Following Dr. Dale Tuggy’s debate with Mr. Chris Date on “Jesus is human and not divine,” I joined the Trinities Podcast Facebook group and asked for clarification on one of his thought experiments. I recall that he used a similar line of reasoning in his “Case Against Preexistence” episode on the podcast, and the fact he utilized it again in the debate shows (if it didn’t already) that he finds it significant.
Tuggy found it worthwhile to respond to my plea for clarification. He quotes my Facebook response in full, but (appropriate to fit his replies) slightly out of order. Here’s my original post (plus some corrections, slight clarifications, and links):
I’m hoping Dr. Dale Tuggy can clarify his “demon possession” thought experiment for us. If not here, then in his published statement in the (apparently) forthcoming book with Mr. Date.
The thought experiment is meant to show the following: For models of the Incarnation that hold Christ’s human nature is a concrete particular (both a human body and human soul), the divine Person who assumes a human nature is not truly human. That is because he is merely “piloting” a body [and soul].
Enter the thought experiment. Suppose a demon enters into a compositional union with your human body and soul, and deactivates your soul. This is supposed to be a state of affairs equivalent to that of the Incarnation. Here, Dr. Tuggy suggests, it’s just obvious that the demon is merely piloting a human body [and soul], and therefore clearly isn’t a human.
There are two problems with this thought [experiment] as suggested. The first is that this occurs, apparently, at a later time in the human’s (or “your”) life. I’ll return to this in a moment. The second is that the demon’s piloting your body [and soul] isn’t like the hypostatic union because your human nature doesn’t subsist because of the union with the demon. Why is that a problem? Because when the demon pilots your body [and soul], there are predicates that will be apt [or true] of you, as a subsisting individual, but will not be apt of the demon. For example, it is false that the demon has sensations through your human nature because [you] have them. You are the ultimate subject of predication (what the medievals called a “supposit”) even in this situation, not the demon. But on the Incarnation, the Person of the Son/Word [is] the ultimate subject of predication for all human predicates. How is this at all like what has been traditionally held about the Incarnation?
Side note: Is “deactivating” a human soul even a coherent idea? Maybe, since I thought Dr. Tuggy’s conception of death is “the ceasing of all or most life functions.” Is that what occurs at this “deactivating”? Does the demon kill the human soul? If so, once again, how is this at all like the traditional tenets of the Incarnation?
Here’s one way to try to modify this: Suppose that instead of at a later time in your life, a demon “assumes” a concrete human nature from the moment of [its] conception. There is a truly human soul and body there, and hence a complete [concrete] human nature. Through some compositional model of the Incarnation (like Katherin Rogers’ “action composite” model), we can say the demon is hypostatically united to the complete human nature.
But in this case, it sure seems like that demon really is truly human on the metaphysics presupposed by compositional models of the Incarnation we’ve been discussing. That person [i.e., “rational supposit”] who is really an angel, and in fact a demon, is born, grows up, etc. Through [its] union with the complete human nature, it is true to say it has sensations, acts in the world, and that the human nature only subsists because of its union with the demon. But now the supposed obvious nature of the incoherence of the Incarnation disappears. Where’s the problem here?
Summary: If the “demon possession” thought experiment occurs at a later time in a human’s life, there are obvious disconnects that Dr. Tuggy ignores entirely that, it seems to me, make the intuitive feel of the thought experiment work. When these disconnects are brought to light, it’s not at all obvious that the thought experiment shows what Dr. Tuggy thinks it does. And if we modify the thought [experiment] to be more like the Incarnation in all those ways, we end up with a truly human demon. So what? In that case, thanks for demonstrating the coherence of one way to understand the Incarnation.
What do you make of this exchange? Please let me know in the comments.
Note: I originally wrote my Facebook post on my phone, hence the spelling corrections!