Those who professed this Art are supposed to have been either impostors or under the delusion created by impostors and mountebanks.
Notwithstanding this high Ecclesiastical authority, he who dared accept truth only because it could be proved, or proved to be good, and disregard authority, was commonly stigmatized as an infidel.
They should hold themselves absolutely upon the immovable foundation of truth and nature, whereby alone they can save themselves from misapprehensions and from the danger of being entirely carried away from reality into mere dreams and fictions.
The intolerance of the Middle, and even later, Ages, is a fact all too familiar to every one.
Men wholly bent on wordly treasures were the dupes of their own passions, rather than deceived by the writings or pretenses of those who claimed to be Alchemists.