Health defined as the psychophysiological capacity to act or respond appropriately in a wide variety of situations, is enhanced by many means other than preventing and treating disease and injury. Therefore no choice of a particular medical intervention is likely to maximize health for all people with (or at risk for) a given disease. As a result, if medical practitioners are to be fully competent in the sense of knowing not only how to perform procedures but when and when not to do so, they must be able to support patients (and those who know and care about them) in weighing all of the many factors which bear upon the decision as to which, if any, medical interventions are likely to improve the person's health.