it begins by leaving the present; by going back into the heretofore, by beginning again.... The historical experience is not one of staying in the present and looking back. Rather it is one of going back into the past and returning to the present with a wider and more intense consciousness of the restrictions of our former outlook. We return with a broader awareness of the alternatives open to us and armed with a sharper perceptiveness with which to make our choices. In this manner it is possible to loosen the clutch of the dead hand of the past and transform it into a living tool for the present and future.
(William Appleman Williams, The Contours of American History, Norton, New York,. 1988, pp.19-20)