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Self-Knowledge, Estrangement, and Social Metabolism

Re-making (Re-thinking, Re-acting, Re-structuring) by Marija Lovrić

Re-making (Re-thinking, Re-acting, Re-structuring), combined techniques, 2015. By the Croatian artist Marija Lovrić. See "Marija Lovrić - Back to Nature: Overcoming Technological Alienation," Sketchbook Station, April 2017.

Boris Hennig is an associate professor of ancient philosophy at Ryerson University in Toronto. He earned his PhD from Universität Leipzig. His research focuses on metaphysics, logic, and epistemology.

In this article, I explore two key themes in Karl Marx’s thought, estrangement and political economy, in relation to human self-knowledge. Starting from Marx’s claim that all forms of estrangement rest on the estrangement of human labor, I follow him in describing labor as socially extended metabolism. In order to distinguish between organic and extended metabolism, I draw a distinction between functional and social organization, and argue that socially extended metabolism gives rise to shared values and concepts in the same way that organic metabolism gives rise to life. On this basis, I suggest that both the subject and object of human self-knowledge is a socially extended self, which can connect to itself only when humans freely participate in socially extended metabolism—that is, economy, science, and industry. Estrangement, in contrast, is seen to result from a disruption within socially extended metabolism.

Marx’s critique begins with G. W. F. Hegel. Very broadly conceived, Hegel’s overall philosophical project is to explain self-knowledge by describing the development of a perfect self-knowing subject. Hegel’s quest for self-knowledge is still of fundamental importance for Marx, as can be seen with respect to two of Marx’s most basic concerns. First, the issue of estrangement, most prominent in his earlier writings. If estrangement amounts to a disconnectedness from whom one truly is, its opposite should be a connectedness to that self. This connectedness may take two shapes, a practical and/or a theoretical one, and both amount to a form of self-knowledge. Marx’s concern with estrangement is thus, indirectly, a concern with theoretical and practical self-knowledge.

Second, this concern remains present in a different form in Marx’s later writings. While maintaining that consciousness rests on material processes, Marx follows Hegel in emphasizing its social nature. On the one hand, he describes consciousness as an outgrowth and a mere reflection of a certain form of life. On the other hand, he insists on the social character of this life: “Consciousness is…from the very beginning a social product.”1 Thus, the material process that underlies self-consciousness is not the life of an isolated organism; it is the material manifestation of the social life of a community. The system of material processes and transactions that underlie the life of a structured community is nothing other than political economy (taken as a subject matter, not as a set of theories). When Marx studies political economy, he therefore still explains the material underpinnings of self-knowledge. This makes sense because the underlying material process is one of self-maintenance.

I take a closer look at these two key elements of Marx’s thought: (1) the notion of estrangement, as the opposite of self-knowledge; and (2) Marx’s concern with political economy as the material, social form of life that underlies human self-knowledge.

The notion of estrangement has been a topic of much debate. Some have taken estrangement to be a form of reification.2 Others, inspired by the etymology of the word alienation and its use in social-contract theories, have suggested that estrangement is a result of selling or giving away one’s life activity or one’s authority over oneself.3 Still others have focused on possible consequences of this consignment or surrender by arguing that estrangement consists in a loss of control.4

Rather than reviewing the literature in detail, I will begin by noting that the aforegiven partial and superficial overview suggests that estrangement happens when people cease to own something, which might be taken to imply that all estrangement presupposes the institution of private property. Marx, however, emphasizes that, while private property may cause further estrangement, its institution rests on a more fundamental form of estrangement: “Private property thus results by analysis from the concept of alienated labour, i.e., of alienated man, of estranged labour, of estranged life, of estranged man.”5

Private ownership rests on estranged labor and, ultimately, on estranged human life. If this is so, the best way of understanding estrangement is to look at the ways in which human labor can be alienated (veräußert) and estranged (entfremdet). Therefore, let us begin by looking into what Marx says about labor.


On a rather general level, one might define labor as productive human activity. This raw definition will leave two things to be clarified: (1) What does it mean for an activity to be productive? (2) And what is the specifically human way of being productive? As for the first, labor differs from other life activities in that it leaves behind a detachable product.6 However, Marx does not simply describe labor as an activity that “leads to” a product. He says that labor manifests itself in its product. “The product of labour is labour which has been embodied in an object, which has become material: it is the objectification of labour. Labour’s realization is its objectification.”7

The product of labor, says Marx, is the objectification of this labor. This has been recognized as a version of Hegel’s “externalization account of action.”8 For Hegel, all intentional agency consists in the externalization of something inner.9 Putting it this way avoids a conception of intentional agency as movement merely caused by certain mental states or events. Rather than standing in a causal and as such extrinsic relation to the inner, intentional actions are depicted as external manifestations of something inner. An intentional action is the intention itself in a different form. In defining labor as an activity that manifests itself in an object, Marx adapts this general idea. Just as an action is an intention in a different form, the product of labor is labor in a different form.

Accordingly, Marx describes the product of labor as congealed labor.10 As he sometimes puts it, living labor, when successfully performed, turns into dead labor.11 He describes this process in quasi-chemical terms: “Labor has bonded with its object. It has been objectified, and the object has been processed” (my translation).12

The process that Marx is describing here consists in applying labor to a given object so that the product of labor is a fusion of this object with a certain amount of congealed labor. This means that labor does not objectify itself by literally turning into a material thing. Rather, labor transforms a given object by “going into” it. In Capital, Marx introduces the notion of labor as “a process in which both man and Nature participate,” by which humans “appropriate Nature’s productions in a form adapted to [their] own wants.”13 As a consequence of being “processed,” the product of labor can thus be seen both as a mere physical object and as a manifestation of the labor that went into its appropriation.

