When the body had withdrawn itself, the soul could function as a pure spirit, could contemplate God, and apprehend truths to which others were blind, could prophecy, experience second sight and act upon material things, as is the nature of pure spirits. This corresponds with the views of all Neoplatonists such as Philo, Porphyrius, lamblichus, Proclus. All these ascribed second sight, true dreams, and apparitions to the special powers of the human soul. Indeed this is the consistent teaching of antiquity, and it was from this starting point that Christian writers such as Tertullian, Augustine and Gregory the Great proceeded, though in the time that followed the doctrine was more and more allowed to lapse into oblivion; a confused belief in demons and magic took its place.
In the Middle Ages it was the leading figures of scholasticism who sought to escape from the clutches of a wild belief in demons, as, for instance, St Thomas, who, as already mentioned, speaks in his Summa Theologica (I, q. 86, a. 4) of the soul's power of clairvoyance and states that the soul becomes free in sleep, or when the mind is disturbed and in general when there is the maximum of detachment from the senses. (Hujusmodi autem impressiones spiritualium causarum magis nata est anima humana suscipere, cum a sensibus alienatur; quia per hoc propinquior fit substantiis spiritualibus et magis libera ab exterioribus inquietudinibus.)
In much the same fashion that St Thomas speaks of the higher powers of the soul when it is partly freed from the body, Roger Bacon (d. 1294) speaks of the influencing of souls for the purpose of healing disease, and does so in a manner that suggests the methods of Coué. Mystics like Bonaventure and Meister Eckehart, however, incline to give supernatural explanations when dealing with exceptional states of the soul.
Men in later times were well acquainted with the existence of such states, but did not seem inclined to seek a preternatural explanation for them. Thus Abbot Johann Tritheim (d. 1516) once says in one of his letters: "I am able to communicate my thoughts to one a hundred miles away, who knows this art, and to do so without writing, words or signs; I do not need a messenger at all. It can be made as clear and explicit as may be required, and that by natural means without the aid of spirits or any other kind of superstition."
— Alois Wiesinger, Occult Phenomena in the Light of Theology
