John Trithmius...to Henry Cornelius Agrippa... Your work, most renowned Agrippa, entitled Of Occult Philosophy, which you have sent by this bearer to… - Heinrich Cornelius Agrippa

How Magicians Collect Virtues from the Three-fold World, is Declared in these Three Books. Seeing there is a Three-fold World: Elementary, Celestial and Intellectual — and every inferior is governed by its superior, and receiveth the influence of the virtues thereof, so that the very Original and Chief Worker of all doth by angels, the heavens, stars, elements, animals, plants, metals and stones convey from Himself the virtues of His Omnipotency upon us, for whose service He made and created all these things.

I do not doubt but the title of our book of Occult Philosophy, or of Magic, may by the rarity of it allure many to read it, amongst which, some of a disordered judgment and some that are perverse will come to hear what I can say, who, by their rash ignorance, may take the name of Magic in the worse sense and, though scarce having seen the title, cry out that I teach forbidden Arts, sow the seed of heresies, offend the pious, and scandalize excellent wits; that I am a sorcerer, and superstitious and devilish, who indeed am a Magician: to whom I answer, that a Magician doth not, amongst learned men, signify a sorcerer or one that is superstitious or devilish;' but a wise man, a priest, a prophet that the Sybils were Magicianesses, and therefore prophesied most clearly of Christ; and that Magicians, as wise men, by the wonderful secrets of the world, knew Christ, the author of the world, to be born, and came first of all to worship him; and that the name of Magic was received by philosophers, commended by divines, and is not unacceptable to the Gospel.

I confess that Magic teacheth many superfluous things, and curious prodigies for ostentation; leave them as empty things, yet be not ignorant of their causes. But those things which are for the profit of men — for the turning away of evil events, for the destroying of sorceries, for the curing of diseases, for the exterminating of phantasms, for the preserving of life, honor, or fortune—may be done without offense to God or injury to religion, because they are, as profitable, so necessary.