As I understand it, one of Williamson’s main concerns with Experimental Philosophy is that it has failed to target a unique philosophical method that (experimental philosophers claim) is in need of revision. As Williamson writes:
What the Experimental Philosophy revolution is supposed to change — systematize, restrict, or abolish — is a philosophical method: the use of philosophical intuitions as evidence. Alexander’s starting-point is that such a method is obviously widespread in, and distinctive of, contemporary philosophy (pp. 1, 11). The systematic deployment of elaborate hypothetical cases is indeed an eye-catching feature of much recent analytic work. But what Experimental Philosophers target is neither the systematicity nor the elaboration. Nor, officially, is it the hypothetical nature of the cases. For many of them can be replaced by real life cases.
In support of this claim about experimental philosophy, Williamson seems to be saying that experimental philosophers have failed to identify something that is uniquely “philosophical” about what they call “philosophical intuitions.” As Williamson writes:
Alexander’s own gloss on ‘philosophical intuitions’, ‘what we would say or how things seem to us’, does no better. In both everyday and scientific situations, when I say that P, I would say that P, and (if I am sincere) it seems to me that P. If I am not idiosyncratic, we would say that P, and it seems to us that P. If I believe that I am not idiosyncratic, I believe that what we would say, and how things seem to us, is that P. [emphasis added]
But isn’t that a big IF? I take it that some work in experimental philosophy has shown precisely that intuitions are idiosyncratic insofar as they vary across cultures and are subject to all sorts of effects, such as order and framing effects. In other words, now that the empirical evidence is out there, we (philosophers) don’t get to assume without argument that we (more precisely, our intuitions) are not idiosyncratic.