He wrote two encyclopedic works of natural philosophy,
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.
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)