The scientific method of studying the phenomena of the human mind by founding it on a physiological basis, and thereby tracing the cerebral functions through the lower animals and uncultivated man, according to the plans adopted in other physiological investigations, must necessarily tend to modify or even change much that is contained in our received systems of psychology. In the hands of such men as Darwin and Huxley, the comparative method, when worked out in all its truthfulness, must necessarily bear good fruit, and be unaffected by any of the bias which the purely metaphysical method of the schools is apt to give to the investigation. The objection that it is degrading to compare the human being with the lower animals, or to take mankind in the mass, is of no value to the scientific investigator, who is merely seeking after truth, and knows that no researches of his can in any way affect man's history in the past or for the present; although they may afford many explanations of human conduct.

Some years ago I published a pamphlet (reprinted, with slight alterations, from the “St. Andrew's Medical Graduates' Transactions,” vol. iv., 1868) on Nervous Affections in Inherited Syphilis. At that time I had had bat one post-mortem examination. The patient was a girl, the daughter of the patient Joseph Mx., whose case is the second of two related by me in this Journal for July, 1874. She had epileptic fits. She died of typhoid fever, and no lesion of a syphilitic nature was discovered post-mortem. Thus I learned nothing from this case. In the “Brit. Med. Journal,”* May 18, 1572, I have reported a case of hemiplegia, previously unpublished, in a woman aged 22, who was manifestly the subject of inherited syphilis. That patient was in good general health, and is, I hope, still living.

We were engaged, when we left off last, in considering some points bearing on the prison-conduct of criminals in relation to their crimes; and we now proceed to show how various questions as to mental condition are started by prison-misconduct.

The subject of cannibalism cannot be omitted from such an inquiry. The consideration of this revolting instinct and practice becomes imperative because there are grounds, derived both from history and psychology, for believing that cannibalism, either as a primitive or corrupted instinct, has at one time or other been universally prevalent, has characterised certain states or stages in the progress of every race. This proposition does not exclude the existence, either originally or in certain stages of progress, of purely vegetarian nations. We are so accustomed to regard modern communities in their civilised and mature condition, and in the same manner as the ancients fabled Minerva starting from the front of Jove, perfect, graceful, armed, that we forget that nations had beginnings, that their growth was from a mist or a myth which we cannot grasp, or that they emerged from barbarism so gross and degraded that we can scarcely realise its enormity. It would be a vain and futile task to establish by reference the proposition that a craving for human flesh, or, at all events, its use as food, preceded the habits and manners of civilised life, and we shall confine the allegation to our own progenitors as conveying a lesson at once to our pride and to our philosophy. Montalembert, after eloquently painting the striking and pleasing contrast between the aspect and social state of the west of Scotland, between 412 and 1867, perhaps the very spot in which these words are now written, says “Dion, Strabonius, St. John Chrysostom, and St. Jerome have emulated each other in painting the horrible cruelty, the savage and brutal habits of those inhabitants of North Britain, who, successively known under the name of Caledonians, Scots, or Picts, were most probably nothing more than the descendants of the British tribes whom Rome had not been able to subdue. All agree in denouncing the incestuous intercourse of their domestic existence, and they have even been accused of cannibalism.”

To one who does not admit the divine mission of Mahomet it is very difficult to explain the pretensions of that remarkable man, and at the same time to uphold his sincerity. There have undoubtedly been instances where mere politicians have resorted to religious impostures as temporary expedients to advance their ends; for example, the woman whom Pisistratus got dressed up in the traditional costume of Pallas, and who conducted him back to Athens from exile, or the milk-white hind which followed Sertorius in Spain, and by means of which he was reputed to hold converse with the Gods. But a contrivance of this kind is a very different thing from the foundation of a religion which now numbers about a hundred and forty millions of votaries, and which possesses to this day a very singular power over the minds of its followers. By the persistent claim of being a messenger from God, after a struggle of twenty-one years Mahomet made himself master of the greater part of Arabia, and roused a mighty religious movement which continued after his death. In a few years more a number of wandering tribes, who had previously no more cohesion than the sands of their deserts, had run a mighty career of conquest, which bore them to the banks of the Loire and of the Oxus. It is generally admitted that men cannot excite in others feelings which are wanting in their own breasts. A man without honesty and destitute of religious faith could no more found a religious system like that of Islam than a man without an ear for music could compose an opera. The old notion that Mahomet was a mere impostor appears so difficult of belief that no one of any recognised skill in historical inquiry now upholds it. But it has always been a great difficulty to explain how Mahomet could in good faith say that he had seen the angel Gabriel, and heard voices from heaven calling him the Messenger of God, and revealing chapter after chapter of the Koran. It had long seemed to me that the question was beyond human solution, and that it might have been a very difficult one, even had the inquirer lived in Mecca or Medina during the time of Mahomet's mission.

Before narrating the case which is the basis of this communication, I shall briefly advert to the leading features, and the views held regarding the nature of the remarkable neurosis with whose discovery the name of the late eminent Dublin Professor, Dr. Graves, is most frequently associated. The dependence of the psychical and somatic phenomena on one cause, common to both, will thus be more clearly demonstrated, and the claim which it seems to me the disorder of the mind has to be regarded as a distinct form of insanity will be more apparent.

In the first and second volumes of the West Riding Asylum Medical Reports, 1871–72, there appeared two papers bearing my name, which were entitled, the one “The Sphygmograph in Asylum Practice,” and the other “The Sphygmograph in Epilepsy.” The first paper, besides containing a few general remarks, was, however, confined to the study of the physiology of General Paralysis; the other, as its name implied, referred entirely to certain phenomena observed in Epilepsy, and contained a few speculations as to the origin and nature of these phenomena. Both papers had been hastily prepared, though they really represented an amount of patient labour such as probably I shall never undertake again. The later one had also the disadvantage of being so cut and mutilated for want of space that, when finished, I hardly recognised my own work. I had begun to think that they were to be considered of no real value, and only fit to pass into the limbo of forgotten things, when they were suddenly snatched from a threatening oblivion by having assigned to them a prominent place in the new edition of the work so familiar to many engaged in this special branch of medicine by the names of Bucknill and Tuke. More recently they have been brought into further prominence by being incorporated into that clever, thorough work, “The Pathological Anatomy of the Nervous Centres,” by Dr. Long Fox, where the views originally advanced by myself are put in much clearer and more forcible language than I could ever master. It has occurred to me, then, that now is a good opportunity for considering de novo the bearings which these speculations may have on the further elucidation of the nature of the origin of two diseases, one of which, at least, has hitherto been enveloped in darkness, and which, because of such ignorance, has, until recently, baffled all attempts to effect anything like a certain cure.