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owe the most to Aristotle. His plan was vast and luminous; he laid the basis of science, which will never perish.' "Isidore Geoffrey St Hilaire, speaking from less acquaintance with Aristotle's writings, is splendid in eulogy. He
is in every branch of knowledge like a master who cultivated that one only. He reaches, he extends the limits of all the sciences, and penetrates to their very depths.'
Now, if we reflect for a moment on what minute and laborious dissections our present knowledge of anatomy depends-which again is the foundation of our knowledge of physiology-it is simply impossible that Aristotle, of whom it has been disputed whether he ever dissected the human body, could have laid a sound foundation for these sciences. The knowledge of the structure and functions of our several organs has been the result of repeated examinations conducted under successive conjectures, each of which had become more and more probable, as it was founded on additional information. As Mr Lewes observes, we read into Aristotle the results of a later science, and we gladly blind ourselves to many a confused description, or pass very rapidly over physiological statements which to us are scarcely intelligible, and thus construct for ourselves a text which seems to justify any amount of applause.
"The extent of his survey," Mr Lewes admits, "is amazing, embracing the whole animal kingdom, from sea-anemones to man. But of the accuracy of his knowledge," he adds, "I am compelled, after long and minute study, to form a very different estimate from what is current amongst critics and historians. Reading his works by the light of modern discovery, we are apt to credit him with all that his words suggest to us: we come indeed upon numerous inaccuracies, and on many statements which imply gross carelessness; but whenever his language does not palpably betray him, modern readers insensibly fill out his hints with details from their fuller store. On a superficial examination, therefore, he will seem to have given tolerable descriptions, especially if approached with that disposition to discover marvels which unconsciously determines us in our study of ancient
writers. But a more unbiassed and impartial criticism will disclose that he has given no single anatomical description of the least value. All that he knew may have been known, and probably was known, without dissection. The casual revelations of the slaughter-house and battle-field, together with the intimations gathered from auguries and embalmments, probably furnished his knowledge of man and the larger animals. I do not assert that he never opened an probable that he had opened many. But animal; on the contrary, it seems highly
am persuaded that he never dissected one in the careful systematic style necessary for more than a general acquaintance with the positions of the chief organs. He never followed the course of a vessel or a nerve; never laid bare the origin and insertion of a muscle; never discriminated the component parts of organs; never made clear to himself the connection of organs with systems."
This judgment Mr Lewes has fully established by the examples he has given. Aristotle places the heart higher than the lungs; he describes the human kidney as lobed like that of the ox; and when he passes to the functions of the heart, he determines it to be the seat of sensation, on the ground that it is the centre of the body. He also disputes the claim of the brain, because it is insensible. He says of the brain that it is bloodless, and that it does not extend to the back part of the skull, which is quite empty. He assigned to the brain the function of moderator, its coolness serving to temper the great heat of the heart region. Believing that there was no blood in it (probably from the appearance of the brains of animals cooked for eating), he naturally concluded that it was cold. Credit has been given to Aristotle for the discovery of nerves; but the nerve with him was a duct, and the optic nerve was a duct to nourish the eye. He says nothing of a nervous system forming the mechanisms of sensation and motion.
With regard to those anticipations of some of the latest discoveries of the zoologists, which have made some noise amongst us, they shrink into the fact, curious
preciation of delicate or complex phenomena; but in cases where the phenomena are not too remote or too complex intellect is chiefly tasked, he is no longer for the unassisted senses, where the under the same disadvantage as when having to deal with data discernible only through the arduous research of ages, Here the mighty intellect displays itself; here the mind which could not avoid fall
or not as you choose to look at it, that certain animals only lately known to naturalists, or certain of their habits or functions but lately recognised, had come before the inspection of Aristotle, or had been heard of by him. The Hectorotylus of the Argonaut, an anomalous member which he who is anxious to understand will find accurately describing into absurdities when theorising
ed in the present work; the Parthenogenesis of Bees; a Placental Fish these curiosities had arrested the attention of this wide-surveying naturalist. But they were with him merely isolated facts, they were not wrought into any physiological theory, neither did they conflict with any such theory; they had not the same significance to him as they have to Richard Owen. Inasmuch as they are observations of nature, and not mere guesses at the causes of things, they may have some value, and certainly redound to the credit of this early sage, so avaricious of all knowledge. But isolated observations of this kind, though valuable as materials of science, cannot be designated as anticipations of the discoveries of modern science," because in reality they do not constitute a part of science till they are harmonised with other facts into a consistent scheme of things.
We come next upon a chapter in which Mr Lewes plays himself the part of admirer; not extravagantly or incautiously, but, tired apparently with the task of moderating the praises of others, he takes the more generous office of sounding a hearty note of laudation. We are bound to say that he succeeds better as the accusing spirit, than as the angel of the silver trumpet. But we should be unfair both to Aristotle and his critic if we did not follow him, so far as we are able, now that he puts on the herald's tabard, and proclaims the true style and dignity of one whom all agree to describe, on some ground or other, as the great Stagirite.
