The fact that political ideologies are tangible realities is not a proof of their vitally necessary character. The bubonic plague was an extraordinarily powerful social reality but no one would have regarded it as vitally necessary.
In any case his judgment and set of values acting alone or through his assistants determine not only what is gold and what is dross but the design of the history which he creates out of the metal. The historian decides what is significant and what is not.
