The question was complicated by making consciousness a property of the soul, consciousness being something more than soul—that is to say, a substantial form of the body, the originator of all the organic functions of the body. The soul not only thinks, feels, and wills, but moves the body and prompts its vital functions; in the human soul are united the vegetative, animal, and rational functions. Such is the theory. But the soul separated from the body can have neither vegetative nor animal functions.
A theory, in short, which for the reason is a veritable contexture of confusions.
After the Renaissance and the restoration of purely rational thought, emancipated from all theology, the doctrine of the mortality of the soul was re-established by the newly published writings of the second-century philosopher Alexander of Aphrodisias and by Pietro Pomponazzi and others. And in point of fact, little or nothing can be added to what Pomponazzi has written in his Tractatus de immortalitate animae. It is reason itself, and it serves nothing to reiterate his arguments.
Attempts have not been wanting, however, to find an empirical support for belief in the immortality of the soul, and among these may be counted the work of Frederic W.H. Myers on Human Personality and its Survival of Bodily Death. No one ever approached more eagerly than myself the two thick volumes of this work in which the leading spirit of the Society for Psychical Research resumed that formidable mass of data relating to presentiments, apparitions of the dead, the phenomena of dreams, telepathy, hypnotism, sensorial automatism, ecstasy, and all the rest that goes to furnish the spiritualist arsenal. I entered upon the reading of it not only without that temper of cautious suspicion which men of science maintain in investigations of this character, but even with a predisposition in its favour, as one who comes to seek the confirmation of his innermost longings; but for this reason was my disillusion all the greater. In spite of its critical apparatus it does not differ in any respect from medieval miracle-mongering. There is a fundamental defect of method, of logic.