“A work of meticulous scholarship, Secret Science is must reading for anyone interested in the history of early modern science, the history of cosmography, and the intellectual challenges posed by the discovery of the New World. Of key importance is Portuondo’s understanding of science as an administrative practice that privileged the collection of empirical data as opposed to philosophical speculation into the secrets of nature. The book also questions traditional assumptions concerning Spain’s supposed lack of participation in the early modern revolution in science, and in doing so, forces us to rethink what this revolution was about.”

Richard L. Kagan, Johns Hopkins University

“This impressive and original book finally brings Spain—long neglected by historians of science—into the picture of the Scientific Revolution.  Secret Science takes us on a fascinating voyage through the scientific institutions that King Philip II created in order to build a body of confidential scientific information about his vast empire. María Portuondo creates a vivid portrait of the Spanish royal cosmographers at work, as they devised instruments, drew maps, and described in meticulous detail the physical features of the empire. Besides detailing the achievements of the cosmographers, Portuondo demonstrates that Philip II, far from being a hidebound reactionary, as the Black Legend portrays him, was a pragmatic, modernizing prince who used science and technology to build the first empire in world history over which the sun never set, and in the process created a vast inventory of real, tangible knowledge about the New World. This is cultural history of science at its best:  learned, original, and compelling. Vivid, engrossing, and full of fascinating details, the book will completely change the way we think about the origins of science. It’s a must read for historians of science and cultural historians alike.”

William Eamon, New Mexico State University

"Impeccably researched. . . . Portuondo’s study reveals valuable evidence with which scholars can refashion their images of the Renaissance world and the achievements of Spanish science at the dawn of modernity."

Neil Safier | Nature

“This is an important book about an extremely important subject. . . . [Portuondo’s] elegant prose and meticulous apparatus deftly guide the reader through the wealth of archival, printed and secondary sources that underpin her careful analysis.”

Adam Mosley | Journal for the History of Astronomy