Now, different as the movements of the nervous system, the processes of the brain are from the phenomena of consciousness, there are a number of resemblances between them. Professor Höffding specifies six: (1) As the nervous system is the central, unifying organ of the body, so does consciousness bring together into a unity all the varied phenomena of experience, scattered though they be in time and space. (2) Just as a change is necessary that consciousness may be awakened, (an absence of contrasts tending in the direction of unconsciousness,) so a stimulus is necessary that the nerves may act. (3) A stimulus may produce a commotion in the nervous system out of all proportion to its immediate efficacy, just as a spark may act on a magazine of powder; so a simple sensation may set in motion a whole train of ideas and emotions, owing to the complicated structure and multitudinous inner relations of consciousness. (4) The movements of the body are slow in proportion as they are conscious; now the nerves which appear to be closely related to consciousness act more slowly than those which direct purely physiological (i. e., unconscious) processes. (5) The lower nerve-centres form a system comparatively independent of the higher ones; corresponding to this is the fact that many bodily processes go on unconsciously and only make us aware of them when the circumstances attending them are particularly favorable or unfavorable. The _consciousness_ of the physical state corresponds to the excitation of the higher nerve-centres. Similarly the action of the will has its physiological counterpart; in the struggle between "the flesh and the spirit," the lower nerve-centres with their reflex and involuntary actions correspond to the flesh, the higher centres to the spirit. (6) The construction of the nervous system is similar to the constitution of consciousness; just as consciousness is at once receptive and active, with more or less of intervening reflection or thought, so the nervous system has both sensory and motor organs, with an intervening sphere.