V. Revenge

CHAPTER Y. REVENGE. § 134. Among intelligent creatures the struggle for ex istence entails aggressions. Where these are not the de structive aggressions of carnivorous creatures on their prey, they are the aggressions, not necessarily destructive but cornmonly violent, of creatures competing with one another for food. Animals severally impelled by hunger are inevitably led into antagonisms by endeavours severally to seize . whatever food they can; and injuries, more or less decided, are usual concomitants.~ Aggression leads to counter-aggression. Where both creatures have powers of offence, they are likely both to use them; especially where their powers of offence are approximately equal, that is, where they are creatures of the same species: such creatures being also.those comnlonly brought into competition. That results of this kind are inevitable, will be manifest on remembering that among members of the same species, those individuals which have oot, in any considerable degree, resented aggressions, must have ever tended to disappear, and to have left behind those which have with some effect made counter-aggres sions. Fights,therefore,not only of predatoryanimalswith prey but of animals of the same kind with one another, have been unavoidable from the first and have continued to the last.