The wonderful relativity of psychology to the purely somatic phenomena comprised under the term physiology, while not having altogether escaped the observation of earlier thinkers, did not assume the significance it now possesses till modern science compelled mere psychicists to recognize the invaluable services this new handmaiden bestowed on their favorite pursuit. It had been too much the vogue to frown down attempts at chemical explanations of vital processes as verging towards materialism, and thus materialism was in reality strengthened, since the opponents of modern physiology had shut their eyes to facts as stubborn and undeniable as the soul itself whose cause they were championing. This antagonism was unfortunate; for, though of short duration, it gave rise to the impression in the popular mind that the old science dreaded the new light, and that recent discoveries tended rapidly to overthrow the time-honored belief in the distinct substantiality of the soul. To this same arrogant rejection by pedantic orthodoxists of facts that seemingly conflicted with accepted views, may be ascribed the sneering and triumphant manner of many scientists who fail to take account of the slowness with which men reconcile themselves to truths not hitherto
suspected. Had, however, the data of modern science been at first fully considered, it would have become evident that theories and assumptions alone ran counter to the doctrine of a spiritual soul, and that scientific facts, startling and numerous as they were, did not, when viewed by the light of a just interpretation, conflict with any prior truth. The hasty and groundless character of the assumptions which tend to materialism may be inferred from the claim not long since put forward in the Ecole de Médecine at Paris, to the effect that the science of physiology demands in advance the rejection of any principle of activity in man not amenable to its methods and instruments of research, on the ground that man in his totality is the true objective point of this science, and the admission of aught in him which it cannot determine is equivalent to stating that man is more than he is. According to this authority, therefore, the notion of a soul, viewed as a spiritual substance, distinct and different from the body, hampers science and circumscribes the field of its inquiry. But if the vast strides made by physiology within the last decade have been the occasion of some pernicious speculation, and have seemed to give countenance to materialism, this has been the case only when the science transcended its own data and soared into the region of conjecture. Its legitimate fruits are manifest in the flood of light it has thrown on the most intricate questions of psychology,
and the elucidation of points which, but for it, would have remained for ever in obscurity. Indeed, it may be said to have created a new branch of psychical science, and to have brushed away many cobwebs that clouded the psychology of the schools. The volume before us represents the latest expression of the physiology and pathology of the nervous system, and is characterized by unusual closeness of observation and accuracy of expression, while evincing a proneness to theorize on points concerning which the author is least at home. Dr. Hammond has been a close student at the bedside and an indefatigable worker with those instruments of research which have almost built up his science, but for all an indifferent thinker, as we shall shortly endeavor to prove. It is true that no authority is more frequently invoked, and with good reason, to determine questions relative to mental aberration and unusual conditions of the nervous system; but when he abandons the ophthalmoscope, the cephalohœmometer, the œsthesiometer, and assumes the abolla of the philosopher, he evidently misses his rôle. He is undoubtedly a physiologist of the first rank and a respectable authority on minute nervous histology, but as a theorist he is a failure. Accustomed to dogmatize on facts coming within the scope of the senses, he applies the same procrustean rule of reasoning to purely intellectual processes, and speedily flounders in a quagmire. His mind has tipped the balance in the direction of material things, and has not been able to regain its equilibrium.
As a repertory of interesting facts, gleaned in the course of a long and varied experience, his book is invaluable. It bristles with information
and is replete with comments which prove Dr. Hammond to be an accurate, close, and painstaking observer, as well as an accomplished anatomist. His chapter on Aphasia is intensely interesting, and constitutes a valuable contribution to the theory of localized function. Aphasia is that inability to use language which proceeds, not from paralysis of the labial muscles, nor from hysteria, nor from injury of the vocal chords (aphonia), but from a lesion of that portion of the brain which presides over the memory of words and the co-ordination of speech. Many instances are adduced in proof that this inability results from the impairment of a given portion of the cerebral substance; and from the constant recurrence of the same effects from the same lesion the inference is drawn that a very restricted portion of the brain is concerned in connecting thoughts with words, co-ordinating these, and arranging them in articulate sounds. Authorities, indeed, are not agreed as to what special brain lobe this faculty is to be ascribed, but the fact is borne out by unquestionable evidence that some portion of the anterior convolutions controls and regulates the power of speech. The point of interest is that the function is localized and depends on the minute physical texture of the nerve substance through which it is carried on. Dr. Hammond justly claims the credit of having first observed that the form of aphasia called amnesic (forgetfulness of words) depends on some lesion of the vesicular or gray matter of the brain, since it is unaccompanied by paralysis, while the form called ataxic (inability to co-ordinate articulate sounds) is connected with the corpus striatum which presides over motion,
and so we find this latter form always associated with paralysis.
No summary of this chapter can do it justice, so pregnant is it with facts and abounding with varied suggestion. We would remark, however, that Dr. Hammond has failed to call attention to the remarkable confirmation which the condition of amnesic aphasia offers in support of the inseparable connection between thought and some symbol of expression—a circumstance which Trousseau, in his learned work on Clinical Medicine, has noted at length. Trousseau says: “A great thinker as well as a great mathematician cannot devote himself to transcendental speculations unless he uses formulæ and a thousand material accessories which aid his mind, relieve his memory, and impart greater strength to thought by giving it greater precision. Now, an aphasic individual suffers from verbal amnesia so that he has lost the formulæ of thought.” This fact of aphasia curiously coincides with Vicomte de Bonald’s theory of the divine origin of language, which is based on the supposed impossibility of having a purely intellectual conception without an accompanying formula or word to circumscribe and differentiate it, and that accordingly language, in such relation, must have been communicated.
It is likewise corroborative of the view taken by Max Müller, who says (Science of Language, 79): “Without speech, no reason; without reason, no speech.” And again: “I therefore declare my conviction, whether right or wrong, as explicitly as possible, that thought, in one sense of the word—i.e., in the sense of reasoning—is impossible without language.”
The latest disclosure of science, therefore, so far from conflicting on
this important point with the philosophy of the Scholastics, endorses and sustains it, and is opposed rather to the rationalist view of the question.