This is the first time I’ve been back to Certain Doubts in a while. It seems a bit like walking about a ghost town, with all the posts being announcements and there being no comments. I remember the discussions that went on here. (Those discussions seem to echo about these deserted streets, I’d say – if I were the kind of person to say such a thing.)
In fact, some of my own published work started at in discussions here. And it’s a case of that that brings me back now. Back in June of 2004, I reported the results of some polls I had taken in classes I taught on whether we know that we’re not brains in vats in a post here called “Polls Show that the Skeptic is Right.” The discussion that followed was very helpful to me.
Since then, I’ve conducted the poll several more times — the results of a couple were reported on late-added comments to the old post, and the last time (not reported anywhere until now) was this past January, where the class was quite large, and the results were stronger than ever, in favor of the skeptic.
But I’ve also, in the meantime, with Josh Knobe’s help, conducted an x-phi-style survey on the issue — getting very different results. I suppose, returning to the scene of the crime, this is the place to do an online follow-up report.
And I guess the most efficient way of doing that is to link to how reported and discussed the results in my recent book, The Appearance of Ignorance. I report the survey results in Appendix B of the book and discuss them in Chapter 2, where they play a role in the evaluation of the power of the classical skeptical argument that flows from the key premise that one doesn’t know that one isn’t a BIV. I’ve put that chapter and that appendix (in pre-pub draft form, but this is quite close to how things ended up in the actual book) together into one document, which is here. If you just want the x-phi survey results, the brief appendix which presents them is at the last three pages of that document. If you’re interested in the discussion of the power of the skeptical argument that takes into account those results, as well as the results of my class polls, the relevant part of Chapter 2 is sections 7-9 (at pp. 19-27 of the draft linked to above).
(I suppose also relevant is Appendix A, where I critically (or is it defensively?) discuss two papers in which critics of the classical skeptical argument put forward arguments/paradoxes (a strong argument for a strongly counterintuitive conclusion forms something of a paradox) they claim are better than it is: Jim Pryor’s modified skeptical argument, and Alex Byrne’s championing of the sorites. A draft of Appendix A is here.)