I’m writing this post for a reader of mine. This reader asked why I choose to hold to dualism as opposed to materialism, and so I’ll highlight my reasons here. To be clear, I hold to Thomistic hylomorphism (which is somewhat of a form of dualism, though it is different than substance dualism; substance dualism could be argued for as well, however). The reason I hold to dualism rather than materialism or emergentism is quite simple: mental causation exists. I outlined this in a previous blog entry, citing this article. I have not come across a philosophically coherent way that materialism or emergentism can account for mental causation, and therefore I’m left with some form of dualism, and I think hylomorphism most closely aligns with neuroscience.
Other arguments against materialism–such as Kripke’s argument, or especially Alvin Plantinga’s arguments–hold merit for me. They’re not bulletproof, but I think that it is more probable that they hold than not. Denying some of their premises leads to what I view as absurdities. I’m about to begin reading the anthology, The Waning of Materialism, and I think that at the end of this book I’ll have even more reason to reject this stance. (For my readers who think that this is one sided, I am very familiar with Dennett and Ramachandran–two identity theorists–I’ve read many of Dennett’s articles and two of Ramachandran’s books.)
One problem that I have with emergentism is that it is states that the interconnectivity and complexity of the brain produces consciousness by emergence. This is rather difficult to argue against, because emergentism does not specify why consciousness emerges from brains (as opposed to say, hearts). However, it has a problem related to those who undergo a hemispherectomy or experience extensive brain damage due to hypoxia or heavy drug use. In the former, half of the brain’s complexity and interconnectivity is removed. Due to the fact that we typically ascribe self-awareness exclusively to humans, and a removal of this amount of brain tissue would put an individual far below the level of neural networking present in primates in general, an individual with self-awareness who has undergone a hemispherectomy presents a problem for the emergent theory of mind. This may be argued against by maintaining that the brain’s interconnectivity remains in the other half of the brain, and this is all is needed for emergence–though this runs counter to the emergentist definition of consciousness, and I don’t believe this reply holds water. Additionally, in the latter, extensive brain damage from hypoxia or especially heavy drug use results in extremely limited neural connectivity. Using the emergentist definition of consciousness, these individuals should not have subjective experience or self-awareness. But anyone with contact with an individual such as this can tell you that they seem to be self-aware. Denying that they are, for me, leads to absurdities (I can’t accept a philosophical zombie on any level).
These are my reasons for holding to a form of dualism. They may not convince all, but they are my reasons for choosing a form of dualism.