McDougall dividends the instincts into specific tendencies or instincts and general or non-specific tendencies. He calls attention to the abuse of the term "instincts" and himself defines an instinct as an inherited or innate psychophysical disposition which has the three aspects of all mental processes: the cognitive, the affective and the conative--or a knowing of some object or thing, a feeling in regard to it, and a striving towards or away from that object. "The continued obstruction of instinctive striving is always accompanied by painful feeling, its successful progress towards its end by pleasurable feeling, and the achievement of its end by a pleasurable sense of satisfaction." He reminds us that "the emotional excitement, with the accompanying nervous activities of the central part of the disposition, is the only part of the total instinctive process that retains its specific character and remains common to all individuals and all situations in which the instinct is excited." We may experience the emotional excitement and the impulse to the appropriate movements of an instinct or the re-excitement of an instinctive reaction in its affective and conative aspects without the reproduction of the original idea which led to its excitation. Pleasure and pain but serve to guide these impulses or instincts in their choice of means towards these ends. One of McDougall's important conclusions is that "each of the principal instincts conditions some one kind of emotional excitement whose quality is specific or peculiar to it, and the emotional excitement of specific quality that is the affective aspect of the operation of any one of the principal instincts may be called a primary emotion." This is McDougall's definition of emotion. McDougall then takes up for discussion and analysis the principal instincts and the primary emotions of man which include the following: the instinct of flight and the emotion of fear; the instinct of repulsion and the emotion of disgust; the instinct of curiosity and the emotion of wonder; the instinct of pugnacity and the emotion of anger; the instincts of self-abasement (or subjection) and of self-assertion (or self-display) and the emotions of subjection and elation (or negative and positive self-feeling); the parental instinct and the tender emotion, and such other instincts of less well-defined emotional tendencies as the instinct of reproduction (with sexual jealousy and female coyness), the gregarious instinct, the instincts of acquisition and construction; and the minor instincts of crawling, walking, rest and sleep. McDougall denies the existence of such instincts as those of religion, imitation, sympathy and play.