Survivalist, Platonist, Thomistic Hylomorphism: A Reply to Daniel De Haan and Brandon Dahm

The debate over the personhood of the separated soul enjoys great prominence in recent Thomistic philosophy not only because it has to do with a topic of deep existential importance—whether we survive our deaths—but also because it, more than most other debates, brings together and shows the significance of many of Aquinas’s metaphysical principles. Perhaps no paper has revealed just how much this debate brings together those principles as have Daniel De Haan and Brandon Dahm’s recent papers, both in the Thomist and here in Quaestiones Disputatae.¹ In this response to their papers, I first highlight two of their most important contributions to the debate over the separated soul and then raise four objections to their view. In my own previous contributions to this debate, I have argued that Aquinas is a corruptionist but that survivalism is true and can be defended using some, but not all, of Aquinas’s metaphysical principles.² In raising objections to De Haan and Dahm’s views, I am objecting to some of Aquinas’s own claims as well. My interest in this debate is in defending the truest metaphysics, not merely in giving the best exegesis of Aquinas’s texts.

The first crucial contribution that De Haan and Dahm’s paper makes to the separated soul debate is that it shows that the metaphysics of the person tracks that of the hoc aliquid: if the latter can involve multiple separable modes of completeness, then so can the former. This allows for a broader range of views on persons (and particulars in general) than has been previously acknowledged. Their distinction of operational, existential, formal, supposit, and essential modes of completeness is especially helpful. It helps us see that there are Thomistic reasons for thinking that metaphysical items like the hoc aliquid, the supposit, the essence, and the person can come in degrees. De Haan and Dahm are highlighting a feature of Thomistic metaphysics that shows up in many places. For example, Aquinas holds that immateriality also is not a property that a being either has or does not have; rather, immateriality comes in degrees: sensible species are more immaterial than material forms, while phantasms and intelligible species occupy even higher grades of immateriality.³ As in the cases that De Haan and Dahm highlight, metaphysical features of things rely on multiple conditions, some of which can be met without others. While this idea of metaphysical items coming in grades or degrees is an important feature of Thomistic metaphysics, it is rejected by some other schools of scholasticism. For example, John Duns Scotus rejects grades of immateriality and similarly has a less graded view of essences, supposits, and other metaphysical items.⁴ Incidentally, such views seem to me in many respects more plausible—that is, more explanatory of reality as it is given in our experience—than the Thomistic metaphysics; it is in part for this reason that I hold some of the claims I defend next.

De Haan and Dahm’s second contribution—which in my view is even more important than their first—is to show that what remains after human death on Aquinas’s view is not just the human soul or form. Rather, what remains is a whole composed of soul, esse, powers, habits, and operations, which they call the anima separata. This composite is, in their view, a supposit or subject of operations, albeit an incomplete one; it is also an incomplete hoc aliquid and person and includes an incomplete “I.” Showing this, combined with their first contribution, allows for a view that plausibly is a third way over and above survivalism and corruptionism as they have been defended. It shows the error made by some corruptionists in claiming that what survives death has only one part and so cannot be or constitute a human person in any sense because that would violate the “weak supplementation principle” on which any composite whole must have more than one proper part.⁵ Since what survives death certainly has many parts and because it is a supposit of [End...