This book explores how progress has often been limited, but also on occasion assisted, by the role of ideas. It identifies how health issues, such as HIV/AIDS, pandemic influenza and tobacco control, are framed in such a way as to resonate with a set of ideas, or worldviews, associated with particular policy communities. A successful framing can generate possibilities for action, but can also lead to competition when ideas conflict or suggest different pathways of response. Global Health Governance is therefore an arena of competition as well as cooperation, where ideas matter as well as resources and political will. This book was originally published as a special issue of