Paradoxically, studies of early modern Iberian science have only been carried out coherently and collaboratively during the last few decades, even though fierce debates on the subject have dominated Spanish historiography for more than two centuries. Since the late 1700s, Spain has been the stage of an often bitter controversy known as ‘la polémica de la ciencia española’. The polemic has been played out between criticos, lamenting the absence of Spanish contributions to modernity, and apologistas, presenting Spain as a leader rather than a failure in the intellectual and scientific history of Europe. The former have mourned the role of the Inquisition, censorship, and religious orthodoxy, and the intellectual isolation of early modern Spain cemented by Philip II’s 1559 decree, which prohibited Spanish students and scholars from teaching and studying abroad. According to these critics, the mid-sixteenth century represented the opening stage of subsequent centuries of cultural and intellectual backwardness, and their conclusions often advocated the needs of radical and immediate reforms of Spanish society. In strong opposition to this pessimist view, the apologists, regularly referred to by their counterparts as nationalistas or triunlistas, have presented the period in question as ‘a golden century’ (Siglo de Oro), the glorious culmination of Spain as an unequalled European superpower and creator of the first global empire.