Shiffman rightly raises questions about who exercises power in global health, suggesting power is a complex concept, and the way it is exercised is often opaque. Power that is not based on financial strength but on knowledge or experience, is difficult to estimate, and yet it may provide the legitimacy to make moral claims on what is, or ought to be, on global health agendas. Twenty years ago power was exercised in a much less complex health environment. The World Health Organization (WHO) was able to exert its authority as world health leader. The landscape today is very different. Financial resources for global health are being competed for by diverse organisations, and power is diffused and somewhat hidden in such a climate, where each organization has to establish and make its own moral claims loudly and publicly. We observe two ways which allow actors to capture moral authority in global health. One, through power based on scientific knowledge and two, through procedures in the policy process, most commonly associated with the notion of broad consultation and participation. We discuss these drawing on one particular framework provided by Bourdieu, who analyses the source of actor power by focusing on different sorts of capital. Different approaches or theories to understanding power will go some way to answering the challenge Shiffman throws to health policy analysts. We need to explore much more fully where power lies in global health, and how it is exercised in order to understand underlying health agendas and claims to legitimacy made by global health actors today.