This paper is a reflexive account of the use of critical social theory within my practice as an action researcher. It is set within the ongoing debates between pragmatist and critical tendencies within action research. The paper discusses how a selective deployment of key constructs from the work of Jurgen Habermas has supported my work as a second-order action researcher. It demonstrates how these constructs can help deal with the practical and theoretical tensions faced when supporting groups of action researchers. It focuses on one of the key issues faced by any external agent trying to work within such groups: how to avoid imposing their own agendas and interpretations. It does this by discussing three foundational points within the process of action research--the nature of practitioners' practical reasoning and the bases of critical self-reflection and collective action. (Contains 1 note.)