"I have indicated the reason," he says, "why Aristotle could not have made a discovery when it involved a precise ap
about Heat without the aid of a thermometer, and about Physics without knowledge of the laws of motions, rises into admirable eminence when treating of the higher generalities of Life and Mind.”
It is the treatise De Animâ' which calls forth this ardent praise. "The extreme interest of its problems," he says, "and the profundity of its views, render it the most valuable and valued of ancient attempts to bring the facts of life and mind into scientific order." Aristotle here, he adds farther on,
stands at the point of view now generally occupied by the most advanced thinkers."
Aristotle is applauded for the wide generalisation which embraces the plant and the animal under the one great class of living things, and regards the mind of man itself as only the highest development of life. He did not hold with Stahl that mind was the agent in all vital functions as well as the intelligential, but, on the contrary, taught that "mind is only the highest development of life." Now, in the first place, it is difficult to determine on a subject of this kind-still so open to mere speculation-what is the point of view now generally occupied by advanced thinkers. And presuming this established, we doubt if any point of view which a modern thinker adopts would find itself represented in Aristotle's writings. Judging only by the analysis of this treatise given here by its admirer, we find ourselves baffled by its inconsistencies and its peculiar modes of metaphysical thought, and altogether unable to detect the identity of Aristotle's doctrines, and what Mr Lewes represents as the advanced views of modern physiologists.
"Life," according to the definition Mr Lewes proposes, "is the dynamical condition of the organism." And he describes Mind as the highest development of Life, the highest dynamical condition, therefore, of the organism. But,
1. Is this accepted as the last word of science and, 2. Does it really accord with what Aristotle taught? It is this second question with which are chiefly concerned, and to which we shall first apply ourselves. "One great source of confusion,' Mr Lewes observe, "has been the radical error of conceiving Life to be an entity apart from, and only inhabiting, the organism; just as the several forces were for centuries conceived to be independent of matter, instead of being regarded as matter in dynamic conditions. To escape from such a confusion, and to have seen thus early the positive solution of the difficulty, implies immense intellectual force." But, as we read the extracts given us in this very chapter from Aristotle, we are unable to see in the old Greek a representative of the positive philosophy. We find him constantly speaking of a Vital Principle, which is the source of all vital phenomena, and discussing whether there is more than one such Vital Principle. "The vitality of plants," he says, "is due to a kind of soul." This is surely what the positivist describes and condemns as the metaphysical stage in the development of science. Sometimes the vital principle is said to be essentially one in plants, in animals, and in man. But Mr Lewes has himself furnished us with a passage in which Aristotle also speaks of mind "as another kind of soul, alone capable of separation, as the everlasting from the perishable." It is impossible to reconcile all the statements of Aristotle with each other. And besides this, there is, as we have intimated, a mode of thinking, running through the whole treatise, so peculiarly Greek, that it is equally impossible to fix Aristotle, at any moment, in an attitude of thought
identical with that of the advanced modern thinker to whom he is assimilated.
It is true that this vital principle, this ux, is again and again asserted to be inseparable from the animal body. It is an animal body because it has this. The Greek philosopher defined all things as consisting of Matter and Form. In many cases we can translate Form by our word Property. Matter, we say, is endowed with certain properties. These we do not consider as having a separate existence from matter. Their union with matter makes the thing to be what it is. This use of the word Property leads to some misunderstandings.
But the old word Form was constantly assuming a vague independence, and if at one time we translate it by the word property, at another time we are compelled to translate it by the word essence, or some term that vaguely suggests a species of reality in itself. Life is the entelechie that reality which, being added to body, makes it a living organism. "Therefore it follows," we quote from Mr Lewes's Analysis, "that the Vital Principle must be an essence, as being the form of a natural body holding life in potentiality; but essence is a reality (entelechie). The vital principle is the original reality of a natural body endowed with potential life; this, however, is to be understood only of a body which may be organised. even of plants are organs, but they are organs that are altogether simple, as the leaf which is the covering of the pericarp, the pericarp of the fruit. If, then, there be any general formula for any kind of Vital Principle, it is the primary reality of an organism."
Thus the parts
A Positive philosopher may read into this his theory that Life. is the dynamical condition of the organism; or, if he were so disposed, he might detect in it a constant tendency to fall "into the radical error of conceiving life to be an entity."
As to the definition which Mr Lewes, or the positive philosopher, offers to us of Life and Mind, our observations must necessarily be very brief. Without dispute, the phenomena of mere Life are inseparable from those of Mind, as developed in the human being. What would be the will, or all that region of thought which deals with action, if you were to separate the faculty of thinking and feeling from the contractility of a muscle? So neither could we separate Life from the activity of inorganic matter. We say, something new comes in with organic life, with the germ that grows, but it would be utterly impossible to conceive the Organic as existing or developing itself without the Inorganic. But it appears to us that if anywhere a line of demarcation can be drawn of this kind—namely, here, at this point, in a world, in an organism previously prepared for it, enters a quite new property -it is precisely a line drawn between Life and Mind. All phenomena in this world, including those of organic life-all phenomena except those of mind-resolve themselves into the laws of motion. Atoms in motion or rest (that cohesion or reciprocal pressure we call rest) represent for us all we can know of physical phenomena. But here, at the first dawn of sensation or consciousness, at the first wince that an animal makes, in whom contact brings this newcomer pain, and in whom pain (another surprising novelty) causes motion, there is that introduced which is quite as original in its nature as motion itself. If motion produces it, it again produces motion. It cannot, like all previous phenomena, be conceived of under formula of matter and motion.
