Japan stood on the verge of a crisis, and it was saved from catastrophe by two causes. First, by the ceaseless importation of high Chinese civilisation, which steadily encouraged the political concentration; secondly, by the necessity of centralisation so as to push on vigorously the attack on the still powerful Ainu. As I have mentioned several times before, the Ainu had been a losing party in the racial struggle with the Japanese, yet their resistance had been a very stubborn one, so that at the end of the sixth century they could still hold their ground against the Japanese on the southern boundary of the present provinces of Iwaki and Iwashiro, which roughly corresponds to latitude 37 deg. N. The northern part of Japan, therefore, was still in constant danger of incursions by the hairy race. For a country in the infant stage of consolidation, as Japan was at that time, it was by no means an easy task to ward off the frequent inroads of that race, and at the same time to continue the process of the inner organisation of the state. One would perhaps wonder at my conclusion, starting from the consideration that the Ainu scare was not such a fearful thing as to influence the natural growth of a state formed by the stronger race. This misconception arises from the ignorance of the fact that the famous dictum "delenda est Carthago" was only pronounced after the first Punic war. Necessity by itself does not create the desire to secure what is necessary. The desire to attain any aim first comes into consciousness when one begins to feel strong enough to venture to attain it. When the Ainu was very powerful, the Japanese had to contend with them mainly in order to secure a foothold against them. It was none the less necessary for the Japanese to continue to struggle with the Ainu, when the former became strong enough to face the antagonist evenhanded. Lastly, the time arrived now when it became an urgent necessity for the Japanese to crush the Ainu, in order to achieve undisturbed a full political organisation in the domain within the four seas. In short, when the Japanese became so convinced of their might that they could not tolerate any rival within the principal islands, they found it even more indispensable to organise themselves as compactly as possible under one strong supreme head than ever before.