Over the last two decades or so, several important works have rescued the ecological core of Karl Marx’s work, challenging the idea that Marx ignored ecological questions and putting his ideas back at the heart of a revolutionary critique of capitalism and its destruction of the natural world. But several questions remain: how did Marx come to those ideas, and to what extent did they inform his theory at different stages of his life?

Until the late 1990s, Marx’s work on the interaction between human society and nature had been neglected and misunderstood. Two important works helped change this: Paul Burkett’s Marx and Nature (1999) and John Bellamy Foster’s Marx’s Ecology (2000). Both offered fundamental insights into Marx’s ecological thought, and have helped to encourage a new generation of Marxists to think and write about environmental issues. Kohei Saito’s new book builds on these firm foundations and further develops the work of Burkett, Foster, and others through a detailed examination of Marx’s recently published notebooks. It is an important book whose detailed study of Marx’s work makes clear the long process of his engagement with contemporary science, as part of the development of his own political economy. It was this process that allowed him to develop the ecological core of his thought.

Recently Ian Angus has highlighted the importance that Marx and Engels placed upon engaging with the sciences in developing the basis of their socialist ideas. Angus writes that they

tested their ideas about how the world works and changes through active participation in workers’ movements and through intense study of history, economics, and the natural sciences. They did this not merely to satisfy their intellectual curiosity…but because they knew it was impossible to understand and combat capitalism without a thorough understanding of the material context within which it had developed and could change in the future.1

Understanding Marx’s approach to ecology means seeing the development of his own thought in the context of his materialist method. In this sense, there is no break between the early Marx and his later thinking, but rather a development of his approach and ideas. While this has always been acknowledged in accounts of Marx’s economic writings, it has not been recognized that this is also true of his thinking on the natural world. As Saito puts it: “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.”

Marx argued that this suggested the need for a society whose “central task” was the “conscious regulation of this physiological metabolic exchange between humans and nature by the associated producers.” It is a “conceptual change” that Saito describes as remarkable, but which cannot be separated from the development of Marx’s own political economy.

Saito argues that Marx was not “ecological from the start”; indeed, he points to “naive,” Promethean tendencies in Marx’s early writings, reflecting a belief that never-ending improvements in science and technology—as applied to agriculture, for instance—could overcome the Earth’s natural limits. That Marx held such ideas should not surprise us: as Saito shows, leading scientists of the period thought similarly. An important influence on Marx in this area was the Scottish agriculturist James Anderson, who argued that “the melioration of the soil must ever be proportioned to the means that are used to augment its productiveness…. Under skilful management, the degree of melioration will be proportioned to the labor that is bestowed upon the soil.” This attracted Marx for two reasons. First, the argument supported his view that a rational agriculture was possible, and centered it on human labor. Second, such an argument countered those, like Thomas Malthus and David Ricardo, in whom the decline in soil fertility inspired pessimistic visions of future disaster.

But it was precisely because Marx engaged in detail with the works of such scientists, learned from them, discussed them, and read their critics, that he was able to develop a much more rounded approach. Marx “deepened his own insight that nature cannot be arbitrarily subordinated and manipulated through technological development,” concluding that “there are insurmountable natural limits.”

The development of Marx’s ideas here is most evident in his engagement with the works of the German agricultural scientist Justus von Liebig (1803–73). Several earlier books have highlighted Liebig’s importance to Marx’s ecological thought. What Saito shows in explicit detail is that Marx closely engaged with Liebig’s works (which appeared in numerous editions, with many subtle changes) as well as the scientific debate around Liebig’s ideas, to develop his own theories rooted in the natural science of the time.

Initially, Marx read Liebig not to develop his own ecological thought, but for ammunition in his economic critiques of thinkers like Ricardo. In particular, Marx drew on the law of diminishing returns, the idea that agricultural yields from soil will inevitably decline, even with the use of fertilizers or the investment of capital in improvements. This was important for an understanding of ground rent. At this point, Marx “assumed the proportional increase of agricultural productivity” and did not yet consider the question of soil exhaustion and the limits of natural resources as a major problem, precisely because he saw it as a conflict that “only occurs in capitalism.”

However, by the time Marx began writing Capital, he had changed his position. He took from Liebig the notion that the “robbery system of agriculture” is a “specific modern manifestation of material limits in the sphere of agriculture.” Liebig provided Marx with two vital points: first, that capitalist agriculture is limited by nature—soil types, local climates, and so on—and even if a farmer can invest endless capital, the return on investment will always be restricted by these natural factors. Second, Liebig highlighted the way that the organization of modern agriculture systematically removes nutrients from the soil as plants are grown, and then fails to restore them. Instead the nutrients are dumped as human waste into rivers, where they are lost to agriculture. Saito notes Marx’s “excitement” on learning of this phenomenon, which stems from the “scientific expression of the theme ‘antagonism between town and country.’”

While Liebig and other agricultural scientists convinced Marx that a rational agriculture was possible, it became equally clear that this could not be through capitalist agriculture. Under capitalism, as soil fertility declines, costs increase, because improvements can only be made through human labor, not by appropriating “a free natural power.” As Saito puts it, Marx had a “new critical insight that profit-orientated agriculture under capitalist relations is not capable of sustainable and long-term improvement of the soil and that production costs go up due to increasing capital investments as a countermeasure against soil exhaustion.” But capitalist agriculture is geared to the maximum use of the “free forces of nature” in order to maximize profits. Only a new economic system able to rationally organize this relation could overcome the historic decline in soil fertility.

Thus Marx developed his theory of the “metabolic rift” as a result of his engagement with Liebig and other scientists. His understanding of capitalist agriculture as a system of robbery came relatively late, in the 1860s. This is not to say that Marx had not engaged with the subject earlier, but that previously he focused on the positive vision of writers like Liebig, in particular their optimistic belief in the ability of chemical fertilizers to solve the problem of soil fertility.

