DYCODE – Franz Dietrich: "Beyond Belief: Logic in multiple attitudes" (joint work with A. Staras and R. Sugden)
January 28, 2020, 16-18 ct
S 106 (FAN)
Logical models of the mind focus on our beliefs, and how we reason in beliefs. But we also have desires, intentions, preferences, and other attitudes, and arguably we reason in them, particularly to make decisions. Taking a step towards logic in multiple attitudes, we generalize three classic logical desiderata on our beliefs towards multiple attitudes: consistency, completeness, and closedness under implication. These three `logical' desiderata on our attitudes stand in interesting contrast with standard `rationality requirements' on attitudes, such as the requirement of having transitive preferences, non-contradictory beliefs, non-acratic intentions, intentions consistent with preferences, and so on. However,
there is a systematical correspondence between logical desiderata and rationality requirements: each logical desideratum (consistency, completeness, or closednes) is equivalent to a class of rationality requirements, as shown in a theorem. Loosely speaking, this correspondence connects logic to rational choice theory. This has important implications for whether reasoning in multiple attitudes can help us become consistent, complete, or implication-closed in our attitudes.