Why is this underlying determination of value by labor time not apparent in the movement of exchange value- i.e. why is the ‘absolute’ determination of value magnitudes by quantities of labor only ever manifest in this indirect and ‘relative’ exchange value form?

“In actual fact, the concept “VALUE” presupposes “EXCHANGES” of the products. Where labor is communal, the relations of men in their social production do not manifest themselves as *“values” of “things”.

While common to different kinds of society, the regiment of time only assumes a value form in a society in which individuals are compelled to maintain themselves through the exchange of commodities.

“In all states of society, the labor time that it costs to produce the means of subsistence must necessarily be an object of interest to mankind, though not of equal interest in different stages of development.”

“Political Economy has indeed analyzed, however incompletely, value and its magnitude, and has discovered what lies beneath these forms. But it has never once asked the question why labor is represented by the value of its product and labor time by the magnitude of that value.” Capital Vol.1

Why is the magnitude of the value of commodities measured by the labor time expended in their production?

Along with the newly produced value, one portion of the value of every commodity replaces or buys back the conditions expended in producing that commodity.

The total value of a commodity is the sum of the newly expended labor required for its production plus the past labor that went into the material conditions of production used up in this new expenditure of labor.

All the material conditions that were used up in producing a commodity production are themselves commodities produced in a certain duration. The value of the material conditions that were used up in that labor process is transferred to the its product.

All labor expended in the production of commodities requires the combination of the separately owned conditions of production in a process measured by its socially necessary duration.

Value relations between the products of labor are social relations between the individuals compelled to exchange the products of their labor for the equivalents they require. But they are at the same time the social relations between the owners of the separately owned conditions of that labor.

Labor, in this sense separated/alienated sense of the term, is not itself a commodity which can be owned and exchanged, although the embodied human capacity to labor can be owned and alienated (given over for) an equivalent.

Labor, in this sense, was a production process taking place within a social relation grounded in the separation of the conditions of labor from the laborers themselves, compelling them to produce for exchange in competition with others.

This conception of labor did not imply any special role for human agency- in contradistinction to the role of machines and natural forces- within this production process.

In the obscure social language of commodity exchange, every private commodity could be said to posit its equivalence to every other commodity in proportion the labor that went into their production.

Every theory of value identifies a common quality, or substance- of which exchange values are merely the relative forms, the relations of equivalence each commodity posits to every other. Let us now examine these relative 'forms of value' more closely.

In the absence of a technology-driven process of economic change, the value level of analysis would be rendered superfluous.

The labor theory of value identifies a process operating through a more general supply and demand price mechanism, entailing constraints of supply and varying elasticities of demand.

This very general assumption is then qualified to take into account the varying elasticities of demand for different kinds of use values, for “only just so much of it is required for the satisfaction of social needs.”

The reduction in the quantity of labor required to produce a specific kind of commodity decreases its unit value: as the progress of technology cheapens products, the demand for them grows proportionately.

Marx cuts through this apparent causal circularity between two different senses of what is meant by a labor quantity:

In this formulation, the order of determination of the law of value at the macro-level seems to go from the distribution of effective demand for different commodities to a corresponding allocation of the aggregate labor of society into the branches producing those commodities.

"Only just so much of it is required for the satisfaction of social needs. The limitation occurring here is due to the use value. Society can use only so much of its total labor-time for this particular kind of product under prevailing conditions of production."

“This quantitative limit to the quota of social labor-time available for the various particular spheres of production is but a more developed expression of the law of value in general, although the necessary labor-time assumes a different meaning here." Karl Marx, Capital vol. 3

On the other, the proportion of society’s total labor time that was necessary to produce the total amount of this species of use value that there ended up being a demand for.

Building on this conception, socially necessary labor time as Marx defined it has two-interrelated dimensions: on the one hand, the technically determined production time of a single commodity of a particular kind representing all others of its kind.

The classical theory of value assumed that differences in the amount of labor it took different producers to make the same use value could be disregarded on the assumption that the lowest amount it took quasi-automatically became the standard by the pressure of competition.

They embody different quantities of labor. This quantitative measure can be conceived as a temporal measure on the assumption that all producers must maximize output over every unit of time in which that labor can be set into motion.

Following in the footsteps of classical political economy Marx maintained that what they have common is that they are all products of labor. What determines the proportions in which one commodity exchanges for another?

All these commodities have the quality of value itself, a quality that is being expressed in one or another relative form as an exchange value equation.