The discussion of these questions may be approached by pointing out a contrast between contemporary psychology and the psychology of former days. The contrast is a triple one. Earlier psychology regarded mind as a purely individual affair in direct and naked contact with an external world. The only question asked was of the ways in which the world and the mind acted upon each other. The entire process recognized would have been in theory exactly the same if there were one mind living alone in the universe. At present the tendency is to conceive individual mind as a function of social life—as not capable of operating or developing by itself, but as requiring continual stimulus from social agencies, and finding its nutrition in social supplies. The idea of heredity has made familiar the notion that the equipment of the individual, mental as well as physical, is an inheritance from the race: a capital inherited by the individual from the past and held in trust by him for the future. The idea of evolution has made familiar the notion that mind cannot be regarded as an individual, monopolistic possession, but represents the outworkings of the endeavor and thought of humanity; that it is developed in an environment which is social as well as physical, and that social needs and aims have been most potent in shaping it—and the chief difference between savagery and civilization is not in the naked nature which each faces, but the social heredity and social medium. Studies of childhood have made it equally apparent that this socially acquired inheritance operates in the individual only under present social stimuli. Nature must indeed furnish its physical stimuli of light, sound, heat, etc., but the significance attaching to these, the interpretation made of them, depends upon the ways in which the society in which the child lives acts and reacts in reference to them. The bare physical stimulus of light is not the entire reality; the interpretation given to it through social activities and thinking confers upon it its wealth of meaning. It is through imitation, suggestion, direct instruction, and even more indirect unconscious tuition, that the child learns to estimate and treat the bare physical stimuli. It is through the social agencies that he recapitulates in a few short years the progress which it has taken the race slow centuries to work out.