Signs, Symptoms, and Systematics

A patient presents an array of signs and symptoms which his physician evaluates and analyzes for "diagnostic clues" he hopes will lead him to an understanding of the mechanism of the patient's illness, if not its cause. This diagnostic process followed by each physician should be recognized as one of identifying the patient as being similar to other patients the physician has read about or seen himself. Diagnostic labels derived from such patient study have little importance except as representations of more or less loose association of similar patients about which some statements may be made regarding common mechanisms or causes of illness or regarding therapeutic choice, response and prognosis.¹ Development of a systematic classification of patients into "diagnostic" groups or clusters with similar characteristics is a somewhat different problem and one that must essentially precede the one of identification of the individual patient as belonging to a given