Mou Zongsan's philosophical Confucianism adopts the originally Buddhist figure of a perfect teaching (yuanjiao 圓教). This essay investigates Mou's adoption of this concept, showing why Mou thinks it provides a possibility to conceive the essential meaning of moral practice. The rhetoric of the perfect teaching is assumed to warrant its irrefutability and hence underlines, by its very form, the incommunicability of the content of Mou's philosophy allegedly disclosed to the moral subject in an intimate experience of "intellectual intuition." Although Mou's blending of Confucianism, Buddhism, and Kantianism becomes traceable, the application of the schema of the perfect teaching on Kantianism in Mou's intended sense remains problematic. The essay closes with a comparison of Mou's philosophical reconstruction of Confucianism with Hegel's justification of Christian faith and an outlook sketching the author's view of how to make good sense of Mou's philosophy.