Part Four — The Production of Relative Surplus-Value Chapters 12–15. Relative surplus-value, co-operation, the division of labour in manufacture, and machinery and large-scale industry.

Part Three produced surplus-value by lengthening the working day. But the day has a limit — physical, moral, and now legal — and once the collective worker has forced a normal working day, capital needs another method. Part Four supplies it. If the day cannot be lengthened, the necessary portion of it can be shortened, so that more of a fixed day falls to surplus labour. This is relative surplus-value, and producing it requires revolutionizing the mode of production itself. Chapter 12 defines the concept and shows the individual capitalist's incentive hardening into the coercive law of competition. Chapters 13, 14, and 15 then trace the three historical stages through which capital raises the productivity of labour and reorganizes the labour process to that end: simple co-operation, the manufacturing division of labour, and machinery with large-scale industry.

The through-line is the transformation of the labour process by capital in pursuit of relative surplus-value, and the cost of that transformation to the worker. Each stage raises the social productive power of labour and each stage appropriates that power as a power of capital, so that the collective productivity the workers create confronts them as the property and the domination of another. Chapter 15, on machinery, is the culmination and the longest chapter of the book; its material on the subordination of living labour to the machine is a charter capture-target and is caught here with sustained engagement.

With the working day fixed, surplus labour can be increased only by contracting necessary labour — pushing back the point at which the worker has reproduced the value of his own labour-power. Excluding the option of simply paying below value (ruled out by the assumption that everything sells at its value), this requires that the value of labour-power itself fall, which requires that the means of subsistence be produced more cheaply, which requires higher productivity. From this Marx draws the pair of definitions that names the two methods of producing surplus-value.

I call that surplus-value which is produced by the lengthening of the working day, absolute surplus-value. In contrast to this, I call that surplus-value which arises from the curtailment of the necessary labour-time, and from the corresponding alteration in the respective lengths of the two components of the working day, relative surplus-value.

Marx, Capital I, page 432.

No individual capitalist sets out to cheapen the general value of labour-power; each is driven by a nearer motive. The first to raise productivity produces below the prevailing social value and pockets the difference as an extra surplus-value — until the method spreads. Marx names the mechanism that both rewards the innovator and compels the rest: the law of value operating as the coercive law of competition.

The law of the determination of value by labour-time makes itself felt to the individual capitalist who applies the new method of production by compelling him to sell his goods under their social value; this same law, acting as a coercive law of competition, forces his competitors to adopt the new method.

Marx, Capital I, page 436.

Aggregated across the economy, this drive gives capital a permanent tendency, and Marx states its endpoint bluntly: the cheapening of commodities is, in the end, the cheapening of the worker.

Capital therefore has an immanent drive, and a constant tendency, towards increasing the productivity of labour, in order to cheapen commodities and, by cheapening commodities, to cheapen the worker himself.

Marx, Capital I, pages 436–437.

This solves the riddle Quesnay used to pose — why the producer of exchange-value forever strives to lower exchange-value — since relative surplus-value rises exactly as commodity values fall. And it disposes of the apologists' claim that rising productivity benefits the worker: the aim is never to shorten the worker's day but to shrink the part of it he works for himself and enlarge the part he works for capital.

The objective of the development of the productivity of labour within the context of capitalist production is the shortening of that part of the working day in which the worker must work for himself, and the lengthening, thereby, of the other part of the day, in which he is free to work for nothing for the capitalist.

Marx, Capital I, page 438.

The first method of raising productivity is the simplest: assemble many workers in one place under one capital. Co-operation is not merely additive. Combining many labours creates a productive power that the same number of isolated workers could never reach — a power that belongs to the collective as such, not to any individual in it.

Whichever of these is the cause of the increase, the special productive power of the combined working day is, under all circumstances, the social productive power of labour, or the productive power of social labour. This power arises from co-operation itself. When the worker co-operates in a planned way with others, he strips off the fetters of his individuality, and develops the capabilities of his species.

Marx, Capital I, page 447. The opening clause abbreviates Marx's long list of the specific sources of co-operation's productivity gains.

Co-operation requires assembly, and assembly under capitalism means simultaneous employment by one capital — so the scale of co-operation depends on the size of the capital commanded. It also requires direction, and here Marx makes the move that runs through the whole Part: the necessary function of coordinating social labour and the specific function of exploiting it are fused, so that command over the labour process appears as an attribute of capital. Directing labour is despotic in form, carried out through an "industrial army" of managers and foremen.

