 The origins of Descartes’ method are coeval with his initiation into a radical form of natural philosophy based on the combination of mechanics, physics, and mathematics, a combination Aristotle proscribed and that remained more or less absent in the history of science before the seventeenth century (on the relation between mechanics, physics, and mathematics in medieval science, see Duhem 1905–1906, 1906–1913, 1913–1959; Maier 1949–1958; Clagett 1959; Crombie 1961; Sylla 1991; Laird and Roux 2008). Descartes first learned how to combine these arts and sciences from the Dutch scientist and polymath Isaac Beeckman (1588–1637), whom he met in 1619 while stationed in Breda as a soldier in the army of Prince Maurice of Nassau (see Rodis-Lewis 1998: 24–49 and Clarke 2006: 37–67). Beeckman described his form of natural philosophy as “physico-mathematics” (see AT 10: 67–77 and Schuster 2013), and the two men discussed and corresponded about problems in mathematics and natural philosophy, including problems in the theory of music, hydrostatics, and the dynamics of falling bodies (see AT 10: 46–47, 51–63, 67–74, 75–78, 89–141, 331–348; Shea 1991: 1–121; Damerow et al. 1992; Schuster 2013: 99–167).