Infancy, prolonged period of in man, [10-12].
Inquisition, [327-28].
Instinct, and habit, [7], [27]; acquisitive, [140-42]; definition of, [2], [18]; of curiosity, [22], [62], [74-75], [369], [387-89]; fear, [125-28], [143], [253], [300-02]; gregariousness, [83-90], [138], [181]; hunger, [4], [67-68]; leadership, [22], [119-23]; mental activity, [72-76]; parental, [4], [124], [245]; physical activity, [69-72]; pity, [123-25]; play, [22], [70-71]; pugnacity, [111-115]; self-preservation, [4]; sex, [67-69], [190-95], [243]; shelter, [67-68]; submission, [116-19], [123]; sympathy, [22], [90-96], [158-59].
Instincts, and education, xii, xiii, [458-59]; and emotion, [43], [45]; basis of morals, [411-14], [440], [454-56]; conflict of, [413-14]; control of, [19-26], [59], [413-14]; happiness comes from satisfaction of, [25-26]; interpenetration of, [6], [110-11], [411]; modification of, [5-7], [11], [18-19], [22], [52-53]; number and variety of, [3-6]; repression of, [20-26]; specific not general, [3]; unchanged since prehistoric times, [xi-xii], [21].
Intelligence, a conscious adjustment of habits, [40]; influence of heredity on, [202-06], of race, [196-202], of sex, [191], [195]; makes possible control of nature, [16]; measurement of, [188], [191], [197], [209]; types of, [187-88].
Interests, conflict of in society, [413-14].
Intolerance, [327-28].
Intuitionalism, [448-49].