Archive for the ‘philosophy of language’ Category

mixing speech and non contextual logic

October 29, 2011

Geach and Horwich both criticise Strawson’s performative analysis of the truth predicate in English on grounds that seem to me not only mistaken, but a common mistake, really a category error, conflating the speech situation with logic uncontextualized — the logic you study in college. Not just a common mistake, it’s just about everywhere. Here’s their argument:

If Strawson is right that the truth predicate is some kind of gesture of agreement, then accepted deductive arguments will fail, e.g.,

1. Phil’s claim is true

2. Phil’s claim is that snow is white

3. conclusion: snow is white.

If (1) means that the speaker is agreeing with Phil’s claim, then there’s no deduction from the speaker’s agreement to the fact in the conlcusion. At best, the argument concludes that the speaker agrees that snow is white. But even that wouldn’t hold, since agreement, like belief, is probably an opaque context — imagine a speaker who always agrees with Phil whether he knows the details of what Phil thinks, not knowing that Phil has been deceived by someone and believes something that the speaker knows is false.

The Horwich argument is itself a fallacy of equivocation. Assertions in logic are distinct from logical assertions in speech. Speech is always contextualized, so no facts about the world can ever be deduced from it, except the facts of the speakings and believings and, following Strawson, the gestures indicating attitude. To get from speech to facts, you have to move on up to a meta-assertion like, <If S said x and x is true, then what S says is in fact true of the world> where the words “and x is true” is not spoken by any speaker, but sits in a noncontextual world of assertions about the world.

The proper form of the argument in speech goes like this:

1. (I assert/believe) Phil’s claim is true = (I assert/believe) I agree with Phil’s claim

2. Phil’s claim = snow is white

3. (I assert/believe) snow is white is true = (I assert/believe) I agree that snow is white

Now (1) is still an opaque context, so the conclusion might actually not fit with the speaker’s actual prima facie beliefs, but this is exactly the right argument to show why the context is opaque. It’s armed with this argument that you confront the speaker who doesn’t believe that snow is white but who does believe whatever Phil claims, and explain that there’s something wrong with his assumptions about Phil’s claims. That is to say, this argument shouldn’t arrive at any better conclusion than the one it does.

There is, I think, vast confusion about this. You simply can’t shift from speech to non contextual logic. One is necessarily opaque, the other transparent. To derive facts from speech beyond the facts of the speech and it’s speaker, you need a metalanguage.

Now, you might ask whether there is such a thing as non contextual logic — aren’t all statements spoken or written by some speaker or writer. The answer is, that’s solipsism and should be assumed and forgiven. Alternatively, add a hypothetical meta-metalanguage beyond the solipsistic language. It’ll be speculative — “suppose there is a noncontextual logic and it says…”.