An alert and conscious adjustment of habits to a changing environment constitutes intelligence. The technique of this adjustment is the technique of thinking or of reflective behavior, which we shall examine in more detail in the following chapter. EMOTION. All human action, whether on the plane of instinct, habit, or reflection, is, to a lesser or greater degree, accompanied by emotion. While there is considerable controversy among psychologists as to the precise nature of emotion, and the precise conditions of its causation, its general features and significance are fairly clear. Emotion may be most generally defined as an awareness or consciousness on the part of the individual of his experiences, both those in which he is the actor and those in which he is being passively acted upon. This awareness or consciousness is not detached intellectual perception, but is accompanied by, as it is by some held to be merely the consciousness of, certain specific bodily disturbances. Thus the emotions of fear and grief are not cold and abstract perceptions of situations that belong in the classes dangerous or deplorable, respectively. The awareness of these situations by the individual is intimately and invariably connected with certain outward bodily manifestations and certain inner organic disturbances. Fear, rage, pity, and the like are not unimpassioned judgments, but highly charged physical changes. So close, indeed, is the connection between specific bodily conditions and the subjective or inner consciousness that we call emotion, that James and Lange simultaneously came to the conclusion that emotions are nothing more nor less than the blending of the complex organic changes that occur in any given emotional state. Thus James: What kind of an emotion of fear would be left if the feeling neither of quickened heart-beats nor of shallow breathing, neither of trembling lips nor of weakened limbs, neither of goose-flesh nor of visceral stirrings, were present, it is impossible for me to think. Can anyone fancy the state of rage, and picture no ebullition in the chest, no flushing of the face, no dilation of the nostrils, no clenching of the teeth, no impulse to vigorous action, but in their stead limp muscles, calm breathing, and a placid face? The present writer, for one, certainly cannot. The rage is as completely evaporated as the sensations of its so-called manifestations, and the only thing that can possibly be supposed to take its place is some cold blooded and dispassionate judicial sentence, confined entirely to the intellectual realm, to the effect that a certain person or persons merit chastisement for their sins. In like manner of grief; what would it be without its tears, its sobs, its suffocation of the heart, its pang in the breast-bone? A feelingless cognition that certain circumstances are deplorable, and nothing more.[1] [Footnote 1: James: _Psychology_, vol. II, p. 452.]