Editing Transformation problem (section)

=== Labour as the "value-creating substance" ===
Marx defined the "value" of a [[commodity]] as the total amount of socially necessary labour embodied in its production. He developed this special brand of the labour theory of value in the first chapter of volume 1 of ''Capital'''. Due to the influence of Marx's particular definition of value on the transformation problem, he is quoted at length where he argues as follows:

<blockquote>Let us take two commodities, e.g., corn and iron. The proportions in which they are exchangeable, whatever those proportions may be, can always be represented by an equation in which a given quantity of corn is equated to some quantity of iron: e.g., 1 quarter corn = x cwt. iron. What does this equation tell us? It tells us that in two different things&mdash;in 1 quarter of corn and x cwt. of iron, there exists in equal quantities something common to both. The two things must therefore be equal to a third, which in itself is neither the one nor the other. Each of them, so far as it is exchange value, must therefore be reducible to this third.</blockquote>
<blockquote>This common 'something' cannot be either a geometrical, a chemical, or any other natural property of commodities. Such properties claim our attention only in so far as they affect the utility of those commodities, make them use values. But the exchange of commodities is evidently an act characterised by a total abstraction from use value.</blockquote>
<blockquote>If then we leave out of consideration the use value of commodities, they have only one common property left, that of being products of labour. […] Along with the useful qualities of the products themselves, we put out of sight both the useful character of the various kinds of labour embodied in them, and the concrete forms of that labour; there is nothing left but what is common to them all; all are reduced to one and the same sort of labour, human labour in the abstract.</blockquote>
<blockquote>A use value, or useful article, therefore, has value only because human labour in the abstract has been embodied or materialised in it. How, then, is the magnitude of this value to be measured? Plainly, by the quantity of the value-creating substance, the labour, contained in the article.
:—Karl Marx, [http://www.marxists.org/archive/marx/works/1867-c1/ch01.htm#35b/ ''Capital'', Volume I, Chapter 1]</blockquote>