Book excerpt: In this rich and broad-ranging volume, Giovanni Sartori outlines what is now recognised to be the most comprehensive and authoritative approach to the classification of party systems. He also offers an extensive review of the concept and rationale of the political party, and develops a sharp critique of various spatial models of party competition. This is political science at its best – combining the intelligent use of theory with sophisticated analytic arguments, and grounding all of this on a substantial cross-national empirical base. Parties and Party Systems is one of the classics of postwar political science, and is now established as the foremost work in its field.