WHEN MARTIN DIAMOND died prematurely of a sudden heart attack in 1977, he had chosen the title for, but had not otherwise begun to organize and edit, a collection of his previously published essays. William Schambra has now selected and arranged such a collection, guided by Diamond’s title.  Schambra elucidates the meaning of that title in a most helpful and thought-provoking synoptic introduction. We are all in Schambra’s debt for a volume that will remind those of us who learned from Diamond just how much we learned about American politics, while affording a new generation an opportunity to share in the riches.