Carl Ginet is running an excellent seminar here at Cornell on Timothy Williamson’s Knowledge and Its Limits. Here is a point that David Liebesman and I were pushing a couple of weeks ago against Williamson’s idea that knowledge is the most general factive mental state.
Imagine we discovered a community that had a word “schnow”, which is like our “know”. Their view about schnowledge is quite like our view about knowledge. For instance, they unhesitatingly say that Gettier cases are not cases of schnowledge. But they hold that there are fewer defeaters for schnowledge than we think there are for knowledge. For instance, in case like Harman’s example of the person who happens to not see the misleading newspapers saying the dictator is still alive, they will say that the person schnows that the dictator is dead. In general, it turns out, they don’t think that unobtained misleading evidence defeats schnowledge. They are, however, future externalists in the following sense. The fact that someone will obtain misleading evidence may defeat current schnowledge, though it doesn’t defeat current justification. I’m going to assume (perhaps wrongly!) that their view on schnowledge is strictly weaker than our view on knowledge, since we allow never unobtained misleading evidence to defeat knowledge, but strictly stronger than our view (and theirs) on justified true belief.
Now here are two questions for Williamson.
First, is schnowing that p a mental state? I can’t see anything in the arguments for knowledge being a mental state that would count against schnowledge being a mental state. Note, in particular, that it isn’t (easily) factorisable.
Second, is schowledge weaker than knowledge? That is, do they denote a weaker relation by ‘schnows’ than we denote by ‘knows’? I can see going either way here. On the one hand, they do use ‘schnows’ in a slightly different way to how we use ‘knows’. On the other, when it comes to normative terms, we are generally quite generous about allowing that people with different usage nevertheless have the same meaning. When Osama says, for instance, “Killing Christians is good”, he is falsely saying something using our common concept of goodness, not truly saying something using a different concept of goodness. Perhaps the people in question are just misusing ‘schnows’, or perhaps we are misusing ‘knows’.
But I think there is a problem for Williamson on either answer he gives to this question. If schnowledge is weaker than knowledge, then knowledge is not the most general factive mental state, because schnowledge is more general. If schnowledge is the same as knowledge, then it turns out our term ‘knows’ is not plastic. Small deviations, even large deviations, don’t produce a difference in denotation. But in Vagueness, his view was that vagueness in language is grounded in semantic plasticity. And it would be intolerable to say that ‘knows’ is not vague. So I don’t see a way to hold on both to the view that knowledge is the most general FMS, and the view that vagueness is a product of semantic plasticity.