OF VOLITION, AND THE PASSIONS.
WE have frequently had occasion to refer to the ope rations of the will, and to the connexion which it has with the action of the muscles, upon which is founded the division of muscular motions into the two classes of voluntary and involuntary. It will be necessary for us to make a few observations upon both these points ; first, up on the mode in which volition produces its effects upon the muscles, and, in the second place, upon the cause of the difference between the voluntary and the involuntary muscles.
The act of volition is connected with the brain, while the exercise of it depends upon the co-operation of the nerves and muscles, and no volition can become effective, unless the brain, the nerve, and the muscle, be each of them in a sound state. The nature of the connexion be tween them is very much concealed from our view, but we know that when the mind forms a volition, we acquire a feeling of power, and that the effect instantly follows, without our being at all acquainted with the nature of the process, or with the mode in which the different parts of the operation are connected together. NVe have sufficient proof that the nerve is the medium through which the impression is transmitted from the brain to the muscle, and indeed we have every reason to suppose, that the great use of the nerves that are sent to the voluntary mus cles is to place them under the control of the will. It fol lows that some change must be induced upon each of these three parts, and that in regular succession ; first up on the brain, then upon the nerve, and, lastly, upon the muscle ; but we are totally ignorant of the nature of the change that takes place in the two first, as well as of the mode in which they are connected together. Hartley has indeed attempted to explain this point, by referring the actions of the nervous system to vibrations, but we con ceive that his system is without proof, and, even if it were adopted, would throw little light upon the subject. In order that the hypothesis of Hartley be established, it would he necessary to show, that the changes of the ner vous system consist in a vibratory motion among its par ticles. Now we apprehend that no proof of this kind has ever been adduced. We conceive that they do not exhi
bit any characteristic of this kind of motion, and that there is not a single circumstance which affords any direct evidence of its existence. Nor do we think that any light would be thrown upon the subject by admitting the exist ence of this motion among the particles of the nervous matter, or that we can have any clear conception of the manner in which this vibratory motion could produce those effects which originate in the action of the brain and nerves, or that it tends to explain the connexion between the ma terial and the intellectual parts of our frame.
It appears then, that although we are so well acquaint ed with the phenomena of voluntary motion, we are ig norant of the series of changes by which it is effected. The ultimate objects of voluntary motion are certain ac tions of the organs of speech, and of the muscles con nected with the joints ; and we may class them under two divisions, or consider them as existing in two states, which may be termed direct and remote ; the first, comprising those cases where the will is immediately directed to the contraction of the muscle; the second, where we overlook the action of the muscle, and only regard the effect that is to be produced by it. These two varieties are well illus trated in the learning of any mechanical art ; here, in the first instance, we only think of the particular motion of the hands or fingers, whereas afterwards, as these become familiar to us, our attention is directed solely to the effect that is produced by them.
It has been remarked that the idea or consciousness of power always enters into our volitions ; and it may be pro per to inquire in what this consists, or how it is exercis ed. The effect to be produced is the contraction of cer tain muscles, but these are not the objects of the will, because, in most cases, we arc entirely unconscious or ig norant of their existence. We know, by Previous expe rience, that certain feelings are associated with Lert.in motions, and we seem to have the capacity of reproducing these feelings at pleasure, so that the idea which we have of power would appear to consist in the recollection of these feelings; beyond this we have no knowledge of the nature of the operation.