Franz Anton Mesmer's 1766 thesis on the influence of the planets on the human body, in which he first publicly presented his account of the harmonic forces at work in the microcosm, was substantially copied from the London physician Richard Mead's early eighteenth century tract on solar and lunar effects on the body. The relation between the two texts poses intriguing problems for the historiography of medical astrology: Mesmer's use of Mead has been taken as a sign of the Vienna physician's enlightened modernity while Mead's use of astro-meteorology has been seen as evidence of the survival of antiquated astral medicine in the eighteenth century. Two aspects of this problem are discussed. First, French critics of mesmerism in the 1780s found precedents for animal magnetism in the work of Paracelsus, Fludd and other early modern writers; in so doing, they began to develop a sophisticated history for astrology and astro-meteorology. Second, the close relations between astro-meteorology and Mead's project illustrate how the environmental medical programmes emerged. The making of a history for astrology accompanied the construction of various models of the relation between occult knowledge and its contexts in the enlightenment.

Stud Hist Philos Biol Biomed Sci. 2010 Jun;41(2):158-68. Schaffer S. Department of History and Philosophy of Science, University of Cambridge, Cambridge CB2 3RH, UK. sjs16@cam.ac.uk