In 1908, a reaction against the formalism and legalism of the traditional political approach was expressed by Graham Wallas, an Englishman, and Arthur F. Bentley, an American. Not until the "Chicago school" of political science during the nineteen twenties and thirties did the behavioral approach achieve an empirical focus. Behavioralism gathered force in the forties, and its status in the fifties was a "movement of protest." In the sixties, behavioralist succeeded in reaching high and strategic positions in academic and the American Political Science Association, and an empirical political science has firmly established within the discipline. Starting from 1967, a post-behavioral "revolution" was underway in American political science. The revolution was motivated by a deep dissatisfaction with the contemporary political science as a discipline and as a profession. Post-behavioralists demand active political involvement. They believe that it is impossible to maintain a value-free position; that it is the moral obligation of the political scientist to take a more active role in politics for the reshaping society. At present the behavioralism in the American political profession is dominan; the post-behavioralist has survived.