The reason that Marx uses these terms is two-fold. Firstly, there is a sense in which labour is embodied within the commodity, just as it is in any product. That is in the sense of concrete labour. Secondly, Marx uses the terms simply as shorthand. In other words, if he had to write in full detail, to express his ideas, in precise language, every time he uses a concept, not only would it be tedious, but it would make his writing almost unreadable. Moreover, as Engels points out, when Marx uses concepts and definitions he does so in accordance with his scientific method. Those who seek fixed frozen definitions, that are cut and dried, from Marx, Engels says, simply have not understood that method.
“They rest upon the false assumption that Marx wishes to define where he only investigates, and that in general one might expect fixed, cut-to-measure, once and for all applicable definitions in Marx’s works. It is self-evident that where things and their interrelations are conceived, not as fixed, but as changing, their mental images, the ideas, are likewise subject to change and transformation; and they are not encapsulated in rigid definitions, but are developed in their historical or logical process of formation.” (Capital III, Preface, p 13-14)
For example, in Capital II, Marx makes clear that capital, as capital, has no value. This concept is central to his analysis in Capital III, of the rate of interest, as the price of loanable money-capital, in other words, of capital itself as a commodity. Capital as capital, i.e. as self expanding value, has no value, like land, because it is not the product of labour. Capital, as capital, has a market price – the rate of interest – despite the fact that it has no value, for the same reason that land has a market price – rent – despite the fact that it has no value. Both land and capital are use values. Land has a use value, because of its role in production, whilst capital has the use value of being self-expanding value. Both have become commodities that are bought and sold in the market, and like every other commodity that is bought and sold, they, therefore, acquire a market price, because the owners of these use values will not relinquish them for free.
Yet, despite the fact that capital, as capital, has no value, Marx repeatedly talks about capital value, or the value of capital, or the value of constant capital, and so on. This appears to be then a complete contradiction in what Marx is saying, but that is so only if you read every word or phrase that Marx utters as though it stands alone as a literal representation of his ideas, rather than taking such phrases within the overall context of his ideas. In that case, the use of such phrases poses no problem whatsoever, and the intelligent reader can then see that no such contradiction exists, and that Marx is simply using such terms as a shorthand.
When Marx talks about “the value of constant capital”, for example, he is actually referring not to the value of the constant capital, as capital, of which it has none, but to the value of the commodities that comprise the constant capital, i.e. the value of the buildings, machines and so on that comprise the fixed capital, and of the materials that comprise the circulating constant capital. Capital value, in this context, simply refers to a quantity of value that exists in one or other form of capital – money-capital, productive-capital, or commodity-capital, and the fact that within the circuit of industrial capital, this capital value continually metamorphoses from one of these forms into another.
The same is true when Marx talks about “embodied labour”.
There are several ways in which labour is embodied within a product. The concrete labour of a carpenter is embodied in the chair he produces, for example, just as is the concrete labour of the spinner in the yarn they produce. Not only is the nature of the chair determined by the fact that it is the product of the labour of a carpenter rather than a spinner, but even the nature of a particular chair is determined by the fact that it was produced by this carpenter rather than some other, or even by the fact that it was produced by this carpenter today rather than by the same carpenter a year ago.
In other words, this concrete labour is defined by its particular use value, and it is this use value that is embodied within the product, and thereby determines the specific use value of that product. Carpenter A and carpenter B, may both produce chairs, and they may be technically of equal quality in their construction and so on, but they will not be the same chair, because each will reflect the particular style and so on of the carpenters that built them, and which is embodied within the chair. Similarly, the chair will reflect other concrete labour embodied within it.
The chair is constructed of wood, whose use value itself will reflect the concrete labour that went into its own production; it may comprise leather and other materials, each of which reflect the concrete labour that went into their own production, and each of these will be embodied within the chair whose construction they participate in. For that reason, each individual product will be different from every other, in terms of its use value, even if by relatively negligible amounts. Even aside from these differences, in the use value of the materials that the carpenter uses, his own concrete labour will vary from one chair to another, and even one day or hour to another. If the carpenter is feeling ill, or tired, then its likely that this will be reflected in the labour he performs during that period. This can be seen in relation to the labour of the collective worker too, for example, the phenomenon of the Friday afternoon car, which rolls off the production line, notoriously being of poorer quality than cars produced during the rest of the week.
But, it was this fact, which, Marx says, also led Adam Smith to view productive labour as only that which produced material products, in which this embodied labour was visible. This view of embodied labour is specifically rejected by Marx, because concrete labour may be embodied in a product, which is not itself a material object.
“It may be that the concrete labour whose result it is leaves no trace in it. In manufactured commodities this trace remains in the outward form given to the raw material. In agriculture, etc., although the form given to the commodity, for example wheat or oxen and so on, is also the product of human labour, and indeed of labour transmitted and added to from generation to generation, yet this is not evident in the product. In other forms of industrial labour, the purpose of the labour is not at all to alter the form of the thing, but only its position. For example, when a commodity is brought from China to England, etc., no trace of the labour involved in the thing itself (except for those who call to mind that it is not an English product).
