Book excerpt: This work is an introduction to the study of political parties and party systems. It focuses primarily, but not exclusively, on liberal democracies through a comparative approach. The aim of Political Parties and Party Systems is to explain to students of politics how and why parties and party systems differ from one country to another. However, it also seeks to provide a more detailed understanding of party politics in five particular countries. Most of the chapters are divided into two sections. First, general themes and arguments about a topic are introduced, and examples from a large number of countries are discussed in relation to that topic. Then, particular attention is paid to five of the largest liberal democracies--Britain, France, Germany, Japan, and the United States.