This paper concerns the character of argumentation in inner dialogue, i.e. dialogue that an individual keeps to herself in her own mind. The problem of inner dialogue research is the methodological difficulty connected with its externalization. In the text, the activity of crisis diary-writing is suggested as a way of naturally externalizing inner decision-making. By adopting a pragma-dialectic approach to argumentation, the text attempts to characterize crisis diary-writing as an argumentative activity type. The argumentative characterization of crisis diary-writing involves identifying (...) the institutional point and implemented genre as well as distinguishing the empirical counterparts of the four stages of critical discussion. For illustration, the paper draws its examples from Anne Frank’s Diary. As a result of the characterization achieved in the paper, it is concluded that crisis diary-writing is a conventionalized deliberative activity type preconditioned by implicit norms governing the conduct of argumentation. (shrink)