Doctoral Dissertation Student: Deborah E. Harkness; Title of Dissertation: "John Dee's Mathematical Philosophy and the Language of Nature." The "mathematization of nature" is one of the major factors in the success of modern science. The ability to use mathematical equations to describe the action of physical forces has allowed scientists to achieve unprecedented degrees of accuracy in their predictions. Yet why nature should act in ways that can be described mathematically is not at all obvious even today. Philosophical arguments continue about the "reality" of the relationships described in scientific theories. But whether the mathematical relations are "real" or not, it is clear that they are incredibly useful for science. Ms. Harkness is examining John Dee's mathematical philosophy. Dee was one of the first of early modern natural philosophers who made the case for the use of mathematics in the study of nature. Her study explores the connections between the mathematical philosophy of John Dee and the other facets of his natural philosophy to analyze the ways in which mathematics became the dominant language of science during the 17th century. Drawing on manuscript and printed materials from 13 libraries in the United States and Great Britain, Ms. Harkness is examining Dee's intellectual corpus and is placing Dee's mathematical natural philosophy in the context of previous and subsequent work on mathematics and the natural world.