Shin Chaeho
The term "pure blood" refers to the belief that Korean people are a pure race descended from a single ancestor. First invoked during the period of resistance to colonial rule, the idea of having pure blood gave Koreans an impetus for developing a sense of ethnic homogeneity and national pride, as well as a potential catalyst for racial discrimination and prejudice. As a way of resisting colonial rule, Shin Chaeho published his book "Joseon Sanggosa" in the 1920s, proclaiming that Korean descent is based on the Goguryeo kingdom, formed from the intermingling of the descendants of Dangun Joseon with the Buyeo kingdom. This raised a sense of ethnic homogeneity which persists as a major element in the politics and foreign relations of both Koreas. A survey in 2006 showed that 68.2% of respondents considered "blood" the most important criterion of defining the Korean nation, and 74.9% agreed that "Koreans are all brothers and sisters regardless of residence and ideology."