Cardan

Cardan (Ital. Cardano; Latinised Cardanus), JEROME, a celebrated mathematician, naturalist, physician, and philosopher, was born at Pavia, September 24, 1501, the natural son of a jurist of Milan. His education was as irregular as his birth, but he finally completed his studies at the universities of Pavia and Padua, graduating in medicine at the latter. He became professor of Mathematics at Milan, at the same time practising medicine, and though at first obscure and poor, gradually gained a high reputation. In 1552 he visited Scotland, on an invitation from Archbishop Hamilton, and managed to cure the primate of an inveterate asthma, which had defied the skill of the most celebrated physicians. In 1559 he became professor of Medicine at Pavia, later at Bologna, where he continued teaching till 1570, when we find him in prison for heresy or debt, or both. Having regained his liberty in 1571, he went to Rome, where he was speedily admitted a member of the medical college, and pensioned by Pope Gregory XII. The rest of his life he spent, without public employment, in Rome, where he died September 2, 1576, a few weeks after finishing his remarkably candid and interesting autobiography, De Propria Vita. Some writers have asserted, but on no sufficient authority, that he starved himself to death, to fulfil a prediction which he had made as to the time when he should die. He was a devoted astrologer, and cast horoscopes for himself and others, while he believed himself one of the five or six celebrated men who had, like Socrates, a familiar demon. Cardan was one of the most remarkable men of his age, and reveals throughout his works an intellect of rare subtlety and force, with a really sound conception of scientific method in spite of all the empiricism and imperfection of his knowledge. He too often spends his strength in merely futile attempts at explanations of natural phenomena for which the necessary data were not to be collected for centuries later; but he occasionally lets fall hints of scientific principles so profound, looked at in the light of after-years, that he himself cannot at all have even guessed at their significance. A summary of his notions on physics and metaphysics is given in his two works—De Subtilitate Rerum, in 21 books, and De Rerum Varietate, in 17 books. He wrote more than a hundred treatises on physics, mathematics, astronomy, astrology, rhetoric, history, ethics, dialectics, natural history, music, and medicine. A formula for the solution of certain kinds of cubic equations is called 'Cardan's formula,' and was published by him, as his own invention, in the Ars Magna sive de Regulis Algebræis (1545); but it would appear that the formula was really the invention of Nicolo Tartaglia. His numerous writings were collected and edited by Charles Spon (10 vols. Lyons, 1663). See Lives by Henry Morley (2 vols. 1854) and W. G. Waters (1898).