The c. 1590 Caigentan (菜根譚, 'Vegetable Roots Discourse') is an eclectic compilation of philosophical aphorisms that combine elements from Confucianism, Daoism, and Chan Buddhism.
The Qing dynasty catalog to the Siku Quanshu summarizes the Xianfo qizong: It covers episodes of about sixty-three Daoists from Laozi to Zhang Sanfeng; comments on immortality; nineteen patriarchs of Indian Buddhism, from Sakyamuni to Prajnatara (c. 457), and forty-two patriarchs of Chan Buddhism, from Bodhidharma (c. 502) to Chuanzi 船子 (ninth century); and mysteries of eternity.Hong is a historically enigmatic figure.
Yu Kongjian was a high-ranking scholar-bureaucrat in Wanli's administration, but he resigned in 1588 after involvement in a controversy, returned to his birthplace in Jintan (Jiangsu Province), and devoted himself to writing and teaching, including lectures at the Donglin Academy.
The fact that he uses the words "vegetable roots" to designate his discourse has its origin in his purifying experience of poverty, and is also based upon a comparison of the cultivation of human morality with that of plants.
"We glean from this work that Hong might have suffered, like his friend Yu Kongjian," say Aitken and Kwok (2006:173), "a disappointing departure from official life joining the increasing ranks of recluses in the towns and lake areas of the lower Yangzi River region."