 Aquinas, Jean Buridan, and Nicole Oresme, among others of the late medieval period, assimilated Aristotelian economic thought to Biblical teachings and, by and large, cast commercial activities in a negative light (Jones 1989; Langholm 1998). To buy low and sell high was to engage in deception and hence to violate the Golden Rule. To practice usury contravened the Biblical dictum, to “lend, expecting nothing in return” (Luke 6:35). The late medieval philosophers dug more deeply into the evolving legal practices of their time, insofar as wholesale grain merchants, partnerships, and debasements had become increasingly commonplace. Aquinas and Buridan each accepted, albeit with qualifications, that money is but a unit of measure set by men, and thus decreed that the crown might alter the denomination to serve the common good (Kaye 1998; Hirschfeld 2018). Oresme’s Treatise on Money (1358) went further, acknowledging the problematic shortage of specie and thereby promoting the use of copper or “black money”, since the coins had turned this color from overuse. He positioned the currency within the commercial sphere and thus broke all the more from the Christian view that the established coins emanated from God via divine rule, and were thus the sole property of the prince (Lapidus 1997).