This book provides a clear, concise and readable introduction to complexity thinking, its application to the social sciences and public policy, and the relevance of some of its various tools to those fields of politics, health, the international realm, development, planning and terrorism. The authors argue that the foundation for many of the current crises in these areas can be traced to the attempt by social scientists and policy-makers to treat these systems and processes as fundamentally orderly, predictable and controllable. By providing an overview of complex systems, a practical introduction to basic concepts and tools of these systems, and examples for understanding and managing them in real life policy situations they provide an exciting new perspective for rethinking our basic approaches to the social sciences and for understanding and managing the increasingly interdependent world of public policy. The book is vital reading for students and scholars of the social sciences and public policy, and also policymakers and the policy actor audience.