performed with the hands be explained, all those that are very familiar in life passing from the original automatic state through the several degrees of voluntariness till they become perfectly voluntary, and then repassing through the same degrees in an inverted order, till they become secondarily automatic on many occasions, though still perfectly voluntary on some, viz. whensoever an express act of the will is exerted.
I will, in the next place, give a short account of the manner in which we learn to speak, as it may be deduced from the foregoing proposition. The new-born child is not able to produce a sound at all, unless the muscles of the trunk and larynx be stimulated thereto by the impression of pain on some part of the body. As the child advances in age, the frequent returns of this action facilitate it; so that it recurs from less and less pains, from pleasures, from mere sensations, and lastly from slight associated circumstances, in the manner already explained. About the same time that this process is thus far advanced, the muscles of speech act occasionally, in various combinations, according to the associations of the motory vibratiuncles with each other. Suppose now the muscles of speech to act in these combinations at the same time that sound is produced from some agreeable impression, a mere sensation, or a slight associated cause, which must be supposed to be often the case, since it is so observable, that young children, when in a state of health and pleasure, exert a variety of actions at the same time. It is evident, that an articulate sound, or one approaching thereto, will sometimes be produced by this conjoint action of the muscles of the trunk, larynx, tongue, and lips; and that both these articulate sounds, and inarticulate ones, will often recur, from the recurrence of the same accidental causes. After they have recurred a sufficient number of times, the impression, which these sounds, articulate and inarticulate, make upon the ear, will become an associated circumstance (for the child always hears himself speak, at the same time that he exerts the action) sufficient to produce a repetition of them. And thus it is, that children repeat the same sounds over and over again, for many successions, the impression of the last sound upon the ear exciting a fresh one, and so on, till the organs be tired. It follows, therefore, that if any of the attendants make any of the sounds familiar to the child, he will be excited from this impression, considered as an associated circumstance, to return it. But the attendants make articulate sounds chiefly; there will therefore be a considerable balance in favour of such, and that of a growing nature: so that the child’s articulate sounds will be more and more frequent every day—his inarticulate ones grow into disuse. Suppose now, that he compounds these simple articulate sounds, making complex ones, which approach to familiar words at some times, at others such as are quite foreign to the words of his native language, and that the first get an ever-growing balance in
