“Ishani”:http://philosophy.syr.edu/maitra.html pointed out something the other day about Moore’s paradox that I’d come close to noticing, but never quite noticed. Well, two things actually, one of which had almost occured to me and the other of which never did. These might be well-known to Moore’s paradox afficianados, but I suspect they are new. Consider the sentence (1)

(1) I can’t bench press 1000 pounds, but I don’t know that I can’t bench press 1000 pounds.

The typical philosopher’s reaction is to say that the sentence is somehow pragmatically defective, and then tell (or rehash) their favourite story about why it is defective. Ishani’s first point is that it isn’t obvious that _every_ token of (1) is defective. In particular, with the right kind of stress on _know_ in (1), it might almost be properly assertible.

It’s a little remarked upon fact in epistemology that to make seriously sceptical claims you have to use a non-standard focal pattern. Listen to what an ordinary sincere utterance of (2) sounds like. (This isn’t an audioblog, so you’ll have to pronounce it yourself. But think about how you’d say it, if you meant to be saying it truly.)

(2) I don’t know that I can’t bench press 1000 pounds.

I think you need strong, perhaps super-strong, stress on _know_ to get that to work. It’s the kind of stress you’d indicate in writing by italicising the word. (Here’s “Josh Marshall”:http://www.talkingpointsmemo.com/archives/001930.php, who for current purposes will do as a man on the street, using just that convention.) Conversely, it’s possible, well maybe _possible_, that if you do stress _know_ this way, (2) is true. This is a respect in which _know_ does resemble a gradable adjective, although I’m still impressed by “Jason’s list”:http://www.rci.rutgers.edu/~jasoncs/LingContext.pdf of the ways in which it does not. In any case, there’s a certain kind of setting where (2) is acceptable with the right kind of inflection, whether or not it is actually true.

For another demonstration of this, consider the following example. I’m sitting at home watching a Red Sox game, and the Sox are down big in the late innings. Someone tells me I should give up on the game and head to the bar, because the Sox are going to lose. Compare the stress patterns, especially the stress on _know_, in these two possible answers.

(3) You don’t know they’re going to lose – teams have been known to climb out of deeper holes.
(4) I know they’ll lose – but if they come back I want to be able to say I saw it.

Both are acceptable answers (well, relatively acceptable answers) but only with _know_ stressed in (3) and destressed in (4).

Here’s Ishani’s first point then, the one that I’d almost noticed. With this kind of heavy stress, the kind that makes _know_ pragmatically equivalent to _is absolutely certain_ , (1) could be acceptable. Or at the very least, with that stress (5) could be acceptable.

(5) I don’t _know_ I can’t bench press 1000 pounds, but I can’t bench press 1000 pounds.

That’s interesting, and should be a constraint on a theory of how Moore’s paradox works. Here’s the more interesting point, the one that I was completely surprised by. (1) isn’t the only kind of Moore paradoxical sentence. There’s also (6).

(6) I can’t bench press 1000 pounds, but I don’t believe that I can’t bench press 1000 pounds.

And here’s the new point. No amount of focal stress on _believe_ changes the fact that (6) is defective. (6) is just plain defective. That looks like an important disanalogy between the belief case and the knowledge case. And it suggests, strongly suggests to me, that the two cases reflect subtly different phenomena.

One caveat on the point about (6), one that doesn’t affect the overall point. If you put the right kind of stress on _believe_, so that the negation in (6) becomes metalinguistic negation, (6) might almost be acceptable.

(7) I can’t bench press 1000 pounds, but I don’t _believe_ that I can’t bench press 1000 pounds.

But that isn’t quite right either. The problem is the ‘but’. (8) is relatively OK, but means something quite different.

(8) I can’t bench press 1000 pounds. I don’t _believe_ that I can’t bench press 1000 pounds(, I _know_ I can’t bench press 1000 pounds).

Stress makes _believe_ turn into _merely believe_ and _know_ turn into _is absolutely certain_. So the effect of stress on the “Moore paradoxical sentences” (1) and (6) is very very different. Again, this suggests that we aren’t necessarily looking at a unified phenomena.