Swamp Thing About Mary at Philosophy Sucks!

Richard Brown has posted a thoughtful discussion of my recent Swamp Mary talk: Swamp Thing About Mary at Philosophy Sucks!

Richard writes:

I suggested in discussion that Pete was running over the distinction between ‘knowing what it is like’ in the general sense, and ‘knowing what it is like FOR one’. To know what it is like for one too see red requires that one have, or be able to recall, a red experience and to be able to say, so to speak, to one’s self ‘this is what it is like to see red’. To know what it is like in the generic sense is to know what it is like to see red in the way that pre-release Mary is typically thought of by the type-b physicalist. She can know a lot about what it is like to see red. She can know that it is more like seeing something pink than it is like seeing blue, and all other kinds of facts. But intuitively she doesn’t know what it is like for her to see red. Once we have this distinction in mind we no longer have a problem with Swamp Mary. Swamp Mary knows what it is like in the generic sense, in just the same way as pre-release Mary, but she does no know what it is like for her to have the experience, again just like pre-release Mary.

Here are my main thoughts on this right now:

Here are two problems I have with the alleged distinction between generic phenomenal knowledge and for-me phenomenal knowledge.

The first problem is something I was trying to articulate during the Q&A in terms of a corner of room that you’ve never been in before. You’ve been in every part of the room except that corner, and the corner is completely visible from the rest of the room. The only knowledge that you lack by necessity of having never been in that corner is the knowledge indexically expressible as “I’m here now”. But aside from this thin and trivial sense that there’s a piece of knowledge you lack prior to arriving in that corner, it doesn’t look like there’s anything substantial that you couldn’t have known already about what’s going on there. It’s hard to see the hubub about the experience requirement as just reducing to this fact about indexicals.

The second problem is something I don’t think we’ve talked about much. It has to do with the generality of the experience requirement. I think a lot of people who are attracted to the experience requirement do *not* think that it generalizes to all experience. So, for example, if someone had seen all shades of gray except for 45% gray, it’s implausible that they would need to experience that shade in order to know what it’s like to experience it. The experience requirement is intuitively powerful for examples like red. But not so much for the missing shade of gray. So what’s the second problem? It’s the problem of supplying an account of what knowing what it’s like FOR one in such a way that you don’t wind up with the fully generalized experience requirement. Now, if the account of for-me phenomenal knowledge just is the indexical thing, then you wind up with an implausibly generalized experience requirement where there’s no significant difference between never having seen red before and never having seen 45% gray before.