educated motor centre is not only a necessary agency in the performance of a voluntary act, but I maintain that it positively enters as a mental element into the composition of the definite volition; that, in fact, the specific motor faculty not only acts downward upon the motor nerves, thus executing the movement, but also acts upward upon the mind-centres, thereby giving to consciousness the conception of the suitable movement-the appropriate motor intuition. It is certain that, in order to execute consciously a voluntary act, we must have in the mind a conception of the aim or purpose of the act. The will cannot act upon the separate muscles, it can only determine the result desired; and thereupon the combined contraction, in due force and rapidity, of the separate muscles takes place in a way that we have no consciousness of, and accomplishes the act. The infant directly it is born can suck, certainly not consciously or voluntarily; on the first occasion, at any rate, it can have no notion of the purpose of its movements; but the effect of the action is to excite in the mind the special motor intuition, and to lay the foundation of the special volition of it. We cannot do an act voluntarily unless we know what we are going to do, and we cannot know exactly what we are going to do until we have taught ourselves to do it. This exact knowledge of the aim of the act, which we get by experience, the motor intuition gives us.

The essential intervention of the motor intuition, which is, as it were, the abstract of the movement, in our mental life, is best illustrated by the movements of speech, but is by no means peculiar to them. Each word represents a certain association and succession of muscular acts, and is itself nothing more than a conventional sign or symbol to mark the particular muscular expression of a particular idea. The word has not independent vitality; it differs in different languages; and those who are deprived of the power of articulate speech must make use of other muscular acts to express their ideas, speaking, as it were, in a dumb discourse. There is no reason on earth, indeed, why a person might not learn to express

every thought which he can utter in speech by movements of his fingers, limbs, and body-by the silent language of gesture. The movements of articulation have not, then, a special kind of connection with the mind, though their connection is a specially intimate one; they are simply the most convenient for the expression of our mental states, because they are so numerous, various, delicate, and complex, and because, in conjunction with the muscles of the larynx and the respiratory muscles, they modify sound, and thus make audible language. Having, on this account, been always used as the special instruments of utterance, their connection with thought is most intimate; the Greeks, in fact, used the word λóyos to mean both reason and speech. But this does not make the relations of the movements of speech to mind different fundamentally from the relations of other voluntary movements to mind; and we should be quite as much warranted in assigning to the mind a special faculty of writing, of walking, or of gesticulating, as in speaking of a special faculty of speech in it.

What is true of the relations of articulate movements to mental states is true of the relations of other movements to mental states: they not only express the thought, but, when otherwise put in action, they can excite the appropriate thought. Speak the word, and the idea of which it is the expression is aroused, though it was not in the mind previously; or put other muscles than those of speech into an attitude which is the normal expression of a certain mental state, and the latter is excited. Most if not all men, when thinking, repeat internally, whisper to themselves, as it were, what they are thinking about; and persons of dull and feeble intelligence cannot comprehend what they read, or what is sometimes said to them, without calling the actual movement to their aid, and repeating the words in a whisper or aloud. As speech has become the almost exclusive mode of expressing our thoughts, there not being many gestures of the body which are the habitual expressions of simple ideas, we cannot present striking examples of the powers of other movements

to call up the appropriate ideas; yet the delicate muscular adaptations which effect the accommodation of the eye to vision at different distances seem really to give to the mind its ideas of distance and magnitude. No one actually sees distance and magnitude; he sees only certain signs from which he has learned to judge intuitively of them—the muscular adaptations, though he is unconscious of them, imparting the suitable intuitions.

