CONDITIONS OF AN ISOLATING DISCHARGE.

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tongue is an organ of great natural activity, being endowed with many muscles, and having a wide scope of action; the nervous communications between it and the brain are considerable, and the isolation of its movements in the primitive discharges of spontaneous power, corresponds to the remarkable degree of voluntary control subsequently acquired. A like capacity of isolation belongs to the movements of the eyeballs, which come very early to the stage of mature volition. If these movements were as closely linked with others as the five toes are linked together, it would be exceedingly difficult to gain a voluntary command of the act of vision. We see the proof of this in the united action of the two balls, which can never be broken up; no provision apparently existing for confining a nerve current to one at a time. The case is different with the eyebrows and eyelids, which, although prone to act together in opening and closing the eyes, are yet so far liable to separate promptings, that we are able ultimately to command each without the other; at least the generality of persons can do so, for there are constitutional differences as regards the extent of the primitive separability of the various individual movements, just as the higher vertebræ excel the lower in this important property. The group of activities contained under the designation of the features of the face, are both conjoined and separate. The mouth, the nasal muscles, and the eyebrows, are disposed to work together, and the two corresponding sides have, as just remarked, a very great tendency to conjoint action; but there is still a sufficient amount of occasional isolation, to furnish a basis for a confirmed voluntary command of any one apart from the rest. The working up of this region of activity is the business of the actor.

4. It is impossible to trace, and even difficult to imagine, the anatomical mechanism that serves for thus isolating single movements, in the course of the outward flow of cerebral power. Distinctness of nerve communication is one essential condition; the other conditions referring to the interior organization of the brain, it is not in our power to specify them. It is manifest as a fact, but for which the growth of

volition seems altogether inexplicable, that the central brain can and does discharge its power in solitary streams for the stirring up of single movements, and that while a great number of outlets may appear to be open, one is preferred to the exclusion of the rest. This property of exclusiveness in the currents is compatible with other attitudes of the nervous centres, under which entire groups of members are moved simultaneously, or in orderly alternation. In some organs, as we have seen, the possibility of isolation is very limited; in others the opposite holds true; in the first, voluntary control comes with difficulty, in the second with ease.

5. To illustrate the necessity of a spontaneous beginning of movement, as a prelude to the command of the will over the particular organ, I may cite the external ear, which in man is usually immovable, although possessed of muscles. Here we have the absence of a central stimulus from the commencement, and consequently no power of bringing about the effect. Instances sometimes occur of persons able to move their ears, as most quadrupeds can do very readily, and the only account that we can render of this exceptional operation of the will is to suppose that, from the outset, a proper nerve communication has been established between the brain and the aural muscles, whereby these have shared the spontaneous stimulation of the other voluntary muscles. Even after we have known what, it is to command our limbs, trunk, head, jaw, mouth, eyes, voice, &c., if we were attempting to force the ear into motion we should in all probability fail; in the absence of spontaneity we have no basis to proceed upon. Should the organ at any time be moved of its own accord, that is the instant for establishing a beginning of voluntary control, and if the attention were directed upon it every time the spontaneous impulse was repeated, we should in the end bring this part of the system into the same subjection as the other voluntary organs.

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Circumstances governing the spontaneous discharge.

6. It is requisite for the further prosecution of this difficult inquiry, to advert specifically to the conditions that determine the more or less vigour of the central discharge. We have to prepare the way for rendering an account of those occasions, when the will operates with a promptness and energy resembling the explosion of gunpowder, while at other times the movements are tardy and feeble.

The first circumstance deserving of mention is the Natural Vigour of the constitution. There are as we have seen men and animals so constituted as to give forth a more than usual stream of activity; and all creatures have their periods of greater or less abundance of discharge. Youth and health, the plentiful nourishment and absence of drain, the damming up of the accumulating charge by temporary restraint—are predisposing causes of a great and sudden outburst, during which the individual's active capacity is at the highest pitch. We see this well illustrated in the daily experience of children, whose exuberance is manifested at their first awakening in the morning, after meals, and on release from lessons. On all these occasions, we see evidently nothing else than the discharge of an accumulated store of inward energy. It is not any peculiar incitement from without that is the cause of all this vehemence. The effect is explosive, as of the bursting open of a floodgate. It would not be difficult at those moments, indeed it would be the natural course of events, to perform some great feat of active exercise that might happen to be called for. The boy let out from school, incontinently leaps over ditches, breaks down barriers, and displaces heavy bodies, and should these operations be wanted at the moment, no special or extraordinary stimulus would be needed to bring the requisite power into play.

