As simple nerves, or a nervous cord, such as that of the spinal marrow, is the proper organ of sensation or feeling, the gland of a brain, from which the nervous cord usually, though not always, shoots, is the proper organ of intelligence; and as I had occasion to observe in a former study, when lecturing upon the subject of the senses, the degree of intelligence appears, in every instance we are acquainted with, to be proportioned, not, indeed, to the size of the brain as compared with that of the animal to which it belongs, as was conjectured by Aristotle, and has been the general belief almost to the present day, but as compared with the aggregate bulk of nerves that issue from it. * The larger the brain and the less the nerves, the higher and more comprehensive the intelligence: the smaller the brain and the larger the nerves, the duller and more contracted. In man, of all animals whatever, the brain is the largest, and the nerves comparatively with its bulk the smallest in the monkey tribes it makes an approach to this proportion, but there is still a considerable difference; in birds a somewhat greater difference; in amphibials the brain is very small in proportion to the size of the nervous cord; in fishes it is a bulb not much larger than the nervous cord itself; in insects there is no proper brain whatever; the nervous cord that runs down the back originating near the mouth; sometimes of an

* Vol. I. Ser. I. Lect. xv.

uniform diameter with the cord itself, and sometimes rather larger; and in infusory and zoophytic worms we have no trace either of nerves or brain.

In these last, therefore, it is possible, and indeed probable, as I have already observed, that there is no sensation: the vital principle, and the instinctive faculty, which is the operation of the vital principle, by the exercise of certain natural powers constantly appertaining to such principle, alone producing all the phænomena of life as in plants. In most insects, for the same reason, it is possible, and indeed probable, that though there is sensation, there is little or no intelligence: the brain, which is the sole seat or organ of intelligence, being totally destitute, in most of them, and of very minute compass in the rest. In fishes we have reason to apprehend different degrees of intelligence; in many amphibials somewhat more; more still in birds and quadrupeds, and most of all in man. But what is intelligence, which is a distinct principle from sensation, and to which, as in the case of sensation, a distinct organ is appropriated? An organ, moreover, which, like that of simple sensation, may be also produced out of an insentient egg by the mere application, so far as we are able to trace the different substances in nature, of a certain proportion of heat; for the egg of the hen, unquestionably insentient when first laid, becomes equally hatched and endowed with the organs and properties both of sensation

and intelligence, by the application of a certain portion of warmth, whether that warmth be derived from the body of the hen, of a dung-hill, an oven, or the sun. But though we know the organ, what information does this give us of the thing itself? In what respect is intelligence connected with the brain? Does it result from its mere peculiarity of structure, secreted, like the blood, but of a finer and more attenuate crasis, or is it a something superadded to the organ? Is it matter in its most active, elaborate, and etherialised form, or is it something more than matter of any kind? and, if so, how has this superadded essence been communicated?

To this point we can proceed safely, and see our way before us: but shadows, clouds, and darkness rest on all beyond, while the gulf on which we sail is unfathomable to the plummet of mortals.

It is something more than matter, observes one class of philosophers, for matter itself is essentially unintelligent, and is utterly incapable of thought. But this is to speak with more confidence than we are warranted; and unbecomingly to limit the power of the Creator. It has already appeared that we know nothing of the essential properties of matter. If it be capable of gravitation, of elective attractions, of life, of instinct, of sensation, there does not seem to be any absurdity in supposing it may be capable of thought: and if all these powers or endowments result from something more

than matter, then is the visible world as much an immaterial as a material system.

On the other hand, it is as strongly contended by an opposite class of philosophers, and the same train of arguments has been continued, almost without variation, from the days of Epicurus, that the principle of thought or the human mind must be material; for otherwise the frame of man, we are told, will be made to consist of two distinct and adverse essences, possessing no common property or harmony of action. But this is to speak with as unbecoming a confidence as in the former case. The great visible frame of the world seems to point out to us in every part of it a co-existence either of different essences or of different natures-- of matter and a something which is not matter; or of common matter and matter possessed of properties that it does not discover in its common form. Yet all these, so far from being adverse to each other, subsist in the strictest union, and evince the completest harmony of action. And hence the soul, or intel ligent principle, though combined with matter, though directly operating from a material organ, may be a something distinct from matter, and more than matter, even in its most active, etherial, and spiritualised forms: though, whatever be its actual essence, it undoubtedly makes the nearest approach to it under such a modifi cation.

In reality, under some such kind of etherial or shadowy make, under some such refined or

spiritualised and evanescent texture, it seems in almost all ages and nations to have been handed down by universal tradition, and contemplated by the great mass of the people, whatever may have been the opinion of the philosophers, as soon as it has become separated from the body. And the opinion derives some strength from the manner in which it is stated to have been first formed in the Mosaic records, which intimate it to be a kind of divine breath, vapour, or aura, or to have proceeded from such a substance; for "God,” we are told," breathed into man's nostrils THE BREATH OF LIFE, (n )) and he became a living soul."

Opposed as the two hypotheses of materialism and of immaterialism are to each other, in the sense in which they are commonly understood, it is curious to observe how directly and equally they tend to one common result, with respect to a point upon which they are conceived to differ diametrically; I mean an assimilation of the human soul to that of brutes.

The materialist, who traces the origin of sensation and thought from a mere modification of common matter, refers the perception and reflection of brutes to the very principle which produces them in man; and believing that this modification is equally, in both instances, destroyed by death, maintains that "as the one dieth, so dieth the other; so that a man hath

* Gen. ii. 7.