December 30, 1918 (of Wu Wu the winter months 28), sen Sun Yat-sen doctrine "into a book. 30,,

1918 12 the sen Sunwen doctrine "into a book. This is a part of the "nation-building strategy". The book made the "difficult to know" doctrine. That the "line after the Prophet", ie the practice prior to the awareness, knowledge is obtained from the line, the line is validation standards known to express the point of view of the materialist epistemology. That foresight, hindsight and unknowingly, they are caught up in spiritualism. He stressed that "difficult to know" for to inspire revolutionaries suffered a setback, to promote the development of the revolution, has played a useful role. May 20, 1919, "Sunwen doctrine," Volume "easier than" printed issued June 5 Qianghua bookstores.