The emancipatory goal that underpins critical theories of teaching and learning is built on a theory of rational self-determination. In the context of physical education, critical educators believe that through a process of enlightenment teachers can recognize and transform elements of injustice and inequality that exist, albeit unwittingly, in their practice. However, despite the broad appeal of this orientation there are relatively few empirical accounts of how theories of enlightenment manifest themselves in the practice of emancipation. Propelled by the lacuna that clearly exists between critical theory and critical practice, this paper reports on the introduction of critical social discourses to a preservice PE program. It uses a case study methodology to report on two student-teachers' engagement with a range of critical social discourses during a year-long PE unit. The paper discusses some of the ways these students engaged with the theory and practice of a critical orientation for teaching and learning in physical education. Aspects of their experiences are then interpreted through Fay's (1987) critical but postmodern "limits to change" thesis. The paper concludes with tempered optimism about the potential for critical social discourses to guide preservice teachers in practical ways.