Although the importance of prognosis (preknowledge or forecasting) in medicine was clearly appreciated by Hippocrates, it has progressed very little and very slowly through the many centuries in contrast to the scientific development of etiology, pathology, diagnosis, and treatment. In the Dark and Middle Ages it drifted almost wholly into superstition. It still remains a stepchild in medical advance partly because it is a difficult subject and partly because, for some reason or other, it has rarely been studied scientifically. The few sentences devoted to it in the account of almost any disease or condition in almost all textbooks and papers are little more than a sop to the conscience. In cases of cardiovascular disease, the statement of prognosis often ends with the word "guarded," largely to play safe. Granted that we can not foretell the future with any certainty, I feel sure, nevertheless, that we can do better than