‘The essential difference between the various economic forms of society, between, for instance, a society based on slave-labour, and one based on wage-labour, lies only in the mode in which this surplus-labour is in each case extracted from the actual producer, the labourer.’ —Marx

Our global ecological crisis has created an increasing interest in Marx’s theory of metabolic rift as a crucial aspect of capitalism (Foster 2013). To appreciate fully how capitalism creates this rift, it is important to examine the human metabolic relation with nature in general and theoretical terms.