together by community of interests, and that can adjust their mutual relations by legal discussion without coming to blows. In the preceding lecture we considered this process of political integration as variously exemplified by communities of Hellenic, of Roman, and of Teutonic race, and we saw how manifold were the difficulties which the process had to encounter. We saw how the Teutons--at least in Switzerland, England, and America--had succeeded best through the retention of local self-government combined with central representation. We saw how the Romans failed of ultimate success because by weakening self-government they weakened that community of interest which is essential to the permanence of a great political aggregate. We saw how the Greeks, after passing through their most glorious period in a state of chronic warfare, had begun to achieve considerable success in forming a pacific federation when their independent career was suddenly cut short by the Roman conqueror. This last example introduces us to a fresh consideration, of very great importance. It is not only that every progressive community has had to solve, in one way or another, the problem of securing permanent concert of action without sacrificing local independence of action; but while engaged in this difficult work the community has had to defend itself against the attacks of other communities. In the case just cited, of the conquest of Greece by Rome, little harm was done perhaps. But under different circumstances immense damage may have been done in this way, and the nearer we go to the beginnings of civilization the greater the danger. At the dawn of history we see a few brilliant points of civilization surrounded on every side by a midnight blackness of barbarism. In order that the pacific community may be able to go on doing its work, it must be strong enough and warlike enough to overcome its barbaric neighbours who have no notion whatever of keeping peace. This is another of the seeming paradoxes of the history of civilization, that for a very long time the possibility of peace can be guaranteed only through war. Obviously the permanent peace of the world can be secured only through the gradual concentration of the preponderant military strength into the hands of the most pacific communities. With infinite toil and trouble this point has been slowly gained by mankind, through the circumstance that the very same political aggregation of small primitive communities which makes them less disposed to quarrel among themselves tends also to make them more than a match for the less coherent groups of their more barbarous neighbours. The same concert of action which tends towards internal harmony tends also towards external victory, and both ends are promoted by the co-operation of the same sets of causes. But for a long time all the political problems of the civilized world were complicated by the fact that the community had to fight for its life.