Here we need to keep in mind two ways in which natural selection works. When a certain form of organization exists in a given group, the group may abandon it and adopt another in its place, or the group itself may come to an end; in either case the form of organization disappears. A type of school government may come to an end because the school using it loses support and goes out of existence, or because the school changes its form of government. The continued existence of any group whatsoever depends upon its adoption of those forms of organization which lead to success and the timely abandonment of those which lead to failure. The continuance of any idea or institution depends on its helping its supporters in their struggle for existence.