Girolamo Cardano 1501 – 1576

Girolamo Cardano was an Italian Renaissance polymath, physician, mathematician, astrologer, and natural philosopher whose life spanned brilliance and scandal. He produced foundational work in the algebra of cubic and quartic equations, the early theory of probability, and clinical medicine, and he wrote a remarkable autobiography, The Book of My Life, that has become one of the most read documents of Renaissance self-understanding. His De Subtilitate and De Rerum Varietate offered an encyclopedic natural philosophy of marvels and causes. He died in Rome after a final imprisonment for an indiscreet horoscope of Christ.

Girolamo Cardano was born in 1501 at Pavia, the illegitimate son of a Milanese jurist and mathematically gifted lecturer. He took his medical degree at Padua in 1526, struggled for years to be admitted to the College of Physicians of Milan because of his birth, and from the 1540s built one of the most celebrated medical practices in Europe, with patients including Cardinal John Hamilton of Edinburgh.

His writings are enormous and uneven. The mathematical Ars Magna (1545) gave the first published solution of the cubic and quartic equations and broke open the history of algebra; the Liber de ludo aleae offered the first systematic mathematical treatment of probability; the encyclopedic De Subtilitate (1550) and De Rerum Varietate (1557) collected his speculations on natural philosophy; and the autobiographical De Vita Propria Liber, written near the end of his life, is one of the most striking Renaissance self-portraits.

Cardano combined an Aristotelian-Renaissance natural philosophy of subtilitas with sustained interest in astrology, dreams, and mathematics, and embodied the transition from Renaissance polymathy to early modern science. Imprisoned for heresy in 1570 over a horoscope of Christ, he was released and pensioned in his last years by Pope Gregory XIII. He died at Rome in September 1576, by tradition having predicted the day of his own death.