"This person, a seeker after an occult philosophy, which had possibly acquainted him with some secrets in nature beyond the pale of our conventional experience, though, when analyzed, they might prove to be quite reconcilable with sober science, startles you with an undefined mysterious charge against the young man who had previously seemed to you different from ordinary mortals. In a room stored with the dead things of the brute soulless world, your brain becomes intoxicated with the fumes of some vapour which produces effects not uncommon in the superstitious practices of the East; your brain, thus excited, brings distinctly before you the vague impressions it had before received. Margrave becomes identified with the Louis Grayle of whom you had previously heard an obscure and, legendary tale, and all the anomalies in his character are explained by his being that which you had contended, in your physiological work, it was quite possible for man to be,--namely, mind and body without soul! You were startled by the monster which man would be were your own theory possible; and in order to reconcile the contradictions in this very monster, you account for knowledge, and for powers that mind without soul could not have attained, by ascribing to this prodigy broken memories of a former existence, demon attributes from former proficiency in evil magic. My friend, there is nothing here which your own study of morbid idiosyncracies should not suffice to solve." "So, then," said I, "you would reduce all that have affected my senses as realities into the deceit of illusions? But," I added, in a whisper, terrified by my own question, "do not physiologists agree in this: namely, that though illusory phantasms may haunt the sane as well as the insane, the sane know that they are only illusions, and the insane do not."