One can make a strong case for William Buchan's Domestic Medicine being the most widely read – nonreligious – book in English during the half century following its Edinburgh publication in 1769. Certainly it was the most frequently reprinted medical treatise in Britain and the United States. Its pages illustrate with particular clarity the shared knowledge and assumptions that bound professionals and lay people together in a community of ideas and healing practice. Buchan concedes the reality of lay practice and the widespread distribution of medical knowledge, yet seeks to define a special role for the credentialed physician.

I had long felt a bookshop browser's interest in Buchan's treatise; it was the only pre-1850 medical text that one was almost certain to find in the “old medical” section of any used or rare bookshop. But when I began my academic work in the early 1960s, it had not seemed an appropriately dignified subject for research. After writing the previous chapter on traditional therapeutics in the mid-1970s, however, I began to think more systematically about the day-to-day aspects of Anglo-American medical care and Buchan seemed an obvious place to start. A growing interest among professional historians in popular ideas and world-views also made the Edinburgh physician's effort to improve “domestic medicine” a potential tool for use in evaluating the relationships among high, low, and middle orders. Material that had seemed marginal – quaint and anecdotal – when I began graduate school in the late 1950s had gradually become acceptable, even exciting to a growing number of professional historians.