God, wishing to render intelligible to men the idea of inspiration, has given them a kind of glimpse of it in sleep. In fact, man perceives while asleep the things of the invisible world either clearly manifest or under the veil of allegory to be subsequently lifted by divination. If, however, one was to say to a person who had never himself experienced these dreams that, in a state of lethargy resembling death and during the complete suspension of sight, hearing, and all the senses, a man can see the things of the invisible world, this person would exclaim, and seek to prove the impossibility of these visions by some such argument as the following: “The sensitive faculties are the causes of perception. Now, if one can perceive certain things when one is in full possession of these faculties, how much more is their perception impossible when these faculties are suspended.”
The falsity of such an argument is shown by evidence and experience. For in the same way as reason constitutes a particular phase of existence in which intellectual concepts are perceived which are hidden from the senses, similarly, inspiration is a special state in which the inner eye discovers, revealed by a celestial light, mysteries out of the reach of reason. The doubts which are raised regarding inspiration relate (1) to its possibility, (2) to its real and actual existence, (3) to its manifestation in this or that person.
To prove the possibility of inspiration is to prove that it belongs to a category of branches of knowledge which cannot be attained by reason. It is the same with medical science and astronomy. He who studies them is obliged to recognise that they are derived solely from the revelation and special grace of God. Some astronomical phenomena only occur once in a thousand years; how then can we know them by experience?
We may say the same of inspiration, which is one of the branches of intuitional knowledge. Further, the perception of things which are beyond the attainment of reason is only one of the features peculiar to inspiration, which possesses a great number of others. The characteristic which we have mentioned is only, as it were, a drop of water in the ocean, and we have mentioned it because people experience what is analogous to it in dreams and in the sciences of medicine and astronomy. These branches of knowledge belong to the domain of prophetic miracles, and reason cannot attain to them.