History, prophecy, and the stars: the Christian astrology of Pierre d'Ailly, 1350-1420 (review)

286 Reviews temperance that is examined in Chapter Six. Throughout, Payer's work is copiously documented. The end-notes account for approximately one-third of the book's length. There is also an index and a comprehensive bibliography of both sources and studies. Judy Quinn Department of English University of Sydney Smoller, Laura A., History, prophecy, and the stars: the Christian astrology of Pierre d'Ailly, 1350-1420, Princeton, Princeton University Press, 1994; cloth; pp. xii, 233; 5 figures; R.R.P. US$35.00. Petrus de Alliaco is a well-known figure of the late Middle Ages. In the course of his life he was Chancellor of die University of Paris, close to the royal court of France, andfinallya cardinal and a papal legate. However, the important role played by his several astrological writings, including Imago mundi, De legibus et sectis contra superstitiosos astronomos, Vigintiloquium de concordantia astronomice veritatis cum theologia, and Elucidarium astronomice concordie cum theologia et cum hystorica narratione has not been given the attention it deserves until now. Laura Smoller shows how d'Ailly, atfirstsuspicious of astrology in the same way that his famous pupil, Jean Gerson, was of alltilingssuperstitious, gradually came to see astrology as a way out of die Great Schism. The French cardinal showedtiiroughthe science of astrological calculations that the coming of Antichrist was not indeed imminent, in spite of the fact that many contemporary theologians feared the impending approach of this apocalyptic event because diey believed that the Great Schism was dial split, 'discessio', predicted in 2 Thessalonians. By putting die date of Antichrist's arrival on earth to 1789 [sicl], d'Ailly helped churchmen take a more positive attitude to a council's potential to rid the Church of the pernicious divisiontiiathad torn it apart since 1378. At the Council of Constance in 1414, Pierre d'Ailly, in his capacity as papal legate, was to be instrumental in the proceedings which led to the successful resolution of the Schism. The first two chapters provide an excellent and eminently readable account of the terminology of astrology in the Middle Ages, together with a succinct history of the Church's attitudes to it. Smoller makes the point that at the time astronomy represented theoretical knowledge about the Reviews 287 heavens, whereas astrology was the applied version of the science of the stars. Technical vocabulary such as 'triplicities, houses, cardinal points, descendant, midheaven, exaltation, trine sextile and quartile, and conjunction' is clearly expounded with examples. Major figures in the history of astrology are all treated in the text: Isidore of Seville, St Augustine, Ptolemy, Adelard of Bath, Bernard Silvestris, Albertus Magnus, Roger Bacon, Thomas Aquinas, Nicolas Oresme, and Henry of Langenstein. Their contributions to the growth of astrological knowledge are analysed and the substance of their important declarations noted, dieir Latin treatises being quoted in the very full notes. Smoller sets the scene for a discussion of d'Ailly's contribution to the astrological debate by pointing out the two opposing sets of traditions discernible in the medieval reaction to astrology from the age of the Church Fathers. At first astrology had been seen as a remnant of pagan superstition, dangerous because it brought into question human freedom of will. Theological problems about God's omnipotence are of course involved here and Smoller returns several times in the course of the book to discuss d'Ailly*s position on potentia ordinata and potentia apsoluta. However, from about the twelfth century on, astrology was widely accepted, especially under the influence of the rediscovery of Aristotelian texts. The body of the book is concerned with a detailed examination of the way in which d'Ailly's various treatises on astrology show how his position on the usefulness of this science evolved. W e see his reading in astrological texts gradually increase in the chapter 'The making of an astrologer'. Then the relationship of astrology to history is examined, generally atfirstin 'Astrology and history' and then specifically in 'The Great Schism and the coming of the Apocalypse'. The main thesis of Smoller's work is that the impetus for d'Ailly's close study of astrology was linked to the prevalence of apocalyptic thought in the later...