On the side of Niels Bohr, not to mention a few other physicists, there is an honest acknowledgment of a difficulty in understanding Einstein's objection to the “completeness” of the Ψ-function description of the quantum phenomenon. Yet the weight which Bohr himself attaches to Einstein's insistence may indicate that if the latter's difficulty could be understood, then, through the cooperation of understanding physicists, another great accomplishment of unification might be obtained which would be as fruitful for the future as either or both the general theory of relativity and Bohr's statistical theory have been to the present.