their favour, from the cause just now taken notice of; also, that they are associated with visible objects, actions, &c. and it will be easily seen, that the young child ought, from the nature of association, to learn to speak much in the same manner as he is found in fact to do. Speech will also become a perfectly voluntary action, i.e. the child will be able to utter any word or sentence proposed to him by others, or by himself, from a mere exertion of the will, as much as to grasp: only here the introductory circumstance, viz. the impression of the sound on the ear, the idea of this sound, or the preceding motion in pronouncing the preceding word is evident; and therefore makes it probable, that the same thing takes place in other cases. In like manner, speech, after it has been voluntary for a due time, will become secondarily automatic, i.e. will follow associated circumstances, without any express exertion of the will.
From the account here given of the actions of handling and speaking, we may understand in what manner the first rudiments are laid of that faculty of imitation, which is so observable in young children. They see the actions of their own hands, and hear themselves pronounce. Hence the impressions made by themselves on their own eyes and ears become associated circumstances, and consequently must, in due time, excite to the repetition of the actions. Hence like impressions made on their eyes and ears by others will have the same effect; or, in other words, they will learn to imitate the actions which they see, and the sounds which they hear.
In the same manner may be explained the evident powers which the will has over the actions of swallowing, breathing, coughing, and expelling the urine and fæces, as well as the feeble and imperfect ones over sneezing, hiccoughing, and vomiting. As to the motion of the heart, and peristaltic motion of the bowels, since they are constant, they must be equally associated with every thing, i.e. peculiarly so with nothing, a few extraordinary cases excepted. They will therefore continue to move solely in the original automatic manner, during the whole course of our lives. However, association may, perhaps, have some share in keeping these motions, and that of respiration, up for a time, when the usual automatic causes are deficient in any measure; and may thus contribute to their equability and constancy. It seems certain, at least, that where unequable and irregular motions of the heart and bowels are generated, and made to recur for a sufficient number of times, from their peculiar causes, in full quantity, a less degree of the same causes, or even an associated circumstance, will suffice to introduce them afterwards. And the same thing may be observed of hysteric and epileptic fits. These recur from less and less causes perpetually, in the same manner, and for the same reasons, as original automatic motions are converted into voluntary ones.
I will add one instance more of the transition of voluntary
