Neurčité situace a logika

The article surveys and evaluates various approaches to the logic of indeterminate situations. Two types of such situations are discussed: future contingents and quantum indeterminacy. Approaches differ according to whether they can salvage (i) classical tautologies (such as the law of excluded middle) as logical truths, (ii) bivalence and (iii) truth-functionality. What I call “the first solution” denies bivalence and either saves classical logical truths (supervaluations) or truth-functionality (multi-valued approach), but not both. The so-called “second solution”, saving all aforementioned features, harbors difficulties for the contingency of future contingents and is inapplicable in the quantum realm. Finally, the third solution saves bivalence but, at least in the case of quantum logic, abandons truth-functionality.