Cognitive neuroscience has already established that many of the most obvious things introspection tells you about your mind are illusions. (The Atheist’s Guide to Reality, p. 148)
That science has found surprising things is not in dispute; I love reading on these as much as anyone (as my wife can attest). Rosenberg’s mistake, in my view, is to leap from this conclusion to the idea that we should reject introspection completely. He boldly declares:
The notion that thought is about stuff doesn’t even approximate what is going on in the brain. (ibid, p. 208)
This is, of course, both unwarranted and self-contradictory in at least two ways. I’ve already discussed the idea that the thought about the idea that thoughts can’t be about things is incoherent. But it is no more so than the idea that neuroscience can invalidate introspection as a source of knowledge about our minds.
That is to say that neuroscience relies on introspection. It maps brain-states, and correlates them with what test subjects tell the scientists about what they are experiencing internally. In short, introspection is a foundational tool of neuroscience.
Of course, this doesn’t mean that introspection is perfect any more than our sensory perceptions are perfect. But, as with the physical senses, science is a tool to correct our mistakes and sharpen those perceptions, not simply reject them.
This unwarranted jump from “introspection isn’t perfect” to “introspection is completely worthless as a source of knowledge” seems fairly common, and I think we need to be careful about it. Rosenberg himself criticizes others for trying to take an overly simple approach to philosophy, and I think his warning applies here.
It would, after all, be very easy if everything that existed were observable through science. It would give us the comfort of certainty about what life is like, and clear-cut answers to its biggest questions. Part of me suspects that this is the reason why materialism is so appealing to many.
But, whether or not I’m right about that last, it is too simple–too easy to say that we can simply wave off our basic experience of life. We can’t simply reject introspection, as Rosenberg suggests.
Of course, I would argue that refusing to reject introspection means rejecting materialist accounts of the mind. And this is precisely why Rosenberg is so interested in discrediting introspection; he knows it is inconsistent with his materialism.
As much has been said, I’ve still not touched on all the ways in which Rosenberg shows how materialism breaks down into self-contradiction. I don’t think it is an exaggeration to say that his book has done more to convince me of the falsehood of materialism than anything I’ve read from a theist.