Thoughts on Nagel

During this semester in my freshman Honors College class, we read an article called "What is it like to be a bat?" by Thomas Nagel. If you're not familiar with him, Nagel is an anti-physicalist, or more specifically an anti-reductionist, who believes that there is a subjective experience which cannot be explained by a physical description of the world. His argument is as follows.

He asks, what is it like to be a bat? He doesn't mean what would it be like for us to be a bat; he wants to know what it is like for a bat to be a bat. Take part of a bat's sensory apparatus: echolocation. Bats send out a pitch that is out of our hearing range, receives it after it bounces back, and interprets it in such a way that it has some sort of visualization of where it is or where prey is. Everything about this notion is strange to us, or at least most of us. Ben Underwood, among others, is an exception, although because of the lower sound range of the noises these people make, they can only discern larger objects than bats, and there's no way of knowing just how sharply they can make out the object. In any case, I at least can't imagine using echolocation, or what it is like for a bat to use echolocation, since they way a bat's brain interprets sound is different from the way my brain interprets sound.

Now, just as we can't imagine what it is like to be a bat, which is vastly different from us, we can't imagine what it's like to be a different person, which is similar, but everyone has different experience. Ask someone what they see when he sees red, and he will be unable to tell you other than by saying what wavelength the light is and how his eyes and brain react to it. But he still has the experience of seeing red, just as I do, but it's impossible to tell if I really am seeing the same thing he is. Language is a barrier that doesn't allow us to share subjective experience. In addition, we don't know enough about our brains to be able to draw a connection between the physical and chemical brain and subjective experience. This all makes perfect sense, and I think Nagel is right in these respects.

But then he makes a leap that I think is a little rash and, in a way, ignorant and insulting of science. He says that because there is subjective experience that can't be described physically, then a purely physical description of the world, i.e. physicalism, is false. There are a few things that he doesn't take into account in this assertion. First, he assumes that science has somehow reached its endpoint. Maybe right now we don't know how or where to find subjective experience in the human physical brain, but we can't rule out the possibility that science has yet to discover a way. Many brilliant scientific conclusions were thought to be impossible but have since been proven true.

Another argument brought up by a friend of mine goes like this: imagine we have a computer. We can examine it all we want, turn it on and off, track the electricity as it flows through it, maybe even imagine what it would look like when a monitor is plugged in, but until we actually plug the monitor in and see what shows up, we can't see the computer's "subjective experience." We could even take it literally and say that we can observe a brain, see all the neurons firing and different areas lighting up when electrodes are placed on it, but until we can somehow invent a way to literally visualize the thoughts on a monitor, or in some other way make the subjective experience available to the experience of others, we can't experience that person's subjective experience. But in both of these cases there is a distinctively material cause for the phenomenon of subjective experience.

Another argument is mood-altering drugs, like anti-depressants. A person's subjective experience is changed by a condition such as depression, and an anti-depressant provides a physical means of changing subjective experience.

So to recap, I agree with Nagel in that other people, and animals, have a subjective experience that I can't experience myself, unless I could "jack into" their experience as if I were jacking into the Matrix, which can't be ruled out as a future possibility. But he makes a mistake in thinking that just because I can't share my subjective experience or someone else's that it's something that has nothing to do with the physical universe. But this doesn't rule out Nagel's view completely, or proof physicalism completely. Remember that my philosophy is that anything is possible. But Nagel's method of proof is poor at best, while there seems to be a much stronger argument against him and for physicalism.