Last Wednesday's class was, as I'd warned, on Dummett's paper "Truth". As I mentioned in my last post, the students in the class did an amazing job with the paper. Their responses, posted to the courses Canvas site, were all very, very good. I don't wish to take credit for that. It had, in the obvious sense, nothing to do with me. But the reading guide I posted for them, definitely seems to have helped. I've taught this paper many times, and I've never seen people make so much sense of it.
The discussion in class was at a correspondingly high level. We ended up spending the whole time talking about Dummett's two arguments against the explanatory sufficiency of Convention T.
The first, concerning non-referring names, isn't that hard to understand, but we worked through the question exactly what the argument assumes, and when one does that it becomes clear that it has a very narrow target: Frege, basically.
The second is much more interesting. The rough idea is that, if all there is to say about truth is given by Covnention T, then truth cannot play the role in logic that it is often assumed to play. In particular, the truth-tables can have no explanatory value. But what does that mean? That's the hard question.
Ultimately, I think the answer turns on the notion of truth-functionality: A deflationist cannot really make sense of the notion of truth-functionality. The usual way to try to do so is to talk about inferences like:
- A & B
- B <--> C
- So A & C
- (B & C) v (~B & ~C)
I don't know how many people have tried giving students extensive reading notes for papers like "Truth". But I'm going to keep doing it, that's for sure, and I'd recommend trying it to everyone.