I will analyse some properties of abduction that are essential from a logical standpoint. When dealing with the so-called ‘inferential problem’, I will opt for the more general concepts of input and output instead of those of premisses and conclusions, and show that in this framework two consequences can be derived that help clarify basic logical aspects of abductive reasoning: (i) it is more natural to accept the ‘multimodal’ and ‘context-dependent’ character of the inferences involved, (ii) inferences are not merely (...) conceived of in the terms of the process leading to the ‘generation of an output’ or to the proof of it, as in the traditional and standard view of deductive proofs, but rather, from this perspective abductive inferences can be seen as related to logical processes in which input and output fail to hold each other in an expected relation, with the solution involving the modification of inputs, not that of outputs. I will also describe that if we wish to naturalize the logic of the abductive processes and its special consequence relation, we should refer to the following main aspects: ‘optimization of situatedness’, ‘maximization of changeability’ of both input and output, and high ‘information-sensitiveness’. (shrink)

Henrike Jansen’s “The strategic formulation of abductive arguments in everyday reasoning” insightfully explores the terrain of abductive argumentation. The purpose of this note is to continue the exploration along lines marked out by her paper. This further exploration proceeds in two stages. Section 2 of the paper addresses the nature of abductive inference by distinguishing two types of abduction, identifying some of abduction’s formal and nonformal properties, and relating abduction to enthymematic inference. Section 3 focuses on some of Jansen’s examples, (...) paying particular attention to the distinction between abduction and argument from sign. Whereas Jansen maintains that some arguments from sign are not abductive, the paper suggests an alternative perspective from which arguments from sign can generally be viewed as one sort of abductive inference. (shrink)