From the patristic period to the beginning of the seventeenth century curiosity was regarded as an intellectual vice. Curious individuals were considered to be proud and "puffed up," and the objects of their investigations were deemed illicit, dispute engendering, unknowable, or useless. Seventeenth-century projects for the advancement of learning had to distance themselves from curiosity and its dubious fruits or, alternatively, enhance the moral status of the curious sensibility. Francis Bacon's proposals for the instauration of knowledge were an integral part of a process by which curiosity underwent a remarkable transformation from vice to virtue over the course of the seventeenth century. The changing fortunes of this human propensity highlight the morally charged nature of early modern debates over the status of natural philosophy and the particular virtues required of its practitioners. The rehabilitation of curiosity was a crucial element in the objectification of scientific knowledge and led to a gradual shift of focus away from the moral qualities of investigators and the propriety of particular objects of knowledge to specific procedures and methods.