The principal legacy of Duverger?s work on political parties is without question his typology of political parties. However, this was often misunderstood. It is important therefore to understand that this work is not based on the question of the number of party members but on the structure of their relations within the party?s structure. On the other hand, Duverger?s views on the historical necessity for a two-party system have been disproved by the facts. We may therefore conclude, along with Hans Daalder, that from the start, Duverger?s obsession was to put an end to centrism, "that eternal swamp."