Let us take fatigue in some of its very simple phases, as it applies to your life and mine. The first thing to recognize is that it can affect any organ; our stomachs can get tired just as well as our legs. When a patient complains of pain, vertigo, nausea, we first ask ourselves, "What disease has he got?" That is correct. Disease must be found if it is there. But the chances are he has no disease, but only a tired stomach, since fatigue easily and frequently affects that organ. When the whole person has been strained by physical, moral, and especially by emotional work, he may give out anywhere. He may give out in his weakest spot, as we say. That weak spot is different in different people. Therefore the study must be individual. We cannot do anything important with our own lives until we learn how and when we get tired. It is the same with people whom we try to help in social work. Fatigue, then, may be _referred_ to any particular spot in the body. People often go to an oculist to see what is the matter with their eyes, when there is nothing in the world the matter with their eyes: the honest oculist tells them that they are tired, and that for some reason unknown to him their fatigue expresses itself in the eyes. This is a very common and very misleading fact. The patient finds it hard to believe that medicine ought seldom to be put on the spot where he feels his pain. If the pain is in his stomach he wants some medicine to put in his stomach and not a harangue on his habits, which is usually the only thing we can really do to help him. If he has a pain in his back he wants a plaster or a liniment for his back. It is very hard to get people out of that habit of mind, and we shall surely fail unless we are clear about it ourselves. It must be perfectly clear in our minds, or better, in our own experience, that fatigue may be referred to one spot or to another, in such a way as seriously to mislead us. I suppose that half of all the pains that we try to deal with in a dispensary--and pain, of course, is the commonest of complaints--are not due to any local or organic disease in the part. Doubtless there are some wholly unexplored diseases or disturbances of nutrition in that part, as there may be in the eyes when they ache because you have been walking up a mountain. But medical science knows nothing about that. What we do know is that the pain, if it is to be helped, will be helped not by thinking about that spot or doctoring it, but by trying to get that person rested.