H umans tend to over-commemorate. Almost no historical event is adjudged so minor that some group can’t gather for a parade and speeches. I read recently, for example, of massive festivities marking the 213th anniversary of the Cherasco armistice, which apparently settled certain affairs between Napoleon and the Kingdom of Sardinia. I’ll pass on that one, but this summer and fall bring the 20th anniversary of a series of events very much worth celebrating–because embedded in those events are lessons about an idea liberals still grapple with, in new forms, today.