Medical men have always been, and I suppose will always be, divided into two groups: first, the Hippocratic group, composed of those who, like Hippocrates, object to the unnecessary multiplication of diseases and who prefer to assign so-called new diseases to their proper places under already recognized pathologic processes; and, second, the Cnidians, for whom every new symptom and every complication constitutes a new disease. But though my own inclinations lean toward the former school, it is impossible to deny that new clinical entities are from time to time recognized by acute observers, and that in this way both the science and the art of medicine are advanced. Consider, for instance, appendicitis: Is it, or is it not, a distinct disease? The Hippocratic group will argue that it is not a new disease but merely an ordinary disease which is known as inflammation; and so far they will be correct.