Putnam and others have argued that an examination of structures arising in quantum mechanics can lead to a non-classical propositional logic, quantum logic. In this paper it is argued that the procedure by which quantum logic is said to be discovered, a process called reading off, is fundamentally flawed. A parody fable shows that reading off leads to absurd consequences. The fable also leads one to cast doubt on the following claims central to the quantum logic program: (i) logic can (...) be reformed locally; (ii) classical logic is read off classical physics; and (iii) reading off is a justifiable process because quantum logic resolves quantum paradoxes. (shrink)

Using formal techniques, Schrodinger's 1935 cat argument is reproduced. Assumptions of the argument are made explicit as axioms and rules of inference; from these a contradiction is derived. The formal statement is then used to elucidate several crucial distinctions, to reject several commonly proposed resolutions, and to sketch an Einsteinian perspective for the argument.

A reformulation of the Kochen and Specker Theorem is used to show how quantum disjunctive facts have presented an insurmountable obstacle to mainstream attempts to motivate quantum logic. The failure of these attempts represents a progressive retrenchment of the program of connecting quantum logic to quantum theory. However, a recent program proposed by Allen Stairs gives those who embrace a realist ontology of quantum "facts" reason to believe quantum logic may yet be read off quantum theory.

To the memory of John D. TrimmerThis paper assesses the impact of disjunctive facts on the quantum logic read off procedure. The purpose of the procedure is to transfer a significant quantum structure to a set of propositions; its first step is an attempt to discover that structure. Here I propose that disjunctive facts as traditionally conceived have blocked the procedure at its first step and have therefore subverted the best-known attempts to read off quantum logic. Recently however Allen Stairs (...) has proposed a view of disjunctive facts which re-establishes the possibility of reading off quantum logic. Both the traditional conception and Stairs’ revision of disjunctive facts are interesting in their own right, independent of quantum propositional logic. Too many things are called ‘quantum logic’. The term is disentangled and notation is fixed in this preliminary step which relies on basic lattice theory. (shrink)