This study describes a discourse approach to explanation aware knowledge representation. It presents a reasoning model that adheres to argumentation as found in written discourse, intended for use in intelligent human-computer collaboration and inter-agent deliberation. The approach integrates the Toulmin model with Rhetorical Structure Theory and Perelman and Olbrechts-Tyteca’s (1958) strategic forms of argumentative processes to define a set of constraints for governing argumentative interactions and formulating explanations in an ontologically normalized manner. Arguments, when satisfied, are instantiated into a dynamic rhetorical network that represents the system’s model of the situation. Two modalities of instantiation are proposed. Inferential instantiation is used when a claim may be inferred from a ground, and synthetic instantiation is used for descriptive argumentation where both ground and claim must be satisfied for the argument to be instantiated. The instantiation process maps arguments into the network using interaction links. Defined interactions include accrual, concomitance, backing, substantiation, dissociation, rebuttal, undercut, and confusion. It is envisioned that communities of agents endowed with reasoning capabilities would engage in collaborative explanatory argumentation, using these interactions as mechanisms for detecting and managing conflict and agreement.