Gerolamo Cardano (1501-1576)

Gerolamo Cardano is certainly one of the most colorful figures in the history of mathematics. He was the most renowned physician in Europe in his day, yet throughout his life he was plagued by numerous maladies, including ruptures, hemorrhoids, and an irrational fear of encountering rabid dogs. A doting father, his beloved sons broke heart-his favorite was eventually beheaded for murdering his wife. Cardano was also a compulsive gambler; indeed, this vice may have driven him to write the Book on Games of Chance, the first study of probability from a mathematical point of view. In Cardano's major mathematical work, the Ars Magna, he detailed the solution of the general third and fourth degree polynomial equations. At the time of its publication, mathematicians were uncomfortable even with negative numbers, but Cardano's formulas paved the way for the acceptance not just of negative numbers, but also of imaginary numbers, because they occurred naturally in solving polynomial equations.