"Whence it is evident that they, since they are demoniac spirits, know some things both more quickly and more perfectly [than men]; for they are not retarded in their learning by the heaviness of a body. And therefore they, as being spirits, know without delay and without difficulty what physicians attain after a long time and by much labour. It is not wonderful, therefore, if they know somewhat more than men do; but this is to be observed, that what they know they do not employ for the salvation of souls, but for the deception of them, that by means of it they may indoctrinate them in the worship of false religion. But God, that the error of so great deception might not be concealed, and that He Himself might not seem to be a cause of error in permitting them so great licence to deceive men by divinations, and cures, and dreams, has of His mercy furnished men with a remedy, and has made the distinction of falsehood and truth patent to those who desire to know. This, therefore, is that distinction: what is spoken by the true God, whether by prophets or by diverse visions, is always true; but what is foretold by demons is not always true. It is therefore an evident sign that those things are not spoken by the true God, in which at any time there is falsehood; for in truth there is never falsehood. But in the case of those who speak falsehoods, there may occasionally be a slight mixture of truth, to give as it were seasoning to the falsehoods.