Since the beginning of the eighteenth century, the philosophy of art has been engaged in the project of defining fine arts by finding out what they have in common. Peter Kivy’s purpose is to trace the history of that enterprise and argue that the definitional project has been unsuccessful, with absolute music as the continual stumbling block. His fruitful change of strategy entails exploring the differences among the arts instead of engaging in an obsessive quest for sameness. He presents five case studies in both literature and music.