When your level of generalization becomes impossibly high; when history becomes a collection of glittering generalities divorced from incidents, processes, and personalities; when sources become specks on a landscape 20,000 feet below, then you are ready to lecture on all wars, everywhere, at all times and to discern their Greater Historical Meaning. It was all James McPherson's idea. "I can see we've conducted a war of attrition," joked Harvard's Charles Maier, as he watched his fellow association members quietly but steadily get up to leave.