No other possible explanation offers itself than that he is born with certain tendencies to definite action. These we call instincts--man's provision to keep him going, as it were, till reason develops. Instincts are handed down from all the past. Definite tendencies, they are, to certain specific reflex actions in response to certain sensations. These responses, from the very beginning of animal life, have been toward avoiding pain, and toward receiving pleasure. It is as though the stimulus presses the trigger--instinct--and the muscle responds instantly with reflex action. This mechanism is the means of protection and advancement, and takes largely the place of intelligence in all animal life. It is what makes the baby suck and cry, clutch and pull, until a sense memory is established. So instinct is really race memory. We call instinctive those immediate, unthought reactions which are the same with all mankind. The pugnacious instinct--the desire to fight--is the natural reaction of every human being of sane mind to attack. The inner necessity of avenging is so strong in the child or man of untrained mind or soul that he acts before he thinks. He strikes back, or shoots, or plots against his enemies. Only rare development of spirit or the cautious warning of reason which foresees ill consequences, or a will trained to force control, can later make the instinct inactive. Where instinct ends and sense memory, imitation, and desire step in is difficult to determine. Later in life probably most of what we consider instinctive action is simply so-called reflex action, depending on sense memory, action learned so young that it is difficult to distinguish it from the true reflex action, which is due only to race memory. James, in his _Talk to Teachers_, gives us a partial list of the instincts. Thus: Fear Ownership Shyness Love Constructiveness Secretiveness Curiosity Love of approbation The ambitious impulses: Imitation, Emulation, Pride, Ambition, Pugnacity To this partial list we would add self-preservation, reproduction, etc. But instincts conflict with each other, and man carries about with him in babyhood many of them which may have been very useful to his prehistoric ancestors, but which only complicate things for him. Fear and curiosity urge opposite lines of conduct. Love of approbation and shyness are opposed. Love and pugnacity are apt to be at odds. So, gradually, as intelligence increases, the child refuses to allow such impulses to lead him to action. When fear-instinct and love-instinct are at war, reason is provided to come to the rescue. _Instincts_ are racial tendencies of sensational or emotional states to determine action.