But in the second place there is also, as I have already indicated and as was seen by Darwin (though he did not draw this distinction), a second kind of competition, the competition between groups. Now the group competition has as its end the continuance and efficiency of the group, be it horde or tribe or nation, or be it one of those subsidiary groups which enter into national life. In this competition between groups it is clear that those qualities will be favoured by natural selection which contribute to the efficiency of the group; and the qualities which contribute to the efficiency of the group are not those only which contribute to the efficiency of the individual, but also qualities implying self-restraint and even self-sacrifice on the part of one member of the group for the sake of other members of the group or of the group as a whole. The habit of obedience, for example, obedience to the authority of the group or its representative, may be of fundamental importance in maintaining the existence of the group as a group, although that habit of obedience has no place at all in promoting the interests of the individual when he is competing with other individuals. Thirdly, there is still another kind of competition which is a little more difficult to make quite clear, because it is not on the plane of individual life and it is not to be identified with the life of the community. It is a competition on the intellectual level, the competition between ideas, and with this one may also couple (so far as it does not directly concern the struggle for social existence and thus belong to the second class) the competition between institutions, including therein also habits and customs. The various institutions in our national life, and the various habits of our life, may be said to be forms which have to maintain themselves often in competition with other and antagonistic forms of institution. The same holds of our various ideas or general conceptions, whether about morality, which we have now specially in view, or about matters more purely intellectual. For instance, forty or fifty years ago, there was a fierce controversy amongst biologists between the group of ideas represented by Darwin's theory and the group of ideas represented by the traditional view of the fixity of species. There was a long conflict between these two groups of ideas, and we may now say that the Darwinian group of ideas has emerged from the conflict victorious.