As so often happens, there is an interesting conversation underway over at The Maverick Philosopher. In this case the topic is the recurring theme of mind-body dualism, and in particular how a non-physical mind might causally interact with a physical body. (The original post has to do with a rather arcane metaphysical system known as “hylomorphic” or “Thomistic” dualism, but a lively chat ensued.)
Dualism has a lasting appeal, and it is easy to see why. Our inner life is private and entirely subjective, and it does indeed seem that there is a bidirectional causal connection between our mental states (which it is hard to see as being in any sense material) and the physical world. In particular, it appears to us that our immaterial mental states are causally responsible for the voluntary actions of our bodies. But the world, as we look out upon it, seems entirely physical, as do all the ordinary interactions we can observe. Can it be that the only exception is for the ghosts inside our skulls? And if there is such a link between our immaterial minds and the coarse matter of which we are built, what possible form could it take? It is so difficult to imagine how such an interaction could work that no serious model has ever been put forth.
The intuition is strong, however, and dualism is still taken very seriously by quite a few philosophers (although, unsurprisingly, by almost no scientists). Why? Well, consider two prominent alternatives:
One possibility is that there is a mental world — but rather than there being any genuine causal connection, the mental and physical do not interact at all, but still march in lockstep — a regularity maintained by God, or by some unknown agency. This, I think, seems extraordinarily contrived.
Another way things could be is for consciousness to be a subjective “view” of the processes of the brain, but without itself exerting any causal influence. This means that our conscious awareness is just “along for the ride”, and it means also that our sense that it is our consciousness that drives our actions is simply an illusion. This model is known as “epiphenomenalism”.
Neither of these is particularly appealing, as they seem to take the reins from our hands (although in the former case a convoluted sort of causality is still possible, albeit through a mediating agent).
There is, as yet, no way to conclusively refute any of these views, so we must go with our intuitions. I favor epiphenomenalism; I am simply not inclined to posit an entire abstract world of inexplicable causal interactions simply in order to make an exception for a small clade of bipedal apes. I think epiphenomenalism squares well with recent developments in neuroscience, and I believe that a sophisticated interpretation leaves our dignity intact, and is the most parsimonious account of the phenomena. I will take this up again shortly, but for now, it is late, and interested readers are invited to wander over to the discussion at Dr. Vallicella’s place.