each tissue, has its specific properties, the activity of each organ is the sum of these properties, organism is the connexus of the totality. Life is then only a conception drawn from particular facts. But we have forgotten it, and we have realized this abstraction; we have declared that this resultant is a necessary antecedent. We have spoken of a vital principle anterior to all organic activities, and independent of them. Although this hypothesis has at the present day eminent partisans, it suffices, to dissipate the illusion, that we should resolve the abstract into the concrete forms from which it is drawn.

A shred of muscle detached from the organism will manifest all its vital properties so long as its specific constitution of *muscle shall subsist, so long as it shall resist disintegration; it will absorb oxygen, exhale carbonic acid, it will contract itself under an appropriate stimulus. A gland separated from the body continues to be a small laboratory of chemical changes, secreting as it secreted in the organism. A nerve detached from the body continues to manifest its specific property of neurility. These phenomena prove that what each part does in the organism each part does out of the organism. In other words, the life of the animal is the sum of particular vital activities; it is not the source of the phenomena, but their personification.1 The action of life is similar to that of mechanism, and differs from it only by the greater complication of its parts and of its effects.

Many persons, however, object to such a conception. Life seems to them the antithesis of mechanical action. This repug

nance will be diminished if they could get well into their minds that between a mechanism and an organism there is resemblance, but not identity; that organism is a mechanism, but a vital mechanism, vitality being the source of profound differences. Attention has in general been fixed upon mechanical adju tmen, and the sensations which guide it have been forgotten. No doubt animal mechanism, when it is put in action, acts like the mechan

1The life of the individual is the sum of a multitude of lives, each belonging of right to one of the elements of the organism.’—Milne-Edwards's Rapports sur les progrès des sciences zoolog., pp. 50 and 59.

ism of a watch, but in order to put it in action and to maintain it in action the constant pressure of sensation is necessary. Sensation is an indispensable portion of mechanism, it is the mainspring of the watch, it is the fuel of the steam-engine. In short, organism is a mechanism, and it acts mechanically, in so far as its actions are necessarily determined by the adjustment of its organs, but organism differs from mechanism in that it has sensibility for :mainspring, and that its so-called automatic actions are all determined by the movement of directing sensations.1

The hypothesis of a vital principle, which was held for several centuries, and which is now rejected by every one except by a few metaphysicians and metaphysiologists, was only a verbal explanation; it substituted words for ideas; almost the same might be said of the modern doctrine of vital force or vital forces: this is only a realized abstraction,2 a term which serves to veil our ignorance.

The only three arguments given in favour of a vital principle which deserve consideration are the following ::-1st, Life governs chemical affinities; 2d, Life precedes organization, and consequently cannot be the result of it; 3d, Life is a directing unity.

Does life govern chemical affinities? There is nothing more striking at first than this fact, a living body preserves its form, and does not seem to yield to the destructive action of chemical agents; whereas, as soon as life is extinct, the molecules yield to the action of chemical affinities. But on looking closer we see that instead of saying that the chemical affinities are controlled by vitality, we ought to say that there is no vital action possible without the incessant and complicated action of chemical affinities; nutrition, secretion, movement, all depend on chemical actions.

Does life precede organization? The word organization includes an ambiguity; but if we remark that by this word we understand the totality of the necessary conditions, not less than the organic constitution, we easily understand that life is proportional to the organization. The life of a simple cellule is the totality of the activities of that cellule. The life of an animal of higher

1 Physiology of Common Life, vol. ii. chap. ix.

2 Ibid. chap. xiii.

organization is the sum of the activities of all the forces in motion, and its complexity is in proportion to the complexity of the organization. Life being then a result, and varying according to the degrees of organism, we cannot say that it precedes organization.

:

Is it a directing principle? A superior unity? We say the body is one, all its parts are subordinate, assembled together to form a superior unity our consciousness assures us that life is a unity. This argument is founded upon an important fact, but one which is misinterpreted. Yes, there is a unity, there is a consensus in the organism; but we must not attribute it to a vital principle independent of the organism. It is due to the subordination of the organs; all the parts have relations, all act together by means of the nervous system. Where there is not that connexion between the parts, there cannot be this connexion between the organs. If we cut a polype or a worm into several pieces, each piece will continue to live and develop itself; nevertheless we cannot suppose that in such a case we have cut the vital principle into several principles. It is that there is a life in each part, and a life of the entire organism; each microscopic cellule has its independent existence, furnishes its career from birth to death, and the totality of these lives forms what we call the life of the animal; unity is an aggregate of forces, and not a superior force.

