PTOLEMY, PARAPEGMATA, MATHEMATICS, AND
MONSTERS. THE REFORM OF MUNDANE ASTROLOGY
We recall how the 1524 debates led astrological reformers to advocate a Ptolemaic practice that favored eclipses and lunar phases in mundane astrology. Two motives propelled this methodological shift. On the one hand, it provided rhetorical justification for a lack of public specificity about the future. It enabled court practitioners to distance themselves from the highly competitive world of printed prognostications, and to organize their public practice around suggestions of their private capacities in the service of the prince. Although some prognosticators like the Laet family successfully imitated the new methodological shift, they could not afford to combine this with an equally elaborate form of social secrecy.
On the other hand, Ptolemaic practice illustrated the results that could be obtained from the practice of astrological reform. Ptolemaic practice provided a model where astrological physics claimed to control judicial astrology with a firm hand. This created an unexpected new problem for court practitioners, as their urban competitors began to imitate Ptolemaic practice and its reformist discourse with remarkable ease. This could have eroded the hard earned right to a non-specific public narrative, had elite practitioners not exerted themselves in a further cultivation of astrological reform. In doing so, they managed to patrol the barriers, both linguistic and social, that distinguished them from urban prognosticators. This chapter presents four Louvain examples from the realm of mundane astrology
Interestingly, these four cases mirror the double nature of Louvain astrological interest in Copernican astronomy (chapter 6). In the first two sections, we encounter astrological practitioners who emphasized the reform of judicial astrology, mainly by uncovering and purifying ancient methods of weather prediction. This is followed by a study of two other projects that focused more on astrological physics. These differences were not absolute or clear-cut, however. To a much greater extent than traditional academic astrology, reformed practices and theories were dependent on one another to