“诚”在真德秀思想体系中占有重要地位,《大学衍义》以“诚心”为帝王之学的出发点,《西山读书记》卷十七专言“诚”~②,《西山文集》反复强调“诚”的根源性、现实性和贯通性,《心经》、《政经》也十分重视“诚”的本体与功用。真德秀对“诚”的重视与其师承有关,他早年从游朱子门人詹体仁,詹氏之学“以存诚慎独为主”~③,他私淑的朱子之学也是以“正心诚意”~④为主。真德秀曾追溯“诚”的根源:“唐虞之时,未有诚字。舜典所谓允塞,即诚之义也。至 ”Sincerity “ plays an important role in the system of ZhenDeXiu ideology, ”University YanYi“ takes ”Sincerity “ as the starting point of the study of the emperor, ”Book of Xishan“ ② ”Xishan Anthology“ repeatedly emphasizes the origin, reality and continuity of ”honesty“. ”Heart Sutra“ and ”politics“ also attach great importance to the noumenon and function of ”honesty“. In his early years, he traveled to Zhan Ziren (Zhu Zi Men) and Jennifer’s School (诚 之 之 學) to ”give priority to honesty and cautiousness“. The study of his selfish Shu was also based on ” Sincere heart “~ ④-based. The true moral show has been traced back ”sincere “ the root causes: ”Tang Yu time, there is no sincere word Shun Code so-called allow plug, that is,