Page:Philosophical Review Volume 1.djvu/423

No. 4.] the results of his other work, all of which have been substantiated by various independent experimenters. It is in line with the general trend of the doctrine of specific energies in our day, and, as we hope to show, in accord with the widest range of facts known regarding our subject in general.

Until the discovery of Goldscheider it seemed quite certain that, if the stimulation were sufficiently intense, pain would rise from nearly all the sensory nerves of the body. No doubt this has given greater foundation to the doctrine that pain is a general attribute of sense than any other supposed physiological fact. It fell in so exactly with the traditions of philosophy and of ethics as to seem to leave no room for suspecting their soundness or for examining further the phenomenon in question. But we now find the evidence going entirely against the view that most of the nerves of sense are painful. Long before Goldscheider's discoveries, it was found that the optic nerve, one of the largest in the body, is but little if at all sensible to pain. Some of the best authorities inclined to the belief that the pain which sometimes appears to come from violent excitation of the optic nerve really was due to simultaneous irritation of portions of the tri-geminus. Then it was found that the other nerves of the major senses were also but indifferently painful, if indeed at all so, due regard being given to the fibres of other nerves in close proximity to or intermingled with the specific nerves in question. All this makes it entirely certain that, if the special sense nerves are painful, the pain is by no means proportioned to the size of the nerve trunk. Yet we should have expected, if pain were a general attribute of all sense, that it would be most prominently developed in and where the sense of which it were an attribute was also most developed — would have developed parallel with its matrix. The reverse is unquestionably the case; and the discovery of specific nerves of pain now makes it probable, if not quite certain, that whatever pain does come from irritation of the other special nerve trunks is due to specific pain fibres interwoven within the same sheath. This intermingling of the fibrils of one nerve with the trunk of another is now known to be