 Disputation could be pursued for a variety of ends, some extolled by ancient writers, some condemned. Constructively, it could be a means of clarifying and defending the right way (dao). Through it, one could lead others to distinguish shi/fei (this/not-this, right/wrong) correctly and thus obtain knowledge. Of disputation in this sense, Xunzi says that “the gentleman must engage in disputation” and The Annals of Lü Buwei remarks that in the course of study, one must occasionally engage in “disputation and persuasion” (bian shuo) in order to expound the Way  (dao).[4]  This would also be the sense in which  Mencius  explains that he has no choice but to engage in disputation, since as a follower of the sages he must attempt to rectify people’s hearts and refute the pernicious sayings of Yang Zhu and  Mo Di  (Mencius,  3B:9).[5]