Moreover, the writings of men primarily devoted to science continued through the sixteenth and on into the seventeenth century to contain much the same occult theories that Michael Scot, Roger Bacon and Albertus Magnus had accepted and discussed. Jerome Cardan, one of the most prominent men of his time in mathematics and medicine—indeed, the discoverer of new processes in the former science—nevertheless believed in a strong attraction and sympathy between the heavenly bodies and our own, cast horoscopes and wrote on judicial astrology. In his _Arithmetic_ he treated of the marvelous properties of certain numbers; in other writings he credulously discussed demons, ghosts, incantations, divination and chiromancy. His thirteen books on metoposcopy explain how to tell a person’s character, ability and destiny by a minute examination of the lines on different portions of the body and by warts. He owned a selenite which he believed prevented sleep and a jacinth to which he attributed an opposite influence.[41] The vagaries of Paracelsus are notorious, and yet he was far more than a mere quack. Tycho Brahe (1546–1601) was a faithful follower of experimental method. He saw that the science of the stars could amount to little unless based on a mass of correct observations, and was one of the first to devote his life to that foundation of patient and systematic drudgery on which the great structure of modern science is being reared. His painstaking endeavor to have accurate instruments and his care to make allowance for possible error were the marks, rare enough in those days, of the true scientist. Yet he made many an astrological prognostication, and was, as his biographer puts it, “a perfect son of the sixteenth century, believing the universe to be woven together by mysterious connecting threads which the contemplation of the stars or of the elements of nature might unravel, and thereby lift the veil of the future.”[42] He also dabbled in alchemy, believed in relations of occult sympathy between “the ethereal and elementary worlds,” and filled his mind with the teachings of Hermes Trismegistus, Geber, Arnald of Villanova, Raymond Lullius, Roger Bacon, Albertus Magnus, and Paracelsus. Finally, even Francis Bacon, famed as the draughtsman of the chart which henceforth guided explorers in the domain of science, thought that there was considerable value in physiognomy and the interpretation of natural dreams, though the superstition and phantasies of later ages had debased those subjects;[43] and in divination if not “conducted by blind authority.”[44] He said that by a reformed astrology one might predict plagues, famines, wars, seditions, sects, great human migrations and “all great disturbances or innovations in both natural and civil affairs.”[45]