All in all, Marx describes labor as a certain form of life and in doing so exploits a systematic ambiguity of this latter notion. Form of life may refer to either the activity of leading a life (a form of living) or to the organism that results from such activity (a living being). The life activity of animals and plants transforms matter into parts of their organic body, such that this body is a direct manifestation of the activity that produced it. In this sense, a form of living literally manifests itself in a living being. Marx aims to suggest that the same is true of labor. Just as a form of living manifests itself in a living being, living labor manifests itself in its product. And just as the resulting living organism can be referred to as a form of life, Marx therefore refers to the product of labor as a form of labor.

However, Marx also highlights a distinction between the intimate relation of forms of living to the organisms that manifest them and the somewhat less-tight connection of labor to its product. We might register this distinction by saying that whereas the body of a living being is an intrinsic manifestation of its life activity, the product of labor is an extrinsic manifestation of this labor. The product of labor is extrinsic in the straightforward sense that it does not (typically) constitute a part of the organic body of the living being that produced it.

Famously, Marx further identifies the labor that manifests itself in its product with the value of this product: “Human labour…becomes value…in its congealed state, when embodied in the form of some object.”14 Marx introduces the term value as a label for one of the two respects in which the product of labor can be considered. Considered as a physical thing, it is a merely extrinsic manifestation of the activity of making it. As such, it may be detached from the activity of producing it. Considered as a value, however, it cannot be detached—it always remains a manifestation of labor.15

This partial detachability of the product of labor makes estrangement possible. The product of labor remains tied to its maker—a manifestation of their life activity, even when it is physically withheld. This explains why the separation of workers from their product can deeply affect them. For Marx, labor is the “active species-life” of humans, that is, the most characteristic human life activity.16 This means that labor, both in its liquid and congealed forms, occupies a central place among the things that humans do and make in order to lead their lives.

When labor and its product are detached from workers, they are taken out of their immediate life contexts. To the extent to which labor and its product are assigned a crucial place in workers’ lives, their separation will leave a gap; something essential will be missing. Workers will presumably be able to fill this gap by spending their wages on purchasing the necessary means of life. However, while this will keep workers alive, it will not fix the estrangement that comes with the separation between workers and the manifestation of their life activity.

So far, we have seen that Marx distinguishes between two forms of life activity. The life activity that animals and plants engage in manifests itself in their organic bodies. In addition to this, humans also engage in a form of life activity that manifests itself in an extrinsic, detachable product. This activity is labor and, like all manifestations of life, its product can be seen in two respects: first, as a mere material object resulting from a material process, and second, as a manifestation of the life activity that gave rise to it. The product of labor, however, cannot only be seen in these two different respects. Rather, one can actually physically separate the material product of labor from the human being whose labor is manifest in it. This makes estrangement possible.

The Extended Body

Let us now turn to the second issue: In what sense is labor specifically human? Marx is aware, of course, that animal activity can result in extrinsic and detachable products. Bees make honey and we often take it from them.17 But Marx does not seem to think that this leads to an estrangement of bee life. While animals can engage in productive activity, it is not the same as what Marx calls “labor.” Why not?

For my purposes, it does not matter whether only humans are capable of the form of life that Marx attributes to them—some nonhuman animals might be able to do what humans do as well. What is important is that Marx draws a firm distinction between two forms of life, such that only one of these is capable of labor, social interaction, and conceptual mediation. I will follow Marx in referring to this life form as “human.”

In Capital, Marx remarks that humans, in contrast to other animals, produce “in their head” before producing in practice.18 The implication is that human production differs from animal production in that it is guided by a conscious plan. This seems odd, however, given that, elsewhere, Marx downplays the significance of mental representations. In the Economic and Philosophic Manuscripts of 1844, he helpfully draws the distinction in slightly different terms: “An animal…produces one-sidedly, whilst man produces universally.” As opposed to other animals, he describes humans as “species beings” because “in practice and in theory [man] adopts the species (his own as well as those of other things) as his object.”19

When Marx refers to humans as species beings, he often means that they take themselves to be members of the human species. However, in the aforecited passage, he has something slightly more general in mind. By “species being,” he means a being that is capable of treating things of any sort as instances of species. He is using “species” in its logical sense, referring to a classificatory unit or universal. That humans are species beings therefore means that they classify whatever they engage with as instances of species. As such, human life activity is conceptually mediated. Conceptual mediation need not be conscious. One might treat a thing as an instance of a species without wasting any conscious thought on doing so. If this is how humans differ from animals, we should ask how conceptual mediation relates to the capacity for what Marx calls labor. It is important to note that Marx introduces the notion of a species being by reference to intellectual comprehension rather than productive activity. Shortly after characterizing humans as species beings, he writes: “Just as plants, animals, stones, air, light, etc., constitute theoretically a part of human consciousness, partly as objects of natural science, partly as objects of art—his spiritual inorganic nature, spiritual nourishment which he must first prepare to make palatable and digestible—so also in the realm of practice they constitute a part of human life and human activity.”20

The suggestion is that, cognitively, humans process their environment by bringing its parts and elements under general concepts, allowing them to digest the information. Again, Marx casts a characteristic of human activity as an expression of life. Just as plants and animals appropriate their material environment by turning it into parts of their organic bodies—that is, literally digesting them, humans appropriate their environment by turning it into parts of their “spiritual inorganic nature.”