Growth is but a new arrangement of particles of matter which we are already able to trace in part to the known laws of chemistry; and those unconscious movements in animals (if any such there be) which are unconnected with sensation, and due to what
some physiologists have called mere irritability, may admit, perhaps, of being classed amongst electrical phenomena. The periodicity which distinguishes muscular or nervous action, suggests the analogy of the collection and discharge of electrical force; and the muscle seen under a powerful microscope reveals a structure an arrangement of discs, approaching and receding from each other-which gives countenance to the supposition that its contractility is due to electrical action. If we could thoroughly understand what takes place when a Leyden jar is charged, we feel that we should be nearer than we are to the explanation of muscular action, so far as such action takes place independently of sensation. But we and all men feel convinced that no advance in physical science could in any way explain the quite original fact, that motion produces, somewhere in something, not motion, but sensation, and that this sensation again produces motion. Vegetable life and the first stages of animal life belong to physics; with sensibility enters a new class of phenomena. Hitherto the particles of matter have but two properties, motion and pressure (which is arrested motion, and gives the shape or form of things). At this point an altogether new property comes into play, or else an altogether new substance, marked by this wonderful property, enters into combination with the material organism. There is, some would say, a sensitive substance and a moving substance-one whose property is feeling in all its varieties, one whose property is motion in all its varieties and these together form the sensitive and conscious creature. Those who adopt this view would probably add, that in man the spiritual substance which mingles with the vital organism is of a class apart and distinct from that which animates the rest of the sensitive creature.
But our business is not to discuss the question of materialism or im
materialism. We have to decide upon the opinion of Aristotle; and Mr Lewes himself teaches us what our verdict should be-namely, that it is impossible to classify him either with the materialist or immaterialist of modern times. Not with the materialist-not with him who looks upon thought simply as the function of the brain; for Aristotle is constantly introducing his ux, which, whatever else it may be, is at least a cause for our consciousness other than the brain; and not with the immaterialist, for this ux embraces what we understand by vital as well as mental function, and by no means responds to our intellect or soul.⚫
The allusions we have incidentally encountered here to the Positive school of philosophy remind us of an omission we have made. Our author, dealing as he does with the development of science, could not fail to present us with some general ideas of the nature of that development. This he does in an early part of the work, entitled "The Dawn of Science." This chapter is certainly not the least interesting in a work which throughout, even where the subject is least attractive, keeps the attention awake. It ought not to have been passed over without some especial notice; but this perhaps is as good a place as any other to introduce the few observations which it suggests to us. Dropping, therefore, any further attempt to follow the analysis of Aristotle, of which we have given perhaps a sufficient specimen, we shall occupy the rest of our space with an examination of the theory of the development of science which we find laid down in this chapter.
That theory is the one which bears the name of Auguste Comte. It is thus briefly stated:—
"The history of human development shows that there are three modes by which we conceive phenomena; and there are only three. The second being a transition from the first to the third, we might in strictness admit of only two distinct modes of conception. The first
of these supposes that the order and succession observed in phenomena are due to the influence of outlying agencies-powers which are super-natural-above the objects, not belonging to them. The second supposes that the order of phenomena is due simply to properties inherent in the objects themselves, which properties are realities, and form part of the nature of the objects. Obviously, things must either be conceived as by nature passive or active; if passive, they can only be moved by superior power independent
of them; if active, they possess in themselves the conditions of their activity. Thus, on one of two fundamental assumptions respecting the activity of objects rests every possible explanation we can frame of the mysteries around us.
"The attitude of mind which is based on the first of these assumptions is that which is common to all primitive theories. It characterises what Auguste Comte names the theological stage in human development. On this assumption all phenomena not of the simplest and most familiar kind are referred to the agency of invisible powers, spirits, deities, or demons. To these powers, and not to any activity inherent in the objects themselves, the changes in the phenomena are assigned. It is the will of some spirit which moves the objects."
We pause here to remark, that this belief in gods and demons afflicting or preserving us through the agencies or events of nature does not originate in any desire to explain these events. It can hardly, therefore, be called the first stage in the development of science, although such a belief plays a very conspicuous part in the subsequent history of science. It is a much stronger passion than curiosity; it is the passion of fear or of hope that gives origin to the belief that some god either flashes out in anger on us in the lightning, or beams beneficently in the sun. It is not to explain the uncertainty of events that a power which can hear prayers or be propitiated in some way is imagined. The uncertainty of events and the terrible anxieties of men have kindled this imagination. And such imagination, we freely admit, is the first outbreak of thought (of any other thought than that which had for its end the immediate gratification of