The central claim of this book is that thinking about ‘dependence’ should be at the core of political theory principally because it helps us to think about issues of economic justice. Unlike political theories that either condemn or celebrate dependence, the book argues that dependence is an inescapable fact of social life, neither good nor bad in itself. The real political issues are about how we as a society organise and judge various forms of dependence. And this is, in fact, what much political debate is about if we dig beneath the surface. On the one hand, we disagree about how we should organise vulnerability; on the other hand, we disagree about who we should condemn as parasitical. Vulnerability and parasitism are thus key concepts for understanding political debate about forms of dependence. Showing the tension between these two sides to the problem of economic dependence is the recurring theme of the book, and its unique feature as a work of political theory. The book aims to show how political argumentation, both in theory and in the public sphere, builds on, builds up, and sometimes attempts to completely reverse, our assumptions about who depends on who in a society, about who is unproductive, and ultimately about who should be labelled an economic parasite. The book contributes to the political theory of capitalist welfare states, and uses the topic of dependence as a means to explore issues of power that are largely overlooked in current philosophical approaches to economic justice.