It is not because he is a leader of industry that a man is a capitalist; on the contrary, he is a leader of industry because he is a capitalist. The leadership of industry is an attribute of capital, just as in feudal times the functions of general and judge were attributes of landed property.

Marx, Capital I, pages 450–451.

The chapter's decisive thesis, which Chapters 14 and 15 will develop, is that the social productive power the workers generate by co-operating is appropriated as a power of capital. The workers do not combine themselves; capital combines them, and because it does, the collective power they create costs capital nothing and appears to be capital's own.

Hence the productive power developed by the worker socially is the productive power of capital. The socially productive power of labour develops as a free gift to capital whenever the workers are placed under certain conditions, and it is capital which places them under these conditions. Because this power costs capital nothing, while on the other hand it is not developed by the worker until his labour itself belongs to capital, it appears as a power which capital possesses by its nature – a productive power inherent in capital.

Marx, Capital I, page 451.

The second stage refines co-operation into the manufacturing division of labour, the dominant form of capitalist production from the mid-sixteenth to the late eighteenth century. Manufacture arises in two ways — by combining different handicrafts under one command, and by splitting a single handicraft into its detail operations — and its product is the detail worker, the specialized "living instrument" who performs one fragment of the process for life. Marx reconstructs the specialization of tools, the two forms of manufacture (heterogeneous assembly and the serial organic form), and the "collective worker" made up of specialized organs. The gain in social productivity is real; so is its cost, which the chapter's fifth section states without mitigation.

Marx also draws the distinction that later readers have leaned on hardest: the division of labour within the workshop is planned, concentrated, and despotic — one capitalist's authority allocates the labour — whereas the division of labour in society is unplanned, distributed across independent producers and regulated only after the fact by the market. The same bourgeois mind that celebrates the planned division inside the factory denounces any conscious social regulation of production outside it as an assault on property and freedom.

The fifth section, on the capitalist character of manufacture, is where the human reckoning is entered. The detail division does not merely distribute work among individuals; it divides the individual, cultivating one aptitude by suppressing all the others.

It converts the worker into a crippled monstrosity by furthering his particular skill as in a forcing-house, through the suppression of a whole world of productive drives and inclinations, just as in the states of La Plata they butcher a whole beast for the sake of his hide or his tallow. Not only is the specialized work distributed among the different individuals, but the individual himself is divided up, and transformed into the automatic motor of a detail operation, thus realizing the absurd fable of Menenius Agrippa, which presents man as a mere fragment of his own body.

Marx, Capital I, pages 481–482.

The crippling has a precise correlate on capital's side: what the worker loses in individual capacity is concentrated in the capital confronting him. The knowledge and judgement that leave the detail worker reappear as the "intellectual potentialities" of production, now the property of another and a power ruling over him. Marx traces this separation across the three stages of the Part, and it is the sentence that binds co-operation, manufacture, and machinery into one movement.

It is a result of the division of labour in manufacture that the worker is brought face to face with the intellectual potentialities [geistige Potenzen] of the material process of production as the property of another and as a power which rules over him. This process of separation starts in simple co-operation, where the capitalist represents to the individual workers the unity and the will of the whole body of social labour. It is developed in manufacture, which mutilates the worker, turning him into a fragment of himself. It is completed in large-scale industry, which makes science a potentiality for production which is distinct from labour and presses it into the service of capital.

Marx, Capital I, page 482.

In manufacture, the social productive power of the collective worker, hence of capital, is enriched through the impoverishment of the worker in individual productive power.

Marx, Capital I, page 483.

Marx marshals Adam Smith's own admission — that the man confined to a few simple operations "generally becomes as stupid and ignorant as it is possible for a human creature to become" — to show that classical economy knew the cost and filed it away. Manufacture is thus the first system to generate an industrial pathology of body and mind. Yet manufacture remains limited: because it still rests on handicraft skill, capital cannot fully subordinate the worker, who retains a bargaining power and a residual craft autonomy. That limit is what machinery, in Chapter 15, is brought in to break.

