| In placing the sun near the center of the universe and eliminating the equant, Nicolaus Copernicus unified the previously separate disciplines of mathematical and cosmological astronomy as they had been defined in the hierarchy of the sciences since antiquity.;This hierarchy was a combination of the classical division of the sciences, Arabic philosophy, and mediaeval Christian metaphysics. The universities of Europe institutionalized the hierarchy: theology, civil and canon law, and medicine were marked by advanced degrees and increased professional status; mathematics and natural philosophy were less important. The division of the sciences by methodology precluded the use of mathematical demonstrations for causality. The naturalist astronomer, concerned with planetary nature, composition and true motion, and the calculatory astronomer, concerned with determining positions of planets in order to construct calendars and horoscopes, had complementary but separate roles.;How completely these roles were divorced in the century just prior to Copernicus is the subject of this thesis. The conflict between the Ptolemaic and Aristotelian accounts was recognized throughout the middle ages. In the late middle ages, the scholars who had received criticisms of both systems from their Arabic predecessors tried to clarify the separate theories in commentaries on the De caelo and in introductory texts to Ptolemy--the De Sphaera of Sacrobosco and the anonymous Theorica planetarum were among the most popular--as well as tables and instruments. Within these texts, however, the authors transgressed the dividing lines of the disciplines to criticize, or relate, the corresponding theories of the other approach.;To examine the relationship between the natural philosopher and the practical astronomer in the late middle ages, this study examines the theoretical organization of knowledge which existed in the fifteenth century, and its origins in the classical and medieval writings on the division of the sciences; the curricula of the medieval universities as they were shaped by the considerations of organization of knowledge; and the commentaries on the De caelo and the De sphaera which comprised the main textbook tradition in astronomy until the end of the century. |
