Excerpt:

Being to write of the generation of natural things, I must ingenuously confess, that I learned it not in the books of the Athenian Sophisters (he means the Schoolmen, and the followers of Aristotle; this term he borrowed from Paracelsus, for he first called them so, and writing his Mysterium Magnum, entitled it, Philosophy for the Athenians, for Aristotle’s school was at Athens), but by the true Light of Nature: Neither will I borrow any thing from them, or their books, and convert it in this discourse, like a Plagiary, to my own use or Glory; for the truth is not to be found in their books, but most gross ignorance and errors, grounded upon and supported by the vain men, which opinions the credulous people esteem and cry up as the utmost bounds and Non Ultra of all wisdom and perfection.

As men are killed by fighting, so truth is lost by disputing; for while they only dispute and wrangle about Nature, every one of them in particular, and all of them in general are so filled and swollen up with a testy intolerable Pride and self worship, that each of them arrogating a kind of infallibility to his own Chimera’s or monstrous conceits, does with all might and main labor to refute and demolish the airy castle and fond imaginations of the other, and by this ridiculous continued feud, they wander from the Bath and fundamentals of true knowledge, entangling themselves and too credulous posterity in an inextricable Labyrinth of quarrels and Errors, fortified with fictitious and groundless Principles never reduced to practice or trial, but merely suppose and implicitly believed, so that he would get out of this spacious and wearisome wilderness, cannot do it without much difficulty and laboriousness, and shall not do it without their general envy and opposition.

Leaving therefore these lewd contenders and their verbosity, let us, the divine mercy assisting us, go directly to the house of wisdom by the Light of Nature, that by the simple and peaceable contemplation of the creatures, and her operations in them, we may truly discover and describe unto others the perfect manner of Generation, and so come not only to the certain knowledge of ourselves, but learn also how to produce and prepare out of perfect bodies and substance such a Medicine or Medicines as will innoxiously and faithfully cure all diseases that are incident t our own frail bodies: For as Men, Corn and Herbs are, every one of them, generated and born out of their own Specific Seed, so or in the same manner is the true Medicine of the Ancients (than which there cannot be a better) generated and prepared out of the most perfect bodies and essence. Look not therefore with careless and transient eyes upon what is offered thee in this book, but know and be assured that this Doctrine is the most profitable and advantageous for thee, by whose Light and guidance thou will be most prosperously led to the true knowledge of the Secret generation of all Animals, Vegetables, and Minerals, and to the finding out of that rich and rare Medicine which perfectly cures all imperfect Metals.