Resumo

ALESSIO, Claudio Andrés. Reinstatement, defeat and defuse: a discussion about arguments acceptability. Cuad. Fac. Humanid. Cienc. Soc., Univ. Nac. Jujuy [online]. 2016, n.50, pp.213-231. ISSN 1668-8104.

Reinstatement is a principle in Argumentation Systems according to which defeated arguments should be regarded as justified if the arguments defeating them are themselves defeated. The kind of defeat involved in the process is irrelevant. All defeats are equivalent to any other. In the paper, this idea is questioned and motivates the following question: ¿How reinstatement should be re-defined? We answer the question following a usual method in the field: first, we show some well-behaved example with respect to standard reinstatement and others examples suggest that reinstatement cannot be taken as a general principle. Second, we compare both kinds of examples and identify similarities and differences into the examples. Later, we analyze possible causes of such differences and propose a way of interpreter this situation. As a result we have that in the well-behaved examples there is special kind of defeat that is not present in the others. This defeat can be characterized like this: the acceptation of the defeater argument leads to accept that defeated argument is based on false, improbable, or incorrect support. This special kind of defeat is named defuse in the paper. So, the new meaning of reinstatement proposed here is: an argument can be justified if all defeaters are in turn defused by a justified argument

Palavras-chave : Default Reasoning; Defeasible Argumentation; Reinstatement.