RésuméDans cet article, je soutiens qu'Aristote utilise une approche de la logique que l'on retrouve chez les praticiens de la logique informelle d'aujourd’hui. Même si sa position est complexe, Aristote privilégie des interprétations intensionnelles plutôt qu'extensionnelles de sa logique syllogistique. Il n'utilise pas les fonctions de vérité, mais adopte une version de la sémantique qui accentue le rôle du langage naturel qui ouvre, pour ainsi dire, une fenêtre sur la réalité métaphysique. Le mouvement de la logique informelle fut, en grande (...) partie, une initiative canadienne représentée par des auteurs bien connus tels Johnson, Blair, Govier et plusieurs autres. (shrink)

It is usually accepted that deductions are non-informative and monotonic, inductions are informative and nonmonotonic, abductions create hypotheses but are epistemically irrelevant, and both deductions and inductions can’t provide new insights. In this article, I attempt to provide a more cohesive view of the subject with the following hypotheses: (1) the paradigmatic examples of deductions, such as modus ponens and hypothetical syllogism, are not inferential forms, but coherence requirements for inferences; (2) since any reasoner aims to be coherent, any inference (...) must be deductive; (3) a coherent inference is an intuitive process where the premises should be taken as sufficient evidence for the conclusion, which on its turn should be viewed as necessary evidence for the premises in some modal range; (4) inductions, properly understood, are abductions, but there are no abductions beyond the fact that in any inference the conclusion should be regarded as necessary evidence for the premises; (5) monotonicity is not only compatible with the retraction of past inferences given new information, but it is a requirement for it; (6) this explanation of inferences holds true for discovery processes, predictions and trivial inferences. (shrink)