Hylemorphic Dualism Immune to the PDCI?

Interactionist dualism (ID), as proponents of the problem of dualistic causal interaction (PDCI) claim, have a conceptual difficulty accounting for the causal interaction between non-physical and physical events, as was set forth in the previous post. More specifically, it is efficient causation that the objectors believe give the dualist its problem. We can, crudely, think of efficient causation like the following:

(EC) X brings about Y = either X brought into existence Y or X alters Y.

Think again of the proverbial billiard ball example. When the cue ball hits another (say, the eight ball) and causes it to move across the pool table, it is efficient causation, specifically, that is in view. The cue ball is said to have ‘brought about’ the subsequent moving (a spatial alteration) of the eight ball. Likewise, in terms of efficient causation, the non-physical event is regarded as ‘bringing about’ the ensuing physical event.

Hylemorphic dualism (HD), as opposed to ID, is immune to the PDCI. HD believes that material objects, including human beings, are constituted by both form (soul) and matter (body), and are thus a single substance. So, on this view, there is no interaction, as it were, between a non-physical and physical substance. That there are not two disparate substances interacting, I think, the PDCI loses much of its (supposed) intuitive force (since its typical target is Cartesian dualism). We do not have to picture on HD, how a non-physical and physical substance come in contact with one another, much like we picture billiard balls coming in to contact.

But is there still not a problem at the level of events? That is, is there not a problem with respect to the interaction of non-physical and physical events? The hylemorphic dualist like any dualist will admit to this type of interaction. Again, the causal interaction that PDCI envisages is at the level of efficient causation. But HD denies this. What HD claims is that the causation involved between non-physical (i.e. thoughts, beliefs, and desires) and physical events (i.e. neural events and physiological behavior) is not efficient causation, but rather, formal (i.e. that which makes a thing what it is or a things essence) and final causation (i.e. the end or purpose for which a thing is done).

Take for instance the event: my going to McDonald’s to get a coke. My desires and beliefs, as it pertains to acquiring a coke at McDonald’s, along with my intention to go to McDonald’s, serve not as an efficient cause of subsequent neural and physiological behavior. Rather my desires, beliefs, and intention are the formal-cum-final causes of the one event: my going to McDonald’s to get a coke. Nowhere on this model is it countenanced that efficient causation is the fundamental relation between non-physical and physical events. As the HD sees it, the sole reason the PDCI even gets off the ground is because what the objector has in mind is efficient causation. But since the HD does not envisage the relation between non-physical and physical events as being efficient causation, HD is immune to the PDCI.

A similar approach—in terms of denying that efficient causation is the type of interaction between non-physical and physical events—has recently been taken by E.J. Lowe. Lowe claims that this causal interaction is intentional causation as opposed to bodily causation (i.e. event causation). Intentional causation is fact causation. As Lowe argues, “a choice or decision to move one’s body…is causally responsible for the fact that a bodily movement of a certain kind occurs, whereas a neural event, or set of neural events, is causally responsible for a particular bodily movement which is a particular event.” Either approach, since they deny that efficient causation is the kind of relation that exists between non-physical and physical events, is immune to the PDCI. Or so I surmise.