Realization and Causal Role-Playing: An Essay on the Mind/Body Problem

In this dissertation I argue that one of the central ideas of late twentieth and early twenty-first century philosophy of mind -- that the mind/body relation is the so-called “realization” relation, where realization is explicated as causal role-playing -- is unworkable and ought to be discarded. As a result, a fundamental reevaluation of recent work on the nature of mental states and mental causation is in order. My argument is neither reductionist nor anti-reductionist in intent, since in recent philosophy of mind both reductionists and anti-reductionists have relied upon causal role realization in the construction of their views. Rather, my target is the quasi-behaviorist assumption shared by both reductive and anti-reductive functionalists that the definitive characteristics of mental states are their causal roles; in the memorable phrase of David Lewis, their “syndromes of most typical causes and effects.”;My argument proceeds as follows. In order to identify realization with, or explicate realization as, causal role-playing, it is necessary to identify realized properties such as mental properties with one of the kinds of property that are associated with the causal role-playing relation. I argue that there are four such kinds of property: core realizers, total realizers, and two kinds of role-property that I call A- and B-type role properties. (I show that reductive functionalists attempt to identify realized properties with core or total realizers, while non-reductive functionalists attempt to identify realized properties with one of the two sorts of role property.) But realized properties cannot be identical to any of these four. Realized properties cannot be identical to total realizers or to either type of role property because realized properties are supposed to be causally efficacious but these three kinds of role-related property are not causally efficacious. Core realizers are causally efficacious but realized properties cannot be identical to them because realized properties do not supervene on core realizers.;The argument presented in the previous paragraph constitutes the bulk of my dissertation. As an additional matter I investigate another sort of realization, different from the sort that finds its ancestry in the functionalist philosophies of mind developed by Hilary Putnam or David Lewis. So called “cross-level realization” finds its roots in Jerry Fodor’s use of multiple realization to establish the autonomy of the special sciences and is today employed by many metaphysicians of science. Cross-level realization is not claimed by metaphysicians of science to be explicable as causal role-playing. I argue that philosophers who make use of cross-level realization have not offered any explication of it at all, correct or otherwise, of the sort that causal role-playing purports to be for the sort of realization employed in the philosophy of mind.;I do not propose, in my conclusion, to offer an alternative account of realization. Rather, I argue that the wish for realization is the wish for a metaphysical panacea that makes naturalism metaphysically easy. More technically, it is the wish for a kind of property that strongly supervenes upon lower-order (or lower-level) properties that both do and do not perform requisite legitimating causal duties. This cannot be had; therefore, in particular, the mind-body problem remains unsolved.