"Les maladies héréditaires:" 18th century disputes in France.

This paper describes and analyses the discussions on the subject of hereditary disease that took place between 1748 and 1800 among French physicians. Two essay competitions which set prizes for dissertations on the hereditary transmission of disease (Dijon, 1748; Paris, 1788-1790) prompted several writers to try and specify the peculiarities of hereditary causes. The publication of a sceptical essay written for the first competition by Antoine Louis was a major cause of concern for medics wishing to preserve hereditary influence as a valid etiological category. Louis' analytical denial of even the possibility of the existence of an hereditary cause led both the judges and the best medical writers who took part in the Paris competition to force the situation towards the establishment of clear criteria for isolating the hereditary cause from other pathological influences. The transition from a humoralist to a solidist view of the human constitution (body) provided the frame within which the different criteria for heredity were discussed. The prize essays of the Paris competition shared the position that hereditary influence was characterized by a latent, predisposant kind of causation, which could produce some well known phenomena like atavism (or regression) and homochrony. The solidist causes were thought by most to be better candidates for that role. These developments turned out to be crucial for the emergence and strength of 19th century French (and European) hereditarianism, in medicine and other fields.