Perhaps he both believes it and understands it. The subject is not, after all, so complex as is usually thought. Or, conversely, perhaps he believes it in the sense of professing “Yes, QM is true”, but does not have any strong beliefs in the sense of anticipation-constrainers.
Did he believe in quantum mechanics?
He is still alive.
But is he suffering?
Perhaps he both believes it and understands it. The subject is not, after all, so complex as is usually thought. Or, conversely, perhaps he believes it in the sense of professing “Yes, QM is true”, but does not have any strong beliefs in the sense of anticipation-constrainers.