Against the heightened awareness brought about by the bicentennial of the French Revolution, it is surprising to (re)discover that Duverger chooses to dismiss the Jacobins as a mere parliamentary group. In fact, they became the first mass party. This is the key to an organizational explanation of the course taken by the Revolution. It raises new and compelling doubts about the identification of mass parties with the working class and about the democratic credentials of such parties. It also raises the broader question whether the modernity of political parties is a matter of organization or, rather, of legitimacy.