As Spain colonized the Americas during the sixteenth century, Spanish soldiers, bureaucrats, merchants, adventurers, physicians, ship pilots, and friars explored the natural world, gathered data, drew maps, and sent home specimens of America's vast resources of animals, plants, and minerals. This amassing of empirical knowledge about Spain's American possessions had two far-reaching effects. It overturned the medieval understanding of nature derived from Classical texts and helped initiate the modern scientific revolution. And it allowed Spain to commodify and control the natural resources upon which it built its American empire. In this book, Antonio Barrera-Osorio investigates how Spain's need for accurate information about its American colonies gave rise to empirical scientific practices and their institutionalization, which, he asserts, was Spain's chief contribution to the early scientific revolution. He also conclusively links empiricism to empire-building as he focuses on five areas of Spanish activity in America: the search for commodities in, and the ecological transformation of, the New World; the institutionalization of navigational and information-gathering practices at the Spanish Casa de la Contratación (House of Trade); the development of instruments and technologies for exploiting the natural resources of the Americas; the use of reports and questionnaires for gathering information; and the writing of natural histories about the Americas.