<p>This paper reconstructs Plekhanov’s theory of the social organism as a systematic extension of Marx’s historical materialism with direct relevance for contemporary ecological Marxism. Although Marx articulated a metabolic understanding of the relationship between society and nature, these insights remained largely programmatic and insufficiently specified at the institutional level. Plekhanov develops this ecological kernel into an organological framework that distinguishes conditions from causes and situates ecological constraints within mediated processes of social reproduction. By conceptualizing productive forces, institutions, and natural conditions as analytically distinct yet reciprocally related, Plekhanov avoids both environmental determinism and voluntarist social constructivism. Through close textual reconstruction and sustained dialogue with contemporary ecological Marxist approaches, including metabolic rift theory, fossil capital analysis, and world-ecology, the paper clarifies both the originality and the limits of Plekhanov’s contribution. It further demonstrates how the organological framework can inform empirical research, methodological pluralism, and socio-ecological policy, illustrated by the case of the Aral Sea. The paper argues that Plekhanov should be read not as a proto-ecological theorist, but as a theorist of mediation whose organological grammar remains conceptually productive for analyzing socio-ecological transformation under conditions of capitalist modernity.</p>