On a conceptual level, property dualism does not make much sense. Given a property dualist view, I’m often wondering how a nonreductive mental property could be instantiated in a physical substance. It seems odd how this could be coherent within the system. William G. Lycan expresses some of my same concerns. Lycan explains:
“Why or how on earth would a merely physical object, even one as complex as a brain, give rise to immaterial properties? We do not see how it could. If persons have immaterial mental properties, then most likely the persons themselves are or incorporate immaterial things. The idea would be that while there is nothing puzzling about an immaterial substance’s having immaterial properties, it is extremely strange to think that an otherwise purely physical object might have them.” (4)
This is what I find puzzling about property dualism. On a conceptual level it does seem that irreducible mental properties would have to be instantiated in a mental substance and not a physical one. Peter van Inwagen does not see how one can distinguish between properties. He says that properties are about things and do not ontologically differ. “[T]he properties that it is a cat and that it is an angel are things of exactly the same sort: they are both things that can be said about things… They differ not in their natures but in their content” (Inwagen 215). Now it is important to note that I am not making an argument against property dualism here. I am merely pointing out a problem I have with conceiving a non-physical property with a physical substance. The second thing that is to be noted is that Chalmers says that we “should take experience as fundamental” and a theory “requires the addition of something fundamental to our ontology, as everything in physical theory is compatible with the absence of consciousness” (Chalmers 1995; 14). Under Chalmers’s view why, is an irreducible mental property more fundamental than an immaterial mental substance? It seems that substance is more fundamental than property as property depends on substance to inhere to. Properties are contingent on the particulars. Both of these questions are not arguments. They could be areas of further reflection and discussion amongst property dualists and substance dualists. My skepticism about the above the coherence of property dualism could be boiled down to an incredulous stare. But, I do think there are legitimate arguments that establish substance dualism over property dualism.
The first argument I will put forth is against epiphenomenalism. Chalmers does advocate a form of this view in his work. He finds it much more plausible than my view of interactionism (Chalmers 2003). Epiphenomenalism is the view that there is only a one-way interaction between the physical substance and the irreducible mental property. Interactionism argues that while there are two different substances both mental and physical, these both interact with one another and have a two-way causal relationship. Chalmers calls epiphenomenalism Type-E Dualism for short and interactionism Type-D Dualism (I will be using this same terminology) (Chalmers 2003; 29-36). On the onset, a Type-E view seems to be counter to our phenomenal experience. It seems that our P-consciousness is efficacious. Consider this thought experiment: suppose I have a vivid experience of the color red. Also, suppose I have no direct access to this experience – it is completely phenomenal. The experience is so wonderful in my subjective experience that it becomes my favorite color outside of my control. Now, suppose I want to buy a car. Could it be possible that my experience of red persuade me to choose a red car over a different color car? It is definitely possible and highly likely. People choose things on the basis of their subjective experiences all the time and many times these subjective experiences can be outside of their control. There does seem to be some sort of interaction from the mental states we have to the physical states in the world. What about the creation of art in general? Music, painting, poetry, cinematography, these are all subjective aspects of the human experience working in the physical world. It seems unlikely that these aesthetic preferences are anything but forms of P-consciousness. My phenomenal experience of hearing a great drummer such as Steve Gadd causes me to play the drums myself. Chalmers argues that the above objections to the Type-E view do not necessarily work. He relies on Hume’s view of causation in order to get around the above objections. He argues, in the same way Hume argues, that just because there is a seeming causal link between the mental and the physical does not in-fact show that there is (Chalmers 2003; 34). This objection is similar to a post hoc ergo proper hoc fallacy. This fallacy points out that just because event A comes before event B does not mean that event A caused event B. This is a valid criticism, but why think that event B causes event A (if we take event B to mean physical events and event A to mean mental events)? It seems like this Humean objection could also work in favor of forms of psychophysical parallelism, but it is unlikely that Chalmers would want to advocate that view. Parallelism is the view that there is no causal connection between the mental and the physical – they both run their causal course independently from one another. Typically, this view is advocated by substance dualists (Robinson). But, it seems that a property dualist such as Chalmers could also fall into this conundrum. In his view there are psychophysical laws that govern the mental (Chalmers 2003; 35). It seems possible that our experiences just coincidentally match up with physical events without any causal link between the two. I contend that if there is a two-way interaction between our experience and our physical states then a Type-D view is correct.
We have looked at strong reasons to reject epiphenomenalism, but now I wish to give a positive argument that establishes substance dualism. In his work Naming and Necessity, Saul Kripke gives us reasons to think that there can be necessarily true a posteriori truths. A necessary a posteriori truth would be an identity claim. The common example Kripke gives is that water is H20. This is a necessary truth that we discover empirically. The identity between water and its molecular structure is true in all possible worlds. It is impossible to conceive of water being something other than H20. The word water does not pick out any accidental properties it has but rather it picks out what it is, namely its molecular structure (Kripke 126-9). How can one use these Kripkean philosophical tools in order to understand the mind-body problem with more clarity? At the end of the book Kripke uses these concepts to explore identity theses of consciousness. He says that the type-type physicalist must prove a necessary identity between the stimulating of C-fibers and pain – that the mental and the physical are identical (144-46). This is why, as we saw, Chalmers’s zombie thought experiment works. If it is possible that the mental and the physical are not identical, then the mental and the physical are in fact not identical. Chalmers was relying on the modalities of distinguishing possibility and impossibility through our capacity of conceivability. But, as Kripke mentions, the converse of the zombie argument is also true. Kripke says the following about the identity of the mental and the physical:
“Here I have been emphasizing the possibility, or apparent possibility, of a physical state without the corresponding mental state. The reverse possibility, the mental state (pain) without the physical state (C-fiber stimulation), also presents problems for the identity theorists which cannot be resolved by appeal to the analogy of heat and molecular motion” (154).
