All theories of this kind appear to us extremely liable to degenerate into dangerous errors. Considered in themselves, they may be harmless speculations; but they are always liable to take a particular tone and character from the minds of those who adopt them: and if that be of an irreligious nature, they may very easily convert the visionary views of some speculative physiologist into the vehicles of most fatal error, productive of the worst practical consequences, and spreading far and wide their insidious infection; not the less poisonous and deadly in its effects, because it is conveyed to unthinking minds in association with an entertaining and ingenious system. If the idea of giving a local habitation to the mental faculties, be understood as implying that those parts of the brain are the actual agents of thought, the consequences are dangerous in a religious point of view :-if on the other hand it be meant to confine an immaterial principle to a certain physical space, the idea is philosophically speaking absurd, so that either way such speculations can do no good, and may, and probably will, do much harm. They tend either to mislead philosophy, or to destroy religion.

. The nerves by their arrangement in two distinct systems appear to be the instruments of two different sets of functions, voluntary and involuntary. The former constituting our external actions, the latter our internal sensations, and the various processes which go on in the body. Yet though thus distinct, the different sets of nerves act in close connexion with one another. Thus tending in various ways to keep up that perpetual balance and harmony between all the various functions which is so essential to vitality. This is a part of physiology of considerable importance in regard to the connexion of these with intellectual phenomena. Our author has given many interesting views of this part of the subject from which we extract the following passage.

"But this intimate connexion between the different parts of the nervous system becomes scarcely perceptible in the lower orders of animals. Where the bulk of the brain is greatest in proportion to the nerves connected with it, as in man, we find this union most intimate. As the bulk of the brain decreases, in proportion to the bulk of the nerves, the connexion ceases to be so close. In reptes and fishes this is so conspicuously displayed that it becomes difficult to induce death. The brain or the spinal marrow may be removed, and yet the other functions of life still proceed for a considerable time. Among the mollusca an equal want of sympathy among the different parts, is well known to prevail. As we descend still lower, to those animals in which the nervous system, instead of appearing in the form of brain, nerves, or ganglia,

is uniformly diffused, we observe scarcely any dependent connection between the different parts. When portions of the body are removed they are speedily reproduced, and the detached fragments even begin to enjoy independent existence." P. 161.

This sketch of one of the most curious parts of comparative physiology, may tend to suggest considerations bearing in some measure on those topics which we have professed to be our more immediate object in the present article. This apparent diffusion of the vital principle in many animals, in such a way throughout their various ganglia and separate systems of nerves, as to admit of conferring separate vitality on detached portions, shews clearly that in those animals at least the vital principle is not confined to any one spot. And since each of the separate parts to which it can be communicated is furnished with a certain nervous system complete in itself; it seems that such a complete nervous system, having its parts connected in a certain way, is the essential datum for the superinduction of life. Wherein that completeness consists, and what is the precise nature of the requisite connexion remains to be investigated. But life seems to go on by the agency of such a system disseminated throughout the animal frame: to depend for its continuance on the joint operation of the whole in connexion, not on the insulated function of any particular part. And this corresponds with the idea of an immaterial principle, which as we before observed, it would be contradictory to limit to one particular spot. And at the same time such a view of the subject excludes materialism, or at least reduces it to this, that the whole animal frame thinks. Which is surely too absurd an hypothesis even for unbelievers to adopt.

The proximate cause of nervous action is a topic on which physiologists have, as might be supposed, entertained the most opposite, and in many instances the most hypothetical opinions and moreover, in the cause thus assigned have supposed that they had discovered the vital principle. Our author comments very sensibly on these opinions.

"It would be to no purpose to enquire into the nature of that action which is excited in the nerve, either in sensation or volition; because the subject is yet in obscurity, and its elucidation, perhaps, impracticable. The rapidity with which the functions of the nervous system are executed, have induced some to consider its action as performed by means of some fluid similar to electricity, secreted by the medullary matter, and restrained by the tunics of the brain and nerves. All this may be true; but it is without proof. Others, from contemplating the effects of electricity on the

parts of dead animals, have concluded, that the nervous and electrical fluids were identical. There is, however, one experiment, easily performed, which proves the fallacy of this conclusion. The nervous energy is suspended or destroyed by the compression or section of the nerve, while the electrical matter is not arrested in its progress, provided, in the latter case, the cut ends of the nerve are brought in contact."

This experiment is conclusive, and, we think, very impor tant; since it at once destroys the hypothesis of the vital functions going on merely by galvanism: an hypothesis which seems to have been a favourite one with many who would rather adopt any supposition than that of a spiritual existence. Many of these profound philosophers look upon man as nothing more than a walking galvanic battery. They suppose that the nerves act upon the system, and the system re-acts upon the nerves by a set of galvanic combinations; that this constant circuit is the cause of life, and is life itself, and is, moreover, the effect of life, all at once; that the brain is part of the combination which keeps up the galvanic current; that the galvanic currents make the brain act; while the action of the brain produces the galvanic currents; that the action of the brain is thought; and, consequently, that thought produces galvanic currents, whilst they reciprocally produce thought. Such is the rigid, the inductive, the philosophic system of materialism! It is ably and briefly exposed by our author in the following passage.

