For this reason it is necessary that a movement should, from the sheer instinct of self-preservation, close its lists to new membership the moment it becomes successful. And any further increase in its organization should be allowed to take place only with the most careful foresight and after a painstaking sifting of those who apply for membership. Only thus will it be possible to keep the kernel of the movement intact and fresh and sound. Care must be taken that the conduct of the movement is maintained exclusively in the hands of this original nucleus. This means that the nucleus must direct the propaganda which aims at securing general recognition for the movement. And the movement itself, when it has secured power in its hands, must carry out all those acts and measures which are necessary in order that its ideas should be finally established in practice.