Abstract: Tan Sitong is the first person who wanted to build a system of philosophy in Modern China.His system is focused on his book Benevolence,and the thought of Benevolence on the 27 Definitions.The thought of the 27 Definitions is clear,Buddhism and Taoism outside while Confucianism inside.He combinated Confucianism?Buddhism and Taoism in one,which core is the tradition Confucianism.He wanted to give the concept“Tong”or“Yi”a philosophical explanation,and“Tong”or“Yi”is the philosophical basis of the concept of“equality”in ethics and politics.So,from the study to the 27 Definitions,we can see that the essence of Tan Sitong’s Benevolence is just like that with Buddhism and Taoism outside while Confucianism inside.

Key words: Tan Sitong, Benevolence, the 27 Definitions, Buddhism and Taoism and Confucianism