"I have chosen the middle ages because, in spite of many diversities, they have a certain great stamp of unity, and, above all, of simplicity. The Englishman of the twelfth century had much more in common with the Frenchman and the German of his day than is the case now. They were all one in one faith, and all acknowledged one supreme spiritual head. The papal court was a common meeting place for the best intellects from all lands. There was one common language for all formal interchange of thought. There was one great system which separated all Europe into classes, and made all the members of a given class akin. A nation... had little influence on its neighbour, mingled seldom in that neighbour's quarrels."