BLOODS: AN ORAL HISTORY OF THE VIETNAM WAR BY BLACK VETERANS by Wallace Terry; Random House; 311 pages; $17.95
There was a time when historians laboriously gathered and sifted evidence before beginning to write. The invention of the tape recorder offered a short cut. By pointing a microphone at enough people and asking them to reminisce about something, would-be chroniclers could now simply market their research. Hence oral histories, an important-sounding term for a form with some serious drawbacks. These include impressionism (not what happened but how it felt) and the notorious unreliabilities...