# The Labyrinth of Quantum Logic. (arXiv:1802.01834v1 [physics.hist-ph])

Quantum mechanics predicts many surprising phenomena, including the two-slit

interference of electrons. It has often been claimed that these phenomena

cannot be understood in classical terms. But the meaning of "classical" is

often not precisely specified. One might, for example, interpret it as

"classical physics" or "classical logic" or "classical probability theory".

Quantum mechanics also suffers from a conceptual difficulty known as the

measurement problem. Early in his career, Hilary Putnam believed that

modifications of classical logic could both solve the measurement problem and

account for the two-slit phenomena. Over 40 years later he had abandoned

quantum logic in favor of the investigation of various theories--using

classical logic and probability theory--that can accomplish these tasks. The

trajectory from Putnam's earlier views to his later views illustrates the

difficulty trying to solve physical problems with alterations of logic or

mathematics.