This extension of ethics, so far studied only by philosophers, is actually a process in ecological evolution. Its sequence may be described in ecological as well as in philosophic terns. An ethic, ecologically, is a limitation on freedom action in the struggle for existence. An ethic, philosophically is a differentiation of social from anti-social conduct. These are two definitions of one thing. The thing has its origin in the tendency of interdependent individuals or groups to evolve modes of co-operation. The ecologist calls fees symbioses. Politics and economics are advanced syrnbioses in which the original free-for-all competition has been re placed, in part, by co-operative mechanisms with an ethical content.