The central focus in this article is that how language is used can constitute the basis for power relations. In the first place, power functions through linguistic expressions in relationships of superiority and subordination (commands, reprimands etc.). Secondly, language acts can appear as representations of discourse, i.e. linguistic and cognitive conventions that contribute to squeezing out certain subjects and opinions as being inappropriate. Thirdly, the rhetorical effectiveness of propositions will depend on the linguistic perspectivizing in the propositions. This last-mentioned position can be teased out through rhetorical analysis of language use. The power perspective, however, seems only partly to have been brought into recent rhetorical analysis. In this article, I attempt to analyze how the way language is used can constitute the foundation for power relationships, and I take my point of departure in a case study of a Norwegian school. The focus is placed on communication between management and teachers. The central theoretical challenge is the question of what may be gained by evaluating the relevance of rhetoric as a heuristic in the understanding of communicative power. Further, I argue that rhetoric is relevant to the evaluation of what is a breach of communicative reasonableness. Rhetorical criticism can also be useful in itself for giving authority to the individual teacher. (Contains 5 endnotes and 1 table.)