When Marx describes comprehension as a form of digestion, he does not mean that human comprehension involves literally taking in and transforming the relevant object. The object of comprehension remains in its place, spatiotemporally external to the human being. However, by comprehending an object, humans, as the expression goes, wrap their heads around it to turn it into a part of what one might call their extended mind. Marx does not use the phrase extended mind and his interest is different than what later authors have proposed under this term.21 To him, the most significant distinction is that the extended mind encompasses all of nature.22 Here, nature is presumably meant in the Kantian sense, that is, as human environment insofar as it is humanly comprehended: “The existence of things, insofar as that existence is determined according to general laws.”23 Marx’s “spiritual inorganic nature” is thus the human environment insofar as humans have brought it under general laws and concepts.

The point of Marx’s appeal to something like an extended mind is to motivate an analogous conception of an extended body. Human labor does not merely cause a product, but rather manifests itself in this product. Following from this, to the extent that humans shape their environment, their environment turns into a manifestation of their productive life activity, not unlike the way in which the food that animals eat turns into their organic bodies. The difference is that human productive activity, like intellectual comprehension, is mediated by concepts, and its manifestation is usually extrinsic to the organic bodies of the humans involved. On the face of it, these appear to be two independent features: on the one hand, human labor is conceptually mediated; on the other, its result is a part of the human environment, as opposed to the human organism. How are these two features tied together?

I will get to this question. For now, let us linger on the close connection that Marx establishes between humans and the manifestation of their labor by referring to the latter as a sort of extended human body. Humans, says Marx, appropriate their environment by comprehending and shaping it, so that the result is “a human object or objective man.”24 Furthermore, a person “duplicates himself not only, as in consciousness, intellectually, but also actively, in reality, and therefore he sees himself in a world that he has created.”25 Marx thus distinguishes between two modes of appropriation, comprehension and production, such that the first manifests itself in the “spiritual inorganic nature” and the second in what he calls “man’s inorganic body”—Marx’s terms for what I call the extended mind and body. Together, the extended mind and the extended body add up to an extended self. Marx does not use the term extended mind, and he speaks of an extended body (verlängerter Leib) only once.26 In the Economic and Philosophic Manuscripts, he refers to the manifestation of labor as “man’s inorganic body.”27 Discussions of the latter phrase have focused on the underlying contrast between the organic and the inorganic, but this bit of terminology can be misleading.28 The point is not that the human environment contains only inorganic matter, since plants and animals are in fact parts of our humanly comprehended and shaped environment. Nor is it that the parts of our extended body do not have the status of tools, which the term inorganic might also suggest.29 On the contrary, the most important parts of “man’s inorganic body” are precisely the tools that humans use in order to facilitate their life.30 Two of the most obvious connotations of inorganic thus point the wrong way.

However, Marx does have good reasons for calling the extended body (and mind) “inorganic.” Marx’s terminology is explained by the notion of organization, as opposed to a free play of forces, as employed by Moses Hess. Much like Marx, Hess describes the humanly appropriated environment as “the body of the social human being,” contending that, where property and appropriation are mediated by money, this body is not “alive,” because money is “inorganic” (Über das Geldwesen; my translation).31 Further, according to Hess, humanity is currently at a stage where “the world of spirit,” Hegel’s label for the socially extended self of humanity, is “not yet organized” (Fortschritt und Entwicklung; my translation).32 This is why, for Hess, property is merely an inorganic body, a body that fails to be a properly organized extension of the human organism. He suggests that once the “world of spirit” is properly organized, which will only happen in communism, our extended body will transform into an organic body. Although Marx does not follow Hess in this latter regard, his idea of an inorganic body is similar: something that belongs to humans, but is not organized in the same sense that organic bodies are internally organized.

The most important element of the term inorganic body is the notion of a body. Marx refers to the human environment as an extended body in order to express a sense of belonging broader than property ownership; a belonging that rests on the specifically human way of appropriating nature. He turns John Locke’s idea, that humans own their organic bodies, upside down.33 Rather than explaining the peculiar relation of humans to their organic bodies in terms of ownership, Marx generally characterizes ownership, the natural result of appropriation, in terms of embodiment.34

Humans, argues Marx, have two bodies—two spheres in which their life activity manifests itself. Their immediate body is the organic one, limited by their skin and maintained and reproduced by the type of metabolism that nonhuman animals engage in as well. Given that this metabolism is not mediated by general concepts, it is not a species activity. After all, humans do not need to classify in order to digest.35 Their extended body, however, is their environment insofar as it is actively appropriated and shaped in accordance with concepts. Labor is the appropriation, maintenance, and reproduction of this extended body. Therefore, labor can be described as an extension of organic metabolism.


Extended metabolism, the activity by which humans actively appropriate their environment, naturally manifests itself in an extended body—something that belongs to them but is extrinsic to their organic bodies. Under conditions of estrangement, the manifestation of their labor ceases to be an integral part of their extended self and, thus, extended metabolism is disrupted.

In order to understand estrangement, then, we need to understand extended metabolism. This is to assign a crucial role to the notion of metabolism; a role that Marx turns to in his later writings, particularly in the Grundrisse, after largely abandoning the term inorganic body. Just as organic metabolism amounts to the activity of maintaining and reproducing individual organic bodies, extended metabolism amounts to the activity of maintaining and reproducing an extended body.

