some value. \[...\] Noting that gzit[e5]{} replaces only under the circumstance that we make no attempt to measure $B$, we are lead to say that the statement, ‘$B$ had some value,’ may be meaningless whenever we make no attempt to measure $B$.”* ]{}

Feynman’s argument sounds convincing but it has a flaw in the assumption of , the conditional independence of $c$ from $a$, given $b$, for all states summed over in . This assumption is inconsistent with quantum mechanics.

Indeed, one of the characteristic features of quantum mechanics is its inseparability, the impossibility of splitting a quantum mechanical system into two that are independent. According to the Copenhagen interpretation ([Bohr]{} [@Boh]), and verified abundantly by experiment, the [*whole*]{} space-time set-up must be specified to determine the correct outcome of an experiment. The contradiction obtained by Feynman in comparing and therefore need not have the consequence that $B$ sometimes has no value, but serves more naturally as [*a strong argument for quantum inseparability*]{}.

The Markov property does typically not even hold for consecutive events; due to the inherent noncommutativities, states “remember” something about their whole history and “anticipate” something about their whole future. To see this, pick $a,b,c$ as observations 