Beyond Belief: Logic In Multiple Attitudes

Franz Dietrich (1, 2, 3) , Antonios Staras (4) , Robert Sugden (5)

1 CNRS - Centre National de la Recherche Scientifique
2 PSE - Paris School of Economics
3 CES - Centre d'économie de la Sorbonne
4 Cardiff University
5 UEA - University of East Anglia [Norwich]

Logical models of the mind focus on beliefs, and how one reasons with beliefs. But we also have desires, intentions, preferences, and other attitudes-and arguably we reason with them, particularly when making decisions. To enable a logical analysis of someone's psychology and decision-making, we generalize three classic logical desiderata on beliefs -- consistency, completeness, and implication-closedness -- towards multiple attitudes. The three resulting 'logical' desiderata on our psychology contrast with the classic notion of 'rationality requirements': requirements of having transitive preferences, non-contradictory beliefs, non-acratic intentions, intentions consistent with preferences, and so on. We prove a theorem that connects the logical desiderata to rationality requirements: each of the three logical desiderata (generalized to multiple attitudes) is equivalent to the satisfaction of a certain class of rationality requirements. This result connects logic with choice theory and psychology, and has implications for whether reasoning can make our attitudes consistent, complete, and closed.

Domaines: Philosophie; Economies et finances; Psychologie

Franz Dietrich, Antonios Staras, Robert Sugden. Beyond Belief: Logic In Multiple Attitudes. 2019. ⟨halshs-03023012v1⟩