The case is stronger, however, in regard to our emotions. Visible muscular expression is to passion what language or audible muscular expression is to thought. Bacon rightly, therefore, pointed out the advantage of a study of the forms of expression. "For," he says, "the lineaments of the body do disclose the disposition and inclination of the mind in general; but the motions of the countenance and parts do not only so, but do further disclose the present humor and state of the mind or will." The muscles of the countenance are the chief exponents of human feeling, much of the variety of which is due to the action of the orbicular muscles with the system of elevating and depressing muscles. Animals cannot laugh, because, besides being incapable of ludicrous ideas, they do not possess in sufficient development the orbicular muscle of the lips and the straight muscles which act upon them. It is because of the superadded muscles and of their combined actions-not combined contraction merely, but consentaneous action, the relaxation of some accompanying the contraction of others that the human countenance is capable of expressing a variety of more complex emotions than animals can. Those who would degrade the body, in order, as they imagine, to exalt the mind, should consider more deeply than they do the importance of our muscular expressions of feeling. The manifold shades and kinds of expression which the lips present—their gibes, gambols, and flashes of merriment; the quick language of a quivering nostril; the varied waves and ripples of beautiful emotion which play on the human countenance, with the spasms of

passion that disfigure it—all which we take such pains to embody in art—are simply effects of muscular action, and might be produced by electricity or any other stimulus, if we could only apply it in suitable force to the proper muscles. When the eye is turned upward in rapt devotion, in the ecstasy of supplication, it is for the same reason as it is rolled upward in fainting, in sleep, in the agony of death: it is an involuntary act of the oblique muscles, when the straight muscles cease to act upon it. We perceive, then, in the study of muscular action, the reason why man looks up to heaven in prayer, and why he has placed there the power whence cometh his help." A simple property of the body, as Sir C. Bell observes the fact that the eye in supplication takes what is its natural position when not acted upon by the will -has influenced our conceptions of heaven, our religious observances, and the habitual expression of our highest feelings.

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Whether each passion which is special in kind has its special bodily expression, and what is the expression of each, it would take me too long to examine now. Suffice it to say that the special muscular action is not merely the exponent of the passion, but truly an essential part of it. Fix the countenance in the pattern of a particular emotion-in a look of anger, of wonder, or of scorn-and the emotion whose appearance is thus imitated will not fail to be aroused. And if we try, while the features are fixed in the expression of one passion, to call up in the mind a quite different one, we shall find it impossible to do so. This agrees with the experiments of Mr. Braid on persons whom he had put into a state of hypnotism; for, when the features or the limbs were made by him to assume the expression of a particular emotion, thereupon the emotion was actually felt by the patient, who began to act as if he was under its influence. We perceive then that the muscles are not alone the machinery by which the mind acts upon the world, but that their actions are essential elements in our mental operations. The superiority of the human over the animal mind seems to be

essentially connected with the greater variety of muscular action of which man is capable: were he deprived of the infinitely-varied movements of hands, tongue, larynx, lips, and face, in which he is so far ahead of the animals, it is probable that he would be no better than an idiot, notwithstanding he might have a normal development of brain.*

If these reflections are well grounded, it is obvious that disorder of the motor centres may have, as I believe it has, no little effect upon the phenomena of mental derangement. In some cases of insanity there are genuine muscular hallucinations, just as there are in dreams sometimes, when the muscles are in a constrained attitude; and, where the morbid effects are not so marked, there is good reason to suppose that a searching inquiry along this almost untrodden path will disclose the mode of generation of many delusions that seem now inexplicable.

But we cannot limit a complete study of mind even by a full knowledge of the functions of the nervous and muscular systems. The organic system has most certainly an essential part in the constitution and the functions of mind. In the great mental revolution caused by the development of the sexual system at puberty we have the most striking example of the intimate and essential sympathy between the brain as a mental organ and other organs of the body. The change of character at this period is not by any means limited to the appearance of the sexual feelings and their sympathetic ideas, but, when traced to its ultimate reach, will be found to extend to the highest feelings of mankind, social, moral, and even religious. In its lowest sphere, as a mere animal instinct, it is clear that the sexual appetite forces the most selfish person out of the little circle of self-feeling into a wider feeling of family sympathy and a rudimentary moral feeling. The consequence is that, when an individual is sexu

*There may be no little trath, therefore, though not the entire truth, In the saying of Anaxagoras, that man is the wisest of animals by reason of his having hands.