lives as original endowments of their nature. Like all the instincts pugnacity has two aspects, the mental and the physical, and appears in the forms of anger and of combat. In both its forms, it is a very early, a very permanent and a tremendously powerful instinct. Its outward signs, bared teeth, stiffened body and the rest, are known by everybody and explained by the biologists as the persistence, in bodily attitude, of reactions useful in the preservation and propagation of animal species. Pugnacity is widely diffused among animals, and very early observed among children; and it persists, a strong instinct, throughout adult life. People differ, to be sure, in the degree of their combativeness; and one man’s pugnacious feelings and actions are far more readily excited than another’s. Yet every normal man is a potential and, at times, an actual fighter; and everybody knows by his own experience how the flame of an intense anger may devour all other feelings and obliterate all memory and all thought, and how it may lick one’s mind clean and bare of every control and restraint.
Pugnacity is always incited by opposition. Animals and men alike fight when they are thwarted or balked in the free play of any instinct, or (if we confine ourselves to human pugnacity) in the exercise of any volitional activity. It follows that pugnacity is excited in many specifically different ways and that it is affiliated now with one and now with another instinct. For our purpose this intimacy of interrelation is of utmost significance, and our valuation of pugnacity must hinge largely on our estimate of the fellow-instincts by which it is excited and which, in turn, it may reinforce and invigorate.
Pugnacity, in the first place, is sometimes excited when the instinct of curiosity is thwarted; as when a child shows anger if balked in his investigation of the contents of a wastebasket. Curiosity is an instinct common to animals and to human beings and so strong that hunters often appeal to it in decoying wild animals. It has many forms, appearing sometimes as component of the play impulse, and again, when it involves awareness of danger, as daring.