It is no accident that the notion of metabolism lends itself to Marx’s purposes. When the German word for metabolism, Stoffwechsel, came into use in the beginning of the nineteenth century, one of the expressions it replaced was oeconomia animalis.36 The idea was, right from the beginning, that living beings may be described as a kind of household, the maintenance of which involves the intake, processing, and disposal of material. It is therefore a straightforward move for Jacob Moleschott to reapply the notion of metabolism to society as a whole and for Marx to describe the exchange of commodities as a form of “social metabolism” (gesellschaftlicher Stoffwechsel; my translation).37

We tend to think of metabolism as the set of chemical processes that constitute and explain the life activities of a living being. Justus von Liebig, however, one of the most efficient popularizers of the notion of metabolism in Marx’s time, was not ready to explain all phenomena of life in terms of metabolism. Although his general project was to describe organic life in terms of processes that are also at work in inorganic nature, he actually ended up with three independent explicatory devices: chemical, mechanical, and vital forces.38 Chemical and vital forces, in particular, often seem antagonistic in his view, but are closely connected insofar as a decrease in one occasions an increase in the other, and vice versa.39

With respect to vital forces, Liebig’s position has been described as “inconsistent and confusing,” but it is in fact rather straightforward.40 On the one hand, he rejects the assumption of a vital force as an explanatory bedrock and instead takes it to be “a collective term, embracing all those causes on which the vital properties depend.”41 This clearly suggests that vital forces might turn out to be chemical ones. We just do not know yet. On the other hand, Liebig resists the temptation to preemptively attribute all phenomena of life to chemical and mechanical forces. In the absence of sufficient evidence, he argues, such generalizations would amount to superstition.42

In the present context, it is important to understand the reason for Liebig’s hesitation. His hesitation stems from the fact that the description of a process made up of chemical and physical forces does not bring out its functional role in a living being. Liebig claims to be in a position to explain many processes within living beings, including the decomposition of materials, in terms of chemistry. Yet, he cannot see how the generation of organic matter could be explained in a materialist fashion. While he understands the chemistry of catabolism, he is unable to account for anabolism.43 There is thus something about the transition from inorganic to organic matter that remains inexplicable by way of chemistry, which is why Liebig, being cautious, attributes it to a vital force.

If the transition from inorganic to organic matter cannot be explained by chemical or physical forces, the difference between them cannot be a chemical or physical one. Liebig suggests, naturally enough, that the distinction is one of organization. “By ultimate chemical analysis we do not obtain the slightest clue to the real properties of organic compounds. Hence, in investigating the different vital products of plants, chemists have latterly directed all their efforts to ascertain the order of grouping of their elements, on which they see that their properties are dependent.”44

The generation of organic matter (anabolism), as opposed to its decomposition (catabolism), is a matter of “the order of grouping of…elements”—that is, a matter of organization. If vital force is a collective name for whatever explains the distinctive character of living beings, it must be taken to refer to this organization itself, rather than any of the physical or chemical features of the objects being organized. This ultimately leads to the position that Hermann von Helmholtz contrasts with vitalism: “The life of organic bodies…[is] the result of forces that are also active in lifeless nature, only peculiarly modified through the mode of their interaction” (my translation).45

Helmholtz, like Liebig, suggests that life is explained by a form of organization, a mode of interaction of forces. In this light, there is a sense in which Liebig is not actually a vitalist. What he calls a vital force is ultimately not a force, but a certain form of organization.

All this is important because there seems to be a counterpart to Liebig’s residual vitalism in Marx. For a vitalist, life results from the exercise of a special force. For Marx, value might seem to result from the exercise of an equally special force: labor force.46 More to the point, Marx says that labor creates value because workers put their lives into the products of their work, and that living labor brings things to life.47 He also says that the surplus value created by labor “has all the charms of a creation out of nothing,” and that the capital produced by labor is “a live monster that is fruitful and multiplies.”48 These are metaphors, to be sure, but they seem to furnish labor with a mysterious capacity for creating value where there was none, thus adding more to its product than labor needs in order to sustain itself.49

It is indeed important for Marx that only human labor can create value. In Wage Labour and Capital, he points out that a fully automated factory could not possibly generate any surplus value, and hence no capital. “If the whole class of wage-workers were to be abolished owing to machinery,” he writes, “how dreadful that would be for capital which, without wage labour, ceases to be capital!”50

Presumably, machinery without any human contribution could not produce capital because only human labor can create value, and only the exploitation of human labor can yield surplus value. This makes it seem that value, like life for a vitalist, has no purely physical source or explanation. The cause appears to be a mysterious human force that goes beyond mechanics or chemistry.

This, however, would be a misunderstanding of the analogy Marx establishes between life and value.51 Marx does not explain value by reference to a special force that alone can generate it. When he insists that only human productive activity can generate value, the reason is precisely that human labor differs from animal or machine productivity by virtue of its social character. In this respect, Marx follows Liebig. Liebig, as we have seen, ultimately traces the difference between inorganic and organic matter to the functional organization of the whole. Marx continues this line of thought by adding that the difference between human life and other organic life lies in its social organization. He emphasizes this, for instance, in the famous section on the Fetishism of Commodities: “The products of human labour appear as values only because of the social character of the labour that is manifest in them.”52

Social Interaction and Conceptual Mediation

According to Marx, humans differ from animals in three main ways. First, humans’ characteristic life activity—labor—involves conceptual mediation. Second, this labor manifests itself in an extended body, as opposed to an organic one. Third, it is essentially social. Just as the functional organization of organic metabolism explains the emergence of life, the social organization of extended metabolism explains the emergence of value. In order to understand extended metabolism and its product, the extended body, we must therefore understand the difference between functional and social organization.

We can shed some light on this difference by adopting an Aristotelian perspective, which posits biological organisms as basic and primary units. In this perspective, the unity, identity, and interaction of the parts of an individual organism are functions of the characteristic activity of the whole to which they belong. The unity of an organism is more fundamental than the unity of its parts, because the organism is what unifies each of its parts in the first place. The unity, identity, and behavior of a community of organisms, however, is a function of the interaction of its members. A social community is not in itself an organic unity but rather a structured collection of numerically distinct organic unities.

