SummaryMuch medical, psychiatric and social thinking in the second half of the nineteenth century was influenced by the concept of progressive hereditary degeneration most systematically formulated by the French psychiatrist B.A. Morel (1809–1873). Alcoholism was one of the conditions postulated by Morel as leading to direct hereditary consequences for the offspring. This essay examines the pervasiveness of hereditary degenerationism in general, and alcoholic degenerationism in particular, in British and European psychiatry in the period, and then describes the work of several individuals who challenged this notio