From the earliest ages in the history of man, we find evidences of the existence of beings stunted in body and defective in mind, whose relations with their fellows varied through the centuries. At one epoch they were exalted almost to the level of a deity, and their symptoms were interpreted as manifestations of Divine will. At another they were looked upon with loathing and disgust, not unmingled with fear. Still later, they were either the playthings of kings or the victims of cruel jibe and blow, and their existence at the present day, and the associated conditions of insanity, crime and intemperance, constitute one of the most serious, if not the most serious problem which a civilised community is called upon to solve.