It was an optimism that Marx shared to a certain extent, as evidenced by a quotation from Liebig he copied into one of his London notebooks in the early 1850s: “Whether this restoration [of agriculture] will be effected by means of excrement, ashes, or bones, is in a great measure a matter of indifference. A time will come when fields will be manured with a solution of glass (silicate of potash), with the ashes of burnt straw, and with salts of phosphoric acid, prepared in chemical manufactories” (Marx’s italics). Saito comments that Marx’s approval of this faith in purely technological solutions to the crisis of soil fertility in his 1851 notebooks was “too optimistic” and that “it is safe to conclude that Marx’s reading of Liebig before 1863 does not include a truly critical attitude toward modern agriculture. However, this changes in Capital.”

So what made Marx change his mind? In writing Capital, he became more closely focused on the ways that, under capitalism, labor is abstracted from its historic role in fulfilling human needs, and serves only to maximize capitalism’s accumulation of wealth. This, he wrote, “causes various disharmonies in the lives of workers, such as overwork, mental and physical disorders, and child labor…. This domination by capital goes beyond the reorganization of labor in the factory…[and] produces various discordances in the material world by disturbing the natural metabolic interaction between humans and nature.”

Marx returned to his studies of agricultural science to try to understand this new insight. According to Saito’s readings of his notebooks from 1856–66, Marx was aided in this developing critique by Liebig’s own changing ideas. Liebig was strengthening his criticism of capitalist agriculture, noting that attempts to improve crop yields only worked at the expense of the soil itself: “A larger amount of crop was achieved not because the nutrient matters in the soil became richer but because it was based on techniques that made them poorer more quickly.” Liebig’s conviction that capitalist agriculture depended on a system of “robbery” deepened with his observation of the use of guano from islands around the globe. He described England’s agricultural industry as a “vampire” on the rest of the world, sucking up natural resources, but, crucially, “without any real necessity of permanent gain.”

Using this material, Marx transformed his arguments. He abandoned his “optimistic” focus on technology and science and, in Saito’s words, came to see “profit-oriented” technology as “causing unexpected and destructive consequences such as soil exhaustion and scarcity of natural resources.” Liebig’s writings were part of a wider debate among scientists over resolving the crisis of soil fertility. This included an intense argument between those who argued for a “chemical solution” and those, like Liebig, who promoted a “mineral solution.” Marx also studied the work of the German scientist Carl Fraas, whose work he thought demonstrated an “unconscious socialist tendency.” Fraas argued that there were ways to improve soil fertility other than injecting chemicals into the ground through artificial fertilizers, including using river floods to replace soils and nutrients naturally, and thus not to rely on costly chemical fertilizers. This too bolstered Marx’s conviction that a rational agriculture was possible.

Intriguingly, Fraas also prompted Marx to think about the question of climate and its impact on agriculture and civilization. Marx read Fraas’s book Climate and the Plant World Over Time (1847), which studied the impact of deforestation on climate. Fraas concluded that the systematic destruction of trees and other vegetation leads to a “deep transformation” of a region’s natural character. Marx made extensive notes on Fraas’s writings on deforestation and desertification, further developing his own understanding of how capitalism disrupts the human-nature metabolism. Saito concludes that

Fraas’s historical investigation opens up an even more expanded vision of ecology than the earlier reception of Liebig’s theory of soil exhaustion. Climate change is a new and important element for Marx’s investigation into the historical disturbances in natural metabolism caused by humans…. Climate and the Plant World Over Time makes Marx aware that this development of modern capitalist production accelerates the disturbance of metabolism between humans and nature.

Fraas reached the pessimistic conclusion that commerce and industry inevitably degrade the environment, but Marx understood that through the democratic control of the means of production, the rational regulation of the interaction between humanity and nature could help restore their unity and close the metabolic rift. But this, of course, required a break with capitalism.

Marx thus arrived at his metabolic theory by way of a prolonged and deep engagement with contemporary scientists and their debates. But to fully understand how we can move toward a sustainable world, we need to understand precisely why capitalism is so destructive. Here, Saito argues, the centrality of Marx’s value theory to his ecological critique cannot be ignored.

It is not enough to argue that capitalism simply destroys the planet in its rush to make profits. As Saito points out, this would go “against Marx’s ‘materialist method.’” Instead we must probe deeper and examine the way that the logic of capital distorts the interaction between humans and the natural world, organizing “social production and circulation in such a way that their metabolic interchange necessarily gets disrupted.” Crucially, as Saito writes, “since the allocation of the sum total of labor and the distribution of the sum total of products in capitalism are arranged through the mediation of value, the metabolic interaction between humans and nature is inevitably carried out under the primacy of abstract labor.”

Capitalism mediates the relationship between nature and society only in the interest of maximizing its ability to accumulate wealth. This has the consequence of degrading nature and “exhausting labor.” Thus the great ecological crises we face today are caused not by a lack of technology or scientific knowledge, but by the way capital is organized. This is why all attempts to deal with climate change over the last quarter-century have met with failure. They rely on technological solutions or the application of market mechanisms or combinations of the two. They fail to challenge the fundamental way that capital distorts the interaction with nature, and hence cannot solve capitalism’s ecological crisis.

Karl Marx’s Ecosocialism shows convincingly that Marx’s ideas about the interaction of human society and the natural world did not arrive fully formed, but arose from his rigorous engagement with science and philosophy. Marx’s insights equip us with unparalleled tools to understand how capitalism destroys the environment. Saito’s book traces the progress of Marx’s ecological thought, and is thus invaluable in reasserting metabolic rift theory and its importance. It is an essential read.

Note