Since the QT3 community splintered, I find that I’ve been spending more time on the erstwhile refugee forum, Broken Forum, recently. While QT3 isn’t exactly dead, it does feel that Broken Forum has more interesting stuff now and the Politics & Religion subforum feels more pleasant and less pointlessly antagonistic. Anyway, the subject of mind/body dualism popped up the other day, I felt inspired to write some short posts in response. It’s been a while since I last participated in a philosophical discussion so I thought I’d clean up my posts and expand on them here.

I’m not going to go into a complete description of the topic. If you need to, Wikipedia offers a perfectly good summary of the basics. Or if you feel up to it, David Chalmers has a good overview of the entire topic, though he is of course probably the leading proponent of dualism in modern philosophy. Instead, I’m just going to examine two of the most interesting objections to physicalism I’ve seen in the thread. Neither of the objections are very strenuous. I guess physicalism and the scientific worldview are too well entrenched by now. So they’re more like niggling doubts rather than outright objections, but here we go anyway.

1. Physicalism satisfactorily explains all seemingly intelligent behavior but fails to explain consciousness itself.

This line of attack doesn’t try to deny the success that the natural sciences have had at explaining the observable characteristics of intelligence, complex behavior, speech, sense of self etc. Instead, it argues that there is a special characteristic about consciousness, the subjective experience that gives being oneself and being conscious a distinct feeling. This is called qualia, the ephemeral thisness of experience. What is interesting to me is that this argument treats consciousness as if it were superfluous, that is to say science can explain motivations, behavior, memory, even information processing, but consciousness doesn’t seem necessary and therefore doesn’t fit in. This is what I wrote in response in the Broken Forum thread:

You’re talking as if the consciousness itself is just a byproduct. But what if it all that behavioral complexity, sense of self in the past, present and future, a complex web of different and often contradictory intents and motivations, that are all part and parcel of the decision-making and behavior that you say you have no trouble believing that physicalism can account for, can exist only if consciousness exists? I.e. all that meat machinery creates your consciousness, your consciousness then creates the decisions and behaviors that evolution “deems” desirable.

Another poster also referenced the infamous Mary’s Room thought experiment. Another poster correctly pointed out that the thought experiment is inherently flawed if it posits that Mary has all the physical information color and yet is not allowed to process that information using that part of the brain that specializes in vision. After all, to ordinary people, it’s seem obvious enough that possessing academic knowledge of a subject, i.e. reading about it, is not the same thing as experiencing it via your senses firsthand. My response:

It’s not really a hard refutation to understand but it is an excellently written one. Basically reading all of the facts about an experience is not the same thing as experiencing it for yourself, for very obvious reasons. To work fairly the Mary thought experiment would need to be rewritten into something like the following:

Mary was born blind and has therefore never seen anything with her own eyes. However clever scientists have rigged up a direct interface into her visual cortex which thankfully remains intact, transferring whatever visual data they want. Thus Mary can see, in a sense, through cameras or recorded video.

But Mary isn’t content with that and thinks how wonderful it would be to see the world with her own flesh and blood eyes. Then one day, another group of clever scientists manage to create a set of organic eyes cloned from her own cells and implant them into her. Mary anxiously waits for the day when the bandages come off and looks forward to seeing the world in a whole new way.

She is bitterly disappointed to learn that the world just looks exactly the same.

Finally, in response to a direct question about what qualia actually is then, I answered:

To me, philosophers who talk only about the “thisness” of qualia, as distinct from every other aspect of sensory experience, don’t make any sense. Everything that I experience is inextricably tied to my memories of previous experiences. As such the qualia of red that I perceive is different from the qualia of red that you perceive because this is part of who I am. If I did not have qualia, how would I even know that I am perceiving red and how would that instantly bring to mind all of the associated memories and programmed behaviors linked with red? Qualia is at once information received by my senses, the processing of that information, the retrieval of associated memories and my reaction to all of that.

2. Physicalism implies a completely deterministic universe. If determinism is true, then we don’t have free will. However, since we obviously have free will, our decisions must come from something that is nondeterministic. Therefore, physicalism is false.

The second line of argument appeals to free will. My original response to this was very succinct as I simply pointed to Daniel Dennett’s Elbow Room which explains why determinism need not be incompatible with free will. To expand on this a bit, Dennett divides free will into two distinct definitions. The first definition is what he calls freedom to choose. This is free will in the everyday life sense. For example, did someone hold a gun to your head to force you to sign that document? Did you deliberately let the girl fall or did someone push you?

The second definition is what is often used in philosophy and what makes intuitive sense upon first glance, which Dennett calls the unmoved mover. You have free will if when you make a decision, there is nothing else except your own will that drives your decision. This means that given exactly the same situation, you could choose a completely different option. Dennett claims that determinism is compatible with freedom to choose but not unmoved mover. And I posted on Broken Forum on why the concept of unmoved mover doesn’t make much sense once you really go into it:

But think about what an unmoved mover version of free will would truly entail. Here you are, with a lifetime’s worth of memories and influences in your psyche and you perceive some sensory stimuli, say, the chirp of a bird or a pang of hunger. And therefore you act. But if that decision to act is not influenced by that stimuli, by all of the memories and knowledge that you have accumulated, by the present state of your mind and body, then where does it come from, ex nihilo?

Is not a decision that pops into one’s consciousness seemingly out of pure chaos not more abhorrent that a decision that is the culmination of a whole string of past events and causes?

Another poster expanded on this a lot more, stating that it is our entire history up to the point of the decision that determines who we are and what our choice would be. So even if it is all deterministic, we still have free will in the ordinary sense of the term.

Anyway, nothing particularly novel in all this, but it is a lot of fun to get back into discussions like this. So why can’t I find smart people to have conversations like this in real life?