Argument

This chapter discusses how formal models of argumentation can clarify philosophical problems and issues. Some of these arise in the field of epistemology, where it has been argued that the principles by which knowledge can be acquired are defeasible. Other problems and issues originate from the fields of informal logic and argumentation theory, where it has been argued that outside mathematics the standards for the validity of arguments are context-dependent and procedural, and that what matters is not the syntactic form but the persuasive force of an argument.

Formal models of argumentation are of two kinds. Argumentation logics formalise the idea that an argument only warrants its conclusion if it can be defended against counterarguments. Dialogue systems for argumentation regulate how dialogue participants can resolve a conflict of opinion. This chapter discusses how argumentation logics can define non-deductive consequence notions and how their embedding in dialogue systems for argumentation can account for the context-dependent and procedural nature of argument evaluation and for the dependence of an argument's persuasive force on the audience in an argumentation dialogue.