The Ars Magna (The Great Art, 1545) is an important Latin-language book on algebra written by Gerolamo Cardano.

It was first published in 1545 under the title Artis Magnae, Sive de Regulis Algebraicis Liber Unus (Book number one about The Great Art, or The Rules of Algebra).

Cardano submerged himself in mathematics during the next several years working on how to extend Tartaglia's formula to other types of cubics.

The book, which is divided into forty chapters, contains the first published algebraic solution to cubic and quartic equations.

Cardano called this "sophistic," because he saw no physical meaning to it, but boldly wrote "nevertheless we will operate" and formally calculated that their product does indeed equal 40.

It is a common misconception that Cardano introduced complex numbers in solving cubic equations.