a unity, in which humans can only produce something by combining the organic and inorganic body: “Nature is man’s inorganic body—nature, that is, insofar as it is not itself human body.… Nature is his body, with which he must remain in continuous interchange if he is not to die. That man’s physical and spiritual life is linked to nature means simply that nature is linked to itself, for man is a part of nature.”5 Thus humans cannot transcend nature; they realize a unity with it, mediated by labor.
This mediating activity of labor is a unique human activity, and it is through this labor that humans differentiate themselves from other animals, in that humans through labor can “purposefully” and “freely” produce in and with nature and transform their environment in accordance with their will. In contrast to the instinctive activity of animals, which is limited by a given environment and by their unreflected physical needs, humans are able to go beyond this and teleologically modify the sensuous world. The young Marx argued that the act of objectification through human labor cannot be reduced to a mere process of satisfying unmediated physical needs, which is only the case with modern alienated labor. He claimed that the universal freedom particular to humans becomes manifest as a historical process of the humanization of nature and the naturalization of humanity.
However, the interactive relationship between humans and nature undergoes a significant transformation due to the dissolution of their original unity. As a result, unity transforms itself into the opposite of what it should be, that is, a loss of freedom, dehumanization, and enslavement to the product of one’s own labor. “In estranging nature from man,” it is no longer possible to produce anything without the inorganic body. Thus the first and fundamental alienation in modern society is not arbitrarily defined by Marx as alienation from nature. It is the separation from the objective conditions of production that brings about the decisive change in the way humans relate to the earth. Marx dealt with various negative effects on workers as a consequence of their alienation from nature, such as serious impoverishment and the loss of meaning in life. Despite this original insight, his early analysis in the Paris Notebooks did not contain any noteworthy ecological critique of capitalism. Marx in the following years began to gradually close this theoretical blind spot.
Marx in his later economic works still maintained this insight of 1844, even as his research on political economy and other disciplines greatly deepened and developed it. In the Grundrisse Marx points to the same “separation” of the producers from nature as a decisive step toward the emergence of modern bourgeois society, but in the paragraph below, Marx illustrates the same phenomena with a physiological concept and no longer with Feuerbach’s terminology. Marx now defines the “separation” as cutting off the natural objective conditions for humans’ “metabolic interaction with nature”:
It is not the unity of living and active humanity with the natural, inorganic conditions of their metabolic interaction with nature, and hence their appropriation of nature, which requires explanation or is the result of a historic process, but rather the separation between these inorganic conditions of human existence and this active existence, a separation which is completely posited only in the relation of wage labor and capital.6
It is true that Marx continues to regard the central characteristics of capitalist production as the disruption of the incessant interaction between humans and nature after the labor process is subsumed under capital. Yet it is noteworthy that Marx now characterizes the “separation between these inorganic conditions of human existence and this active existence” as the obstruction of humans’ access to their “natural, inorganic conditions of their metabolic interaction with nature.” Of course, the “metabolic interaction” does not get completely interrupted insofar as humans still need to interact with nature in order to live. The interactive process of material exchange between humans and nature in the labor process nonetheless takes a fully different shape from that of precapitalist society in that it can take place only on the basis of the radical separation posited “in the relation of labor and capital.” This specifically modern “separation”—which completely destroys the “original unity”—and its historical consequences in capitalist society are exactly what Marx regards as necessary for a scientific discipline of political economy to explain.
During the preparation of Capital, Marx intensively investigated this problem. He no longer propagated the realization of the philosophical idea of “humanism = naturalism” and instead tended more and more to describe the central task of the future society as the conscious regulation of this physiological metabolic exchange between humans and nature by the associated producers. This conceptual change is remarkable.
In this context, Michael Quante argues for the continuity of Marx’s philosophical conception of the relationship between humans and nature “even if Marx no longer describes it with anthropological and philosophical categories but with the natural scientific category of ‘metabolism.’”7 But then he criticizes both Marx’s “ambivalences” between philosophy and natural science and an “anti-philosophical trait” in Capital that is the result of this conceptual shift.8 However, Quante refrains from going into the new dimensions of Marx’s natural sciences in detail. Evidently his critique of Marx is grounded in his own interpretation, in which he hopes to rediscover the basic philosophical motives in the later economic works. The transition from a “philosophical” terminology to a “natural scientific” one is not a simple change of Marx’s personal preference, but reflects the development of his “materialist method” in The German Ideology as a guideline for understanding the historical transformations of the metabolism between humans and nature. In this sense, even if there is an “anti-philosophical trait” there are no “ambivalences” in his later works.
In contrast to the earlier philosophical scheme that simply imposes a utopian ideal on the estranged reality, Marx learned to analyze the concrete process between humans and nature, which is, on the one hand, transhistorical as an “eternal necessity,” but is, on the other hand, thoroughly socially mediated, given that the economic function of labor differs considerably in each mode of production. In The German Ideology, Marx became fully aware that the metabolic interaction takes place within a tight entanglement of both historical and transhistorical aspects. Marx carefully analyzed this dynamic social process in nature in order to comprehend the material conditions for transcending the “separation” in the metabolic interaction between humans and nature.
Marx’s research in the following years became more and more characterized by this unique duality. He studied political economy as an analysis of the social forms of economic categories, and simultaneously studied the natural sciences to achieve a scientific basis with regard to material qualities in the physical sphere. As emphasized in the following section, Marx’s ecology deals with the synthesis of the historical and transhistorical aspects of social metabolism in explaining how the physical and material dimensions of the “universal metabolism of nature” and the “metabolism between humans and nature” are modified and eventually disrupted by the valorization of capital. Marx’s analysis aims at revealing the limits of the appropriation of nature through its subsumption by capital.
This enormous project nonetheless cost Marx time and energy, so much so that he was not able to finish his magnum opus. Nonetheless, this does not mean that the project was a failure because Marx succeeded in elucidating his theory of metabolism in Capital and various economic manuscripts. Furthermore, there are a number of hints for his further theoretical development in his excerpt notebooks that are of great importance. Before analyzing these notebooks, it is helpful first to trace his own description of “metabolism” in the context of its usage in natural scientific and political economy.
ON THE GENEALOGY OF METABOLISM
The concept of “metabolism” was first employed in physiology at the beginning of the nineteenth century, even though it is often claimed that Liebig’s “book on Organic Chemistry in Its Application to Physiology and Pathology (1842) was the first
