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inductive evidence by that drawn from analogy, we suspect he is only at the beginning of his task, for he has not yet advanced a single argument of this kind which is able to stand on its own foundation, much less fitted to be employed to beat down the arguments of others. Indeed he never attempts to combat the principles of phrenology, but merely magnifies the difficulties of putting them in practice; and in this he acts wisely, for it is only thus that the real feebleness of his reasoning has any chance of escaping detection. With all his caution, however, he is not altogether safe. To prove that one organ may perform all the operations of the mind, he argues thus: “ Does not the same “ stomach digest very different and even opposite kinds of “ aliments ? yet we do not find that one portion of that
organ is destined for the digestion of meat, and another “ for that of vegetables." Very true; but the function is the same in all, the subject only is different. Digesting is no more than digesting, whether it be performed on turtle or roast beef, animal food or vegetable. In like manner, no phrenologist ever asserted that one part of the organ of causality reasoned in political economy, another in metaphysics, and a third in medicine; or that one portion of the organ of tune was destined to produce soft and plaintive notes, and another bold and warlike music. We only maintain, that as the stomach cannot secrete bile, nor perform the office of kidneys, neither can the organ of causality produce a relish for music, nor that of tune a talent for logical reasoning. We have never said that causality cannot be exercised on all sorts of subjects, sacred or profane, important or trifling; but we have said, that no change of subject will ever change its specific function of reasoning, any more than any change of diet will change that of the stomach from digestion to the secretion of bile.
Dr Roget states, as strong analogical arguments against a plurality of mental organs, that “ nerves perform the double “ office of volition and sensation; but no anatomist has yet “ separated the different bundles of fibres which convey
" each impression;" and that “the same organ serves for “ the hearing of acute and of grave sounds,” and “ the " whole 'retina, and not merely different portions of its sur“ face, receives the impression of different kinds of colour : “there is not one organ for the perception of blue, and an“ other for the perception of red rays." “ Guided by such
analogies as these,” says he, “ might we not be equally
justified in concluding that the same part of the brain may “serve for the memory of words and for the memory of “ things, and that the same portion of that organ which “ enables us to conceive the idea of figure may also suggest " to us that of size ?"
The first of these analogies is the only one that, if sound, would be applicable, because in it alone there is a real difference of function, or a manifestation of two distinct powers, volition and sensation. But, unfortunately for Dr Roget, it has been demonstrated since he wrote, that for each of these functions there is a different bundle of fibres, although they are enclosed in a common sheath, and seem to constitute only a single nerve. This analogy therefore falls completely to the ground as an argument against phreno logy. Nay, it becomes a powerful support of its doctrines. Many years ago, Dr Spurzheim and some other physiologists inferred, from the fact of motion remaining in some cases where feeling was lost, and vice versa, that the nerve must really be double. Now, with this fact before us, when we observe that the memory of things frequently remains after that of words is lost, and vice versa, as in Mr Hood's and Dr Gregory's cases, mentioned in the Phrenological Transactions, does not the inference naturally follow, that there must be a distinct organ for each of these kinds of mental manifestations ? We refer our readers for particulars to an article in our last Number on the functions of the nerves.
The second and third analogies evidently arise from Dr Roget confounding a modification of the same function with two distinct functions. Hearing acute and hearing grave sounds amount to nothing more than hearing sounds.
Again, the perception of blue and that of red colours are nothing more than perception of colours. We maintain that there is one organ for hearing sounds of every kind, and another for perceiving colours of every hue, but not that one organ perceives one colour, and another another; so that the Doctor's analogy again totally fails him. We are only surprised that he never stumbled upon this plain fact in any of Dr Spurzheim's works, where it is repeatedly mentioned.
Dr Roget thinks the phenomenon of mental fatigue being relieved by passing from one kind of study to another, as from philosophy to music, equally explicable on the supposition of a single organ of mind as on that of a plurality; and he entertains the same opinion of the facility of explaining the phenomena of dreams, somnambulism, partial insanity, the very essence of which is the activity and healthy manifestation of one or more faculties co-existing with the inactivity and diseased manifestations of others; or, to use the analogy of the five senses, Dr Roget is able to conceive how sight and smell may be lost or diseased, while hearing, taste, and touch are in a different state, equally well, on the supposition of all being functions of a single organ, as on that of each having an organ to itself. This analogy is a palpable one, and we use it because there cannot be a greater difference between smell and taste than between destructiveness and veneration. We can offer no argument against Dr R.'s power of conception ; but, to render the analogy effective, he ought to have referred to some created being in which all these different functions are performed by a single organ. This he has not done, and, therefore, we are not enlightened by his argument.
