We now have three concepts: use-value, exchange-value, and value. (I’m not sure under what conditions Marx capitalizes the V in value; it seems inconsistent, but I’m guessing there is a reason for it somewhere).
Use-value refers to the material particulars of the commodity; size, weight, chemical composition, shape, &c. Exchange-value refers to the quantity of that commodity that can be exchange for given quantities other commodities. Value refers that which is carried by the commodity that permits it to be exchanged for definite quantities of other commodities; we might say that exchange-value is the reflection of value, or how value is expressed in the market.
Value, in other words, is the expression of human labor in the abstract– by abstract, we mean that, when discussing value, we no more care about the particular nature of the labor that produced the commodity, then we care about the use-value.
Page 38: “We have seen that when commodities are exchanged, their exchange-value manifests itself as something totally independent of their use-value. But if we abstract from their use-value, there remains their Value as defined above. Therefore, the common substance that manifests itself, whenever they are exchanged, is their value.”
“A use-value, or useful article, therefore, has value only because human labour in the abstract has been embodied or materialized 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. The quantity of labour, however, is measured by its duration.”
Well, okay, that makes sense. But what if the labor is, well, badly done? How do you derive value from shoddy work (unless you’re Microsoft)?
Page 39: “Some people might think that if the value of a commodity is determined by the quantity of labour spent on it, the more idle and and unskilful the labourer, the more valuable would his commodity be, because more time would be required in it’s production. The labour, however, that forms the substance of value, is homogeneous human labour, expenditure of one uniform labour-power. The total labour-power of society, which is embodied in the sum total of the values of all commodities produced that society, counts here as one homogeneous mass of human labour-power, composed though it be of innumerable individual units. Each of these units is the same as any other, so far as it has the character of average labour-power of society, and takes effect as such; that is, so far as it requires for producing a commodity, no more time than is needed on an average, no more than is socially necessary. The labour time socially necessary is that required to produce an article under the normal conditions of production, and with the average degree of skill and intensity prevalent at the time.”
So then: the value of a commodity is determined by the amount of labor necessary for it’s production, not the amount that, in a given case, it actually took. If it takes me twice as long to make a brick as it takes most people, it doesn’t mean my bricks are worth twice as much, it means I’m about to be fired from my job as a brick-maker.
But this brings up the next question: How do we compare the labor of me, an humble brick-maker, with that of, for example, the architect who created the blue-prints for these townhouses my bricks will be used on? He is paid a great deal more than me, presumably his labor is worth more.
Glancing ahead, it seems we will be getting to that. For now, I will quietly mediate on socially necessary labor time.