Tuesday, January 28, 2003

This is a moral philosophy blog, but let’s take a break from that for a moment. It’s epistemology and metaphysics time.

Falsification and Consciousness

Aaron Haspel asked about falsification in the comments below. I gather that “all men are mortal” seemed to him to be meaningful and true though not falsifiable. (I was confused when I suggested that his comment was slightly confused, by the way.) “All men are mortal” is falsifiable, meaningful, and, for presently living men, we are justified in accepting it as true. If we found some billion-year-old people who easily survived all the disasters we could imagine, and if we found that this resilience indicated resistance even to any final state of entropy of the universe, or any ultimate return to singularity that the universe might experience (say, we noticed that their bodies underwent no entropy, and we exposed them to black holes to no effect, etc.), then we would be justified in believing that these people were not mortal but would live forever. Even lying on our death beds, we would be justified in believing this. We wouldn’t need to see that they have lived forever, which it would be conceptually impossible for anyone, immortal or not, to do.

The claim that “all men are mortal” is not falsifiable is an attractive claim only when it seduces one into believing that one would need to see that someone has lived forever in order to falsify it. But one needn’t see that a proposition is certainly false in order to falsify it; certainty isn’t necessary for sufficiently robust falsification. If this weren’t so, then “some men are mortal” would not be falsifiable. We’ve seen apparent deaths, but one might wonder whether the corpses were mere decoys, that all of these apparent deaths were actually placements of these decoys and simultaneous light-speed transports of the real, living person to another planet. One can never see that someone certainly has died.

So, yes, maintaining that a proposition is meaningful only if falsifiable does not run aground on the sentence “all men are mortal.” Therefore, it can be true only if falsifiable. Why does this matter? Because of the deeply important question of the nature of consciousness: Is it physical?

Some like to say that the smell of lilac and the taste of chocolate - that is, these two experiences - are not physical. But - and here is a crucial point - if mind is non-physical, then it would be meaningful to say, “Joe is physically and behaviorally just like anyone else, but he has no conscious states, no mind; in other words, Joe is a zombie.” But this concept of a zombie, a being physically just like us and acting just like us - saying “ow” to pin pricks and “mmm” to chocolate licks - is meaningless. No one has any idea what would count as evidence that showed that the claim “Joe, who is physically and behaviorally normal, does not lack non-physical consciousness; in other words, Joe is not a zombie” was false. This is because nothing could count as evidence that the claim “Joe is a zombie” was true. Therefore, the concept of consciousness as something non-physical is a pseudo-concept. Using that concept of “consciousness,” you couldn’t even in principle prove that there was someone like us who didn’t have consciousness. But there would have to be a way to prove this in principle, if the concept were to have meaning. In other words, if there is an attribute A which you like to believe that some things have, you need to have standards by which to demonstrate that two things with other attributes being the same were different only in the respect that one has while the other lacks A. No one can tell the zombies from the conscious people. This proves that conscious is physical; mind is brain. The proof turns on the premise that meaningfulness requires falsifiability (and verifiability).

(The attempt to get a materialist to accept that “all men are mortal” is meaningful, true and non-falsifiable is often made in order to force the materialist to admit that the non-falsifiability of the proposition “consciousness is non-physical” is no basis for denying its meaningfulness or truth. But “all mean are mortal” is falsifiable. The same holds for the concept of soul. It’s a pseudo-concept, so it’s not the case that we have souls. What would you take as evidence that you didn’t have one?

In other words, the attempt to rescue anti-materialism from charges of meaninglessness is a move to argue that (a.) the standard of meaningfulness has been raised too high by the materialist when he requires falsifiability, given that (b.) even the materialist will find the standard illegitimately high in the case of propositions which he himself accepts, such as “all men are mortal”. The move that I, as the materialist, have made, is to maintain the high standard and to argue that nothing I ought to believe, including “all men are mortal,” fails to meet it. I then proceed to show that the belief that our minds are non-physical requires that the proposition “Joe is a zombie” is falsifiable, when in fact it is not falsifiable.)