Inversely the descent to the lower social status was much easier than the ascent to the higher rank in any scale. Nay, for various reasons many persons had been obliged to climb down from their original high position in society to a lower status. As the law of primogeniture grew rigorous in its enforcements on the _daimyo_ and the _samurai_, the greater part of the scions belonging to these classes could only fully enjoy the privilege of the society in which they were born during childhood, unless extinction of the main line took place. Descendants of _daimyo_ generally gravitated to _samurai_ rank, and those of _samurai_ had to turn themselves into plebeians, in so far as they did not merit to be called to service as independent _samurai_. Thus the sliding down of classes was necessitated by the law of succession. Could any line of social demarcation be drawn according to the difference of classes in the face of such shiftings upwards and downwards? If it was a difficult matter, then we cannot expect to find any sort of culture monopolised by a certain class to the last. In whichever stratum of society it might have originated, it was sure to penetrate sooner or later into the other classes, and at last the whole people of a territory absorbed a similar and uniform culture. No sort of territorial barriers or social cleavage proved efficient enough to impede the inter-penetration of any cultural movement. This amalgamation of cultures different in their origins had been accelerated by the introduction of European civilisation. Though the free intercourse of the Japanese with Europeans had been cut short in the third decade of the seventeenth century by the ordinances of the Shogunate, the country had never been absolutely closed against foreigners. No Japanese had been allowed to go abroad for any purpose whatever, but we continued to trade in the specially prescribed port of Nagasaki, not only with Chinese but also with Dutch merchants, though in very restricted forms. Thus while the Japanese had been struggling to mould the new national culture out of promiscuous elements which had existed from aforetime, they had been receiving the Western civilisation, not _en masse_ but drop by drop, so that we had no need this time of the process of rumination in digesting the introduced exotic culture, as we had done as regards Chinese civilisation. The rigorous exclusion, carried to the utmost, of all Christian literature, whatever its relation to our religious tenets might have been, naturally induced men in authority to resort to the safest methods, that is to say, to restrict the kinds of books to be imported to the narrowest scope, and to limit their number to the smallest possible minimum. Accordingly, in the first half of the Tokugawa Shogunate, very few useful books were imported into our country, and the nation had, therefore, a very scanty opportunity of getting knowledge through books about things European.