Ordre Nouveau’s “neither right nor left” movement, based on personalism and revolutionary federalism, helped shape modern Catholic political culture in France, the National Revolution instituted by the Vichy regime, the post-war European movement, and the contemporary European New Right. It influenced European youth exchanges, veterans’ organizations, trade unions, religious groups, artists, and architects, even the executive of the French national railway system. In The Communitarian Third Way John Hellman introduces us to the non-conformist Alexandre Marc, a Russian Jew who became a Christian convert and full-time professional revolutionary. rnrnMarc helped Le Corbusier launch Plans, imported the existential philosophy of Husserl and Heidegger to France, helped Mounier start Esprit, and was an important force in revitalizing traditional French Catholic political culture. Hellman uses interviews, unpublished correspondence, and diaries to situate Marc and the Ordre Nouveau group in the context of the French, German, and Belgian political culture of that time and explains the degree to which the ON group succeeded in institutionalizing their new order under Pétain. Hellman also examines their post-war legacy, represented by Alain de Benoist and the contemporary European New Right, shedding new light on the linkages between early national socialism and the political culture of Charles de Gaulle, François Mitterrand, and pioneers of the post World War II European movement.