The longest chapter of the book carries the argument of Part Four to its culmination. Machinery is the material means by which capital finally breaks the handicraft limit that constrained manufacture and completes the subordination of labour. Marx builds it in stages: the machine analysed as tool-carrier (§1), the value it transfers to the product (§2), the immediate effects on the worker — the drawing of women and children into the labour market, the drive to lengthen the working day now that the machine can run without rest, and the intensification of labour once the day is legally capped (§3), the factory itself (§4), the worker's struggle against the machine (§5), the false "theory of compensation" for displaced workers (§6), factory legislation (§9), and the transformation of agriculture (§10). This brief catches the load-bearing theoretical passages in full; the vast documentary record of the intervening sections — the Blue Books, the Children's Employment Commission, the case histories of the potteries, match-works, and lace trade — is reconstructed rather than quoted whole.

In §1 Marx defines the machine against the tool: what distinguishes the machine is that the tool, and with it the worker's skill in handling it, passes over into the mechanism. This destroys the technical basis of the manufacturing division of labour and, with it, the residual craft autonomy that had limited capital's command. The heart of the chapter is §4, on the factory, where Marx reads two descriptions of the automatic factory in Ure and shows that the second — the one in which the machine, not the collective worker, is the subject — is precisely what capitalist use makes true.

In one, the combined collective worker appears as the dominant subject [übergreifendes Subjekt], and the mechanical automaton as the object; in the other, the automaton itself is the subject, and the workers are merely conscious organs, co-ordinated with the unconscious organs of the automaton, and together with the latter subordinated to the central moving force. The first description is applicable to every possible employment of machinery on a large scale, the second is characteristic of its use by capital, and therefore of the modern factory system.

Marx, Capital I, pages 544–545.

This is the inversion the whole Part has been building toward, and machinery is where it stops being a conceptual point about valorization and becomes a physical fact on the shop floor. The relation between worker and instrument is turned over: the worker no longer wields the tool but serves the machine's motion.

In handicrafts and manufacture, the worker makes use of a tool; in the factory, the machine makes use of him. There the movements of the instrument of labour proceed from him, here it is the movements of the machine that he must follow. In manufacture the workers are the parts of a living mechanism. In the factory we have a lifeless mechanism which is independent of the workers, who are incorporated into it as its living appendages.

Marx, Capital I, page 548.

The reversal is so complete that even the relief machinery might bring turns against the worker: lightened labour becomes emptied labour. And the abstract inversion of Part Three — dead labour dominating living — here takes on "a technical and palpable reality."

Even the lightening of the labour becomes an instrument of torture, since the machine does not free the worker from the work, but rather deprives the work itself of all content. … it is only with the coming of machinery that this inversion first acquires a technical and palpable reality. Owing to its conversion into an automaton, the instrument of labour confronts the worker during the labour process in the shape of capital, dead labour, which dominates and soaks up living labour-power.

Marx, Capital I, page 548. The ellipsis drops the intervening sentences on the general inversion common to all capitalist production.

Machinery completes the separation begun in co-operation and developed in manufacture: the intellectual powers of production — now science itself — are wholly detached from the worker and wielded over him as capital, and factory discipline becomes a "barrack-like" code, the autocratic law of the capitalist over an industrial army. Marx grants that machinery, as such, is not the villain — it is the potential basis of shorter labour and human development — but under capital it is turned into the opposite. In §5 the worker's revolt against the machine (Luddism) is read not as blindness but as the first, misdirected form of a struggle that must learn to distinguish the machine from its capitalist employment; in §6 the economists' "theory of compensation," which claims displaced workers are always reabsorbed, is refuted.

The chapter closes, in §10, by carrying the analysis into agriculture, and it is here that Marx states the double robbery — of the worker and of the earth — that has made the passage a touchstone. Large-scale industry raises productivity by exhausting both the human and the natural sources of wealth, disturbing the metabolism between humanity and the soil even as it creates, negatively, the conditions for its rational restoration.

On the one hand it concentrates the historical motive power of society; on the other hand, it disturbs the metabolic interaction between man and the earth, i.e. it prevents the return to the soil of its constituent elements consumed by man in the form of food and clothing; hence it hinders the operation of the eternal natural condition for the lasting fertility of the soil.

Marx, Capital I, page 637.

Moreover, all progress in capitalist agriculture is a progress in the art, not only of robbing the worker, but of robbing the soil; all progress in increasing the fertility of the soil for a given time is a progress towards ruining the more long-lasting sources of that fertility. … Capitalist production, therefore, only develops the techniques and the degree of combination of the social process of production by simultaneously undermining the original sources of all wealth – the soil and the worker.

Marx, Capital I, page 638. The ellipsis drops the sentence on the accelerating destruction where large-scale industry is the background, as in the United States.