This article argues that building an eco-socialist concept of sustainable development must be based on realistic understandings of natural processes and meaningful axiology. First, it focuses on the conflict between Malthus and Marx, which foreshadows modern debates between ecology and socialism. Malthus’s ideas are preferred because in the last instance his principles are logically and ontologically persuasive and empirically relevant. The second part attempts to develop a Marxist perspective on ecological thinking, connecting Marxist economics and thermodynamics using the work of Sergei Podolinsky. This unusual perspective leads to the general conclusion that the ultimate goal of human production is the most effective resistance to the second law of thermodynamics. From these considerations the article derives a norm (value) which states that such resistance should be the supreme goal of advanced civilization. Because life in general is the best counter-entropic barrier, it follows that humanity should strive to expand and develop life. The Marxist critiques of capitalism and of the history of class societies in general are based on the broad notion of “alienation”, which is understood by Marx himself as the opposite of “real life.” Therefore, alienation can be understood as a form of entropy. The biological term “compartmentation” is then used to compare the architecture of biological entities and social systems. Effective compartmentation prevents entropy. Therefore, the study of compartmentation in social entities (capitalism) may indicate where alienation might be structurally incorporated. The article argues that the problem in the last instance is the spatio-temporal scaling of social entities and that all eco-social problems ultimately lie in imperfect interconnection, spatio-temporal and energy scaling or continuity between social entities and between natural and social entities. The conclusion is that we need a completely different metabolic system that mediates the interaction of society and nature.