Strange as all these beliefs seem to us now, they were a very real factor in the intellectual conceptions of the Renaissance period, no less than of the Middle Ages, and amidst them there is to be found at times a foreshadowing of more modern knowledge. Many other persons were also more or less associated with the magical school, amongst them Franz von Sickingen. Reuchlin himself, by his Hebrew studies, and especially by his introduction of the Kabbala to Gentile readers, also contributed a not unimportant influence in determining the course of the movement. The line between the so-called black magic, or operations conducted through the direct agency of evil spirits, and white magic, which sought to subject nature to the human will by the discovery of her mystical and secret laws, or the character of the quasi-personified intelligent principles under whose form nature presented herself to their minds, had never throughout the Middle Ages been very clearly defined. The one always had a tendency to shade off into the other, so that even Roger Bacon's practices were, although not condemned, at least looked upon somewhat doubtfully by the Church. At the time of which we treat, however, the interest in such matters had become universal amongst all intelligent persons. The scientific imagination at the close of the Middle Ages and during the Renaissance period was mainly occupied with three questions: the discovery of the means of transmuting the baser metals into gold, or otherwise of producing that object of universal desire; to discover the Elixir Vitæ, by which was generally understood the invention of a drug which would have the effect of curing all diseases, restoring man to perennial youth, and, in short, prolonging human life indefinitely; and, finally, the search for the Philosopher's Stone, the happy possessor of which would not only be able to achieve the first two, but also, since it was supposed to contain the quintessence of all the metals, and therefore of all the planetary influences to which the metals corresponded, would have at his command all the forces which mould the destinies of men. In especial connection with the latter object of research may be noted the universal interest in astrology, whose practitioners were to be found at every Court, from that of the Emperor himself to that of the most insignificant prince or princelet, and whose advice was sought and carefully heeded on all important occasions. Alchemy and astrology were thus the recognised physical sciences of the age, under the auspices of which a Copernicus and a Tycho Brahe were born and educated. FOOTNOTES: [18] _Cf._ Sebastian Franck, _Chronica_, for an account of a visit of Paracelsus to Nürnberg. CHAPTER V. THE GERMAN TOWN.