Medical knowledge in eighteenth century England was characterized by the growth of numerous often contradictory theoretical systems, founded upon a common underlying analogy of bodily processes. This foundation of metaphor was derived from the ancient humoural model of classical medicine, attenuated by the introduction of concepts imported from contemporary mechanical philosophy. Medical theory may be viewed as a form of social interaction between physicians—the elite of the eighteenth century profession—and their aristocratic patients. The phenomenological conceptualization of disease, the speculative and systematic character of pathology, the psychosomatic interpretation of illness and the swingeing use of heroic therapies may be ascribed to the pre-dominance of the upper class patient in the consultative relationship. Furthermore the contemporary career system constrained physicians both to establish their credentials as members of the upper class and to advertise their services by individual display. Fashion provided a form of social behaviour which reconciled these demands, but also generated a profusion of medical theories. In addition the structure of relationships between patients and practitioners, and among medical men themselves, prohibited the emergence of a scientific community dedicated to the analysis of medical problems.