Abstract

The concept of predisposition in medicine is ancient, and the term diathesis was used to express it since the days of Hippocrates and, especially, of Galen.The concept of diathesis was enormously popular throughout the nineteenth century, despite the vagueness of its actual meaning. It was clarified only in the early years of the twentieth century (1902), when it was however losing its clinical relevance, by a replacement of the concept ofchemical individuality by A.E. Garrod, followed thirty years later by the concept ofinborn factors in disease (1931).