To any observer the French party system is bewildering. On the one hand, he sees that ten parliamentary groups are officially established in the National Assembly (not including the Overseas Independents); and, at the same time, he notes that only five of them are really organized throughout the country, and so entitled to be considered “parties” in the true sense of the word: the RPF, the Radicals, the MRP, the Socialists, and the Communists. On the other hand, he observes that the ablest French specialists in electoral sociology—particularly André Siegfried and his disciple, François Goguel—consider that, behind the apparent profusion of political groups, two basic divisions are always found, the continuing opposition of which has supplied for more than a century the essential dynamics of French politics. These two divisions are, of course, the Right and the Left, traditionally called “Order” and “Movement.” Nevertheless, the brief history of the Fourth Republic reveals an attempt to break down these two blocs, and to build a “Third Force” from smaller units. Under various names, such a Third Force has governed France from March, 1947, to March, 1952; and if our hypothetical observer will look back and analyze the political life of the Third Republic, he will find the same tendency there, not so marked and not so strong, but always present.