I see Tuomas Tahko , besides posting a bunch of pictures from his recent trip, posted also his paper on modal epistemology . It's quite interesting. Title and details below. Two-Dimensional Modal Semantics, Conceivability, and Modal Epistemology ABSTRACT The combination of two-dimensional modal semantics and conceivability purports to be very powerful: it upholds modal rationalism, explains a posteriori necessity, and even accounts for metaphysical impossibilities—all this while committing to only one modal space, conceptual modality. In this paper I will examine whether two-dimensional modal semantics and conceivability can produce a complete account of modal epistemology and argue that they cannot. We will see that the framework fails to account for metaphysical modality or to deal with metaphysically substantial, essentialist statements because it is unable to distinguish between trivial and substantial modal truths.