The world will end in 2012. So it is foretold in the stars— on 21 December of 2012, the December sun will line up with the plane of the Milky Way on the winter solstice with disastrous consequences for life on earth. Or, at least, that’s what some believe. Claims like these, and the astronomical data that buttress them, are mostly met with scorn or amusement today, but they were no laughing matter in the sixteenth century. Anthony Grafton’s marvelous work on the life and works of Girolamo Cardano—a true Johannes-of-all-trades—explores the study of sixteenth century astrology with great sensitivity to the notion that this was very serious stuff indeed for Cardano and his contemporaries. Despite the central importance that the stars had in the lives of sixteenth century men and women, there have been (or at least in 1999, there had been) precious few studies that took astrology as their contemporaries did, as a serious, empirical science. Cardano, Grafton tells us, is an excellent choice to bridge the gap between two different historical interpretations of astrology: the first treats the subject on a social and cultural level, the second dwelled in the more internal, nitty-gritty world of endless calculations. The former usually could not find its way around a deferent, much less the complicated computations that went into a geniture, but the latter often could not dwell in the complicated social reality that made these astrological predictions so crucial in the first place. Never before had the twain met, but these two roads of inquiry converge at Cardano; at a place where his writings and commentaries upon them abound.

In Cardano’s Cosmos, Grafton recreates the world and the works of a typical sixteenth century astrologer—and we have no reason to doubt that Cardano was anything but typical (even if his store of writings and personal introspection was certainly unusual). The book also goes into great detail about Cardano’s biography, and traces his published works from his first treatise on astrology, the 1534 Prognostico, the 1538 Libelli duo, and in the last chapter, Cardano’s own autobiography. In chasing down Cardano’s life and astrological practices, Grafton shows how the man’s astrological prognostications were the end result of a system of knowledge that was both highly empirical and critical, and was indispensable for a Renaissance man or woman’s understanding of their world and themselves.

The work also touches upon several aspects of importance to early modern history. It adds an interesting addendum to the already voluminous chapter of the rise of print culture, since Cardano exploited the new media to disseminate his ideas, and he in effect made his career by bringing into print a realm of materials that had only been in the manuscript tradition before. However, Grafton is quick to point out that this is not a story of the triumph of print over manuscript, but that even in the post-Gutenberg west, the manuscript tradition was alive and well, and in fact, the first few printed horoscope collections were of far inferior quality and low technical level. While print quickly became the preferred media for things like almanacs and astronomical tables, the media for horoscopes, which were so personal, and so dependent upon interpersonal connections, remained the manuscript and the conversation, but they were but one example out of many of texts whose manuscript forms remained standard until well after the advent of print. The work also maps the place of the astrologer in late Renaissance society, and the perils and pitfalls that concerned anyone offering advice in a world of politics, fickle patrons, and great rivalry between practitioners.

Astrology, Grafton writes, was an art that had persisted over centuries, but the application of tools of the trade “depended on the changing needs and situations of their users and their clients and readers” (198). Astrology, then, as now, has always had its critics. In the sixteenth century, the specter of Pico della Mirandola’s debunking of the origin myths of astrology hung over the whole enterprise, yet it lived on; Cardano is a testament to that. But, he also participated in the humanistic endeavor to reform astrology, but his reformation took on the two-pronged approach typical of medical humanists of the day. He sought to re-examining the ancient sources, and attempting to recreate the Imperial astrology which Ptolemy based his Tetrabiblos on, but he also collected new genitures and subjected them to minute scrutiny in hopes of reforming the practice through his own observations. Grafton stresses that, when looked at in its social, political, and intellectual context, astrology was not simply superstitious hokum, but a system of knowledge of the most empirical sort.

A superbly informative history of Renaissance astrology in general, in addition to being an interesting, scholarly biography of the Italian astrologer Girolamo Cardano.