124 THE SOCIAL THEORY OF GEORG SIMMEL The Results of Conflict for the Internal Structure of the Group Apart from the sociological significance which conflicts possess for the relationships between the opponents, they lead also to important modifications of the inner structure of the contesting parties. These modifications are, of course, of sociological importance only if the parties to the conflict are themselves social groups. The outbreak of a struggle forces a group to concen- trate its energies and centralize its activities. In time of peace it can allow a great amount of decentralization and local autonomy, but immediately the struggle breaks out, it becomes necessary to concentrate all the available ener- gies and to place them at the disposal of the central author- ity. The result is that conflicts oftenlead toa purification of groups through the expulsion of inharmonious elements. In times of peace a group can allow within its fold a cer- tain number of antagonistic elements. But a struggle pulls the elements so much together and binds them so closely that the divergent elements must either be forced to har- monize or be repulsed. This makes groups at war so intoler- ant toward their own members. They can allow only small deviations from the norm and must suppress or expel any member whose divergence threatens the harmonious unity on which the strength of the group depends. Especially the small group cannot allow any uncertain elements in its midst, and it gains in actual strength by expelling them, although it loses in numerical strength. A struggle therefore strengthens the unity of groups. The influence of wars on the growth of nationalities and that of heretics on the strength of the Catholic church are only a few of the innumerable illustrations that might be cited from history. But a common opponent not only strengthens unity, but often creates a unity which did not