True Belief and Mere Belief About a Proposition and the Classification of Epistemic-Doxastic Situations

Andreas Herzig (1, 2) , Elise Perrotin (1)

1 IRIT-LILaC - Logique, Interaction, Langue et Calcul
2 CNRS - Centre National de la Recherche Scientifique

Starting from standard logics of knowledge and belief with principles such as introspection of beliefs and 'knowledge implies belief', we study two non-normal modalities of belief: true belief about a proposition and what we call mere belief about a proposition. We show that these modalities suffice to define all possible epistemic-doxastic situations in a combinatorial manner. Furthermore, we show that two consecutive modalities that are indexed by the same agent can be reduced for two of the three logics of knowledge and belief that we consider.

Mots clés: epistemic logic; doxastic logic; doxastic situations

Domaines: Intelligence artificielle [cs.AI]; Complexité [cs.CC]; Logique [math.LO]; Philosophie

Andreas Herzig, Elise Perrotin. True Belief and Mere Belief About a Proposition and the Classification of Epistemic-Doxastic Situations. Filosofiska Notiser, 2021, Årgång 8 (1- Special issue on modal logic), pp.103-117. ⟨hal-03011708⟩