In the Middle Ages the Jews previously inhabiting the Rhine {65} lands found it difficult to fit into western schemes, as we know from English history, and some moved eastwards (Ashkenazim) into the Slav lands to form an important element of the population of the towns, especially in Poland, where their numbers were increased by Tsarist restrictions on their settlement in Russia itself. Their language, Yiddish, is generally described as a modified German dialect written in Hebrew characters and owing some debt to Hebrew tradition in other respects. As they have a linguistic and religious entity of their own, and as inter-marriage with Gentiles has been restricted, it follows that they form a very distinct block, most difficult to work into any State organization of a western type. It must therefore be very open to question whether the recent treaties endeavouring to spread western state-theory eastwards are the best ways to provide for the life of the people concerned. A modern state needs towns and industry; the Jewish element in the towns of East-Central Europe is enormously important, and cannot be dispensed with save at great cost, as well as with the greatest injustice, and yet assimilation of Jew to Gentile in East-Central Europe is almost out of the question. The development of a nation-state is necessarily held back when there are such diverse elements, and League of Nations schemes for protection of minorities offer a valuable line of progress if they can be realized.