Political parties are object of various academic disciplines. This volume takes stock of current party-related debates in political and legal science, in constitutional theory as well es in sociology and organisational theory. The volume includes contributions on the scientific history of party-related research in politicial as well as in legal science, on current challanges for party democracies and the consequences of europeanization for party government. Overall the volume provides a summary of an interdisciplinary "science of political parties." The volume is dedicated to the longtime acadaemic director of the Dusseldorf Institute of German and Internation Party Law and Party Research, Martin Morlok.