'It is surely more philosophical to consider life as an ultimate fact; one of the great revelations of the unknowable; one of the many mysteries surrounding us. We no longer set up fictions of our imagination in the place of a reverent observation. There are minds, indeed, which feel distrust at such resignation; they seem to dread lest life should be robbed of its solemn significance, in the attempt to associate it, even remotely, with inorganic phenomena. But this fear arises from narrow views of nature. It is because reverence for nature has not been duly cultivated, because familiarity with inorganic phenomena has blunted our sense of their unspeakable mystery. Men who are thrilled at the tokens of the past life of man, when they see, or read of, buried cities, Palmyra, Nineveh, or Yucatan, tremble with no delicious awe at the tokens of the past life of this earth,

when they stand in a quarry, or ramble through a geological museum. Yet surely the crystal is not less mysterious than the plant, the ebb and the flow of the tides not less solemn than the beating of the human heart? And if patient observation and induction have enabled us to trace something of the order of nature in crystallization and the tides, without aid from the metaphysician, they may also enable us to understand something of the laws of life.' 1

III.

The theory of consciousness which we are about to study is original in several respects. The author, placing himself especially in a psychological point of view, examines the question of latent or insensible perceptions, so much disputed since Leibnitz, but which appears in these last days to be almost universally accepted. These infinitely littles of perception may play in psychological life a part as important as microscopic organisms in the material world, and one may be more than once surprised at the disproportion which exists between infinitesimal causes and the consequences which they engender. Mr. Lewes accepts them; he even distinguishes varieties, as we are about to see, and builds up, as it were, a hierarchy of consciousnesses.

One of the points which our author is most anxious to establish is, that the sensorium, that is to say, the seat of sensation and of consciousness, is not limited to the brain, that sensibility being the fundamental property of the ganglionary tissue inherent in this tissue, we ought to consider the sensorium as having the same extension as the nervous centres. He then defines the common sensorium 'the sum of all the nervous centres, each centre being itself a small sensorium.' Sensibility is a histologic

property, and not a morphologic one, the disposition of the organ is then secondary.

'The current view is this: sensibility belongs only to the

1 Physiology of Common Life, vol. ii. pp. 22, 23.

2 Ibid. p. 43.

centres within the skull; all other centres have only the property of reflecting impressions. By this reflection of impressions is meant that when an impression is made on a sensory nerve, and by it carried to the spinal cord, the impression there becomes reflected into a motion; the motor-nerve carries the impulse to a muscle, and thus an action results, unprompted or unaccompanied by any sensation whatever. In direct opposition to this, I maintain that unless an impression on the sensory nerve excites a sensation in the centre, no motion whatever takes place.' 1

According to the ordinary doctrine, consciousness being held to have its seat in the brain, we naturally admit that the impression, so long as it is not upon the brain, produces no sensation, and if an animal deprived of the brain gives signs of sensation, physiologists maintain that it has no real sensation, but sensitive impressions which produce reflex actions without consciousness on the part of the animal.

The word consciousness has a very vague meaning. Its most general meaning is sensation. It is indisputable that we have a sensitive organism which is necessarily excited by internal and external stimulus, that each of these excitements is a sensation, and that all these sensations must be elements of consciousness. We also admit that amongst these excitements those only which are of sufficient account to predominate over the myriads of vague excitements of organism are properly called sensations. We say that we have consciousness of them-the rest is considered as non-existent ;-these are the unconscious impressions which lead to actions, but they are not consciousness.

The apparently contradictory expression, 'unconscious consciousness,' 'unfelt sensations,' often employed in such cases, would not be embarrassing if the difference between sensation and perception had been clearly distinguished. 'Sensation is simply an active state of sensibility which is the property of

1 Physiology of Common Life, vol. ii.

2 The distinction drawn by Mr. Lewes between sensation and perception, may be likened to that drawn by Leibnitz between perception and apperception.