Finally, we must bear in mind that purely literary evidence as to the existence of certain national traits needs corroboration from many non-literary sources. If it is dangerous to judge modern Japan by the characteristics of a piece of pottery, it is only less misleading to select half a dozen excellent New England writers of fifty years ago as sole witnesses to the qualities of contemporary America. We must broaden the range of evidence. The historians of American literature must ultimately reckon with all those sources of mental and emotional quickening which have yielded to our pioneer people a substitute for purely literary pleasures: they must do justice to the immense mass of letters, diaries, sermons, editorials, speeches, which have served as the grammar and phrase-book of national feeling. A history of our literature must be flexible enough, as I have said elsewhere, to include "the social and economic and geographical background of American life; the zest of the explorer, the humor of the pioneer; the passion of old political battles; the yearning after spiritual truth and social readjustment; the baffled quest of beauty. Such a history must be broad enough for the _Federalist_ and for Webster's oratory, for Beecher's sermons and Greeley's editorials, and the Lincoln-Douglas debates. It must picture the daily existence of our citizens from the beginning; their working ideas, their phrases and shibboleths and all their idols of the forum and the cave. It should portray the misspelled ideals of a profoundly idealistic people who have been usually immersed in material things."