The concepts of disease.

Concepts of disease have often been influenced by mediaeval scholastic doctrines. Today these are best replaced by the premises of modern class logic. One of the basic problems then concerns the universal class of patients. Its solution depends on the answer to the question: What are the distinguishing attributes of this class? Scadding stipulated that these attributes must differ from the norm of a species and be associated with biological disadvantage. This paper argues that these attributes must be abnormal by the standards of a population and/or the norms of an individual, and must be associated with at least one of three criteria: (a) therapeutic concern for himself experienced by a person, (b) such concern for him experienced by his social environment, and (c) medical concern for him. This solution, though based on subjective criteria, seems to tally with the actual practice in diagnosing disease.