Lu Chiu-yuan (1139-1193) was a Chinese thinker, public official, and man of letters. He is regarded as the representative of the idealistic wing, as distinct from the rationalistic wing, of Sung-dynasty Neo-Confucianism.

Lu Chiu-yuan, better known in China by his literary name as Lu Hsiang-shan, had a remarkably original mind which was noticeable from his childhood. At the age of 4 he asked his father, "Where would one find the limit of heaven and earth"" Later he detected a difference between the Neo-Confucianism of Ch'eng I and classical Confucianism and raised the query, "Why is it that Ch'eng I's words do not seem to agree with those of Confucius and Mencius""

In the course of his study of the ancient classics when Lu Chiu-yuan was 13 years of age, he came across the term yü-chou (universe), on which the commentary said, "The four directions together with what is...