On the basis of this distinction between organic and social wholes, we can see an important link between social interaction and conceptual mediation. We can begin by noting that social activity ceases to be social in two cases: first, when it ceases to be one unified activity, and second, when the participants in it cease to be sufficiently separate. This is partly a point about language: we would not call an activity social unless it is one activity shared by many. To the extent that it ceases to be one unified activity, it dissolves into an aggregate of disconnected actions. Inasmuch as the participating agents cease to be sufficiently different, they turn into mere functional parts of an organic whole. As long as extended metabolism remains social, it must therefore be one activity shared by many discrete organisms. It must be universal in a straightforward, Platonic sense (One over Many).

Platonic universality, however, is not enough. Instances of a Platonic universal are the same by being instances of the same pattern. However, the mere fact that many agents perform instances of the same form of agency does not render their activity social. Rather, the individual contributions to a social activity must somehow respond to other contributions to the same activity. More than merely instantiating a shared pattern or merely conforming to it, they must act in light of this pattern such that their actions are guided by it. For this to be possible, the participants in a social activity must have an understanding of what they share in. Their contributions must be guided by some sort of representation of the common activity.

Furthermore, this representation must be such that it, in turn, can be shared among all participants in the activity. Representing the shared activity must itself be a shared activity. This is the argumentative step that links social activity to conceptual mediation, for, arguably, shareable representations are concepts. If the participants in a social activity must represent that shared activity in a way they can relay to others, and if shareable representations are concepts, then the participants in social activity must conceptualize what they do.

It follows, then, that social activity must involve conceptual mediation and that the two are tied together. Taking it a step further, we may link both social production and conceptual mediation to the notion of an extended body. Why and in what sense do certain manifestations of life end up being external to the individual organisms whose life is manifest in them? If one can think of a spider web as an extension of the organic body of the spider, why is not everything that animals produce a part of their organic body? First, all social activity can be broken down into individual contributions. Every agent involved is in fact an individual living being and each of their contributions to the shared activity is an individual manifestation of organic life. However, that the activity is social means that, from the perspective of each participating agent, the activity as a whole goes beyond each individual contribution. Being social, the activity as a whole is extrinsic to each participant (which is a fancy way of saying that no one can do all of it alone). This makes it natural to think of the result of this activity as equally extrinsic. The result of social metabolism is therefore an extended, as opposed to organic, body. As such, it is as shared as the activity that leads to it and, in order to be shared by all participants, must be extrinsic to each of them.

It does not follow from this that the result of social production cannot in fact be owned by certain individuals and withheld from others. Nevertheless, such ownership requires an institutional setting, as well as certain measures to keep this setting in place. In itself, the manifestation of a shared activity ought to be as shared as the activity itself. This explains, again, why the beings that engage in social production are species beings. They must be such that the activity they participate in, as well as its lasting manifestation, confronts them as something objective, as one thing that they all relate to in potentially different but shareable ways; something that does not naturally belong to any one individual organic body. Social beings must be such as to be confronted with a world of objective activities and objective manifestations of such activities, which they can either share or refuse to share with others.

At this point, conceptual mediation and the emergence of an extended self turn out to be “the same fact,” as John McDowell might put it.53 Concepts are not only shareable representations, but they are also representations of shareable, objective content. Beings whose life activity is conceptually mediated are beings who are faced with objective reality. This objective reality is their inorganic body and their spiritual inorganic nature, or, as I call it, their extended self. This is a distinctively human phenomenon. The products of animal activity do not make up a part of an animals’ extended self, because they do not result from a social and thus conceptually mediated activity. Animals might act in accordance with a shared aim, but they do not act in light of a shared aim, so they do not need to conceptualize their common activity. Therefore, the product of their activity need not confront them as an extrinsic shareable object.54

That humans have an extended body means that they are met with an environment of shareable objects, which they comprehend and shape by means of a social and thus conceptually mediated activity. This is what Marx has in mind when he writes that “the animal does not ‘relate‘ itself to anything.”55 Nonhuman animals do not relate themselves to anything because they are everything that belongs to them.56 Humans differ from animals in that each of them is one thing, an organic body, and relates to another thing, the extended body.57 Which is another way of saying that human life is conceptually mediated.

Social Senses

In a rather tentative set of passages in the Economic and Philosophic Manuscripts, Marx develops the idea of the humanly appropriated environment as an extended body. He describes the access that the members of a community should ideally have to their shared extended body as the development of social senses.

By senses, Marx means ways in which humans appropriate their material environment, including “seeing, hearing, smelling, tasting, feeling, thinking, observing, experiencing, wanting, acting, loving.”58 Note, in particular, wanting, acting, and loving, which Marx later refers to as “practical senses.”59 Marx claims that the abolition of estrangement will emancipate these senses. He writes: “Besides these direct organs, therefore, social organs develop in the form of society; thus, for instance, activity in direct association with others, etc., has become an organ for expressing my own life, and a mode of appropriating human life.”60

The idea seems to be that for nonestranged humans, society itself comes to be an extension of their bodily senses. When this happens, the extended body turns into an organ through which such humans interact with nature. When Marx describes the emancipated human as “the rich human being,” he is thinking of a being with social senses, in contrast to impoverished humans, whose interactions with their environment are limited and restricted.61 The two general terms he uses for such social senses are industry and science, and for an individual to develop these senses is to fully participate in these two communal institutions.62 Industry and science are social activities by which humans appropriate their environment, turning it into a shareable, extended body. Together, they constitute extended metabolism, or, as we can now say, social metabolism. The emancipation of the senses, the development of social senses, is thus the same as the ability to fully participate in social metabolism. Marx describes this participation as a literal extension of the individual. The social activity of an individual, their “activity in direct association with others,” becomes “an organ” for the expression of their own life.63

