A complex and dynamic vision of the natural world emerged within fourteenth-century natural philosophy and, with it, a cluster of logico-mathematical languages capable of describing and bringing order to this vision. Over the course of the century, the traditional image of a world of hierarchically fixed and absolute values began to dissolve, gradually replaced by a shifting, relational world in which values were in constant flux. As philosophers turned from the investigation of perfections and essences to the investigation of motion and change, questions of measurement and gradation came to dominate scholastic discourse. Since the pioneering work of Pierre Duhem in the early years of this century, historians of science have come to recognize the critical place this shift in philosophical concern played in the development of modern scientific thought. The concluding chapters of this book examine the many ways in which the intellectual process of scientific innovation was tied to the social experience of monetization and market development.

The suggestion that fourteenth-century philosophical speculation was influenced by social developments taking place in the society beyond the schools raises a number of questions. If natural philosophers were deeply involved in the world beyond the classroom and sensitive to its changes, why is the phenomenal world – including the world of social experience – so absent from their speculation? Why in the study of nature to empirical observations play a minuscule part within arguments dominated by technical logic?