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Violation of Leggett-Garg inequalities allows proof of the incompatibilitybetween quantum mechanics and the combined premises (called macrorealism) ofmacroscopic realism (MR) and non-invasive measurability (NIM). Arguments can begiven that the incompatibility arises because MR fails $-$ or else, that NIMfails. In this paper, we consider a strong failure of macrorealism, involvingsuperpositions of coherent states, where the NIM premise is replaced byBell-locality. We follow recent work and propose validity of a subset ofEinstein-Podolsky-Rosen (EPR) and Leggett-Garg premises, referred to as\emph{weak macroscopic realism} (wMR). In finding consistency with wMR, weidentify that the Leggett-Garg inequalities are violated because of failure ofboth MR and NIM, but also that both are valid in a less restrictive sense. WeakMR is distinguished from \emph{deterministic macroscopic realism} (dMR) byrecognizing that a measurement involves a reversible unitary interaction thatestablishes the measurement setting. Weak MR posits a predetermined value forthe measurement outcome, for the system defined at the time after theinteraction, when the measurement setting is experimentally specified. Anextended definition of wMR considers the element of reality defined by EPR fora system A, where one can predict with certainty the outcome of a measurementon A, by measurement on a system B. Weak MR posits that the element of realityexists once the unitary interaction determining the setting at B has occurred.We show compatibility of systems violating Leggett-Garg inequalities with wMR,but point out that dMR is falsifiable. We compare with other MR models, andgive an argument for wMR on the basis that wMR resolves inconsistencies pointedout by Leggett and Garg between failure of macrorealism and assumptionsintrinsic to quantum measurement theory.

Weak versus deterministic macroscopic realism, and Einstein-Podolsky-Rosen's elements of reality