Sean Carroll’s new best-selling book The Big Picture runs the risk of preaching to the choir. To my mind, it gives a clear and effective explanation of the usual top physicists’ world view. On religion, mysticism, free will, consciousness, meaning, morality, etc. (The usual view, but an unusually readable, articulate, and careful explanation.) I don’t disagree, but then I’m very centered in this physicist view.
I read through dozens of reviews, and none of them even tried to argue against his core views! Yet I have many economist colleagues who often give me grief for presuming this usual view. And I’m pretty sure the publication of this book (or of previous similar books) won’t change their minds. Which is a sad commentary on our intellectual conversation; we mostly see different points of view marketed separately, with little conversation between proponents.
Carroll inspires me to try to make one point I think worth making, even if it is also ignored. My target is people who think philosophical zombies make sense. Zombies are supposedly just like real people in having the same physical brains, which arose the through the same causal history. The only difference is that while real people really “feel”, zombies do not. But since this state of “feeling” is presumed to have zero causal influence on behavior, zombies act exactly like real people, including being passionate and articulate about claiming they are not zombies. People who think they can conceive of such zombies see a “hard question” regarding which physical systems that claim to feel and otherwise act as if they feel actually do feel. (And which other systems feel as well.)
The one point I want to make is: if zombies are conceivable, then none of us will ever have any more relevant info than we do now about which systems actually feel. Which is pretty much zero info! You will never have any info about whether you ever really felt in the past, or will ever feel in the future. No one part of your brain ever gets any info from any other part of your brain about whether it really feels.
These claims all follow from our very standard and well-established info theory. We get info about things by interacting with them, so that our states become correlated with the states of those things. But by assumption this hypothesized extra “feeling” state never interacts with anything. The actual reason why you feel compelled to assert very confidently that you really do feel has no causal connection with whether you actually do really feel. You would have been just as likely to say it if it were not true. What could possibly be the point of hypothesizing and forming beliefs about states about which one can never get any info?
If you have learned anything about overcoming bias, you should be very suspicious of such beliefs, and eager for points of view where you don’t have to rely on possibly-false and info-free beliefs. Carroll presents such a point of view:
There’s nothing more disheartening than someone telling you that the problem you think is most important and central isn’t really a problem at all. As poetic naturalists, that’s basically what we’ll be doing. .. Philosophical zombies are simply inconceivable, because “consciousness” is a particular way of talking about the behavior of certain physical systems. The phrase “experiencing the redness of red” is part of a higher-level vocabulary we use to talk about the emergent behavior of the underlying physical system, not something separate from the physical system.
There’s not much to it, but that’s as it should be. I agree with Carroll; there literally isn’t anything to talk about here.