There is no consensus in the social and cultural sciences on what theory is, and that is as it should be; a consensus would be outright dangerous for the diversity of intellectual life. The perspectives represented in What is theory? show that theory can be understood as plot, hope, beholding, doxa, heritage, a stalemate, disappointment, personal matter, or family concept. But even if theory can be defined in many ways, it cannot be defined in any one way. Beyond disciplinary and epistemological differences, theory has the steadfast characteristic of being what academics, including students, work with. More than an epistemological matter, the book's title question is an entry into the dynamics of academic practice. The volume consists of a multidisciplinary collection of essays that are tied together by a common effort to tell what theory is. These essays are also paired as dialogues between senior and junior researchers from the same or allied disciplines to add a trans-generational dimension to the book's multidisciplinary approach. What is theory? has been designed for third year undergraduate students, master's degree students, and postgraduates in the social sciences and the humanities, but it should be of interest to anyone who has felt that the question of what theory is can be more easily asked than answered.