Today’s optimists are convinced that free markets provide by far the most powerful tool at our disposal in terms of fashioning a sustainable economy. Today’s pessimists see free markets (as they operate today) as deeply implicated in everything that is unsustainable about today’s economy. But the free market (which often isn’t free at all) is just one of the deﬁning features of capitalist economies: we must also take into account the pursuit of proﬁt, trade, competitiveness, private property and so on. This chapter takes a whirlwind tour through some of these fundamental characteristics of capitalism to assess whether there is any kind of unavoidable incompatibility in terms of achieving a sustainable society, or whether it is more a question of taming and modifying this particular manifestation of capitalism – variously described by people as ‘brute capitalism’, ‘killer capitalism’, ‘crony capitalism’, ‘neo-liberal capitalism’ and so on. No easy answers emerge; but this chapter presents enough of a feel for some kind of theoretical compatibility to warrant further investigation in Parts II and III.