I am not the first to discover the pitfalls which surround the term ‘revolution’, as if to guard its explosive practical potency from scholarly vivisection. Eight years ago Hannah Arendt devoted more than three hundred pages of her-as usual-magnificent erudition to dissecting the elusive meaning of the term. She established that the term was used for the first time in 1688 to denote “bringing things back” rather than “pushing them forward”; she reminded us that when the duke de la Rochefoucauld-Liancourt, on July 14th, 1789, retorted bluntly: “Non, Sire, c'est une révolution” to the Louis XVI' abashed “C'est une révoke”, he had been inspired by the impressive inevitability of freshly discovered motions of celestial bodies, rather than by modish ideas of les philosophes du progrès All this said and done, Hannach Arendt ends up with one more partisan definition, which is exactly the result one could have expected. A quarter of century before this, Crane Brinton choose the seemingly most reasonable path of comparing four, historically well described, events, which nobody would refuse to call ‘revolutions’—only to show once againthat it is the theoretical assumption which shape the empirical data rather than the other way round. Only two years had elapsed at that time since the Henderson-Livingstone translation introduced the Pareto's concept of ‘equilibrium’ to the American scholarly scene. As it has not yet been turned by Talcott Parsons into a symbol of abstract academic sterility, the concept could have seemed to Brinton the right tool of selecting the ‘revolutionary essence’ from the host of ‘empirical data’ on revolutions.