Forging heredity: from metaphor to cause, a reification story.

THETERM'heredity' was brought into the English language to match the French use of 'heredite'. This happened between 1860 and 1870, when a noun was needed to refer to the maturing domain of scientific enquiry that had come to crystallize around the set of phenomena that were previously loosely clustered around the adjective 'hereditary'. French physicians had been using 'heredite' in such a specialized sense for several decades, and 'heredity' seemed a good option (instead of 'inheritance' or 'heritage', for instance) because it could be both directly related to the widespread French noun and to the adjective 'hereditary', which had long been in use in a similar sense, originally brought into English medical parlance by physicians translating from the Latin adjective haereditarius. The adjective 'hereditary', in the natural sciences, is an ancient borrowing from the legal and soeial sense, based on the straightforward analogy between handing down property or titles to descendants and transmitting physical or moral qualities to them. Although in everyday language the metaphorical (analogical) use of the adjective has been common and widespread in most Western languages for centuries, 1 the first consistent technical borrowing of the adjective was done by physicians when they categorized a set of diseases as 'hereditary' .