In ancient China, the arrival of a new dynasty was accompanied by “the rectification of names,” a ceremony in which the sloppiness and erosion of meaning that had taken place under the previous dynasty were cleared up and language and its subjects correlated again. It was like a debt jubilee, only for meaning rather than money.This was part of what made Barack Obama’s first presidential campaign so electrifying: he seemed like a man who spoke our language and called many if not all thin...