歷來討論朱子「中和四札」寫作年代的文獻龐雜，線索多頭，束景南的《朱子大傳》算是較新的研究成果，但他主要的論據，仍沿著王懋竑的《年譜》而來，即是以〈答何叔京〉四札來確定「中和四札」的年代，陳來的《朱子哲學研究》也是如此。他們都依據〈答何叔京〉第三札裡的「天性人心，未發已發，渾然一致」，要來牽合「中和四札」的思想，卻不察這三句話其實是可視為儒者在心性論上所追求的共通境界，並無涉於工夫理論之異同，再加上他們忽略了〈答何叔京〉四札中尚有不少懷念故師李延平的文字，而這樣的情緒是與「中和四札」不類的，所以〈答何叔京〉四札之在丙戌，恰可做為「中和四札」不在丙戌之反證。既然證明「中和四札」不在丙戌，則可順錢穆之說而置於戊子。至於其它的種種佐證，或是由說話的語氣來分析，或是由常情常理來推論，亦都可隨之重新詮釋，藉此扼要地還原「中和四札」的時空背景。

Heretofore, the has been a lot of complicated archives and clues to discuss the writing year of Zhu-Zi's ”Zhong He Four Letters”. They both use a sentence from the third letter in ”Da He-Shu-Jing”, which says ”The enlightended or unenlightended mind is the same mind”, to comply with the thought of ”Zhong He Four Letters”. The kind of saying doesn't mention ways of real practice and ignores that the above guoted sentence should be regarded as a common pursuit to a stable state of mind for Confucian followers. Besides, they neglect that there are many words in ”Da He-Shu-Jing” in memory of their deceased teacher Li-Yan-Ping. This emotion contradicts ”Zhong He Four Letters”. Since it is proven that ”Da He-Shu-Jing” was written in 1166, it is then proven that ”Zhong He Four Letters” was not written in 1166. As a result, we can follow Qian-Mu's textual research that ”Zhong He Four Letters” was written in 1168.