About thirty years ago behavioral scientists introduced the idea of a “zero-sum” game. Poker, chess, and football—these were “zerosum” games. Winning the game implied that someone else lost; an advantage for one party was necessarily a disadvantage for another. At that time the “zero-sum” analogy was not applied to societies as a whole. If the middle class increased its wealth, this did not imply that the resources of the lower class were decreased. The success of Western industrial societies did not necessarily imply the poverty of underdeveloped countries. The total wealth of the planet could expand; the extension of rights to blacks and other minorities did not necessarily undermine the position of the majority. These were the guiding assumptions of liberals in the sixties.

But today these assumptions are under attack. The metaphor of the “zero-sum” game is now thought to describe societies as a whole.