History is vast and complex. It is strewn with perplexing ambiguities. To compound matters further-and to flirt with a pompous truism-its legitimate perimeter is no less than the uncharted range of human imagination, of man's quest for understanding and identity. Everyman, in an intensely relevant sense, is indeed his own historian; and in the observation that each human being is himself a historical phenomenon resides support for the judgment that all knowledge-and ignorance-is historical. One who prefers truth to myth and understanding to mystery indicates, however crudely, some appreciation of the historian's task. The historian, however, is expected to oppose crudeness, superficiality, and conscious abuses of historical evidence; wherever veracity can be established, he is charged to prefer it to viscera. Dilettantism in all its forms is regularly isolated as the most baleful impediment to truths.