Legitimation Inferences: An Additional Component for the Toulmin Model

This paper argues that the choice of backing to certify the authority of a warrant requires a legitimation inference. When brought into question, such an inference becomes a claim defended by showing sound reasons for the selection of backing pertinent to a shared context. Legitimation controversies ensue when an attributed consensus meets objection. It is argued that attention to legitimation controversies renders the Toulmin model a more useful critical paradigm for investigating the development and risks of communicative reasoning in a public forum. The nomination of John Tower as Secretary of Defense is employed to illustrate how critical analysis of legitimation controversies reflexively expands the domain of inquiry for informal reasoning