“Astronomer-Philosopher”: the Genesis of the Concept

Abstract

In his famous Dialogue Concerning the Two Chief World Systems, Ptolemaic and Copernican, Galileo Galilei ascribed to Copernicus the status of astronomer-philosopher. Heliocentric astronomy was a result of Copernicus' dissatisfaction with the traditional astronomer's task of “saving the appearances” and of his insistence on answering the philosophical questions about the constitution of the universe. The author of the article first presents Geminos’ classical description of the relative tasks and epistemological range of astronomy and philosophy, and then shows, through a brief analysis of the astronomical work of Peurbach and Regiomontanus, how the split between astronomy and philosophy was overcome already in the late Middle Ages (or Renaissance). The last part of the article deals with an analysis of Copernicus' programme of “philosophical” astronomy. Copernicus' astronomical-philosophical programme, which resulted in a heliocentric version of Ptolemaic astronomy, was a reply to the Averroistic challenge of the restoration of homocentric astronomy, by which some authors (Amico, Fracastoro) tried to establish astronomy on established, sound philosophical foundations. Contrary to this, Copernicus established an astronomy for which he himself invented the philosophical principles (the movement of the Earth).