So at the APA I was planning to attend this session on epistemic modals featuring Kai von Fintel, Thony Gillies and John MacFarlane. Unfortunately events intervened and Kai couldn’t make it. For better or worse, the organisers decided that it would be best if someone else, namely me, presented Kai’s paper. This kind of thing isn’t unusual at APAs, people often read out other people’s papers, but in this case I just had the slides to go off. Fortunately they were very good slides, as you can see here, and combined with some guidance from Thony and Andy Egan, I was able to stumble through fairly easily. I even learned something interesting from the paper.
Imagine the following situation. I’m standing in the hotel lobby, on the phone to Andy who is back in his room. I see some people coming in from outside with wet umbrellas and water dripping off their clothes. It seems I can say either (1) or (2) to Andy. (I assume he’s not looking out his window, so weather news is really news to him.)
(1) It must be raining.
(2) It is raining.
Now change the situation a little. I don’t say anything to Andy on seeing the wet people, but wait until I step outside, then report. Now (2) is OK, but (1) seems dubious. So in this context we have
(1) #It must be raining.
(2) It is raining.
It seems that (1) is not a proper assertion when I have direct visual knowledge of the rain. Philosophers (at least philosophers of my acquaintance) usually take the difference between (1) and (2) to be that (1) is only true if someone salient knows that it is raining. But it seems that (1) requires more, namely that the knowledge is somewhat indirect.
That’s what Kai suggested in the paper. I had various long discussions with Andy Egan, Kenny Easwaran and others about what might count as direct and indirect knowledge. The upshot seemed to be when it comes to perception, most anything except direct visual inspection counts as indirect, which is somewhat interesting.
But the most interesting thing I heard was a point that Ishani made. It seems that for the purposes of this exercise at least, testimonial knowledge counts as direct knowledge. (This contradicts the chart that Kai quotes in his slides.) To see this, imagine that Ishani tells me that the Packers won, and I thereby come to know that the Packers won, and Andy doesn’t know this. It seems I can use (4) but not (3).
(3) #The Packers must have won.
(4) The Packers won.
Note that I can say something like (5).
(5) Ishani said that Packers won, and she’s always right about these things, so the Packers must have won.
It is just standalone (3) that seems odd. But this isn’t really a distinction with (1)/(2), because it doesn’t sound too much worse to say (6).
(6) I have a visual impression of heavy rain, and my visual impressions are always reliable, so it must be raining.
Well, (6) isn’t great, but neither is (5) if Ishani’s reliability about football is something that is too obvious to mention (as it is).
Anyway, I now think I’ve learned two things in under a week. First, English has evidential terms. Second, the ‘swamp epistemology’ of English groups (at least for these purposes) visual observation and testimony together, and separate from inference, and (arguably) non-visual perception. That’s quite a lot to learn from looking at a few small pairs like that.