SPECIAL ISSUE ARTICLE Corn, cochineal, and quina: The “Zilsel Thesis” in a colonial Iberian setting William Eamon Department of History, New Mexico State University, Las Cruces, New Mexico Correspondence William Eamon, Department of History, New Mexico State University, Box 3H Las Cruces, NM 88003-8006. Email: weamon@nmsu.edu Edgar Zilsel's famous thesis, which argues that modern experimen- tal science was born from the union of artisans and intellectuals in the 16th century, received little support when Zilsel proposed it in the 1940s. In recent years, however, with the turn toward social and cultural history of science, the “Zilsel Thesis” has undergone something of a revival as historians rethink the relevance of arti- sanal knowledge for the history of early modern science. This essay looks at the Zilsel Thesis in a global setting – specifically a colonial Iberian setting – and argues for its relevance in framing natural his- tory, medicine, and the impact of science on everyday life. Using the examples of corn, quina, and cochineal, this essay argues that the agronomic, chemical, and entomological knowledge accumu- lated over generations of practice by indigenous practitioners was in fact artisanal knowledge that was passed on to European intel- lectuals in “global trading zones” to become part of the Western scientific patrimony. KEYWORDS cochineal, Iberia, maize, quina, Zilsel Thesis The Austrian philosopher and historian Edgar Zilsel (1891–1944), whose research inspires many of the articles in this special issue, has been aptly described as a “many-sided marginal man.” 1 The author of a pioneering and distinctive interpretation of the history of early modern science, his work was bold and original, yet was received with deep skepticism and little serious attention during his lifetime, if not stone-cold silence. Zilsel argued that modern science was born from the union of intellectuals and the practical activities of arti- sans in the 16th century. He linked the convergence of these previously alienated traditions to the collapse of the social barriers that had kept craftsmen and intellectuals apart. The breakdown of the barriers between artisans and men of learning was a consequence, he argued, of the rise of capitalism and the decline of craft guilds, which carefully guarded artisanal secrets. The expansion of industry and commerce during the Renaissance opened up 1 Raven & Krohn, 2000, p. xix. Received: 6 October 2016 Accepted: 14 December 2016 DOI: 10.1111/1600-0498.12199 Centaurus. 2018;60:141–158. wileyonlinelibrary.com/journal/cnt © 2019 John Wiley & Sons Ltd 141