'Ideas' have for long been treated as separate from 'ordinary politics'. But it is increasingly difficult to explain the contemporary world without reference to beliefs and values, and the ways in which people, by thinking about politics, construct politics from foreign policy to environmental protection, from gender equality to the rule of law. The articles in this volume do not attempt to cover all aspects of the current debate in political science, nor do they reflect any single theory of the relationship between political thinking and political action, or even a common perception of what those two categories are. Some contributors question the usefulness of the dichotomy all together. But all the contributions reflect a growing recognition within political science of the central place of political thinking as a dimension, perhaps the single most important dimension, of the activity of politics for understanding the contemporary world, and all previous worlds as well.