(after writing this book, Agrippa sent it to Trithemius, who after reading the manuscript and then answered Agrippa) - Heinrich Cornelius Agrippa

Moreover, they ratify and confirm all these with the powers of diverse Intelligences, through the sacred ceremonies of religions. The order and process of all these I shall endeavor to deliver in these three books: Whereof the first contains Natural Magic, the second Celestial, and the third Ceremonial. But I know not whether it be an unpardonable presumption in me, that I, a man of so little judgment and learning, should in my very youth so confidently set upon a business so difficult, so hard and intricate as this is. Wherefore, whatsoever things have here already, and shall afterward be said by me, I would not have anyone assent to them, nor shall I myself, any further than they shall be approved of by the universal church and the congregation of the faithful.

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.

Moreover, I thought it no crime if I should not suffer the testimony of my youth to perish! Also, we have added some chapters and inserted many things which did seem unfit to pass by, which the curious reader shall be able to understand by the inequality of the very phrase, for we were unwilling to begin the work anew and to unravel all that we had done, but to correct it and put some flourish upon it. Wherefore, I pray thee, courteous reader, weigh not these things according to the present time of setting them forth, but pardon my curious youth if thou find any thing in them that may displease thee.