An extensive review of the various approaches to therapy has found that most, if not all, can be described by epithets normally attributed to behaviour therapy, such as arid, rigid and sterile. Little-known papers have shed light on what could be described as existential leaps, or paradigmatic shifts in approaching therapy, leading to the present paper. This paper describes an entirely new approach to therapy, known as Hat Therapy, which embodies a collection of techniques thread through with a unifying theory. The origins, and empirical data supporting the theory behind Hat Therapy are presented, along with an explanation of new terms necessarily coined to encompass the complexity and originality of the approach. Applications for behaviour change are also presented.