law of the jungle

noun

1. a system or mode of action in which the strongest survive, presumably as animals in nature or as human beings whose activity is not regulated by the laws or ethics of civilization.

noun

1. a state of ruthless competition or self-interest

Survival of the strongest, as in The recent price war among airlines was governed by the law of the jungle. This term, alluding to the jungle as a place devoid of ethics where brutality and self-interest reign, was first used by Rudyard Kipling in The Jungle Book (1894).