90 Cronos, 9: 85-98 Why Isaac Newton Rejected Astrology: A Preliminary Reconstruction Galileo then presents a very conspicuous example of this process of naming, conspicuous both in its protagonists-Julius and Augustus Cae sar-and in its failure: This especially noble and admirable invention ofhuman sagacity, howe ver, has been out ofuse for many generations, with the pristine heroes occupying those bright places and keeping them as though by right. In vain, Augustus's affection tried to place Julius Caesar in their number, for when he wished to name a star (one of those the Greeks call Cometa and we call hairy) that had appeared in his time the Julian star, it moc ked the hope ofso much desire by disappearing shortly (30).21

*** This is not to imply that Newton's reform of cometology did not have an astrological dimension; I believe it did. Within its broader system, New ton's revised cometography can reform natural philosophy by exploding the solid spheres, but even more significantly by naturalizing comets and thus bringing them within the domain of regular celestial pheno mena, albeit with wildly eccentric orbits. Reforming comets in this way takes us a long way toward reforming the science of the stars by natu ralizing and thus neutralizing this high-profile astrological component as part ofthe larger goal of rejecting astrology altogether with its corrup ted idolatrous practices.

Here it is important to have a clear structural understanding of how comets were situated within astrology. Newton does not try to reform cometary astrology because comets were thought to be ensouled and thus idolatrous, but because they were used in an extremely popular form of divination; in this sense only did they parlicipate in idolatry.22 Planetary astrology, on the other hand, was condemned on both counts. Indeed, Newton worked to undermine the use of comets in socially dis ruptive prognosticatory practices by transforming their ontological and thus their epistemological status. In this sense it is a parl of astrology, the science or art that interprets celestial phenomena and makes prog nostications on that basis. Comets, however, are a special case when compared with the luminaries, planets and fixed stars, the regular

21 Hoc autem humanae sagacitatis inventum curo primis nobile, ac mirandum multorum iam saeculorum intervallo exolevit, priscis heroibus lucidas illas sedes occupantibus, ac suo quasi iure tenentibus: in quorum coetum frustra pietas Augusti Iulium Caesarem coapta re conata est: nam cum Stellam suo tempore exortam, ex iis, quas Graeci Cometas, nostri Crinitas vocant, Iulium Sydus nuncupari voluisset, brevi illa evanescens, tantae cupidita tia apem deluait. (2,30-3,5; Van Helden'a parentheses) 22 For cometary astrology in early modem England, see Schechner, S.J.(1997); Capp, B. (1979). English Almanacs 1500-1800: Astrology and the Popular Press, Ithaca, Comell Uni versity Press; and Geneva, A (1995). Astrology and the Seventeenth Century Mind; William Lilly and the Language of the 8tars, Manchester, Manchester University Press. For the situation in Italy, see Casall, E. (2003). Le Spie del Cielo: Oroscopi, Lunari e Almanacchi nell'Italia Moderna, Turin, Einaudi. Cronos, 9: 85-98 91