Supposition is frequently invoked in many fields within philosophy, including aesthetics, philosophy of mind, philosophy of science and epistemology. However, there is a striking lack of consensus about the nature of supposition. What is supposition? Is supposition a sui generis type of mental state or is it reducible to some other type of mental state? These are the main questions Margherita Arcangeli explores in this book. She examines the characteristic features of supposition, along the dimensions of phenomenology and emotionality, among others, in a journey through the imaginative realm. An informed answer to the question "What is supposition?" must involve an analysis of imagination, since supposition is so often defined in opposition to the latter. She assesses rival explanations of supposition putting forward a novel view, according to which the proper way of seeing supposition is as a primitive type of imaginative state. Supposition and the Imaginative Realm: A Philosophical Inquiry will be of great interest to students of philosophy of psychology, aesthetics, philosophy of mind, philosophy of science and epistemology.