It is certainly not obvious at first sight how this hypothesis simplifies the problem. For we are trying to find what there can be in common, from the point of view of magnitude, between a physical phenomenon and a state of consciousness, and we seem to have merely turned the difficulty round by making the present state of consciousness a sign of the future reaction, rather than a psychic translation of the past stimulus. But the difference between the two hypotheses is considerable. For the molecular disturbances which were mentioned just now are necessarily unconscious, since no trace of the movements themselves can be actually perceived in the sensation which translates them. But the automatic movements which tend to follow the stimulus as its natural outcome are likely to be conscious as movements: or else the sensation itself, whose function is to invite us to choose between this automatic reaction and other possible movements, would be of no avail. The intensity of affective sensations might thus be nothing more than our consciousness of the involuntary movements which are being begun and outlined, so to speak, within these states, and which would have gone on in their own way if nature had made us automata instead of conscious beings. [Sidenote: Intensity of a pain estimated by extent of organism affected.] If such be the case, we shall not compare a pain of increasing intensity to a note which grows louder and louder, but rather to a symphony, in which an increasing number of instruments make themselves heard. Within the characteristic sensation, which gives the tone to all the others, consciousness distinguishes a larger or smaller number of sensations arising at different points of the periphery, muscular contractions, organic movements of every kind: the choir of these elementary psychic states voices the new demands of the organism, when confronted by a new situation. In other words, we estimate the intensity of a pain by the larger or smaller part of the organism which takes interest in it. Richet[12] has observed that the slighter the pain, the more precisely is it referred to a particular spot; if it becomes more intense, it is referred to the whole of the member affected. And he concludes by saying that "the pain spreads in proportion as it is more intense."[13] We should rather reverse the sentence, and define the intensity of the pain by the very number and extent of the parts of the body which sympathize with it and react, and whose reactions are perceived by consciousness. To convince ourselves of this, it will be enough to read the remarkable description of disgust given by the same author: "If the stimulus is slight there may be neither nausea nor vomiting.... If the stimulus is stronger, instead of being confined to the pneumo-gastric nerve, it spreads and affects almost the whole organic system. The face turns pale, the smooth muscles of the skin contract, the skin is covered with a cold