The Limits of Influence: Pico, Louvain, and the Crisis of Renaissance Astrology (review)

This book is the fourth and most recent volume to come out under the Brill series Medieval and Early Modern Science. Its author, Stephen vanden Broecke, presents a rather exhaustive (though not exhausting) account of sixteenth-century astrological practice in northern Italy and the Low Countries. The Limits of Influence is a delight to read, with detailed historical accounts of important figures and episodes in the reform of late medieval and Renaissance astrological practice. The volume comprises eight chapters, with an "intermezzo" section placed between the fifth and sixth chapters.

The first chapter, "Some Preliminary Remarks on Astrology," is a theoretical chapter that attempts to delineate the boundaries for the subject matter of the book, and vanden Broecke intelligently discusses the difficulties of separating astronomy from astrology, recognizing that the respective terms are used with various degrees of overlap among classical writers of both disciplines. Vanden Broecke notes that astrology was one sixteenth-century discipline among others that sought to disclose future events, and he aptly identifies medical prognosis, proverbs, and theology to be competing ventures in this regard. After some explanation, the working definition of astrology adopted for the volume becomes: "Astrology aims at predicting and/or studying the power of celestial bodies on earth, and measures their positions by means of astronomy" (17).

The second chapter, "Astrology and Late Medieval Academic Culture. Louvain, 1425–1516," describes astrological practice in Louvain in the fifteenth century. Vanden Broecke describes the various genres of academic astrology, ranging from the tradition of annual almanacs presenting the year's prognostications, to the private court consulting services offered to political figures. Notable discussions in this chapter include an account of the December 1465 quodlibetal disputation dealing with the problem of future contingents and its implications for astrological assertions.

The volume's third chapter deals with the content and reception of the Italian philosopher Giovanni Pico della Mirandola's massive posthumously-published diatribe on astrological practice, and is titled "Between Astrological Reform and Rejection: Giovanni Pico's Disputations (1494)." Vanden Broecke presents a controversial thesis, namely, that Pico's attack should be read more as a call for the reform of astrological practice rather than as an outright rejection of the theoretical soundness of astrology as such. Vanden Broecke argues that "While Pico initially defended the option of astrological reform, he ultimately conceded its practical irrelevance" (64). The following chapters of the volume all in some way chronicle the trajectory of Pico's contribution to astrological discussions.

The fourth chapter, "Humanism and Court Astrology: The 1524 Conjunctions at Louvain," presents the principal events surrounding the interpretations of the Jupiter-Mars and Saturn-Mars conjunctions, which were taken by some to portend a second biblical flood. Vanden Broecke shows how astrological practitioners used the vast array of arguments present in Pico's Disputations to argue against the popular predictions of a new flood.

In the fifth chapter, "Astrology and the Louvain Cosmographical Tradition" it is argued that Louvain mathematicians established a connection between the discipline of cosmography and astrology. The chapter presents discussions of the production, sale, and use of terrestrial and celestial globes for astrology and astronomy.

The variegated content of the intermezzo, appearing between the fifth and six chapters, is indicated by its title: "A Few Comments on the Use and Nature of Astrological Reform." Most notably, vanden Broecke argues that astrological practitioners assumed a new public role; rather than focusing on predictions, the public work became that of astrological reform, with particular attention to astrological theory (as opposed to practice).

The final three chapters of the volume each concentrate on a particular feature of astrological reform. Chapter 6 chronicles the reception of the heliocentric astronomical ideas of Copernicus at Louvain and is thus titled "Copernican Astronomy and Louvain Astrology." Chapter 7, "Ptolemy, Parapegmata, Mathematics, and Monsters. The Reform of...