Considerable historiographical controversy surrounds the question of why and how Copernicus decided to overturn the prevailing Earth-centered representation of the heavens. This essay summarizes some key elements of an explanation first laid out in The Copernican Question: Prognostication, Skepticism, and Celestial Order (2011) and subsequently expanded with further evidence in Copernicus and the Astrologers (2016). Copernicus’s defining problem situation is to be found in his involvement in a culture of astrological prognostication during his student days in Bologna (1496–1500). Just before (...) Copernicus’s arrival in the fall of 1496, Giovanni Pico della Mirandola’s attack on the foundations of astrology appeared from a prominent Bologna publisher. This publisher also produced several of the prognostications authored by Domenico Maria di Novara, in whose house Copernicus lodged. Among Pico’s many charges was a claim that astrologers do not agree on the order of the planets. Although the word “astrology” appears only once in Copernicus’s extant writings, it is certain that he was aware of Pico’s account of the astrologers’ disagreements on the matter of planetary order. The Copernican Question sets forth an inference about how and why Copernicus turned to heliocentrism that claims to be not only plausible but also the likeliest to correspond to what actually happened. (shrink)

ArgumentDuring the two decades before the turning point in Copernicus's personal and scientific development in 1510, he had experience of political activity which has been largely ignored by the existing Copernicus literature but part of which is reconstructed in outline in this paper. Given the close linkage between politics and astrology, Copernicus's likely reaction to astrology is re-examined here. This reconstruction also suggests that the turning point in 1510, when Copernicus left his post as secretary to his uncle Lucas Watzenrode (...) the prince-bishop of Warmia, was not only linked to Copernicus's first version of his heliocentric theory in theCommentariolus, but also to major political setbacks being experienced by Watzenrode during these years, and with the publication of Copernicus's translation of theLettersof Theophylactus Simocatta. Some of these considerations contribute to maintaining the view that Copernicus and his work were in several respects exceptional. (shrink)

During most of Copernicus's life he was an inhabitant of political settings rather than scientific settings. His settings from 1492 to 1500 offered him a large amount of information about astrology. Most of Copernicus's known significant contacts at the Jagiellonian University had expertise in astrology, in some cases at national level. Information was available to Copernicus about the inaccuracies and the difficulties of astrological practice as well as about a notably successful astrologer-patron relationship. The experience of astrological practice that was (...) available to Copernicus in Bologna ranged from the benign to the potentially dangerous, and his departure from Bologna was contemporary with the threat of military reprisals against the town which appeared to show the incorrect outcome of the relevant prediction in Domenico Maria di Novara's prognostication for 1500. After this date Copernicus no longer participated in roles in which prognostication was a duty, he generally inhabited locations that were less potentially dangerous than Bologna was in 1500, and while at some later points he was keen to interest astrologers in his astronomical work, astrology is completely absent from his own explanations of the reasons for his astronomical work. (shrink)