The Making of an Astrologer in Fifteenth-Century France. The Notebooks of S. Belle: Lisbon, MS 1711 and Paris, NAL 398

This thesis addresses the practice of late fifteenth-century astrology from the perspective of its techniques and methodology. It offers an internalist view of this topic, as a complement to the existing research into its social and cultural impact. The investigation explores two notebooks written by S. Belle, an astrologer who lived in late fifteenth-century France. They are: Lisbon, Arquivo Nacional da Torre do Tombo, Manuscritos da Livraria, MS 1711, and Paris, Bibliothèque nationale de France, nouvelles acquisitions latines 398. The detailed study of his methodology, his use of the writings of previous astrologers, and the changes and experiments that he makes, show astrology as a living body of knowledge, and how its methods and practices were refined and developed as in any other cutting-edge science. Belle’s work is shown to be an important example of the incipient practice of collecting horoscopes, and of using almanacs and astrometeorology, as well as providing insights into the society of the late fifteenth century.

The study is organized in five sections, each corresponding to different examples of astrological practice: interrogations, conjunctions, solar ingresses and nativities. Each section includes a detailed analysis of the astrological techniques applied by Belle and a comparison with source material, and with other examples of astrological practice in his time. At the end of each section the main topics are highlighted and discussed in the context of the history of astrology. It assesses the duties, professional concerns, and political affiliations of a practicing astrologer, and explores his mentality and personal dilemmas. Moreover, it offers an intimate perspective of astrological practices, techniques, sources, and methods of learning.