Schizophrenia --its nature, etiology, and the kind of therapy to use for it--remains one of the most puzzling of the mental illnesses. The theory of schizophrenia presented here is based on communications analysis, and specifically on the Theory of Logical Types. From this theory and from observations of schizophrenic patients is derived a description, and the necessary conditions for, a situation called the "double bind"--a situation in which no matter what a person does, he "can't win." It is hypothesized that a person caught in the double bind may develop schizophrenic symptoms