The chords of memory may be mystic, as Abraham Lincoln described them, but how accurate and reliable they are as evidence is a dilemma every historian must face. From the time Herodotus walked through Asia Minor two thousand years ago, asking questions, tapping the recollections of hundreds of eyewitnesses, historians have depended on the retentive faculty of the human mind for information about the past, and they have learned that such reliance has its minuses as well as pluses.
I first encountered the negative side of how much to lean on an eyewitness’s memory when I was doing research for the book Decisive Day, about the battle for Bunker Hill.