Mencius (c. 372-289 BC) was a great thinker of the Pre-Qin Confucian school. Although he did not study directly under Confucius — "I have not had the fortune to be a disciple of Confucius, but I have learned from those who followed him" (Mencius, Li Lou II; hereinafter, quotations from Mencius will only indicate the chapter name), he regarded himself as the legitimate successor of Confucius's teachings (551-479 BC). Based on Confucius's concepts of benevolence or ritual, Mencius developed a core ideological doctrine centered around "benevolence and righteousness." He actively promoted and practiced this ideology, traveling extensively and calling for its adoption. Through the ideological doctrines expounded in the book Mencius and Mencius's life experiences, we can see several profound sources of his life spirit that have had far-reaching influence.