine Nature to assume?
The principle belongs to the Divine Nature, which is One in God, but the term of what is assumed does not belong to the Divine Nature as such, but to the Divine Person, the Second Person of the Trinity only.
Only inasmuch as the Divine Nature took human nature to the Second Person is it said that the Divine Nature took it “to itself.” The Nature of the Father and the Son are one, but not the Person of the Father and the Person of the Son.
Article 3. Whether the Nature abstracted from the Personality can assume?
Objection 1. It seems that if the Personality be mentally abstracted, the Nature cannot assume.
Objection 2. Also, then, if the Personality be abstracted, the Nature cannot assume.
I answer that, We can only know God to a certain extent, and what we know separately in our intellect is One and Simple in God, and cannot be separate in His Existence.
Reply to Objection 1,2,and 3. Essence and existence are one in God, and our ability to mentally separate them cannot lead to a real separation in existence. Understanding this answers all three objections.
Article 4. Whether one Person without another can assume a created nature?
Objection 1. “The works of the Trinity are inseparable” so how can one Person assume a created Nature without all Three?
Objection 2. The Nature and the Person being one, how could not all Three assume the human Nature if the Person did?
Objection 3. This assumption pertains to all the Persons; the human nature in Christ is assumed by God.
I answer that, Again, assumption implies two things, the act of assuming and the term of assumption. I here repeat what what said in article 2: The principle belongs to the Divine Nature, which is One in God, but the term of what is assumed does not belong to the Divine Nature as such, but to the Divine Person
Reply to Objection 1. “This reason regards the operation, and the conclusion would follow if it implied this operation only, without the term, which is a Person.” (Thomas quoted verbatim)
Reply to Objection 2. The Nature of God is said to be Incarnate only as nothing is imperfect in the Nature of the Son Who assumed the human nature, but not in that God in all three Persons assumed the human nature.
Reply to Objection 3. Reply to Objection 2, properly understood, also answers this.
Article 5. Whether each of the Divine Persons could have assumed human nature?
Whatever can be done by one Person of the Trinity can be done by the others, or by all Three. There is nothing owing in the Nature of the Second Person making Him capable of becoming Incarnate any different than the other two Persons, for they are of one and the same Nature.
Article 6. Whether several Divine Persons can assume one and the same individual nature?
Objection 1. If more than one Person of the Trinity is joined to one Divine Nature, then there would be one Person out of the two or three of them, destroying the Trinity of Persons.
Objection 2. The Father, Son, and Spirit, being not one Person, cannot assume one nature in the Person, as is said to be where the union of God and a human nature is in the Incarnation.
Objection 3. Whatever could be said of the man assumed would be said of each of the Persons, and this would destroy such differences as the Father begetting the Son, etc.
On the contrary, The three Persons already subsist in one Nature without destroying the distinct Persons, and so unity in One Nature clearly need not destroy distinction of Persons.
Such are the Divine Persons that one does not exclude another from communicating in the one Nature, as they clearly do in one Divine Nature as One God, but are only excluded as being the same Person.
Reply to Objection 1. If the three assumed the hypothesis in one human nature, it would be correct to say that the three Persons were one man, but not one Person.
Reply to Objection 2. The one human nature would have a unity with each Divine Person, the Persons distinct.
Basically, what would be understood in the “one man” as far as nature would be somewhat equivalent to what is understood in the One God and Three Persons. The Nature being one, in this case human, would not destroy the Persons being three.
Article 7. Whether one Divine Person can assume two human natures?
The Incarnation has not lessened the power of God, in Nature nor in each Person thereof. And we said above that, after the Incarnation (but not dependant upon this), the Father could assume a human nature. Now whatever the Father can do, so can the Son. So the Son could assume a human nature, distinct from the human nature already assumed.
Article 8. Whether it was more fitting that the Person of the Son rather than any other
Divine Person should assume human nature?
Objection 1. Some, it seems, were led to confusion, seeing the Son as less than the Father, but this would not have happened if the Father had become Incarnate instead.
Objection 2. The power of creation seems more fitting to the Father, and thus more fitting that He be the one to make us a “new creation” by His Incarnation.
Objection 3. The Incarnation was for the purpose of remitting sin, and the Holy Ghost, says John, is given for this remission. It was more fitting then, for the Holy Ghost to become Incarnate.
“Christ, [is] the power of God and the wisdom of God.”
This is the true Wisdom that needed to be given to man. Now the Son is the exemplar of man, and thus, most appropriate to be that by which we are healed and made “sons of God.” Our likeness is appropriate to the Son in a way it is not appropriate to the Father.
Secondly, if we are sons, we are also heirs. It is adoption as sons that make us heirs of the eternal beatitude.
We fell in the first place by seeking a wisdom we should not seek, and thus we are healed by being given the true Wisdom of God, Who as Person is the Son, the Second Person of the Trinity.
Reply to Objection 1. There is no reason to believe, had the Father become Man, human ignorance and malice would not likewise fall into error about Him.
Reply to Objection 2. The first creation of things was made by the power of God the Father through the Word, and thus it is more fitting that it is though this same Word we are reconciled to God.
Reply to Objection 3. The Holy Ghost is given for the remission of sin, but “as gift,” and thus properly as gift of the Son, Who became Incarnate.