This means that the self of an emancipated social being is literally extended into a social self. We are reaching a point where it is difficult to know how to proceed—a factor, perhaps, in why social senses did not make it into Marx’s published writings. On the one hand, we want to avoid thinking of the extended body as a seamless extension of the organic body. The distinction between the organic and the extended body must remain in place, for, otherwise, extended metabolism ceases to be social. Therefore, social sense organs cannot actually be on par with organic sense organs. On the other hand, we want to think of the emancipated individual as a being that acts and thinks, as an individual organism, on behalf and from the perspective of the community. This is what Marx means when he says that even an isolated individual can act socially, as long as this person acts as a human.64 By human, at this point, he is referring to the fully developed, emancipated, and nonestranged human life form. To act as a human being in this sense is to act as a social being, that is, on behalf of the socially extended self. Further, to act as a fully developed “rich” human being is to be “the subjective existence of imagined and experienced society for itself.”65 Marx is cautious enough not simply to identify the emancipated self with its actual social community, but he goes as far as saying that it takes itself to embody what it takes to be its community.

Marx’s notion of extended metabolism thus leads him to a point where it becomes perfectly obvious that, in order to be what they are, humans must not only create a social object, but must also turn into social subjects. “This is possible only when the object becomes for him a social object, and he himself [becomes] for himself a social being, just as society becomes a being for him in this object” (my italics).66

Extended metabolism, in its fully developed form, will no longer be an interaction between individual organic beings and their inorganic, socially extended body. In fact, it will be a relation that an extended self bears with itself. More specifically, it will be a relation that a “subjective existence” of the extended self bears with, presumably, the objective existence of this same extended self. One might well think of this as a relation of the socially extended mind with its socially extended body. But this is, of course, speculation.

Self-Knowledge and Estrangement

Let us now see what all this implies with respect to human self-knowledge. We have seen that Marx describes the object of human production and comprehension as an extended self. That the object of human comprehension is an extended self implies, superficially, that all human knowledge is self-knowledge. All our knowledge will be knowledge of our extended self. This form of self-knowledge is peculiar, however, since its object will be a communally shared object. When I see myself in my humanly appropriated environment, and you see yourself in your humanly appropriated environment, we see ourselves in the very same thing, which means that we might not actually see ourselves as distinct from one another.

Furthermore, if conceptual mediation is tied to the social appropriation of an extended body, it is conceivable that the extended self is the only self we can know. I have no rigorous and detailed argument for this, but intuitively, if knowledge is a conceptually mediated relation to an object, and if the object of all our conceptually mediated activity is the extended self, then the extended self is all we can know. Marx suggests as much when he treats comprehension as a kind of intellectual digestion, by means through which we reproduce and maintain our extended mind (that is, our spiritual inorganic nature). By knowing an object, we turn it into a part of our extended self. If this is so, all knowledge will again turn out to be knowledge of (parts of) the extended self.

As knowledge, self-knowledge will then have a communally shared object, and as self-knowledge, it will have an object in which knowers can recognize themselves. This leads to a very concrete sense in which successful self-knowledge depends on an intact, nonestranged community. If knowing oneself is knowing one’s extended self, and if the extended self is the result of social metabolism, human self-knowledge will stand and fall with the way in which humans organize their economy, industry, and science. Economy and industry are activities by which a political community maintains its material existence, and this is precisely the activity that we have been referring to as extended metabolism. In a similar way, science will be an activity by which a community generates and regenerates its extended mind.

Finally, following Marx’s tentative suggestions, we might think of estrangement as a lack of social senses and, in contrast, of self-knowledge as a form of life that fully participates in social metabolism and its shared manifestation. This line of thought is, of course, rather tentative. Above all, much more needs to be said about the idea of a “subjective existence of society” in each of its members. If there is anything to it, it demonstrates Marx’s conviction that an individualistic community is necessarily estranged. In particular, if the subject of self-knowledge must be a social subject, self-knowledge will remain out of reach for all members of a capitalist society, including the capitalists.67


Let us take stock. I began by arguing that, for Marx, all estrangement rests on an estrangement of labor, and labor is socially extended metabolism, generating and regenerating a socially extended body. In order to understand the role of the notion of metabolism in this, I have referred to Liebig and pointed out that the crucial difference between organic beings and inorganic beings lies in their functional organization. Complementing this insight, I have distinguished between organic and socially extended metabolism by setting apart the functional organization of an organism from the social, and thus conceptually mediated, organization of a community of organisms. I have argued that labor is for a political community what metabolism is for an organism, and that labor gives rise to shared values and concepts in the same sense in which organic metabolism gives rise to life. On this basis, I have suggested that the subject and object of self-knowledge in Marx is ultimately a socially extended self. Therefore, self-knowledge—the overcoming of estrangement—immediately depends on how a community organizes its extended metabolism, including its economy, science, and industry.


