In this post I am going to lay out an argument for property dualism called The Presentation Argument (TPA). TPA is no longer a prevalent argument for property dualism used by philosophers. Max Black originally formulated it, J.J.C. Smart dealt with it, and Stephen White has recently defended it (Howell 103; cf. White 2010 & Smart 1971).
According to Smart,
“. . . it may be possible to get out of asserting irreducible psychic processes, but not out of asserting the existence the existence of irreducible psychic properties. For suppose we identify the Morning Star with the Evening star. Then there must be some properties which logically imply that of being the Morning Star, and quite distinct properties which entail that of being the Evening Star. Again, there must be some properties (for example, that of being a yellow flash) which are logically distinct from those in the physicalist story.
Indeed, it might be thought that the objection succeeds at one jump. For consider the property of “being a yellow flash.” It might be seem that this property lies inevitably outside the physicalist framework . . .” (Smart 63).
The point being made is that reduction works for two seemingly distinct things or objects, but when it comes to properties, it seems problematic. Smart’s example shows that reduction works when discussing the Morning and Evening Stars, since they are both Venus. But there are distinct properties of Venus which serve as the truth conditions for propositions about the Morning Star, and those are not the same properties which serve as the truth conditions for propositions about the Evening Star. So there has been no reduction of properties, but only things. Smart makes the point in terms of psychic properties and processes, where “processes” seemingly denotes types of things.
When applied to the case of reducing the mind to something more fundamental, such as the physical, TPA becomes more salient. Consider reducing some token instance of a mental property to a token instance of a physical property of the brain. The property token of pain would be reduced to the property token of c-fiber firing. But there is still the appearance of pain, the qualitative feel, which seems quite distinct from the property token of c-fiber firing, or any of its properties. In other words, the appearance of multiple properties is explained by the existence of multiple properties that account for those appearances (Howell 104). In the case of informative property identity statements, it appears as if the number of properties increases (Howell 104).
So, attempting to reduce mental properties to physical properties will leave an appearance residue that must be accounted for by more properties. If those properties are construed as physical, then there will still be more appearances left unaccounted for. Reducing the appearance of pain to some property of c-fiber firing will leave the appearance of the appearance of pain which itself must be reduced to something physical, or be accounted for by properties that do not appear to be physical. If they’re reduced to something physical, you get another iteration of the problem, thus adding more physical properties to your ontology without fully explaining the appearances.
TPA has it that any attempt at property reduction produces more properties. In the case of the mental, there will either be unexplained appearances along with a very large (infinite?) number of physical properties of the brain, or appearances that have non-physical properties as their grounding. So, physicalists who attempt to reduce seemingly mental properties to something more fundamental actually bloat their ontology with appearance properties which are fundamentally mental, or with physical properties and unexplained appearances.
What should be noted is that this is not a unique problem for physicalism about mental properties. Rather, it is a problem for any attempt at property reduction, although what generates it seems to be closely tied to considerations about phenomenal states (Howell 2013). In the case of the Morning Star and the Evening Star, reducing the properties determining the truth conditions for propositions about the Morning Star to those determining the truth conditions about the Evening Star (or vice versa) leaves an appearance residue which will need to be explained. There is nothing overtly mental about this iteration of the problem, and it can generate its own version of TPA. However, note that it still relies on appearances as that which needs to be explained. So, it seems fundamentally tied to considerations about phenomenology.
In a future post, I will present an objection to TPA in all its forms. In the meantime, let me know what you think about this argument in the comments section, or tell me if I’ve been unclear in my presentation of the argument.
Howell, Robert J. (2013) Consciousness and the Limits of Objectivity: The Case for Subjective Physicalism. Oxford: Oxford University Press.
Smart, J.J.C. (1971) “Sensations and Brain Processes,” in David M. Rosenthal (ed.), Materialism and the Mind Body Problem. Englewood Cliffs: Prentice Hall.
White, Stephen. (2010) “The Property Dualism Argument,” in George Bealer and Robert Koons (eds), The Waning of Materialism: New Essays. New York: Oxford University Press.