CARDANO'S COSMOS: The Worlds and Works of a Renaissance Astrologer

Today, Girolamo Cardano (1501–76) is known, if at all, as a physician, mathematician, and natural philosopher. Grafton, however, concentrates on Cardano the astrologer. Like a growing number of scholars, Grafton, a Princeton University historian and the author of The Footnote (1997), argues that astrology in the Renaissance was a rational science, not some quasi-mystical, irrational manifestation of the "dark side," and certainly nothing akin to the facile fortunetelling in today’s newspapers. Through Cardano’s voluminous writings on nature, the stars, and (above all) himself, Grafton establishes his subject’s astrology at the heart of all of those activities we consider central to the Renaissance: politics, print culture, the recovery of antiquity, the marketplace, and the practice of collecting wonders and curiosities.

Cardano hit upon the popular device of publishing an ever-expanding collection of "celebrity" horoscopes (or, as Grafton more properly terms them, genitures), together with gossipy commentaries explaining how the stars were affecting their subjects’ lives. The collection earned Cardano a Nuremberg publisher (the same Petreius who brought out Copernicus) and thereby a share of the lucrative northern European, Lutheran market for astrological literature. Astrology also gave Cardano entrée into the corridors of power and brought him into contact with luminaries in France and England, including John Dee and the young King Edward, for whom he cast an extravagant horoscope.

A not-always-successful student of the Renaissance art of self-promotion, Cardano made enemies, too. He explained his proclivity "to say exactly what will offend my listeners" as a product not simply of heavenly influences, but also of the astrologer’s professional duty to tell the truth. And, with some cagey exceptions, this truthtelling extended to Cardano’s minute published dissections of himself, including the star-laced autobiography he wrote in the months before his death, while under house arrest imposed by the Inquisition.

"In an age conversant with Latin," writes Grafton, "his curious and uncanny autobiography attracted many readers until late in the 19th century." Historian Jacob Burkhardt, in (1860), cited Cardano’s memoir as an example of the self-reflection that made the Italian Renaissance the birthplace of modernity.

Grafton’s methodology, a combination of old-fashioned intellectual history and the newer discipline of the history of books and readers (what he calls the perspectives of "the parachutist and the truffle-hunter"), makes this book more than just an examination of Cardano. Through wonderfully vivid prose, the reader enters Cardano’s cosmos—a place no more unreasonable or contradictory, the author points out, than a world in which scholars "use computers to write and fax machines to submit the conference papers in which they unmask all of modern science as a social product."

—Laura Ackerman Smoller