The idea that societies unify both physical matter (human beings, plants, businesses… etc.) and energy flows within their natural environment.
For example; that interconnectedness between the smell of orange blossoms, the smile on your face and your willingness to plant another tree and spread that happiness and welcome more pollinators into your yard – a yard shared with nature because without nature you would not even exist.
As he wrote in the Economic and Philosophic Manuscripts: “Nature is man’s [sic] inorganic body that is to say, nature insofar as it is not the human body. Man lives from nature ie, nature is his body and he must maintain a continuing dialogue with it if he is not to die.”
For Foster (1999), Marx’s comments on social metabolism