The value of an individual to society will be determined in great measure by the way he feels. His capacity for energy output and activity, his estimate of himself and his attitude toward his environment, are profoundly influenced by his physical condition. That emotion cannot be separated from its physical concomitants has been for many years recognized by psychologists. Dislike of one's work, idling away of one's time, lack of enthusiasm for one's undertaking, and lack of hope, take root probably from some physical basis. Derangement of the metabolic functions is generally the underlying cause for lack of appreciation of the importance of tact, for lack of respect for others and for failure to discern the futility of antagonizing others. No elements of human conduct contribute more to bring about failure than do these.

Much unhappiness results from ease of irritation and oversensitiveness. One's attitude toward authority and conditions in conflict with one's desires are the results of bodily conditions. Except in relatively rare cases where mental defect is inherited there is no gloom in the mind of the physically well. There are not wanting to-day persons with wide experience, who hold the view that much of the delinquency among children and criminal tendencies among adults are due to physical defects. There is danger that we attribute too much to heredity. Treadway (1), in reporting upon his studies of delinquents, says: "Bad progenitors, pernicious environment and poor educational opportunities form an insufficient basis upon which to classify personality."