To speak of the intrinsic pleasure-unpleasure of a sensation is perhaps misleading. The pleasantness of a sensation as we know is a highly variable thing. It may alter completely while the strictly sensory characteristics of the sensation remain as before. The difference in the same smell of liquor, before and after an alcoholic excess is a striking example. A sound which is pleasant for a while may become very unpleasant if it continues and does not lapse from consciousness. And yet indisputably it may remain _qua_ sensation the same. A sound-sensation may remain unchanged in tone, volume and intensity yet vary widely in pleasure-unpleasure. This difference is important. It is one of the chief reasons which have caused feeling (pleasure-unpleasure) to be distinguished from sensation as altogether of a different nature. Tone, volume and intensity are features in the sound closely dependent upon the stimulus, pleasantness is dependent not on external stimulus but upon factors, very obscure at present, in us. All here is conjecture. The close connection of stimulus with sensation we know because it happens to be comparatively accessible to experiment. And introspection of sensations of external origin is for that reason much more easy than introspection of most visceral or organic sensations. We can practise it freely and repeat it and so control our results. To a lesser extent those sensations of internal origin which we can in part consciously control, those due to voluntary movements, share this double accessibility. But all the rest of the multifarious conscious goings on in the nervous system remain obscure. One broad fact, however, is important. The effects in the body of almost all stimuli of whatever nature are extraordinarily numerous and varied. “You cannot show the observer a wall-paper pattern without by that very fact disturbing his respiration and circulation.”[41] And no man knows what other disturbances do not join in. The whole body resounds in what would seem to be a fairly systematic way. Whether the outpouring of this tide of disturbance makes up a part of, gives a tone to consciousness, or whether only the incoming reports of the results can be conscious is a question upon which no conclusive evidence would seem to be yet available. The incoming reports of some at least of these disturbances certainly can become conscious. A lump in the throat, a yearning of the bowels, horripilation, breathlessness, these are their coarser and more obvious forms. Usually, they are less salient and fuse with the whole mass of internal sensations to form the _cœnesthesia_, the whole bodily consciousness, tinging it, altering its general character in some one of perhaps a thousand different ways.