Samantha Matherne defends a systematic interpretation of the philosopher Immanuel Kant's theory of imagination. In contrast with more traditional theories of imagination, as a kind of fantasy that we exercise only in relation to objects that are not real or not present, Matherne argues that Kant theorizes imagination as something that we exercise just as much in relation to objects that are real and present. In short, she attributes to Kant a view of imagining as something that pervades our lives. In order to bring out this pervasiveness, Matherne offers an account of what kind of mental capacity Kant takes imagination to be in general. She then explores Kant's picture of how we exercise our imagination in perception, ordinary experience, the appreciation of beauty and sublimity, the production of art, the pursuit of happiness, and the pursuit of morality. However, she makes the case that Kant's analysis of this wide range of phenomena is underwritten by a unified theory of what imagination is, as a remarkably flexible cognitive capacity that we can exercise in constrained and creative, playful and serious ways.