There was a time when parliamentary assemblies reigned sovereign by democratic destiny. The direct election of the chief of state created a new expectation; power would not be shared. But since when, in France, did the "republican tradition" forget the virtues of deliberation? To respond to this question, the author returns to the enigma of the period following the “great” war. Problems were so numerous and so bitter that the carefully restored parliamentary government wouldn't appear artificially adapted. Yet, from Clemenceau to Poincaré, it continued to be believed that a successful parliamentary debate was indeed the moment of truth for democracy accomplished, that deliberation was the best decision making technique, that collective debate more so than the will of one man offered the most just image of power.