In this chapter, the Carneades Argumentation System is used to model an example of the progress of scientific inquiry starting from a discovery phase. This new procedural bounded rationality model of scientific inquiry is used to show how a hypothesis can justifiably be accepted based on a process of marshaling and testing of evidence pro and contra, once it has been supported strongly enough by this evidential procedure to meet a standard of proof appropriate for the inquiry. Both discovery of a hypothesis and its later proof is seen as part of an orderly rule-governed procedure, modeled by a formal dialectical structure in which evidence is collected, tested and measured against standards of proof, then used to draw a justified conclusion. This context of argumentation was called the inquiry dialogue in Chapter 1.

The model supports an approach to scientific inquiry that could be classified as pragmatic, in that it varies with the standards of proof appropriate for kinds of inquiry in a field of knowledge and with criteria for it to be considered to be evidence. It is based on the theories of inquiry of Peirce (1931; 1984) and Popper (1963; 1972). According to the Carneades model of inquiry (Gordon, Prakken and Walton, 2007; Gordon, 2010), a group of interacting agents is collecting evidence as part of a search for the truth of a matter that they are collaboratively investigating. As they go along during the search process, they verify or falsify hypotheses by testing them using the data they have collected so far, at the same time as they are engaged in the process of collecting new data. As the search for knowledge continues, some hypotheses become better supported by the evidence, but at the same time, some of the hypotheses previously accepted have to be given up, because they are falsified by the new data that are streaming in.