For all the academic ink de- voted to the subject of revolu- tion, history is rarely discon- tinuous, rarely an affair of dramatic leaps or breaks. While rhetoric and the emo-tional environment can shift quickly, the actual workings of a society usually change at about the same rate as the pro- verbial freight train. Just the same, there are occasional turning points in any na- tion's life, when the engine crests a hill or enters a deep curve. The train remains a' train-momentum intact-but thanks...