The Treatment of an Historical Source

What does the historian do when he uncovers historical testimony which flies directly in the face of all accepted historical opinion? Specifically, what does he do with a personal letter apparently written by a high-ranking officer during the United States Civil War, stating that he had just come from a meeting at which Generals U. S. Grant & W. T. Sherman & Admiral D. D. Porter openly stated that the administration of President Lincoln must be overthrown? The document was submitted to various external & internal criticisms recommended by practitioners of historical art. Although it passed the tests of external criticism & was in all probability authentic, it was nevertheless of doubtful credibility, due to the unreliable testimony & character of the witness. Was the document worthless to the historian? No, because the context of the letter provided evidence on such diverse subjects as intra- & interservice rivalries, conflicts between professional & amateur servicemen, & the resistance of professionals to new technology & tactics. To overlook such historical possibilities is to chance overlooking the historically new & unusual. Modified AA.