It seems to be established, therefore, by an ample induction, that muscular actions follow ideas, as invariable antecedent and consequent, in other words, as cause and effect; that whenever we have obtained a command over the ideas, we have also obtained a command over the motions; and that we cannot perform associate contractions of several muscles, till we have established by repetition, the ready association of the Ideas.
I believe that nothing more need be said for the establishing of these truths. I shall adduce a few more instances, chiefly with the view to familiarize my readers with the mode of applying to this 346 interesting class of facts, the principles with which they are now fully acquainted.
There is no part of the body with the use of which we are so perfectly familiar as the hand. There are no actions, of the sort at least to which we are attentive, the repetition of which is so incessant. Of course, the associations of the ideas corresponding to the associate contractions of the muscles which produce the various movements or actions of the hand, are formed in the most perfect manner; and we never have the Ideas, as antecedent, without the movement as consequent. This inseparable connexion between the Ideas, and the contractions, which we call the Power of the Will, is gradually formed. At first the hand of the infant is moved by sensations. If the inside of the hand is touched, so at least as to make the sensation considerable, the fingers bend; and perform more or less of the act of grasping. Here is a train of events. First, the sensation of touch, from the application of the external object; next, an influence from the seat of the sensation in the brain, transmitted along the nerves of certain muscles; then the contraction of the muscles, with the various sensations which the action upon those organs, and the action excited in them, imply. When the sensation has been often repeated, in conjunction with its effect, the Idea of the sensation becomes familiar and distinct; and capable of producing many of the effects which the sensation itself produces. It is also closely associated with the idea of the motion, and all its accompanying sensations as the effect; and the chain of antecedents and consequents proceeds in uninterrupted order.
347 As similar instances of motions, at first produced by sensations, afterwards by ides, we may adduce the remarkable cases of the sphincters of the bladder and anus. At first, children perform their evacuations, as they sneeze and cough, when the sensations excite them. Afterwards, they learn, but by slow degrees, to bring them under the command of ideas. There is no case, however, which affords more decisive evidence of the power of ideas over the actions of particular parts, than those which are called Amatory; because the effects, which are produced by the Ideas, cannot be produced by the will.
There is another set of cases, which deserve attention; those in which the ideas which are followed by the action of certain muscles, acquire associations with other sensations or Ideas which call them up, and thence give action to the muscles, upon very inconvenient occasions. A woman who has accustomed herself to scream out, upon every sudden idea of the slightest danger, cannot abstain from screaming. The awkward motions, for which some, even eminent, men have been remarkable, Dr. Johnson, for instance, are completely explained by this principle. The ideas, whence the motions proceed, have become associated, in ways which can seldom be traced, with sensations, or ideas of frequent recurrence. And hence are the motions frequently produced.
There are equally remarkable cases, in which the associations, necessary to produce the idea on which the muscular actions depend, are prevented by other associations more powerful. Men admitted to the presence of a great personage have found themselves wholly unable to articulate a word. The Ideas of 348 Power and Dignity, with all their associates of terror and of hope, were called up in such irresistible association by the presence of him who was clothed with them; that the ideas necessary to the articulation of words were excluded, and the power of speaking was lost.
We have now established, by an ample Induction, that the action of muscles follows, as an effect its cause; first, upon sensations; secondly, upon Ideas. The language which Professor Stewart has applied to a similar case, is perfectly applicable here. “It may, indeed, be said, that these observations only prove the possibility, that our muscular contractions may be all performed by sensations and Ideas. But, if this be admitted, nothing more can well be required; for, surely, if these phenomena are clearly explicable, from the known and acknowledged laws of the human mind, it would be unphilosophical to devise a new principle, on purpose to account for them.”[12*]
[12*] Elements of the Philosophy of the Human Mind. Chap. ii.
I believe, indeed, that this conclusion is not at variance with the common belief upon the subject. It appears to me to be not inconsistent with the language of the advocates for what is called the Freedom of the Will, to admit, that the action of the muscle takes place in consequence of the Idea; and that our power of willing consists in the power of calling into existence the appropriate Idea; that the power of the will is not immediate over the muscle, but over the Idea.
The following observations of Dr. Reid, though not remarkable for their precision, seem fully to justify this Inference.