The paper analyses the epistemic modal words and expressions of doubt and shared knowledge in linguistic research articles. The restrictive features of the academic argumentation contribute to and connect with the author’s orientation focusing on the expectations and the possible responses of the disciplinary community. The authors evaluate the degree of the credibility of their assertions and modify it by means of epistemic components according to its appropriateness in argumentation contexts and in relation to the general discourse norms of professional interaction continually. From ethic and professional points of view, it is crucial to control the illocutionary force of critical comments especially when they relate to the judgments of the colleagues to be belonged to the same disciplinary community or to the well-known knowledge. Moreover, the important pragmatic aim of academic argumentation is not confrontation, but the way to accept a compromise and to achieve the possible compatibility of the different positions. Since the semantic potential of epistemic units of doubt mitigates the illocutionary force of critical comments and the components of shared knowledge construct the positive underground of the cooperative engagement with the disciplinary community. Then the modal epistemic components are treated as markers of the intersubjective relations between the authors and their target audience. They open a discourse dimension of the hedged polite argumentation and allow the authors to articulate their personal stance against the background of restrained disagreement, additional restrictions and reservations, circumstances, criteria, characteristics etc. They make it possible to downplay the conflict between previous and novel knowledge structures fixated in texts. The paper draws attention of the linguists who are interested in the issues of the science language to the necessity to take into account the discourse dimension of academic writings.