At times confusing, at times insightful, this exploration of the French Revolution relies heavily on Freudian concepts of psychoanalysis and Hegelian concepts of "historical stages" to explain how the Revolution went wrong. Historian Sagan (At the Dawn of Tyranny) conceives of three separate French Revolutions. The first, in 1789, established a constitutional monarchy similar to England's. The second, in 1792, saw King Louis XVI beheaded and introduced a republican form of government. The third, in 1793, involved the violent elimination of the Girondin faction and the beginning of the Jacobin dictatorship. Sagan seeks to explain how what started in the name Enlightenment ideals like liberty and equality ended in "ideological terror" and Napoleonic dictatorship, offering both cultural and psychological reasons for the Revolution's failure. France was unable to develop the concept of "loyal opposition" essential to viable democracy. In an increasingly paranoid political climate, political differences were seen as betrayals. Demands for ideological consensus led to constant governmental instability, and allowed for rampant guillotine use. Napoleon's "conservative dictatorship was finally resorted to in the search for some form of social stability," says Sagan. His exhaustive psychoanalysis of the Revolution and its leaders (especially Robespierre) provides remarkable insights into a warped, bloodthirsty political culture. At times, though, his argument reads like a textbook in psychology, as in his chapter on the "borderline conditions... operating in the pathological places of French culture." General readers will struggle, as Sagan assumes his audience has some grounding in French history and Freudian theory. His thought-provoking though often frustrating account is recommended for serious students of the French Revolution. (Dec.)