In the Critique of Gotha Programme, Karl Marx famously argues that a communist society will be characterised by the principle, ‘From each according to his abilities, to each according to his needs!’ I take up a question about this principle that was originally posed by G.A. Cohen, namely: what makes communism (so conceived) possible for Marx? In reply to this question, Cohen interprets Marx as saying that communism is possible because of limitless abundance, a view that Cohen takes to be (...) implausible for ecological reasons. I develop a new interpretation of Marx's position. On this interpretation, people in communist society achieve self-realisation through providing others with the goods and services required for their self-realisation. Coupled with a reasonably high (but not immense) development of productive power, self-realisation generates conditions in which people can produce according to their abilities and receive according to their needs. I defend this view as an interpretation of Marx and I argue that it represents a more plausible account of what makes communism possible than Cohen's interpretation in which technological advance and limitless abundance play the predominant role. (shrink)