This book provides a thoroughly worked out and systematic presentation of an interpretivist position in the philosophy of mind, of the view that having mental properties is a matter of interpretation. Bruno Mölder elaborates and defends a particular version of interpretivism, the ascription theory, which explicates the possession of mental states with contents in terms of their canonical ascribability, and shows how it can withstand various philosophical challenges. Apart from a defence of the ascription theory from the objections commonly directed against interpretivism, the book provides a critical analysis of major alternative accounts of mental state possession as well as the interpretivist ideas originating from Donald Davidson and Daniel Dennett. The viability of the approach is demonstrated by showing how one can treat mental causation as well as the faculties closely connected with consciousness - perception and the awareness of one's own mental states - in the interpretivist framework. (Series A)