  1. Karl Marx and Frederick Engels, German Ideology, in Marx Engels Werke, vol. 3 (Berlin: Dietz Verlag, 1956–90), 31. Unless stated otherwise, I quote Marx in translation from the Collected Works (Lawrence and Wishart, 1975–2005).
  2. For example, see Herbert Marcuse, Reason and Revolution (London: Routledge, 1941), 279, and Georg Lukács, Geschichte und Klassenbewusstsein (Neuwied: Luchterhand, 1970), 66.
  3. István Mészáros, Marx’s Theory of Alienation (London: Merlin, 1970), 33; Richard Schacht, Alienation (London: Allen & Unwin, 1971), 8.
  4. For example, see Sean Sayers, Marx and Alienation (Palgrave Macmillan, 2011), 114.
  5. Karl Marx, Economic and Philosophic Manuscripts of 1844, in Marx Engels Werke, vol. 40, 520.
  6. Marx is willing to count the teaching of school children as productive activity, akin to the production of sausages. In this case, the “product” would, presumably, be a change in the student’s brains. Karl Marx, Capital, vol. 1, in Marx Engels Werke, vol. 23, 532.
  7. Marx, Economic and Philosophic Manuscripts, 511–12. See, by way of comparison, Georg Lukács, The Young Hegel (London: Merlin, 1975), 549. Like many others, Lukács assumes that Hegel did not distinguish between objectification and estrangement. I am not convinced, but this is a matter for another occasion.
  8. Ernst Michael Lange, Das Prinzip Arbeit (Frankfurt: Ullstein, 1980), 80; Michael Quante, Karl Marx, Ökonomisch-Philosophische Manuskripte (Frankfurt: Suhrkamp, 2009), 236–37; Sayers, Marx and Alienation, 34.
  9. See, by way of comparison, G. W. F. Hegel, Phenomenology of Spirit, trans. A. V. Miller (Oxford: Oxford University Press, 1977), section 400.
  10. For example, Marx, Capital, vol. 1, in Marx Engels Werke, vol. 23, 65.
  11. Marx, Capital, vol. 1, 209.
  12. Marx, Capital, vol. 1, 195. Original: “Die Arbeit hat sich mit dem Gegenstand verbunden. Sie ist vergegenständlicht, und der Gegenstand ist verarbeitet.” The Collected Works translation does not capture Marx’s language here.
  13. Marx, Capital, vol. 1, 192.
  14. Marx, Capital, vol. 1, 65.
  15. This is to give the notion of value in a very general sense. It is sometimes argued that labor gives rise to value only in a commodity economy—see, for example, Isaak I. Rubin, Essays on Marx’s Theory of Value (Montreal: Black Rose, 1973), 146. In the present context, however, I am abstracting from the difference between, for instance, use value and exchange value. I take it that just as Marx sometimes simply says labor when he means wage labor, he sometimes simply says value when he means commodity value.
  16. Marx, Economic and Philosophic Manuscripts, 517.
  17. See, by way of comparison, Marx, Capital, vol. 1, in Marx Engels Werke, vol. 23, 193.
  18. Marx, Capital, vol. 1, 193.
  19. Marx and Engels, Marx Engels Werke, vol. 40, 517; Marx, Economic and Philosophic Manuscripts, 515.
  20. Marx, Economic and Philosophic Manuscripts, 515. Marx might be alluding to the section on natural religion in Hegel’s Phenomenology of Spirit, in which Hegel speaks of the “inorganic nature of Spirit” (section 695).
  21. See, for example, Andy Clark and David Chalmers, “The Extended Mind,” Analysis 58, no. 1 (1998): 7–19.
  22. See, by way of comparison, Marx, Economic and Philosophic Manuscripts, 516.
  23. Immanuel Kant, Prolegomena to Any Future Metaphysics, trans. G. Hatfield (Cambridge: Cambridge University Press, 1997), section 14.
  24. Marx, Economic and Philosophic Manuscripts, 541.
  25. Marx, Economic and Philosophic Manuscripts, 517.
  26. Karl Marx, Grundrisse, in Marx Engels Werke, vol. 42, 399.
  27. Marx, Economic and Philosophic Manuscripts, 516. In Marx, the notion of an inorganic body first occurs in the context of a brief account of feudalism (Marx, Economic and Philosophic Manuscripts, 506). Alfred Schmidt thinks that, therefore, the notion of an inorganic body only applies to such precapitalist societies and that human metabolism acquires a distinctive social quality only in a capitalist system (Alfred Schmidt, Der Begriff der Natur in der Lehre von Marx [Hamburg: Europäische Verlagsanstalt, 1993], 203, 197). This is incorrect. First, if inorganic is the opposite of consciously organized, an economy based on a free play of market forces is still inorganic. Second, all human labor is essentially social and all social labor produces an extended body.
  28. See, for example, John Bellamy Foster and Paul Burkett, “The Dialectic of Organic/Inorganic Relations,” Organization & Environment 13, no. 4 (2000): 403–25.
  29. John P. Clark does not notice this connotation: “The ‘inorganic’ quality of ‘external’ nature signifies its instrumental character” (John P. Clark, “Marx’s Inorganic Body,” Environmental Ethics 11, no. 3 [1989]: 243–58). Since inorganic literally means noninstrumental (organon meaning tool, meaning instrument), it can hardly signify an instrumental character.
  30. See, by way of comparison, Marx, Grundrisse, 602.
  31. Moses Hess, Philosophische und Sozialistische Schriften: 1837–1850 (Berlin: Akademie Verlag, 1961), 343.
  32. Hess, Philosophische und Sozialistische Schriften, 282.
  33. John Locke, Second Treatise on Civil Government, in Two Treatises of Government (Cambridge: Cambridge University Press, 1988), chapter V, section 27.
  34. This might be one of the reasons why Marx characterizes nonestranged ownership as “true personal property” (Marx, Economic and Philosophic Manuscripts, 508). If our relation to our belongings is really a form of embodiment, our relation to our humanly appropriated environment is not one between a human being and a lifeless thing, but a more personal one between a human being and their (extended) body. See, by way of comparison, Marx, Economic and Philosophic Manuscripts, 583, in which Marx suggests that the true property of humans is their own life.