"Of the elementary nature of this exciting power, we indeed know nothing. Physiologists have termed it a secretion of the nervous system; without perceiving that, in the manner of its operations, it is essentially different from any other secretion in the system. That it results from organization, is disproved by the phenomena of death; that it is of electrical or magnetical nature, is contradicted by the totality of its phenomena." P. 164.

Having thus examined the nature of the nervous system, the author next proposes to inquire into the phenomena of the mind. In order to do this the more satisfactorily, he makes a preliminary inquiry into the nature of our different sensations, and the organs employed in their production; and the kind of information which they convey to the mind, with regard to the properties of external objects. In this interesting and detailed account of the different senses (of which, by the way, our author reckons six, by adding the sense of heat) we will not follow him; but proceed to comment on one or two more passages bearing more immediately upon the leading topic of our remarks.

We have just noticed some of the palpable and ridiculous contradictions and inconsistencies which result from the doctrine of the intelligent principle being only a result of organization. We have exposed a few of the glaring absurdities of those who, because they learn from the discoveries of science, that galvanism is capable of producing powerful effects on some part of the animal economy, infer that galvanism is the sole principle of life, and the cause of intellectual phenomena. In other words, they are not content with rejecting revelation, but must also pervert philosophy: they not only offend against religion, but think to excuse it by an equally outrageous offence against all sound principles of reasoning. And when a man shews himself so utterly unable to make correct inferences even in the science which is his professed study, surely no sensible person would trust his judgment in reasoning upon another subject of so totally dif ferent a nature. Yet it is from the reputation of scientific eminence in the proposers of sceptical doctrines, that their authority over their disciples and dupes is chiefly maintained.

Our author views the matter in a very philosophical light; keeping clear from hypothesis in the scientific view of the subject, and superadding the doctrine of revelation.

Thus, speaking philosophically, he observes,

"Of the essence of mind we absolutely know nothing: and hence the various phrases, unity, indivisibility, immateriality, and others, which have been employed to express the nature of this essence, are, in fact, expressions of our own ignorance and presumption. When we witness the mind capable of exciting action in matter, and of being excited to action by matter,-exhibiting its identity by its local residence,-variable in its relations to matter,-variable relatively to its own conditions,-capable of exercising different functions at the same time,-and, last of all, multiplying with an increase of population, we feel overwhelmed with the incomprehensible phenomena which it presents, and admit the suitableness of an expression of our divine master, when applied to the present case, 'Ye know not what manner of spirit ye are of."" P. 214.

How infinitely superior are such views of this important, yet inscrutable point, to the crude theories and flimsy systems of the materialist. Real science is always distinguished by the humility of its pretensions: it teaches us with certainty what human ability is capable of investigating, but it also teaches us where an insurmountable barrier is opposed to those investigations. A false and spurious kind of philosophy, by dazzling the eyes of its votaries with its glittering pretensions, hinders them from perceiving those boundaries, and imposes no limit to their extravagant flights. Real phi

losophy, on the points more immediately under consideration, stops short of the doctrines of Revelation, and therefore leaves the mind open to their reception; and, further, admirably disposes it to receive them. Fallacious theory soars far beyond Revelation, and consequently, makes the mind incapable of humbling itself to admit or revere its sacred truths.

Whilst discussing the subject of the mental faculties, Dr. Fleming has, perhaps, gone somewhat beyond the strict limits of what we should consider the peculiar province of zoological science. We do not think him, upon the whole, so able a metaphysician as he has evinced himself to be a naturalist. It is foreign, however, to the object which we at present wish to keep more immediately in view, to enter upon any examination of the merits of his book in these respects: we will merely continue our remarks upon such passages as have struck us in this part of the work, which bear upon the religious tendency of zoological inquiries.

He has discussed, at some length, the nature of those ideas both from perception and reflection, of which the human mind is susceptible.. Among them he classes" ideas of duty." He comments upon many natural and obvious duties; and then proceeds to enquire what ideas the mind has with respect to the nature of duty, its standard, and obligation. He gives a variety of instances, tending to shew that, by mere natural light, the standard is so various, so vague, and uncertain, as scarcely to deserve such a designation. His resulting observation is as follows:

"We could easily swell the proofs of the variableness of the human standards of duty; and, although all are convinced that there is or ought to be a standard, they differ with respect to its character. This display of a moral deficiency or want in our nature, is the strongest proof that can be urged for the necessity of a revelation. The Christian religion supplies this moral want, and furnishes a standard which, if observed, would make all men, in every condition, happy, exalted, and wise." P. 239.

From the subject of our ideas of moral obligation, the author is very naturally led to that of our notion of a Supreme Being and his attributes. On this awful and important topic we will give his remark in his own words.

"From the displays of our own power and that of others in the production of motion, we are led to attend to the changes which take place around us, as the marks of some other power; and by witnessing the variety of means which are employed in the accomplishment of these various alterations, and the regularity which they exhibit in their succession, we arrive at the conclusion, that