Hankinson provides here the first translation into any modern language of Galen's On the Therapeutic Method together with an introduction and a philosophical commentary. On the Therapeutic Method, written late in Galen's life, represents the distillation in its most complete form of Galen's views on the nature, genesis, proper classification, and treatment of disease. It was one of the most widely read of all classical texts during the Middle Ages and the Renaissance, and formed the core of the medical curriculum in the nineteenth century. It has been unjustly neglected in modern times. The first two books of the work contain a fascinating collection of views on scientific terminology and taxonomy, the application of the logical methods of collection and division to science, the axiomatization of science, and the structure of causation.