490 VOLUNTARY MOTION. 



work after the machinery had all stopped, (supra, p. 4-60.) There 

 is nothing surprising in this, if we consider the counterpart in 

 regard to sensation. For that, on the other hand, we may have 

 sensations and not be aware of them, is shown by persons falling 

 asleep at church and remaining so during the sermon, but awaking 

 as soon as the preacher's voice is silent. The effect of the cessa- 

 tion of the stimulus shows that the stimulus was all along felt. 

 These facts are true of all voluntary muscles : and so likewise 

 are those of the facility of action where there is no habit but an 

 instinctive impulse to will certain motions. In one sense all 

 voluntary motions are instinctive : that is as far as men and 

 brutes know nothing of their muscles, and do not determine upon 

 contraction of these fibres or those, or of this combination 

 of muscles or that, or upon the amount of contraction in each re- 

 spective muscle, but upon such a movement as they choose of a 



momentary to leave any impression on the memory. The other is, that when 

 the rapidity exceeds a certain rate, the operation is taken entirely out of our 

 hands ; and is carried on by some unknown power, of the nature of which we 

 are as ignorant, as of the cause of the circulation of the blood, or of the motion 

 of the intestines. The last supposition seems to me to be somewhat similar to 

 that of a man who should maintain, that, although a body projected with a 

 moderate velocity, is seen to pass through all the intermediate spaces in moving 

 from one place to another, yet we are not entitled to conclude, that this happens 

 when the body moves so quickly as to become invisible to the eye. The former 

 supposition is supported by the analogy of many other facts in our constitution. 

 Of some of these, I have already taken notice j and it would be easy to add to 

 the number. An expert accountant, for example, can sum up, almost with a 

 single glance of his eye, a long column of figures. He can tell the sum, with 

 unerring certainty ; while, at the same time, he is unable to recollect any one of 

 the figures of which' that sum is composed ; and yet nobody doubts, that each 

 of these figures has passed through his mind, or supposes, that when the rapidity 

 of the process becomes so great that he is unable to recollect the various steps of 

 it, he obtains the result by a sort of inspiration." 



The rapidity of the volitions can afford no objection. " A person playing on 

 the harp, dancing, and singing, at the same time, exercises about three hundred 

 muscles at once. (G. Ent, Animadv. in Thrustoni diatribam, p. 130.) " In speak- 

 ing, fifteen hundred letters may be distinctly pronounced in a minute, each 

 requiring a separate volition. The rapidity of thought is still quicker. Ra- 

 pidity, like minuteness, is only relative to what we commonly witness. An ani- 

 mal millions of times smaller than the minutest known microscopic creature 

 might have as great a complexity of parts as ourselves ; movement might be 

 millions of times swifter than any thing we ever observed. 



