Kurt Wischin

Structural irrationality, also known as incoherence, consists in the obtaining or failure to obtain of certain relations among the propositional contents of a subject’s attitudes. For instance, it is structurally irrational to believe in a proposition P and also believe its negation not-P. The content of one belief must not be the negation of the other’s content. But there are two different kinds of content: referential and Fregean. Which of them is the notion of content at issue in structural irrationality? The question is of some importance, for if the answer is “referential content,” it will turn out that many people are incoherent who seem not to be—for instance, people in Frege cases who attribute contradictory properties to the same object, represented under different modes of presentation. Prevailing internalist intuitions about rationality favor the Fregean answer, but is there an argument in defense of this line? In this paper, I argue that such arguments are hard to come by. I examine the two most promising arguments and show that both lead the Fregean to a dilemma: Either they must acknowledge that the argument is inconclusive, or they must embrace the unappealing view that structural irrationality is impossible.