Marx: "Man lives from nature, i.e. nature is his body, and he must maintain a continuing dialogue with it if he is not to die."
"Estranged labour not only (1) estranges nature from man and (2) estranges man from himself [...] it also estranges man from his species. It turns his species-life into a means for his individual life."
Marx suggests that the thing that distinguishes humanity as a species is their ability to fashion a objective or goal, a "species-objectivity"-- he uses this to distinguish humans from bees or ants, who also produce, but without an object in mind (Morton protests this point, 42)
Marx: "estranged labor therefore tears him away from his species-life, his true species-objectivity, and transforms his advantage over the animals into the disadvantage that his inorganic body, nature, is taken from him"