  35. Humans may need to bring things under concepts in order to acquire food.
  36. Johannes Büttner, “Von der oeconomia animalis zu Liebigs Stoffwechselbegriff,” in Stoffwechsel im tierischen Organismus, ed. J. Büttner and W. Lewicki (Seesen: HysChymia Buchverlag, 2001), 62–65.
  37. Jacob Moleschott, Der Kreislauf des Lebens (Mainz: Victor v. Zahren, 1852), 41. See, by way of comparison, Schmidt, Der Begriff der Natur, 87. Capital, vol. 1, 119.
  38. Justus von Liebig, Die organische Chemie in ihrer Anwendung auf Physiologie und Pathologie (Braunschweig: Vieweg, 1842), 227.
  39. Liebig, Die organische Chemie, 248–49. See, by way of comparison, Timothy O. Lipman, “Vitalism and Reductionism in Liebig’s Physiological Thought,” Isis 58, no. 2 (1967): 180.
  40. William H. Brock, Justus von Liebig (Cambridge: Cambridge University Press, 1997), 310.
  41. Justus von Liebig, Chemische Briefe, 4th ed. (Leipzig: Winter, 1859), letter XVI, 242–43
  42. Liebig, Chemische Briefe, letter XXIII, 362. See, by way of comparison, Vance M. D. Hall, “The Role of Force in Liebig’s Physiological Chemistry,” Medical History 24 (1980): 35. For background, see Brock, Justus von Liebig, 310–13.
  43. These terms, catabolism and anabolism, postdate Liebig, but the distinction is older. Xavier Bichat seems to be the first to draw the distinction (Recherches physiologiques sur la vie et la mort [Paris: Brosson, 1800], 40); W. H. Gaskell to introduce the terminology (“On the Structure, Distribution and Function of the Nerves Which Innervate the Visceral and Vascular Systems,” Journal of Physiology 7 [1886]: 46). See also Julius L. Budge, “Stoffwechsel,” in Encyclopädisches Wörterbuch der medicinischen Wissenschaften, ed. D. W. H. Busch et al., vol. 32 (Berlin: Veit et Comp., 1844), 351.
  44. Liebig, Chemische Briefe, letter XXIII, 358; translated in Familiar Letters on Chemistry, 4th ed. (Londong: Walton & Maberly, 1859), 284–85.
  45. “…das Leben der organischen Körper…[ist] das Resultat der auch in der leblosen Natur thätigen Kräfte, nur eigenthümlich modifiziert durch die Art ihres Zusammenwirkens” (Hermann von Helmholtz, “Ueber den Stoffverbrauch bei der Muskelaktion,” Archiv für Anatomie, Physiologie und wissenschaftliche Medicin [1845]: 72).
  46. Marx adds, on occasion, that another source of value is soil (Capital, vol. 1, 58). Soil, however, can lead to value only insofar as labor is applied to it (Marx, Economic and Philosophic Manuscripts, 532).
  47. Marx, Economic and Philosophic Manuscripts, 512; Marx, Capital, vol. 1, 198.
  48. Marx, Capital, vol. 1, 231, 209. A rather loose translation of Marx’s reference to Goethe’s Faust: “ein beseeltes Ungeheuer, das zu ‘arbeiten’ beginnt, als hätt’ es Lieb’ im Leibe.”
  49. Lange, Das Prinzip Arbeit, 205–6.
  50. Karl Marx, Wage Labour and Capital, in Marx Engels Werke, vol. 6, 421.
  51. It might be worth noting that by analogy I do not mean metaphor, but a rather strict conceptual correlation (as in, 4 is to 2 as 6 is to 3). In this case, value is to extended body as life is to organic body.
  52. Marx, Capital, vol. 1, 86.
  53. John McDowell, Mind and World (Cambridge, Massachusetts: Harvard University Press, 1994), 118.
  54. Remember that this is not an empirical claim about actual animals, but an expression of a distinction between social beings, who must be capable of conceptual mediation, and nonsocial beings, who need not. Many kinds of animals might turn out to be human in this sense.
  55. Marx, German Ideology, 30.
  56. Marx, Economic and Philosophic Manuscripts, 516.
  57. Note that our organic bodies may be parts of our extended self, namely insofar as we treat them as our possession, comprehend them scientifically, or shape them technologically.
  58. Marx, Economic and Philosophic Manuscripts, 539.
  59. Marx, Economic and Philosophic Manuscripts, 541.
  60. Marx, Economic and Philosophic Manuscripts, 540.
  61. Marx, Economic and Philosophic Manuscripts, 544.
  62. Marx, Economic and Philosophic Manuscripts, 542, 543.
  63. When Marx praises Hegel for describing the essence of labor in terms of “objectification as de-objectification” (“Vergegenständlichung als Entgegenständlichung”; Marx, Economic and Philosophic Manuscripts, 574), he similarly suggests that the product of human labor (equal to the extended body) ultimately ceases to be an object and becomes part of the subject. The Collected Works translation obscures this point by rendering the above as “objectification as loss of the object.” The object is not lost; rather, it loses its objective character and acquires a subjective one.
  64. Marx, Economic and Philosophic Manuscripts, 538.
  65. Marx, Economic and Philosophic Manuscripts, 539.
  66. Marx, Economic and Philosophic Manuscripts, 541.
  67. In the final passage of the Economic and Philosophic Manuscripts, according to the original order of the manuscript, Marx writes that trust can only be exchanged for trust, not for money (Marx, Economic and Philosophic Manuscripts, 567). One cannot buy trust because monetary exchanges are meant to render trust superfluous. This means that to the extent that truly social interactions essentially involve trust, they cannot be replaced by individual monetary exchanges. If this is so, the capitalist is able to, as such, not engage in truly social interactions.
2019, Volume 70, Issue 10 (March 2019)
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