A primary habit producing widespread illusions may in certain cases become the source of rational knowledge. This possibility will surprise no one who has studied nature and life to any purpose. Nature and life are tentative in all their processes, so that there is nothing exceptional in the fact that, since in crude experience image and emotion are inevitably regarded as constituting a single event, this habit should usually lead to childish absurdities, but also, under special circumstances, to rational insight and morality. There is evidently one case in which the pathetic fallacy is not fallacious, the case in which the object observed happens to be an animal similar to the observer and similarly affected, as for instance when a flock or herd are swayed by panic fear. The emotion which each, as he runs, attributes to the others is, as usual, the emotion he feels himself; but this emotion, fear, is the same which in fact the others are then feeling. Their aspect thus becomes the recognised expression for the feeling which really accompanies it. So in hand-to-hand fighting: the intention and passion which each imputes to the other is what he himself feels; but the imputation is probably just, since pugnacity is a remarkably contagious and monotonous passion. It is awakened by the slightest hostile suggestion and is greatly intensified by example and emulation; those we fight against and those we fight with arouse it concurrently and the universal battle-cry that fills the air, and that each man instinctively emits, is an adequate and exact symbol for what is passing in all their souls. Whenever, then, feeling is attributed to an animal similar to the percipient and similarly employed the attribution is mutual and correct. Contagion and imitation are great causes of feeling, but in so far as they are its causes and set the pathetic fallacy to work they forestall and correct what is fallacious in that fallacy and turn it into a vehicle of true and, as it were, miraculous insight. [Sidenote: Knowledge succeeds only by accident.]