Thorndike’s Consistency. His Researches on the Speculum Astronomiae from 1923 to 1955

Abstract

Lynn Thorndike first became interested in the Speculum when he was writing the second volume of his History of Magic and Experimental Science, and this interest accompanied him throughout his career as he devoted one of his last works to the Further consideration of the ‘Speculum astronomiae’.¹ In the conclusion to the section of the History covering the period from late antiquity to the thirteenth century, Thorndike devoted three chapters to three great scholastic authorities: Albert, Thomas Aquinas and Roger Bacon. A fourth chapter, the LXIIth of the History,was centered specifically on the problem of the attribution of the Speculum astronomiae. The arrangement of the material was not a matter of chance, and the author was right not to exclude Aquinas. Indeed, Thorndike hoped to assemble the data required for a thorough discussion of the attribution proposed by Mandonnet.² After having refuted Mandonnet’s “extraordinary contention that Albert did not believe in astrology”,³ Thorndike showed how this could have logically led to the absurd result of attributing to Roger Bacon a work like the De mineralibus, though it is undoubtedly by Albert.⁴ The History did more than that. Indeed, Thorndike’s enterprise was not limited to an assessment of the role of magic in medieval thought, but also offered a close examination of the science of observation throughout this period. This strategy allowed him to write an important chapter (LIX) on Albert’s attitude towards science, a term rightly understood by Thorndike in all its various thirteenth-century connotations.