212. Relations of Byzantine to Western Philosophy. -- The schism of 858 was the beginning of long ages of alienation and misunderstanding between East and West. Down to the thirteenth century, moreover, there was little or no intercourse between the two civilizations. Each of the two great families went its own way; there was no mutual interchange of knowledge or achievements. The crusades first, and more especially the fall of Constantinople in 1204, put an end to this isolation: in the thirteenth century Byzantine learning made its contribution to the development of Western philosophy.