17.1 The Incarnation and Heresy (SCG 4,28–39)
17.1 The Incarnation and Heresy (SCG 4,28–39)
The people Aquinas singles out as heretical in SCG 4,28–38 include Photinus, Manicheans, Valentinus (second century), Apollinarius (c. 310–c. 390), Arius, Theodore of Mopsuestia (c. 350–428), Origen (c. 185–c. 254), Nestorius (after 351–c. 452), Eutyches, and Macarius of Antioch (seventh century).6 According to Aquinas, all of these figures in one way or other deny that Christ is a divine person with two distinct natures, and all of them stand condemned by a variety of biblical texts.
Thus, for example, Photinus, whom Aquinas takes to have taught that Christ had only a human nature, is refuted by, for example, John 1:14, Philippians 2:6–9, and Ephesians 4:10 (see SCG 4,28).
Again, thinks Aquinas, Manicheans (whom he believes to have said that the body of Christ was an unreal “phantasy body”) are refuted by New Testament texts, such as Luke 24:37–39 (see SCG 4,29).
In SCG 4,30 Aquinas turns to Valentinus, whom he presumes to have held that Christ’s body was a heavenly one (corpus caeleste), not an earthly one. Yet that position is false, he argues, given texts such as Romans 1:3 and Galatians 4:4. Equally false, he adds, is the claim (which he ascribes to Arius) that Christ had no human soul and was united to the Word as a human body is informed by a human soul (see SCG 4,32). That claim, he says, is refuted by Matthew 26:38 (“My soul is sorrowful even unto death”) and John 12:27 (“Now is my soul troubled”). The claim now in question is also, says Aquinas, refuted by the fact that God cannot be the form of a body (see SCG 1,23). So he suggests that one should recognize that “in Christ the soul was one thing and the divinity of the Son of God another.”7
Might it be said that Christ had a sensitive soul (i.e., that Christ was able to desire and experience at a physical level) while lacking mind and intellect? That this should be said is a view that Aquinas attributes to Apollinarius in SCG 4,33; but he rejects it in the light of biblical teaching to the effect that Christ was a human being. If Christ was human, he declares, then he must have had a soul in the way in which we do; he must have been able to operate at both a sensory and intellectual level. “If in Christ there was a sensitive soul without reason, it was not of the same species with our soul, which does have reason. Neither, then, was Christ himself of the same species with us.”8
Having in SCG 4,34–38 considered and rejected some other views about Christ that he takes to be heretical and not in accordance with Scripture, Aquinas, in SCG 4,39, offers a summary of what he takes to be orthodox teaching concerning Christ. He writes:
It is clear that according to the tradition of the Catholic faith we must say that in Christ there is a perfect divine nature and a perfect human nature, constituted by a rational soul and human flesh; and that these two natures are united in Christ … in one hypostasis and one supposit (secundum unam hypostasim et suppositum unum). … One must say that there are in Christ two natures neither confused nor mixed. … As in the Trinity there is a plurality of persons subsisting in one nature, so in the mystery of the Incarnation there is one person subsisting in a plurality of natures.9
Key terms in this passage are “hypostasis,” “nature,” and “person.” These are words that we find in discussions of the Incarnation prior to Aquinas. But how does Aquinas understand them?
By “hypostasis” he means “individual,” as in “I am one individual and you are another.” Aquinas’s “hypostasis” is equivalent to his term suppositum (see chapter 11 here). Naturally occurring things, as opposed to artifacts (such as computers) or as opposed to what we might call “beings of reason” (such as prime ministers) come in different kinds. Computers are made by people for purposes, but they are not naturally occurring substances even if they are built up from what occurs in nature. And prime ministers are not a naturally occurring kind of thing. They are, so to speak, social constructs.10 Yet there are, for example, tons of things that belong to natural kinds, and my cat is one of them. But we can hardly identify my cat with the nature it has insofar as it is feline. My cat is not “sheer felinity.” It is one cat among many. It is Sweetie and not Smokey or Felix. So my cat has individuality as well as nature or essence. And it is individuality in this sense that Aquinas has in mind when he talks about something being a “hypostasis” or suppositum, words that are broadly interchangeable with terms such as “subject” or “individual.” According to him, you and I, for example, are not human nature. We are individual human beings. We are individuals or subjects in our own right, however much we might resemble each other. You are one thing, and I am another.
In fact, so Aquinas would say, you and I are individual persons. On Aquinas’s account, the word “person” can be introduced at this point since an individual can be thought of as not just one thing as opposed to something else. For him, individuals, though unique, can be grouped in certain ways prior to being picked out as the individuals that they are; and some individuals are persons insofar as intellect and will can be ascribed to them. Hence, as I have shown (chapter 16), Aquinas is happy to say that God is a Trinity of persons since there is distinction in God without this resulting in God the Father, God the Son, and God the Holy Spirit failing to be what God eternally is, and Aquinas therefore holds that there are three who are God, and to each of these three he ascribes knowledge and will.