This synthetic tendency was apparent in Wu's later writings and exerted an influence on the development of xinxue [zh] 心學 (the School of the Mind and Heart) in the Ming (1368-1644) and Qing (1644-1912) eras.
He refused local appointments, but in 1309 he served in the Directorate of Education in Dadu (Beijing), leaving in 1312 over differences with those reinstituting the examination system, which had been defunct since the Mongol takeover.
Among Wu Cheng's contributions, there is a famous condemnation of the divination practice as described in the "Great Plan" (Hongfan 洪範) section of the Book of Documents, a classic for which he provided an alternative organization to the orthodox arrangement.
Wu wrote original and critical commentaries on almost all of the classics, and the Dao de jing, but his greatest achievements were philosophical, in discussing the limits on human understanding of ideas like taiji (the Great Ultimate), and in emphasizing the need to crystallize moral truths within oneself (ningdao 凝道).
As a successful and popular teacher, Wu had many students over his long life, and it was as a mentor and inspiration to them that he made his greatest impact as a scholar in the Yuan era.