This is the first English version of Tadao Umesao's classic, published first in Japanese in 1957, with a full description of his ecological theory of civilizations of Eurasia. Dividing the Eurasian continent into three major ecological zones consisting of Western Europe, Japan, and the region between them, he shows how the first two are basically similar and demonstrates fundamental differences between Japan and China. In 1964 a jury of ten intellectuals chose this treatise as one of the 18 most influential treatises since 1945 from among more than a hundred which were considered. In 1998, when an influential monthly, Bungei Shunju, solicited the ten most impactful books in the twentieth century from more than 170 intellectuals in Japan, this book won the third highest vote among 67 books that were nominated.