(Theories of Surplus Value, Part 1, Chapter IV, p 171-2)
But, concrete labour is also thereby embodied within products not just as a use value. Concrete labour is the source itself of value, although it is not the essence or measure of value. A lamp, a candle or the sun are the source of light, but they are not the essence of light, which is the photon. In the same way, the concrete labour of the carpenter or the spinner is the source of value, but it is abstract labour, labour stripped of all the characteristics of any specific concrete labour, which is the essence of value. But, just as photons come from some source, such as a lamp, candle or the sun, so abstract labour itself must have a source, and its source is the performance of some specific concrete labour. Value only exists, in the form of a quantity of abstract labour, because a quantity of real concrete labour has been performed.
If we examine any particular product, say a chair, it will contain a certain quantity of concrete labour. Even leaving aside the concrete labour required for the production of the wood, leather and so on, the concrete labour performed by the carpenter, in producing this chair, will vary from the quantity of concrete labour they perform in producing the next chair, just as this one will differ from the one he produced before it. In other words, each chair will have a quantity of concrete labour embodied within it, in both these senses. It will have a quantity of concrete labour embodied within it as use value, and whose measure is, therefore, its quality, and it will have a quantity of concrete labour embodied in it as value whose measure is time. But, because this is concrete labour this measure in time cannot be simply its own duration, but can only be measured as a quantity of abstract labour-time.
Each form of concrete labour, say the labour of a spinner, can only be treated as a form of complex labour. The value of the product of an hour of each type of concrete labour is, in fact, some multiple or fraction of an hour of abstract labour, dependent upon how much consumers are prepared to pay, in the market, for the product of this labour.
If we take the situation, Marx refers to of Robinson Crusoe, and the same applies to a peasant producing use values, purely for their own consumption, this distinction itself does not arise. The value of an hour of Robinson's concrete labour in producing chairs is the same as an hour of his labour producing yarn, and consequently, each are for him an hour of abstract labour.
“In spite of the variety of his work, he knows that his labour, whatever its form, is but the activity of one and the same Robinson, and consequently, that it consists of nothing but different modes of human labour.”
An hour for him spent in one form of labour is an hour lost to some other form of activity. His only concern then is whether the utility (use value) he obtains from an hour of his labour spent in one activity is greater than the utility obtained spent in some other activity. In terms of value, as opposed to use value, the quantity is the same, i.e. one hour.
For Robinson, or for the self-sufficient peasant, the concrete labour they expend on the production of each individual product is indeed embodied both as use value and value. Yet, even here neither Robinson nor the peasant is really concerned with the labour they embody within each individual product. Both are concerned with the average labour-time required for any particular type of production. They may find that it takes two hours to catch the first fish of the day, but after that, they catch one every fifteen minutes. Its the average time to catch a fish that determines how they will allocate their labour-time between production of fish or some other activity.
Similarly, a metre of cloth may take a week to produce, because the particular batch of cotton is problematic, and requires longer to spin into yarn, and then the yarn repeatedly breaks when being woven. But, the next metre may be produced in three days, because those problems are not present. It is, again, the average time required to produce the cloth that is considered, not the labour-time embodied in any particular metre of cloth.
But, when we come to examine the concept of value within the context of commodity production and exchange, as existed as Engels states from around 10,000 years ago to around the 15th century, even this concept of average value is superseded. It is then no longer just the average value of the products produced by the individual producer – their individual value as Marx calls it – that is relevant, but their social value, the average proportion of total available social labour-time, which they represent.
Marx makes clear that, in this context, the concept of the materialisation or embodiment of labour in the commodity is false.
“The materialisation, etc., of labour is however not to be taken in such a Scottish sense as Adam Smith conceives it. When we speak of the commodity as a materialisation of labour – in the sense of its exchange value – this itself is only an imaginary, that is to say a purely social mode of existence of the commodity which has nothing to do with its corporeal reality; it is conceived as a definite quantity of social labour or money...Therefore, the materialisation of labour in the commodity must not be understood in that way. (The mystification here arises from the fact that a social relation appears in the form of a thing).”
(Theories of Surplus Value, Part 1, Chapter IV, p 171-2)
In other words, the labour is not embodied or materialised as value in the commodity. The phrase is simply intended to reflect the fact that, at any one time, each commodity represents a certain quantity of social labour-time, irrespective of the actual labour that was embodied within that particular commodity unit, and indeed irrespective of the individual value of the commodities produced by that particular producer.
The value of each commodity unit is determined not by the labour embodied within it, but by the socially necessary labour-time required to produce that type of commodity, of which each individual unit is merely a representative. This exchange of things – commodities – creates the illusion that it is these things that have value, rather than being merely the representatives of value. As Marx puts it, every commodity is money, it is a claim to a certain quantity of labour-time, and that quantity of labour-time is equal to the socially necessary labour-time required for its own production.
The commodity does not embody labour within it as value, thereby making that value some intrinsic quality of the commodity. The commodity is rather merely a vessel within which value is contained, and the quantity of that value can be greater or smaller, within the same individual commodity, in accordance with the proportion of social labour time it represents, a proportion which is constantly changing, as social productivity changes.