Witchcraft and the Occult, 1400-1700
Girolamo Cardano (1501-1576)
Cardano was born in Pavia, the illegitimate son of an uneducated woman and a learned father, who was a lawyer, mathematician and friend of Leonardo da Vinci.  He had an unhappy childhood in a quarrelsome household, suffering from nightmares, stuttering and impotence.  He studied first at the University of Pavia and then at Padua, where he graduated in medicine in 1526.  He was twice rejected on the grounds of his illegitimacy by the College of Physicians in Milan, and retaliated in his book, The Bad Practice of Medicine by Physicians (1536).  This book was the start of his fame, resulting in an invitation to Scotland to treat John Hamilton, the asthmatic archbishop of Edinburgh.  He was professor of medicine at Pavia from 1543 to 1560, where he was a friend of the humanist lawyer Alciati and was in contact with Vesalius.
His greatest work in mathematics was the Artis magnae sive de regulis algebraicis liber unus (1545), which led to a long controversy with Tartaglia, who accused him of plagiarism.  He was a pioneer in probability theory, as a result of his fascination with games of chance, and wrote a celebrated De ludo aleae which appeared in his posthumous Opera omnia (Leiden, 1663).

He wrote two encyclopedic works of natural philosophy, De subtilitate (1550) and De rerum varitate (1557), in which he discussed physics, mechanics, cosmology, natural sciences, demonology, astronomy, and the various occult sciences.  Among these last, he was especially interested in astrology, physiognomy and chiromancy.  Cardano connected the Greek terms for the parts of the hand to their
Latin translations, such as Stethos (ball of thumb) and Hypothenar (the ridge of muscle beneath the little finger), to the body and soul, as read in the palm. His belief in chiromancy, palm reading, was so strong that he claimed to have predicted his own death.

De rerum varietate (Basel, 1557) p. 560
In 1570, his interest in astrology led to his arrest by the Inquisition, for casting the horoscope of Christ.  He moved to Rome in 1571, where he gained the support of Pope Pius V and wrote his extraordinary autobiography, shortly before his death.

There are several older biographies and he is the subject of two major works of recent scholarship, by Nancy Siraisi and Anthony Grafton.

The First Book of Jerome Cardan's "De subtilitate", trans. M.M. Cass (Williamsport, PA, 1934)

Girolamo Cardano, The Book of My Life, trans. J.Stoner (New York, 1930; repr. 1962)

Anthony Grafton, "Girolamo Cardano and the Tradition of Classical Astrology", Proceedings of the American Philosophical Society 142 (1998) 323-354

Anthony Grafton, Cardano's Cosmos: The Worlds and Works of a Renaissance Astrologer (Cambridge, Mass., 1999)

Nancy G. Siraisi, "Girolamo Cardano and the Art of Medical Narrative", Journal of the History of Ideas 52 (1991) 581-602

Nancy G. Siraisi, The Clock and the Mirror: Girolamo Cardano and Renaissance Medicine (Princeton,

M Fierz, Girolamo Cardano, 1501-1576 : physician, natural philosopher, mathematician, astrologer, and interpreter of dreams (Boston, 1983)

O. Ore, Cardano, the Gambling Scholar (1953)

W. G. Waters, Jerome Cardan : a biographical study (London, 1898)

A. Wykes, Doctor Cardano : physician extraordinary (London, 1969)