_First, the Movement._--As to the first thing--the movement and locomotion in sleep--it may be accounted for in two ways. We may suppose it to be wholly automatic. This is the view of some eminent physiologists. The conscious soul, they say, has nothing to do with it, no knowledge of it. The will has nothing more to do with it, than it has with the contraction of a muscle, or irritation in an amputated limb. _Objection to this View._--For reasons intimated already, we cannot adopt the automatic theory. It seems to us subversive of all true science of the mind. The body is self-moved in obedience to the active energy of the nervous organism, and this organism again, acts only as it is acted upon by the mind that animates, pervades, and controls that organism. In the waking state, this mental action, and the consequent nervous and muscular activity, are under the control of the will. In sleep, this control is, for the time, suspended, and the thoughts come and go as it may chance, subject to no law but that of the associative principle. The mind, however, is still active, and the thoughts are busy in their own spontaneous movement. To this movement, the brain and nervous system respond. That the brain itself thinks, that the nerves and muscles act, and the limbs move automatically, without the energizing activity of the mind, is a supposition purely gratuitous, inconsistent with all the known facts and evident indications of the case, and at war with all just notions of the relation of body and mind. _Another Theory._--Another, and much more reasonable supposition is, that the will, which ordinarily in sleep loses control both over the mind and the body, in the state of somnambulism regains, in some way, and to some extent, its power over the latter, so that the body rises and moves about in accordance with the thought and feeling that happen, at the moment, to be predominant in the mind. There is no control of the will over those thoughts and suggestions: they are spontaneous, undirected, casual, subject only to the ordinary laws of association; but for the time, whether owing to the greater vividness and force of these suggestions and impressions, or to the disturbed and partially aroused state of the sensorial organism, the will, acting in accordance with these suggestions of the mind, so far regains its power over the bodily organism, that locomotion ensues. The dream is then simply acted out. The body rises, the hand resumes the pen, and the appropriate movements and actions corresponding to the conceptions of the mind in its dream, are duly performed. _The second Point of Inquiry._--This virtually answers the second question, how the somnambulist can perform actions requiring intelligence, yet without apparent consciousness.