The Oxford Graduate Conference this weekend was the best run and most fun conference I've been to. The number of faculty who turned out to multiple student presentations was impressive. I received very helpful and friendly feedback from my commentator, Stephen Williams, and from the grad student and faculty audience members. As well as I can remember, the questions were as follows:
David Alexander asked a follow-up to Stephen Williams' comment regarding the way the "name-perpetuation" and "chain" accounts of internal continuity over-intellectualize the way we keep track of objects over time and space. That gave me a chance to explain that I am most interested in the idea (in Campbell's "Is Sense Transparent?" and in parts of Evans' Varieties of Reference) that there are background presuppositions in place that cut down the number of senses required in a given situation. The next step for this project is to work out exactly what that kind of approach would require. I explained how I thought one thing that it appears to sacrifice is a unified space of reasons, which the (unmodified) Intuitive Criterion of Difference (ICD) makes possible. The point of this paper is to see what you have to do to think about objects if you accept the criterion as stated by Evans. But I'm more than happy to think about ways to modify it.
Timothy Williamson asked about the synchronic status of the ICD and whether I was ignoring that in generating worries about whether we can think the same thought through time. I admitted there was something fishy about the way I generate the worry about thoughts had at different times by claiming that a subject can wonder, at time t1, whether THAT F [currently seen] = THAT F [remembered from a moment ago]. The bracketed bits are supposed to be demonstrations. The left hand side of the identity is a perceptual demonstrative while the right hand side is a memory demonstrative. But what Williamson was querying, I think, was whether showing that the demonstrative, memory-based thought and the demonstrative perceptually-based thought weren't the same thought by application of the ICD thereby shows that there isn't a continuous, present-tense sense that lasts from t1 to t2. I agree that the possibility of doubting that THAT F [currently seen] = THAT F [remembered from a moment ago] doesn't show that there isn't a continuous present-tense sense that lasts from t1 to t2. That's okay, I think, for my purposes in this paper, since what I am concerned with is how our thoughts about an object thought about under different senses at a single time can so much as be valid for the subject (that is, how they can have internal continuity).
Daniel Whiting also asked about presupposition and individuating senses. I said that I thought it was important to be clear that if you make sameness and difference of sense dependent on certain kinds of background presuppositions, you would be making what seemed to me to be a very un-Fregean move. That's not to say that I don't want to make such a move, only that it's important to know what you're getting yourself into (I think you'd be getting yourself into a context-dependent view of sense).
Michael Ayers asked whether a similar problem of internal continuity wouldn't arise in the case of concept-expressions just as with singular terms. Isn't it possible for someone to coherently doubt that, say, "x is sharp" as it appears in different sentences refers to the same property? I said that I thought the answer to his question is "yes", and that we should say similar things about predicates as we did about singular terms. I asked him if he thought there were any special problems posed by concept-expressions, but he didn't say so. But now, on reflection, there might be a serious worry here about the way I try to use anaphora to connect tokens of singular terms together, since there isn't any parallel for anaphora for concept-expressions (I think). So the anaphora aspect of the paper may be a red-herring. This came out in discussion with my moderator after the talk as well.
The chair, Maria Lasonen, asked whether I was entitled to rely on anaphora to explain continuity when it seems that understanding anaphora itself requires understanding the concept of co-reference. (Zed asked a question like this when I gave the paper to the Philosophy of Mind Workshop last year). I said that I wasn't trying to explain the phenomenon of co-reference itself. Invoking anaphora to explain that would be pretty clearly circular. I thought anaphora gave us a kind of co-reference that was achieved simply in understanding a sentence, thereby blocking the kind of doubt the ICD turns on (the ICD requires that it be possible to coherently assent/dissent to two sentences both of which you understand. So the basic trick of the paper is to try to find a kind of co-reference that is guaranteed simply in virtue of understanding the relevant sentences.
I want to post some comments about the other papers I heard, as well as my adventure tracking down an audio recording of a J.L. Austin lecture sometime soon, but right now I'm totally wearied by jet lag.