7. The next circumstance to be considered is what is termed Excitement. This means an unusual flow of the central energy, brought on by various causes, and followed by exhaustion or premature loss of strength. It is a property

apparently co-extensive with mental life, that by some means or other, the ordinary and enduring currents of activity can be converted into an extraordinary discharge of short duration at the expense of the future. When we speak of an excitable nature, we mean an especial proneness to this fitful or spasmodic exaltation. The exciting causes are sometimes physical, as intoxicating drugs and stimulants, disease, &c., and sometimes mental, or such as operate through the sensibilities or consciousness, including a large proportion of our pains and pleasures. Whatever may be the cause of a state of excitement, one effect arising from it is an increase in the vehemence of all the spontaneous impulses occurring at the moment. Any action then performed is done with might. When an occasion for a vigorous display springs up, one way of preparing the system to meet it, is to induce a general excitement of the system, which being directed into the requisite channel supplies the additional succour that is wanted.

8. The class of proper mental stimulants, concerned in spurring the nervous system to these fitful outpourings, demands a special consideration. First we have Pain generally. According to the intensity of the infliction, a state of suffering is apt to induce among other consequences, a feverish exaltation of the nervous discharge. This is an important point in the theory of volition. I am putting out of account at present what will have to be fully discussed presently, the characteristic volitional property of pain, or the prompting to alleviating exertions: I speak only of the influence that acute suffering has, in bringing on a state of more than ordinary wakefulness or excitement generally. A sharp cut with a whip makes an animal for the moment more alive. The movements, whatever they are, are quickened because the nerves are made to contribute more largely of their proper vitality. It is well known that pain is a counteractive of the tendency to subside into tranquillity, repose, or sleep, and is the ready instrument of rousing the mind from the inactive condition. Suddenness is the essentially stirring attribute of pain. An exceedingly sharp and quick application, shocks the whole nervous system, and brings on a profuse outpouring

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of active energy. This is one of the circumstances that strings up the individual for moments of difficulty and danger; the pace of the ordinary volition is not enough, on great emergencies, until some exalting stimulus is applied to the system at large. I conceive that in the use of the whip, the spur, the loud and angry word of command, there is a double effect, that of the general excitement of the nervous system, and the specific action proper to pain.

I formerly remarked, in treating of the emotion of fear, that a peculiar disturbance of the ordinary nerve currents takes place under this passion. There is both a general excitement, and a special concentration of energy in particular organs, more especially the senses, and the active members generally, the organic functions being robbed for the time of their proper share of cerebral support. We may therefore rank the passion of terror among the mental exciting causes that bring about the higher discharges of volitional force. Pain, pure and simple, is an efficacious stimulant; and by passing into the condition of fear may still farther assume this property, although liable also to scatter and dissipate the energies in unfruitful ways.

The passion of Resentment, as we have seen, involves a great stimulus of the active members. This is one of the characteristics of angry feeling. It is not merely the wish to inflict harm on some sentient being, but the reinforced energy of the frame, that we look for in a burst of anger. In this case, too, whatever a man is prompted to do, he does with greater might; an active inspiration, or increased spontaneity, comes upon him. But that is not all. Mere obstruction, thwarting, or resistance, has a remarkably stimulating property, without reference to the emotion of resentment. In any act that we are performing, an obstacle in the way operates like a specific in drawing a more copious stream from the nervous centres: a fact of great moment in the evolution of voluntary energy. We may notice that even a child incontinently puts forth muscular power, when encountering a dead obstruction to its movements. It is not only when we are bent upon some end, and proportion our exertion to the diffi