Modal logic is not truth

*conditional*, and so it has often been proposed as a non-*classical**logic*. However, modal logic is normally formalized with the principle of the excluded middle, and its relational semantics is bivalent, so this inclusion is disputable. What is the epistemological status of the*laws**of**logic*? What sort of argument is appropriate for criticizing purported principles of logic? In an influential paper entitled "Is Logic Empirical?" Hilary Putnam, building on a suggestion of W. V.