One cannot recount the early history of the cryptography manual, or the early history of technical communication more broadly, without addressing the seventeenth-century interest in universal languages and the distrust of alphabetic words “as a source of wisdom.” “Existing languages were seen as unduly irregular” and even “pernicious,” David Cram and Jaap Matt summarize, and “large portions of time were needed to master them.”1 Theologically, universal language was hoped to be a cure for the diversity of world languages that resulted from the Fall, though even this anxiety was motivated by contemporary political and economic uncertainty. Robert Markley sees in Robert Boyle, Isaac Newton, and their contemporaries “the redemption of a fallen world, the fulfillment of prophetic history, and the stability of a sociopolitical order which they perceive as both divinely sanctioned and beset by a variety of internal and external threats.”2 James Knowlson suggests, in his study of universal language schemes from 1600-1800, that scholars like Wilkins were driven by the idea that regionalized languages limited the potential for acquiring knowledge.3 Robert E. Stillman agrees that universal languages supported the “conservative interests” of state power, free commerce, and the national and individual accumulation of wealth.4 The key to achieving personal as well as global intelligence was to bridge the language gaps between cultures by developing a new communication system. The quest for a method of communication of things rather than ideas that do not exist except within the imagination is central in Wilkins’s earlier work in cryptography; I argue that it is in Mercury where Wilkins begins to develop a practical solution for global communication across native languages that grounds, but is not indistinguishable from, his later philosophical language.