||Perception provides us with access to the actual world -- to things that actually exist and to states of affairs that actually occur. In contrast, imagination provides us with access to merely possible worlds -- to things that do not actually exist and to states of affairs that do not actually occur. Imagination is philosophically important for its role in many different domains of inquiry. In aesthetics, imagination is invoked to explain our engagement with fiction, music, and the visual arts. In modal epistemology, imagination is invoked to explain how we can justify our modal beliefs. In philosophy of mind, imagination is invoked to explain our capacity for mindreading. More generally, imagination is thought to connect with creativity and thus to play a role not only in artistic creation but also in scientific and mathematical discovery.