Frege’s Problem: Referential Opacity
Frege’s Problem: Referential Opacity The problem of referential opacity is to explain why a certain inference rule of classical logic sometimes produces invalid-seeming inferences when applied to ascriptions of mental states. The rule concerns substitution of terms for the same object, and here is one of the controversial examples. It involves the mental states of Lois Lane, who believes that Superman can fly. However, she