Short of coming up with new ideas for the blog, I might steal other people’s ideas that don’t seem to have got much attention. Here’s an interesting example Jon Kvanvig wrote in comments to “a post over at CD”:http://bengal.missouri.edu/~kvanvigj/certain_doubts/index.php?p=23.
bq. Take the airport case, and suppose that John visited the doctor recently. He was told everything was OK, but since the visit the doctor has just found a serious illness revealed by his blood test which must be treated immediately or John will die. If the plane is late, the waiting health officials will not be able to help him, but if the plane is on time, theyll inoculate him and everything will be fine. John, of course, knows nothing of any of this. He doesnt check further to see if his itinerary is still accurate. We assume that apart from the health risk story, John knows that his plane will arrive at 11. Add in the health risk stuff. Are you now inclined to say that he doesnt know?
This is the kind of case on which the subjective vs objective versions of subject-sensitive invariantism differ. That is, if we think that what standard S’s evidence must meet before S knows that p depends on (something like) p’s importance to S, is what matters S’s beliefs about p’s importance, or p’s actual importance. If the former, then John knows in this case the plane arrives at 11. If the latter, he doesn’t.
A brief bit of history here. Last year Jason Stanley did a paper on subject-sensitive invariantism at MIT at and after which some people (including me) urged him to definitively adopt the objective position as a way out of some troubles that kept recurring for the subjective version. And Jason, as illustrated in that CD thread, does now hold the objective position. (And rightly so say all of us!) I can’t remember, if I ever knew, exactly what Jason’s position was before the MIT talk – he may have had the (correct) objective position all along and we just shored up his belief. Either way it’s good and important stuff Jason’s working on and the details matter. Hence we look at cases like this.
Anyway, Jon’s case is probably the first I’ve seen where the subjective version has a little more pull than the objective version, but I think that’s because I’m just not focussing on the right factors. Or maybe it’s the kind of case that will push me back to thinking knowledge = (justified) true belief 🙂
By the way, I never understood the original airport case, which was about whether a particular plane stops over somewhere. (Chicago?) Maybe other airlines are different but in my experience it’s really really easy to find out where a plane is stopping _first_ – that’s the city name in 300pt font on the monitor behind the check-in desk. What’s hard is to find out whether it’s the same plane that’s continuing on to New York or wherever you’re going. I know the epistemological relevance of this little empirical datum is not enormous, but it always made it hard for _me_ to think clearly about the case.