particular purpose, such as a political or a religious instinct or an instinct of subordination or of organisation. Comte made egoism and altruism the two master forces of the mind. Sir Henry Maine asserted that “satisfaction and impatience are the two great sources of political conduct,” and, after asserting that “no force acting on mankind has been less carefully examined than Party, and yet none better deserves examination,” he was content to conclude that “Party is probably nothing more than a survival and a consequence of the primitive combativeness of mankind[3].” More recently Prof. Giddings has discovered the principal force underlying all human associations in _Consciousness of Kind_. Butler and the intuitive moralists postulated ‘conscience’ or moral sense as something innately present in the souls of men; while the creators of the classical school of political economy were for the most part content to assume that man is a purely rational being who always intelligently pursues his own best interest, a false premise from which they deduced some conclusions that have not withstood the test of time. Similar vague assumptions may be found in almost every work on the social sciences,—all illustrating the need for a psychology more concrete than the older individual psychology, as a basis for these sciences, a positive science, not of some hypothetical Robinson Crusoe, but of the mental life of men as it actually unfolds itself in the families, tribes, nations, societies of all sorts, that make up the human world.