I came to the writing of history at the age of fifty, having been throughout all the earlier part of my mature life a participant in the unrolling of official events rather than the chronicler of them. I am afraid that I took up the historian's task somewhat casually, never doubting that it would be easier to tell about diplomacy than to conduct it -- and not nearly so great a responsibility. But as this work gradually wrought its discipline upon me, I was both surprised and sobered to realize not only how difficult but also how important it was.

The fact is that there is no means, other than the cultivation and dissemination of historical knowledge, but which a society can measure its own performance and correct its own mistakes. There is no other means by which it can establish criteria for judging, empirically, what is wisdom and what is foolishness, what is promising and what is unlikely to yield good result, in the conduct of its affairs. If we plod along with only the feeble lantern of our vision of contemporary events, unaided by history, we see-to be sure -- a little of the path just under our feet; but the shadows are grotesque and misleading, the darkness closes in again behind us as we move along, and one can not be sure of direction or of pace or of the trueness of motion. It is only when we flash back into the past the beam of light of historical scholarship that we can establish the relationship between effort and result and give to our own habits and tendencies the corrective they must always be given if, as Shakespeare once put it, we are to "dress ourselves fairly to our end." In a democracy, particularly, where wide consensus unavoidably overrides the insight and instincts of the individual as the major source of guidance for statesmanship, the importance of this factor -- of the conscientious review of past actions and the rendering accessible to the broader public of the results of that review -- simply cannot be overrated.