Marx has been establishing the basis of the rate of value on the various commodities in a given society. He has explained that a commodity’s value is based on the quantity of labour (measured in time) that it takes in any given society to produce it. This ‘socially necessary labour time’ determines the value of the commodity as a unit of the overall productiveness of a society:
The value of one commodity is to the value of any other, as the labour time necessary for the production of the one is to that necessary for the production of the other. In general, the greater the productiveness of labour, the less is the labour time required for the production of an article, the less is the amount of labour crystallised in that article, and the less is its value; and vice versâ, the less the productiveness of labour, the greater is the labour time required for the production of an article, and the greater is its value. The value of a commodity, therefore, varies directly as the quantity, and inversely as the productiveness, of the labour incorporated in it.
So an intensely productive society (due to mechanisation of the production process, say) will make for cheaper commodities, while less intensive production will result in more costly commodities due to the extra labour time involved.
A thing can be a use value, without having value. This is the case whenever its utility to man is not due to labour. Such are air, virgin soil, natural meadows, &c. A thing can be useful, and the product of human labour, without being a commodity. Whoever directly satisfies his wants with the produce of his own labour, creates, indeed, use values, but not commodities. In order to produce the latter, he must not only produce use values, but use values for others, social use values.
Natural resources such as air and fresh water are not commodities… Until they are commodified! Bottled water is now widely sold as a commodity, and canned fresh air is a real thing in industrial China. 😢 ‘Social use values’ is an interesting thing to call a commodity. In contrast to home produce for private consumption, they are produced specifically for others to consume in exchange for social value.
So things produced directly for one’s own consumption or use, such as homemade shelving or homegrown… erm… tomatoes (😏) are use values, useful things, which are not however commodities/exchange values.
Lastly nothing can have value, without being an object of utility. If the thing is useless, so is the labour contained in it; the labour does not count as labour, and therefore creates no value.
Someone must want/need the commodity otherwise they won’t make an exchange for it: while exchange value is a complete abstraction of a commodity’s use value (the former being expressed in a quantity of some other commodity entirely), it is however still a necessary condition for the object to be of use to someone for an exchange to happen.
Marx seems to be ‘labouring’ these rather obvious points re the difference between exchange value and use value so as to stress the *social* nature of exchange value, and how personal use values can take on the social dynamic of commodities.