I dreamed I saw this argument on the train here from Boston, and I thought it was worth writing up. I also think it is worth writing a detailed commentary on, because it strikes me as plausibly sound, but that’s for another day. I also also think the argument I dreamed about was considerably more complex than this one, but I can’t entertain particularly complex thoughts while actively conscious. Note that by sensitive here, I mean to denote a property beliefs have to the effect that they would not exist were it not the case that they were true.

1. For all F, if an intuition that a particular justified true belief (JTB) does not constitute knowledge is grounded in the fact that the JTB in question is not F, and it is not true that all knowledge is F, that intuition does not constitite evidence against the theory that all justified true beliefs constitute knowledge. (the JTB theory).
2. If there is no example of a sensitive JTB that is intuitively not knowledge, then the intuition that a particular insensitive JTB does not constitute knowledge is grounded in the fact that it is not sensitive.
3. Not all knowledge is sensitive.
4. There is no example of a sensitive JTB that is intuitively not knowledge.
5. If there is no intuition about a particular case that constitutes evidence against the JTB theory, then the JTB theory is true.
6. Therefore, the JTB theory is true.

As I said, I could go on for a while about the evidence in favour of each of the premises, but for now I’ll just leave you with the argument. It could probably do with some tidying up in places to guarantee its validity, particularly to do with the notion of evidence in premises 1 and 5, but I think it is clear enough what is going on there.