The Brain and its States

Some time ago I was invited to contribute a paper to a forthcoming volume entitled Being in Time: Dynamical Models of Phenomenal Experience. I was pleasantly surprised to find out that I was invited because of my paper “What is a Brain State?” Looking back at that paper, which I was writing in 2004-2005, I was interested in questions about the Identity Theory and not so much about consciousness per se and I wished I had said something relating the thesis there to various notions of consciousness. So I was happy to take this opportunity to put together a general statement of my current views on this stuff as well as a chance to develop some of my recent views about higher-order theories. Overall I think it is a fairly decent statement of my considered opinion on the home of consciousness in the brain. Any comments or feedback is greatly appreciated!

The Problem of Zombie Minds

So I am finally done teaching summer school and am ready to settle in to my two weeks of ‘vacation’ before the Fall semester begins. Just as I am about to switch on the PS3 I am struck by the following line of argument…let me know what you think of it…

Those who know me know that I am fond of an argumentative strategy that I call ‘deprioritizing’ when it comes to a priori arguments against (or for) materialism. The idea is taken from the police. When something is deprioritized we still recognize it is a legitimate thing but also recognize that it is not a high priority. So if we are deprioritize the a priori arguments we can still acknowledge that in principle we can tell a priori what is what but for us it will be an empirical discovery. By the time a priori methods will be useful it will be too late. I do this by introducing shombies and zoombies. A shombie is a physical duplicate of me that has consciousness in the absence of any non-material properties. I have claimed that when we are conceiving of a shombie world we are NOT conceiving a a zombie world. But how do we know that it is not? I tend to think of the shombie world as the close possible world where some kind of higher-order theory is true and we have consciousness just like we do in the actual worlds.

This got me to thinking. How does the other side know that consciousness is absent at the zombie world? According to them to know that one is consciously seeing red is to be acquainted with a red quale in such a way as to have it partly constituting my belief or judgment. So to know that we have consciousness, or to know that it isn’t lacking at the actual world, requires being acquainted with it. So how do we know that it is lacking at the zombie world? Sure can conceive of a word with our physics at some future date but all we can ‘see’ is that there are beings there who look like us, talk like us, etc. It would seem that we have no way to tell from the third-person whether these ‘zombies’ really do lack consciousness and since that is the only way for us to know about zombies we are led to a contradiction. In order to conceive of zombies we must know that they lack consciousness, but it is impossible for us to know that they lack consciousness, thus zombies are inconceivable. We can sum this up in the following argument.

1. If zombies are ideally conceivable then we can know that they (the zombies) lack consciousness
2. We cannot know that they lack consciousness
3. Therefore zombies are not ideally conceivable

An opponent might respond that it is just stipulated that there is no consciousness at the zombie world but this is exactly the reason why physicalist claim that the zombie argument is question begging or that it builds into the very concept of consciousness that it is non-physical.