Such, then, our readers will be surprised to learn, are Dr Roget's refutations of the analogical arguments adduced by Drs G. and S.-not as proofs of their system, as Dr R. would have us to believe, but merely as facilitating its reception, by shewing its consistency with the ordinary laws of the animal economy.
Dr Roget proceeds to object to the anatomical evidence in favour of phrenology, because, says he, “the anatomy of the “ brain is so complex and so void of apparent adaptation to
any purpose we can understand, that it will suit any physiological system equally well. The separation of the
parts of the brain and their diversity of shape can no more “ be evidence of a diversity in their functions” than the lobules of the kidneys, &c. Those of our readers who recol. lect that it is a principle much and justly insisted upon by the phrenologists, that dissection alone is insufficient to reveal the function of any organ, will see at once that Dr R. is here combating an enemy of his own creation. G. and S. had for their object only to shew that the anatomy of the brain was not inconsistent with their physiological discoveries. They do not attempt to go farther than this; and the proof of it is, that the physiology was discovered long before they commenced their anatomical labours. We refer Dr R. to Dr Spurzheim's Outlines, p. 22.
Dr Roget, as if he were instructing Drs G. and S. in an important truth for the first time, states, that “ comparative “ anatomy, upon which so much is made to hinge, is of all “ guides the most fallible in questions of this nature.” No person reading this would imagine that Dr Spurzheim himself had previously said, that “ Although it is of the highest “ importance to know the gradation observed by nature in
perfecting the brains of animals, in order to multiply and “ ennoble their functions, we must allow that, notwithstand“ ing the most assiduous labour, comparative anatomy has “ shown only the mechanical form of different brains, and " that these anatomical notions do not at all determine the “ functions of the cerebral parts.”—(Outlines, p. 24.)
The next objection of Dr R. was onc but is now little noticed. It is, that the want o parallelism in the two tables of the skull, renders it impossible to ascertain the size and shape of the parts underneath. But this objection disappears, when we recollect that the function of every organ has been determined from extreme cases of en
much in vogue,
dowment and deficiency. The whole thickness of the skull varies, in different individuals, from one-tenth to one-fifth or one-sixth of an inch, and therefore when we measure across both sides of the head, the greatest possible inequality, within the limits of health, must be comprised within something less than the greatest aggregate thickness of both sides, viz. two-fifths of an inch; so that when we produce two skulls nearly equal in size, one of which presents one inch more in the region of cautiousness, for example, than the other, there must of necessity be at least three-fifths of an inch more brain at that part in the former, than in the latter; and when such differences are daily found, they are quite sufficient to enable us to determine the functions. But in point of fact, the divergence from the parallel, when it does exist, is seldom more than to the extent of a line, and rarely extends over a whole organ, so far as to affect the accuracy of our observations. In disease and old age, indeed, , the difference is often very great; and for that reason the phrenologist never infers any thing whatever from the development in such cases.
Dr R. next attacks and denies the principle of size of cerebral organs being, ceteris paribus, a criterion of energy ; and he again represents this principle as founded on a loose analogy, instead of resting on the firm basis of experience. “ Let us examine," says Dr R., “ the logic by which the “ above fundamental principle is deduced. "A large mus “cle,' say G. and S., is stronger than a smaller one, and
a large loadstone is more powerful than a smaller one; “ why should it not be the same with regard to the brain ?' “ Thus again,' says Dr R. confiding in a loose analogy,'" &c. Now, Drs G. and S. founded this doctrine on positive observations, that large organs are actually accompanied with stronger manifestations than small ones, and then they pointed out that this fact is in harmony with the analogies of nature, Dr R. therefore does not meet them fairly. He next goes on to describe other conditions which must influence the functions as much as that of size, without ever seeming to