The exertion of the will on the bodily organs having been generally described, it now remains to demonstrate its influence on the mind; and so far as we are enabled to discover, it appears to be performed by the same process. The direction of the several organs of sense to the examination of objects, is an act of the will, and has been named Attention; which, by some writers, has been deemed a peculiar and constituent faculty of the mind; but in the present view it is considered only as the practical result of the operation of volition on the organs of sense, on memory, and on reflection. The soundest mind (as far as it has been hitherto considered) may be attributed to him who possesses the most enduring control over the organs of sense, in order to examine objects accurately, and thereby to acquire a full and complete perception. That memory is the best, which can voluntarily and immediately produce that which has been committed to its custody; and that reflection is the most perfect, which is exclusively occupied with the subject of consideration. There seems also to be a considerable similarity between the morbid states of the instruments of voluntary motion, and certain affections of the mental powers: thus, paralysis has its counterpart in the defects of recollection, where the utmost endeavour to remember is ineffectually exerted; tremor may be compared with incapability of fixing the attention, and this involuntary state of muscles ordinarily subjected to the will, also finds a parallel, where the mind loses its influence on the train of thought, and becomes subject to spontaneous intrusions; as may be exemplified in reverie, dreaming, and some species of madness.