In suppurative disease, such as appendicitis, it is often difficult to decide when nature is doing better than we can do, and when we can do better than nature. The appendix is a hollow tube the size of one's little finger, and hangs off from one part of the large bowel. When it gets inflamed nature at once begins the defences which I have described in the lung, namely, the walling-off process, which tends to make the bacteria harmless. There is danger that they will spread from the neighborhood of the appendix and produce a very dangerous disease, general peritonitis. Hence nature begins to glue around the appendix the adjacent parts of the bowel and anything else at hand. This generally makes it harmless. Most of us physicians now believe that the great majority of cases of appendicitis cure themselves, and that still more would cure themselves if given a chance. On the other hand, there are cases in which nature does not do her work rightly. Then if the surgeon did not interfere the person would die. That is why medical and surgical judgment, the particular, minute, individual study of the person from hour to hour, makes the difference between right and wrong treatment. The surgeon who operates every time he makes a diagnosis of appendicitis, or who says he will never operate, is just as wrong as the person who gives money the first time he sees a case, or who never gives money. But most surgeons are wiser than that. I hope through these illustrations to make it clear that nature generally cures disease. When she does not, it is generally incurable. There is a small residuum left for the doctor. We have a function as physicians or nurses. We have a function, and that function is intermediate between two extremes. In disease or in other misfortune, there are three types of fortune, two extremes and a mean: (1) The people who will get out of their troubles whatever you do, get out of their misfortunes, rally to meet their griefs, pull themselves out of financial difficulties, get over their disease. Then (2) there are people on the other side, who will die whatever you do. Some cases of pneumonia, for instance, seem to be doomed from the start. It is the same with many other cases of disease and with some people's misfortunes. We have to face the fact in social work that there are many people whose mental twists and agonies we cannot help in the least, and many people who will be in money difficulties as long as they live. But (3), intermediate between these two extremes--and our happiness and our success depend on our finding that group--are those cases where what we do makes the difference between success and failure. This triple division indicates a point of view which makes, not only for individual understanding of the situation, but for practical success.