The Rules of Algebra (Ars Magna)

This cornerstone in the history of mathematics first appeared in 1545 as Artis magnae, sive de regulis algebraicis. A primer on "the great art" of algebra, it contains the first revelation of the principles for solving cubic and biquadratic equations, along with other innovations. Author Girolamo Cardano (1501-76) was famous not only for his prodigious gifts as a mathematician, but also for his skills as a physician, astrologer, and gambler. Cardano's novel approach to the treatment of scientific problems reflects the spirit of his era, the zenith of the Italian Renaissance.