In this article, I contrast two of the main schools of thought within eco-Marxism, namely Metabolic Rift (MR) and World-Ecology (WE). These differ above all else in their accounts of the ontological status of society and nature. The Covid-19 pandemic constitutes a moment of concretisation of this long-standing debate, which is able to dissolve at least in part its issues. The article consists of four parts. I begin with a summary of the two schools of thought and their core stances, (...) before proceeding to unpack their respective theoretical points of contention. I subsequently proceed to explore the conceptualisation of health according to the Marxist scientists Richard Levins and Richard Lewontin through the model of dialectical biology. In the third section, I unpack the conceptualisation of the Covid-19 pandemic by the epidemiologist Robert Wallace, before finally concluding with the contrasts of the two schools in the light of dialectical biology. (shrink)