This article reports the results of a one-year longitudinal study examining a teaching intervention designed to enhance students' learning of critical thinking in Hong Kong. Seventy participating students (age 16-18) learned how to make reasoned arguments through a series of collaborative activities, including critical-thinking modelling tasks and group debate. Of particular interest was the role of Chinese traditional values in the students' perceptions of ground rules and the potential influence those rules had on their learning of critical thinking in debate-type discussions. The findings show that Confucian beliefs, such as Li (ritual, "?") and Chi (shame or "face disgrace", "?"), do influence Chinese students' understanding of ground rules. Follow-up analysis revealed positive correlations between the establishment of these rules and students' demonstration of critical-thinking abilities. The results thus refute previous scholars' criticism of the use of ground rules in classroom talk.