Human beings struggle to survive, not only physically as “bare life” but as beings with a “wealth of needs”, in search of dignity and who want to be happy. Not in every society, but certainly in societies which are based on the economic exploitation of human labour in many forms, on unequal power relations grounded in the physical coercion and exercise of authority against weaker groups, and on cultural hierarchies which position many people as subaltern, the struggle to survive as a fully human subject is also a struggle against existing social relationships. It is sometimes said that under these circumstances survival is itself a radical act. If this was automatically true, radical movements would be far stronger than they are: in practice, people often struggle to cope at the expense of those closest to them, or at the expense of other subaltern groups; they can enter into all sorts of clientelistic and collaborative relationships. They can direct their aggression not at those who are exploiting, oppressing or stigmatising them but into domestic violence, addictions, fundamentalist religion, racism, misogyny and many other attempts to cope, or to survive, at other people’s expense. It is partly because these forms of (misplaced) struggle to survive are so widespread, and so “obvious” in our kinds of societies, that sustainable activism – not only seeing beyond these, but acting beyond these and doing so consistently – is an impressive and fragile achievement. In this chapter I want to make a smaller claim: that sustainable activism is a radical achievement. To become, and remain, a member of a community or social movement whose struggle actively challenges dominant relations of power, economics and culture (in the sense used in this book) is radical in the sense of durable participation in the attempt to transform these relationships.