Family therapists are being encouraged to adopt a postmodern approach to therapy and knowledge. Postmodernism is more than a set of beliefs that therapists can either accept or reject; it is an approach to the construction of truth that eschews many of the forms of argumentation, such as appeals to logic or evidence, characteristic of earlier writing in family therapy. In this paper we present some of the alternative rhetorical strategies used by contemporary family therapy and family therapy texts in the construction of novel truths. These strategies include: writing in the first person; making qualified or conditional assertions; implying rather than stating truths; ‘delegitimizing’ conflicting views; and ignoring disagreement. We discuss the value of these strategies in maintaining the authority of therapists and commentators on therapy in the face of the widespread incredulity towards metanarratives, such as science, that characterize postmodern society.