Abstract: The Biographies of Famous Personages of Kunshan (Kunshan Renwu Zhuan) by Ye Junxi, included a letter written by Gu Yanwu to his brother Gu Shu, which was not found in compilations of Gu Yanwu’s writings. In the letter, titled Ji Ziyan Shu, Gu Yanwu asked to adopt Gu Shu’s grandson Shishu as a son to replace Yigu, the only son of Gu Yanwu who had died as a child. The affair was also recorded in the Chronicle of Gu Yanwu. However, as adopting a son to substitute for a deceased child was against the popular understanding of Sangfu Xiaoji of Liji at the time, Gu Yanwu’s adoption was roundly criticized by his peers. Gu Yanwu discussed adopting a son for a dead child in his work Rizhi Lu, and his nephew Xu Qianxue also argued that it was right to adopt a grandson. Gu and Xu’s opinions had such a great impact that many Qing scholars accepted their theory and abandoned the traditional understanding of Sangfu Xiaoji by Zheng Xuan and Kong Yingda. In local legal cases, judges also began to allow adoption of sons to replace deceased children. After 1778, an amendment to the law
allowed the single-heir dual inheritance, which could lead to similar results as adopting a son to replace a dead child or adopting a grandson.