In Chapter 2 it was shown how there are different frameworks of communication in which arguments can be put forward and critically questioned, including persuasion dialogue, information-seeking dialogue, and deliberation dialogue. This chapter will focus almost exclusively on deliberation dialogue, but will also deal with related issues where there is a shift to or from one of these other types of dialogue to deliberation dialogue. It will be shown how practical reasoning is woven through every aspect of deliberation dialogue, and how deliberation dialogue represents the necessary framework for analyzing and evaluating typical instances of practical reasoning in natural language cases of argumentation that we are all familiar with. This chapter will also show how formal models of deliberation dialogue built as artificial intelligence tools for multi-agent systems turn out to be extremely useful for solving the closure problem of practical reasoning in multi-agent settings.

The chapter begins by using four examples to show how practical reasoning is embedded in everyday deliberations of a kind all of us are familiar with. The first one, in Section 1, is a case of a man trying to solve the problem with his printer by looking on Google to get advice and then using a trial and error procedure to try to fix the problem. The second one, in Section 2, is an example of a couple trying to arrive at a decision on which home to buy, having narrowed the choices down to three candidates: a condominium, a two-story house, and a bungalow. The third one, in Section 3, is a case of a policy debate, showing how CAS employs practical reasoning in this setting. The fourth (Section 4), is a town hall meeting on a decision of whether or not to bring in no-fault insurance. Section 5 explains the essentials of the leading model of deliberation dialogue used in artificial intelligence at this point – the McBurney, Hitchcock, and Parsons (MHP) model.