The philosopher Fred Dretske died the other day. I had never read his work, but I had heard of him, of course, as he was one of the most prominent American analytic philosophers of the past half century. Hearing of his death, I thought I would quickly look into the nature of his work, in very broad outline, and I came across a really cool paper titled “Epistemic Operators.” In this paper Dretske argues briskly and convincingly that the following situation is perfectly coherent:
1) David knows that P.
2) David knows that if P, then Q.
3) David does not know that Q.
So here’s the puzzle: without looking up Dretske’s paper or any related materials, can you think of the kinds of example Dretske adduced in support of his remarkable thesis?