Teachers' decisions about pedagogy are informed by a range of educational discourses. These discourses constitute particular kinds of teaching practices and teacher-student relationships in ways that are not immediately obvious. When a particular pedagogy becomes accepted as best practice and it produces desired learning outcomes for the majority of students, it becomes harder to interrogate the underlying assumptions that support it. Even more difficult might be to consider how the practice might disadvantage some students. This article demonstrates the use of a discursive approach to thinking about pedagogy that draws on Foucault's ideas about critique. An analysis of two teachers' rationalisation of their practice is offered in order to demonstrate how dominant educational discourses can close down access to thinking about practice outside those discourses in the moments of everyday decision-making. It is claimed that momentarily disturbing taken for granted practices, in the manner Foucault (1981) suggested, can help teachers to consider more broadly the implications of their chosen pedagogy on the development of students' key competencies.