Some of the maxims found in my works regarding the mysteries of religion have met with objectors of an inferior rank in science, whose intellectual penetration is insufficient to fathom such depths. They assert that these maxims are borrowed from the ancient philosophers, whereas the truth is that they are the fruit of my own meditations, but as the proverb says, “Sandal follows the impress of sandal.”[1] Some of them are found in our books of religious law, but the greater part are derived from the writings of the Sufis. But even if they were borrowed exclusively from the doctrines of the philosophers, is it right to reject an opinion when it is reasonable in itself, supported by solid proofs, and contradicting neither the Koran nor the traditions? If we adopt this method and reject every truth which has chanced to have been proclaimed by an impostor, how many truths we should have to reject! How many verses of the Koran and traditions of the prophets and Sufi discourses and maxims of sages we must close our ears to because the author of the _Treatise of the Brothers of Purity_ has inserted them in his writings in order to further his cause, and in order to lead minds gradually astray in the paths of error! The consequence of this procedure would be that impostors would snatch truths out of our hands in order to embellish their own works. The wise man, at least, should not make common cause with the bigot blinded by ignorance. Honey does not become impure because it may happen to have been placed in the glass which the surgeon uses for cupping purposes. The impurity of blood is due, not to its contact with this glass, but to a peculiarity inherent in its own nature; this peculiarity, not existing in honey, cannot be communicated to it by its being placed in the cupping glass; it is therefore wrong to regard it as impure. Such is, however, the whimsical way of looking at things found in nearly all men. Every word proceeding from an authority which they approve is accepted by them, even were it false; every word proceeding from one whom they suspect is rejected, even were it true. In every case they judge of the truth according to its professors and not of men according to the truth which they profess, a _ne plus ultra_ of error. Such is the peril in which philosophy involves its opponents.