Traditionally, imagination has been considered to be a primitive mental state type (or group of types), irreducible to other mental state types. In particular, it has been thought to be distinct from other mental states such as belief, perception, and memory, among others. Recently, however, the category of imagination has come under attack, with challenges emerging from a multitude of different directions. Some philosophers have argued that we should not recognize belief and imagination as distinct states but rather on a continuum, whereas other philosophers have argued something similar with respect to belief and memory. And some philosophers have suggested that we can reduce imagination to other mental states, whether mental imagery,...