II. The intelligence which is communicated to living beings becomes, to a great extent, dependent upon the organization with which it is combined. Thus every mental faculty is found to have its definite seat and habitat in the bodily frame. The principal successes of modern physiologists have been achieved in determining with what precise parts of the nervous system each affection of consciousness is functionally associated. Different classes of nerves are found to be appropriated to sensation and volition; different parts of the spinal cord are proved to minister to different offices; and of the subdivisions of the brain, each is thought to correspond with a separate faculty, or sentiment, or appetite. So far the mental forces, or operations of a living human being, may be conceived to be essentially esoneural, (εσω νευζον.) Each appears to have its proper and special workshop or laboratory in the nervous system.
III. But there are not wanting facts which make it reasonable to think that our mental forces or operations transcend occasionally and partially the limits of our corporeal frame. The phenomena adverted to in the preceding letter, in connexion with the narrative of Zschokke’s seer-gift, hardly seem to admit of explanation on any other supposition. Nor is it a very improbable conjecture, that phenomena of the same class form, as it were, the complements of many ordinary esoneural operations. Possibly in common perception the mind directly reaches the object perceived, being excited thereto by the antecedent material impressions on our organs, and the sensations which follow. To denote mental phenomena of the kind I am supposing, I propose the term exoneural, (εξω νευζον.) I venture even, following out this idea, to conjecture further, that the Od force may somehow furnish the dynamic bridge along which our exoneural apprehension travels.
IV. The affections of consciousness would thus be in part esoneural, in part exoneural, during the healthy and normal state of our being; the esoneural part being executed in immediate connexion with its appropriate organ, and every manifestation of it being attended with a physical change in the latter.
V. But it is conceivable, on the assumption of mind being a separate principle from matter, that the human soul may be capable of retaining its union with the body in a new, unusual, and abnormal relation. The hypothesis is startling enough. I adopt it only from seeing no other way of accounting for certain facts which, with the evidence of their reality, will presently be brought forward. I venture to suppose that the mind of a living man may energize abnormally in two ways: first, that a much larger share of its operations may be conducted exoneurally—that is, out of the body—than usual; secondly, that the esoneural mental functions may be conducted within the body in unaccustomed organs, deserting those naturally appropriated to them. Two or three instances have been already given, which favour, at all events, the supposition of the possibility of such an abnormal relation between the mind and the body being realized. But in most of the instances hitherto adverted to, the normal relation may be supposed to have remained.