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Tendency of Physiological Studies.

of our existence intimately associated. Every one is persuaded from general experience, that a powerful impression upon the mind affects the body, that the condition of the body influences that of the mind. But while many are content to suppose this union contingent, and that the soul may at another period exist unshackled by a corporeal frame, materialists attempt to prove that mind is the result of organization, that a portion of nervous substance, when existing under certain imperfectly ascertained conditions, necessarily produces thought.

If we abstract our minds from all preconceived ideas upon the subject, it must be admitted that there is nothing, which involves a contradiction in terms, or that is repugnant to common sense, in this supposition. In support of its justness, materialists borrow from physiology evidence of two kinds; consisting on the one hand of an analogical argument deduced from the relation between organs and their functions, on the other of direct proof of the close correspondence of the mental phenomena with the state of corporeal organs.

The analogical evidence brought forward in support of materialism contains a fallacy, the detection of which places in a very strong light the reasonableness of an opposite conclusion.

Physiologists have ascertained that different parts of the human body have different offices: that the formation of bile takes place in the liver, of saliva in other glands, that a power of shortening belongs to certain fibrous parts, that consciousness is connected with the nervous system. Now as the liver is admitted to be necessary for the separation of bile from the blood, as the power of shortening is the result of the structure of a

Tendency of Physiological Studies.

5

muscle, it has been supposed to be an analogical inference that thought is the produce of the brain.

But the separation of one fluid from another, and the shortening of a fibre, are expressions which convey no meaning, if we attempt to abstract them from the notion of material organs or material substance. With the functions of the brain the case is different. Our conception of thought does not involve any attribute of matter; and we are struck with no speculative absurdity in supposing that our consciousness may survive, after every material element with which it has been connected shall have perished. Thus the analogy is destroyed between the dependence of thought upon the brain, and that of other functions upon other organs; and the argument founded upon it falls to the ground.

The second argument comprehends some curious details. If a portion of the brain be removed, the mind seems mutilated likewise. If a polype be cut in half, each portion appears to obtain independent consciousness. Facts of this description are indeed strikingly consistent with the theory of materialism, yet they are perfectly reconcileable with a different hypothesis. When we suppose mind and matter to be arbitrarily united, it is but reasonable to conclude that a very nice adaptation of the frame alone enables the mind to cooperate with matter, and we naturally anticipate, that what deranges the physical structure of the body will obscure the manifestations of consciousness. If it be difficult in this supposition to comprehend how matter can influence mind, it forms at least an equal difficulty in the theory of materialism to imagine how matter can produce mind. The apparent partitioning of consciousness

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Tendency of Physiological Studies.

upon the division of the lower animals, is analogous to the evolution of sentient existence by generation. We have to suppose that in the present scheme of the world there is a provision for adding a principle of consciousness to matter, when corporeally made a fit recipient for it. It might perhaps appear too great a concession to allow that the preceding facts tend to establish the theory of materialism, as much as the presumed fact of the renewal of the brain, while the conviction of our moral identity remains unchanged, tends to prove the reverse: yet these arguments on opposite sides may fairly be compared: they are both as unsound as they are plausible.

But the power, which we possess, of conceiving the separate existence of mind and of matter, constitutes each a substance logically distinct and it forms no contemptible argument in favour of their essential independence, that although experience may be said in one sense to oppose it, our reason, in spite of experience, suggests and compels the belief that their present union is possibly contingent. For evidence to prove this supposition correct, we necessarily look elsewhere; my object is accomplished, if I have succeeded in showing that physiology does not lead to materialism.

It remains to confess that physiological attainments are not made without a sacrifice. The practice of dissection is repulsive to the imagination and to the senses, and the best sentiments of humanity revolt against the performance of experiments upon living animals: yet without the former no one would understand the mechanism of the body, and without the latter the uses of parts would be known by conjecture only. Harvey deduced from experiment proofs of the circulation of the blood,

Distinction of Matter into Organized and Unorganized. 7

and almost every important addition to physiology has been obtained by the same method. It is to be hoped that no one can look without abhorrence upon deliberate or wanton cruelty: but who would brand with either reproach experiments calculated to determine principles directly or remotely of practical importance in medicine and surgery, or deny that they present an advantage to mankind, which may weigh against the attendant evil? He at least, who applauds on the principle of expediency the daily destruction of animal life for other purposes, cannot consistently impugn the moral feelings of those, who shrink not from inflicting pain on inferior creatures, in order that the sum of human suffering may be lessened.

Upon or near its surface

THE globe of the earth is formed of what are termed mineral substances, existing either in a solid, or in a liquid, or in a gaseous form. are found other bodies, which either live, or, being dead, preserve some remains of that shape and structure which they possessed during life. Living bodies are either plants or animals. The elaborate contrivances calculated for special ends or functions, which admit of being displayed in the greater number, have obtained for the whole the general appellation of organized bodies. On the other hand, mineral substances, which taken individually consist of mere aggregations of similar particles, are termed unorganized.

Mineral bodies are perhaps less correctly termed inert. The properties of unorganized matter produce in it continual changes, though of a kind less adapted to excite observation, than those which modify organized bodies.

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Meaning of the Term “Life.”

The surface of the earth is perpetually undergoing alteration, through chemical action or mechanical attrition. The oxygen of the atmosphere is in constant consumption, and is constantly reproduced. The waters, which in various ways become polluted, are rendered pure at the time when by spontaneous distillation they rise in vapour, are again condensed, descend in the form of rain or snow, and becoming impregnated with atmospheric air, are again distributed over the earth to diffuse fertility and health; a combination of functions, which offer a rude type of respiration and of the circulation of the blood in animals. The properties of inert matter again determine the alternations of night and day, the recurrence of the seasons, the revolutions of the planets; a series of changes which may be termed the Life of the World.

In the preceding illustration of its meaning, the term "Life" is employed figuratively. In its direct sense it denotes other changes, which occur exclusively in organized bodies. The term "Life," like the terms "Nature" or "Mind," is a collective expression for an assemblage of phenomena. Each instance, that I have adduced, suggests parallel inquiries. Thus philosophers investigate the laws of life, the laws of the human mind, the laws of nature, by an analysis of the phenomena, which the terms, life, or mind, or nature, comprehend. In either instance, when certain antecedent circumstances are found to be invariably followed by a given change which ensues in no other case, the law or physical cause of that change is ascertained; and some general expression is made use of, which strictly, indeed, denotes no more than the invariableness of the sequence of events, yet