〈喪服〉「為祖後」析論──兼辨朱熹「寧宗嫡孫承重」說

“Being a Grandfather’s Successor”in“Sangfu”: With a Discussion of Zhu Xi’s Theory of“Ningzong Is His Grandfather’s Successor”

「為祖後」是一種重要的代際傳承方式，由於《儀禮．喪服》關於「為祖後」的記載很少，導致歷來關於「為祖後」的爭論眾說紛紜。全面考察〈喪服〉的「適孫」、「為君之祖父」等條目，以及〈喪服傳〉「父卒，然後為祖後者服斬」和《鄭志》「父卒，為祖後者三年斬」，可知「父卒，然後為祖後者服斬」與「父卒，為祖後者三年斬」等同，「父卒」加「（將）為祖後」是「為祖父服斬」的充分必要條件，祖父與（將）為祖後者之間是一種擬父子關係，並可推定不同爵級和宗法地位人員的為祖後情況。〈喪服傳〉「有適子者無適孫」、「父卒，然後為祖後者服斬」（「父卒，為祖後者三年斬」）、「庶子不得為長子三年」這三處傳文具有嚴密的邏輯統一性，完備地規定了「（將）為祖後」的祖孫三代間的喪服關係，這種精密的服制設計兼具尊尊親親之義。在宋孝宗、光宗、寧宗三人的為後關係上，從鄭玄經學來看，光宗是成君且尚未卒，故寧宗並不是為祖後，而是將為父後；寧宗為孝宗服斬並不是由於為祖後，而是由於「天子、諸侯之喪皆斬衰」，故朱熹的「寧宗嫡孫承重」說難以成立。

“Being a grandfather’s successor”is an important means of intergenerational inheritance. Through a comprehensive examination of items such as“legitimate grandson”and“monarch’s grandfather”in the“Sangfu”chapter of the Yili, as well as the“grandfather’s successor puts on zhancui for his grandfather after father’s death,”it can be clarified that“father is dead”plus“(will) be grandfather’s successor”is a sufficient and necessary condition for“put on zhancui for grandfather.”There is thus a quasi-father-son relationship between the grandfather and his successor. The three propositions that“those who have a legitimate son do not have legitimate grandchildren,”“grandfather’s successor puts on zhancui for his grandfather after father’s death,”and“illegitimate sons cannot put on zhancui for his legitimate son,”have a rigorous logical unity, and this precise clothing protocol contains the principles of zunzun and qinqin. From Zheng Xuan’s perspective, Song Guangzong was already an emperor and was not yet dead, Ningzong was his father’s successor, and Ningzong’s putting on zhancui for Xiaozong was not due to his being Xiaozong’s successor, but due to“putting on zhancui for all of the emperors and feudal lords.”Therefore, it would be difficult for Zhu Xi’s theory of“Ningzong is his grandfather’s successor”to be correct.