In article 1, St. Thomas addresses three objections to the question of whether it befits a Divine Person to assume: first, that a perfect Person cannot add to Himself; second, that in assuming something, He communicates something of Himself to what is assumed; and third, that its repugnant for something constituted to assume its constituent because effect does not act on cause. On the contrary, he notes citing Fulgentius, that the only-Begotten of God assumed a nature, and the only-Begotten is a Person, so it’s fitting. He adds, in this case, that in this assumption the Person is both principle and terminus, since the union took place in the Person. He agrees that on cannot add to perfection, but that in union, the Divine perfects man. He clarifies that a Divine Person isn’t communicable in the sense of being predicated of several supposita. However, he notes that nothing prevents several things to be predicated of a Person, so that even in a created person several natures may concur accidentally (for example, quality and quantity). In the Divine Person, who is eternal, it’s fitting for there to be a conjunction of natures in subsistence. To the third objection, he responds that the Divine Person is not constituted a person by human nature but is constituted man by that assumption.
In article 2, St. Thomas addresses three objections concerning whether the Divine Nature assumes. First, he addresses the notion that the Divine Nature did not assume since the union did not occur in the nature. He notes that the Divine Nature is not a distinct suppositum, but that “taking to Oneself” refers back to the suppositum, of which the Divine Nature cannot be separated. Objection 2 poses whether assumption is befitting to all three Persons of the Trinity Who share the Divine Nature, to which the Angelic Doctor responds that to assume is befitting only to the Person of the Word given that the Word assumed. The third objection distinguishes between what acts and how it acts and claims that acting befits a Person not a nature. St. Thomas points out that what acts and how it acts, in God, are one and the same in the Divine Nature. He accedes the propriety of saying that the Person assumes, yet he adds that Divine Nature is the principle of assumption, so it is by no means unfitting to say that the Nature assumes.
In article 3, St. Thomas addresses the question of whether the Nature abstracted from Personality could be said to assume. In objection 1, which posits that Nature only assumes by reason of the Personhood to which it belongs, he responds that all attributes of Nature, which are rational, would still subsist and be a Person and could still assume. Objection 2 suggest abstracting the Person would leave no terminus, but clearly, if the response to objection 1 is true, it follows that there still remains a terminus. Objection 3 posits that nothing remains when Personality is abstracted, leaving no-thing to assume. St. Thomas replies that all of the essential attributes of God still remain, subsist, and hence, are a suppositum that can assume. Even without the relationality of the Persons, there is still rational Nature and all other essential attributes that subsist as a Person.
In article 4, St. Thomas addresses whether one Person can assume without the others. In response to objection 1, which posits that the works of the Trinity are inseparable so precluding the possibility that one can assume without the others, he responds that the action of assumption pertains to all three Persons, the term pertains to the Son only. Objection 2 concludes that since the Divine Nature is common to all three Persons, so the assumption is befitting of all three Persons. To the contrary, St. Thomas responds that Divine Nature assumes by reason of the Person of the Son, and is thus befitting to the one Person alone. The third objection likens the assumption of human nature by Christ to the assumption of all men to God through grace. He responds that the assumption by grace of adoption is terminated in the three Persons, but the terminus of assumption of human nature is Christ, although the principle of each is the three Persons. In conclusion, St. Thomas underscores again that what has to do with the action is common, but what has to do with the term is unique to the Person of the Word.
In article 5, three objections are given to the notion that only the Son could be the term of the assumption: first, that to be otherwise would confuse the distinctions among the Divine Persons; second, that sonship by adoption is a participation in likeness to the natural sonship of the Son, which doesn’t belong to Father or Holy Spirit; and third, that the Father is innascible, incapable of becoming incarnate. St. Thomas notes that while the Father is eternally innascible, temporal birth would not change this. To the contrary, he says that what the Son can do, so can the other two Persons. Otherwise, their powers would be different. The principle of the act of assumption is the Divine power, which is common to all three Persons. The term is the Person of Christ. However, it could’ve been any one of the Persons.
In article 6, St. Thomas addresses whether several Divine persons can assume one human nature.
As an aside, I would say that I like the creativity of the objections in this article, and it’s to his credit that he responds so deftly. I have to wonder, though, whether these are his own manufactured objections or if these disputes were floating around in his day. Perhaps one of our philosophy colleagues could comment.
Anyway, proposed as objections are the following: that several Divine Persons could not assume one human nature because either several gods would result or because one person would result, confusing the distinction of Divine Persons; next, that because assumption terminates in unity of Person, and the Divine Persons are not one person, they could not assume one human nature; and finally, that what can be predicated of one Person to the man would be predicable to the Persons as well, which would allow for something proper only to the Father (such as begetting the Son) to be predicated of the Son. First he notes that “one man” does not equal unity of person, only unity of human nature. Second, he states that the unity occurs in regards the nature to the Persons and would mirror the unity of the Divine nature with each Person. Third, he clarifies that the Person communicates to the human nature, but those distinctions are not communicated from Person to Person. In all, he distinguishes between unity in hypostases versus unity in Person. Just as the Incarnate Person subsists in two natures and the three Persons subsist in one, all three can assume one.
In article 7, St. Thomas addresses the question of whether one Divine Person can assume two human natures. He provides three objections: first, that a Divine Person assuming two human natures would result in a single suppositum composing two natures of one species, which would be a contradiction since one species is multiplied by distinct supposita; second, that an Incarnate Person having assumed two human natures could not be said to be one man, nor two; and third, that two human natures could not be united, because the uniting of human bodies and souls would result in a confusion of Divine Persons. St. Thomas appears to be using the trump card of omnipotence here: God cannot be limited be created things, or He would be limited in power. To the objections, he replies as follows: first, the Incarnation doesn’t result a new supposita, so neither would another assumed nature; second, that unity of nature does not imply unity of suppositum; and third, that unity between one human nature and the Divine Persons would not imply a unity of the two human natures, so there could still be a uniformity in assumption among the Divine Persons without any union between the assumed natures.
In article 8, St. Thomas addresses whether it was more fitting for another of the Divine Persons to become incarnate. First, one objection posits that if the Father had become incarnate, there would be less occasion for error to come into man’s thinking. St. Thomas counters, citing Romans 2:4, that man would still be capable of error in this case. In objection 2, the Father is seen as more fitting since He brought about the first creation. In reply, the doctor notes that the first creation was brought about by the Father through the Word. Finally, because the Incarnation was ordered toward the remission of sins, the Holy Spirit should have become incarnate since remission of sins is a gift of the Holy Spirit. St. Thomas responds that it is proper for the Holy Spirit to be the gift of Father and Son, hence more fitting that the Son become incarnate to bestow this gift upon us. He notes that it is fitting for the Son, Whose concept is the exemplar likeness of the created, to restore mankind, much in the way that a craftsman restores a work that has been damaged or ruined. In addition, he adds that the Son’s natural sonship makes Him the fitting Person to bring mankind into adopted sonship. And finally, the Incarnation is a remedy for mankind’s overweening desire for knowledge, making it fitting that the Word of true knowledge might lead mankind back to God.