Beliefs supported by Arguments

In this paper we explore the relation between an agent’s doxastic attitude and her arguments in support of a given claim. Formally, we build further on Dung’s argumentation framework in Dung (1995). We start by introducing a logic to reason about binary arguments which are either in favor or against a certain claim. Next we explore a number of notions from standard argumentation theory in our system, including the attack of an argument, the acceptability of an argument, the conflict-freeness of a set of arguments and its admissibility. Our setting will allow us to define new concepts, indicating when an argument perfectly defends a given claim P or when an argument only strategically defends a given claim P . The concept of strategic defensibility is then used to link an agent’s arguments to her doxastic attitude. This setting offers a formal characterization of “argument”-based beliefs. As such we address an issue which was raised but not worked out in Dung (1995).