I'm writing a paper on modal knowledge over this Christmas/New Year break. In it I'm trying to argue that we can answer two questions simultaneously:
1. How can experience be a guide to modal truth?
2. How can conceivability be a guide to modal truth?
by proposing that experience grounds our concepts (that is, makes them knowledge-conducive guides to the structure of the world), and that what we can conceive of is constrained by what our concepts are like in such a way that the information about the world's structure which is in encoded in the structure of our concepts is recoverable through the activity we call 'attempting to conceive'.
What's all that got to do with knowledge of what's possible and necessary? Well, things are easy if you think that modal facts are , or metaphysically depend upon, structural facts about the actual world. Because the latter are the kinds of facts that 'attempts to conceive' put us in touch with.
What I'm looking at now are ways in which people who don't like that metaphysical idea might also get in on my epistemological act. Ways, that is, in which you might think that information about actual-world structure can be an epistemic guide to modal facts even though these facts do not depend metaphysically on facts about actual-world structure.
One option is to believe in metaphysical dependence in the other direction: that is, to think that actual-world structural facts depend on modal facts. But that option doesn't have much prima facie plausibility (at least, not to me).
Alternatively you might think both actual-world structural facts and modal facts depend on some other class of facts in a way which explains the correlation between the two. (But what sort of facts would they be?)
There's always the option of brute correlation, but we'll need a damn good story about why we should take the correlation to be brute, to tell to those who think that it's actually evidence of metaphysical dependence in one direction or the other.
Finally, I thought, perhaps you might think there is some satisfying explanation of the correlation which does not appeal to metaphysical dependence at all. (But what would it look like?)
As always, any comments/suggestions/further possibilities are very welcome here.
Happy New Year!