 Historically, the notions of imagination, conceivability, intuition, and understanding have been prominent in explaining modal knowledge. For Descartes, the source of our modal knowledge is a distinctive sort of intellectual grasp based on understanding, which might be interpreted as a kind of conceiving, or intuiting. For Hume, it is imagination as an experientially-informed cognitive faculty that is a guide to knowledge of possibility (see Gendler &amp; Hawthorne 2002). This Humean tradition has been pursued in the early stages of post-Kripkean discussions of the epistemology of modality by a number of authors, and it has maintained a central role in more recent discussions.