As to those who, professing a lip-faith in the Prophet, adulterate religion with philosophy, they really deny inspiration, since in their view the Prophet is only a sage whom a superior destiny has appointed as guide to men, and this view belies the true nature of inspiration. To believe in the Prophet is to admit that there is above intelligence a sphere in which are revealed to the inner vision truths beyond the grasp of intelligence, just as things seen are not apprehended by the sense of hearing, nor things understood by that of touch. If our opponent denies the existence of such a higher region, we can prove to him, not only its possibility, but its actuality. If, on the contrary, he admits its existence, he recognizes at the same time that there are in that sphere things which reason can not grasp; nay, which reason rejects as false and absurd. Suppose, for instance, that the fact of dreams occurring in sleep were not so common and notorious as it is, our wise men would not fail to repudiate the assertion that the secrets of the invisible world can be revealed while the senses are, so to speak, suspended. Again, if it were to be said to one of them, "Is it possible that there is in the world a thing as small as a grain, which being carried into a city can destroy it and afterward destroy itself so that nothing remains either of the city or of itself?" "Certainly," he would exclaim, "it is impossible and ridiculous." Such, however, is the effect of fire, which would certainly be disputed by one who had not witnessed it with his own eyes. Now, the refusal to believe in the mysteries of the other life is of the same kind. As to the fourth cause of the spread of unbelief—the decay of faith owing to the bad example set by learned men—there are three ways of checking it. (1) One can answer thus: "The learned man whom you accuse of disobeying the divine law knows that he disobeys, as you do when you drink wine or exact usury or allow yourself in evil-speaking, lying, and slander. You know your sin and yield to it, not through ignorance, but because you are mastered by concupiscence. The same is the case with the learned man. How many believe in doctors who do not abstain from fruit and cold water when strictly forbidden them by a doctor! That does not prove that those things are not dangerous, or that their faith in the doctor was not solidly established. Similar errors on the part of learned men are to be imputed solely to their weakness."