Kripke seems to think that if you accept the zombie argument, you also have to accept that consciousness could exist without the physical instantiation. For the property dualist this would be a problem because consciousness is identical to a property or set of properties. But, properties have to be instantiated in substance. As Peter van Inwagen stated before, properties are about things. Thus, if consciousness can exist without being instantiated in a physical substance it must be instantiated in a mental substance. Swinburne follows Kripke’s same line of reasoning and gives a thought experiment that shows that a disembodied existence is possible. In order for a physical substance to be my body I must be able to move it and must be able to gain knowledge about the world through it. He imagines that he has powers that allow him to move a chair and learn about the world through the chair. He would not be tied down to merely acting through one physical substance. But Swinburne concedes that this does not show that consciousness can exist without a body (his consciousness still exists in the chair). He forms an argument that looks something like this:
- “It is logically possible that there be pure mental events which do not supervene on physical events.”
- “A person can have successive pure mental events”
- Conclusion: “Hence it is logically possible that I lose all contact with the physical world and yet still have thoughts and feelings”
Swinburne shows that this conclusion also entails that “since ‘I’ is an informative designator, it is not merely logically possible but also metaphysically possible that I could exist without my body; and what goes for me goes for any other human person” (163-4). A pure mental event is an experience of something that does not entail a physical reality. If it is false that mental events are the same as physical events, then it we can have pure mental events. We can “apparently hear the telephone” and “apparently see a desk.” They are experiences that a person has without any physical reality. The pure mental event is designated alone without any reference to a physical event (Swinburne 68-70). Swinburne’s whole argument stands or falls with the first premise just like the zombie argument. Chalmers would agree that premise (1) is true. The rest of the argument follows to the conclusion. Also, consider people who believe in God for a moment. If theism is possibly true then consciousness can exist independently of a physical body. Theism views God as an immaterial entity that exists without a body. God seems to be conceivable to many people and is not an incoherent concept. Lycan tells us to “remember that the conceptual possibility of disembodied existence is granted by nearly everyone, the only exceptions being Analytical Behaviorists and (if any) Analytic Eliminativists” (6). I have shown that given property dualism, substance dualism can be established.
Chalmers is motivated to accept property dualism over substance dualism for two key ontological constraints. The first is parsimony. This constraint takes simplicity to be a good principle when choosing a metaphysical framework (Chalmers 1995; 16-7). William of Ockham has said that we “shouldn’t multiply entities beyond necessity.” There are many interpretive challenges with this principle (Baker). For example, what does necessity mean? Property dualism might be simpler than substance dualism – it does only posit one substance as opposed to two – but, as I have shown, it does not explain all the data of consciousness. I contend that substance dualism does all the necessary ontological work that property dualism cannot do. Parsimony gives us a cleaner ontology without pluralistic messiness but it does not necessarily guide us to the truth. The second principle that constrains Chalmers’s ontological commitments is a naturalistic presupposition. He rejects substance dualism and interactionism because the universe is causally closed (Chalmers 2003; 30). But this seems to be nothing more than an unwarranted and asserted constraint that is based in a naturalistic presupposition. I do not think that either of these constraints is viable in producing a true ontology.
Given the arguments for property dualism, physicalism is in a problematic philosophical place. I have contended that, given the arguments for substance dualism property dualism is in a similar problematic place as physicalism. The problem of consciousness is still a live philosophical debate and it is only with clear principles that one can get to the truth.
Baker, Alan. “Simplicity.” Stanford University. Stanford University, 29 Oct. 2004. Web. 08 June 2015. <http://plato.stanford.edu/entries/simplicity/>.
Chalmers, David J. “Consciousness and Its Place in Nature.” Papers on Consciousness. N.p., 2003. Web. Apr.-May 2015. <http://consc.net/papers/nature.pdf>.
Chalmers, David J. “Facing Up to the Hard Problem of Consciousness.” Papers on Consciousness. N.p., 1995. Web. Apr.-May 2015. <http://consc.net/papers/facing.pdf>.
Inwagen, Peter Van. “A Materialist Ontology of the Human Person.” Persons: Human and Divine. Oxford: Clarendon, 2007. 199-215. Print.
Kripke, Saul A. “Lecture III.” Naming and Necessity. Oxford: Blackwell, 1980. 106-55. Print.
Lycan, William G. “Is Property Dualism Better Off Than Substance Dualism?” (2012): n. pag. 2012. Web. 5 June 2015. <http://www.unc.edu/~ujanel/Is%20Property%20Dualism%20Better%20Off%20than%20Substance%20Dualism_January%202012.pdf>.
Robinson, Howard. “Dualism.” Stanford University. Stanford University, 19 Aug. 2003. Web. 07 June 2015. <http://plato.stanford.edu/entries/dualism/#Par>.
Swinburne, Richard. Mind, Brain, and Free Will. Oxford: Oxford UP, 2013. Print.