““There is in truth no wealth for individuals and for peoples, except when each labours for all” (that is to say, when his labour takes the form of general social labour, for in any other meaning this would be nonsense; since, except in the form of general social labour, an iron manufacturer does not work for all, but only for consumers of iron); “and all for each” (p 207), but Marx points out that what this means is that the concrete labour of each individual must be reduced to abstract labour. The producer of iron does not labour for all, but only for the buyers of iron, and its clear that all do not work for each because total production is divided into a range of individual products, and each individual person does not buy all products, but only specific products.
All work for each only on the basis that all production becomes co-operative, and on the basis that the abstract labour contained in any product is comparable to that in every other product.
“... what this means is therefore only that each special product takes on a form in which it exists for everyone; and it only exists in this form, not because as a special product it is distinct from the product of each other person, but because it is identical with it; that is, once more the form of social labour as it exists on the basis of commodity production.” (p 207)
Ganilh has a purely subjective view of exchange value – much like that of neoclassical economics, which equates exchange value with market price, as being whatever commodities exchange for. If A exchanges for a lot of B,C,D then it has a high exchange value. Moreover, for Ganhilh, wealth and exchange value are identical. But, as Marx continues to explain, if value only exists because of exchange, then if we take the totality of commodities, they have no exchange value!
“Exchange-value consists of the relative proportion in which products exchange for each other. The total quantity of products has therefore no exchange-value, since it is not exchanged for anything. Hence, society, whose wealth consists of exchange-values, has no wealth. Consequently it follows not only, as Ganilh himself concludes, that the “national wealth, which is composed of the exchange-values of labour” (p.108), can never rise and can never fall in exchange-value ( therefore there is no surplus-value), but that it has no exchange-value whatever, and so is not wealth, since wealth consists only of exchangeable values.” (p 208)
If, on the other hand, we take the total of those products and consider them as values outside of exchange, it is quite clear that this value continues to exist, whether or not they are exchanged or simply consumed. The coal producer, who uses a portion of their output to fuel their steam engines, does not exchange the coal as a commodity, but uses it for their own productive-consumption, in just the same way that a peasant farmer uses a part of their output of wheat as seed, to replace that used in growing the wheat. Yet, in both cases, its clear that both the coal and the wheat have value, despite taking no part in commodity exchange.
The totality of production, whether exchanged or not has value, determined by the labour-time required for its production. That value can be expressed as an amount of exchange value, again whether it is exchanged or not, simply by equating it with money. The commodities have exchange value, not because they are exchanged, but because irrespective of whether they are exchanged, they have value as a product of labour, and the relation of these values determines that exchange value.