So far two aspects of the commodity --use-value and exchange-value --have been examined,but each one separately.The commodity,however,is the direct unity of use-value and exchange-value,and at the same time it is a commodity only in relation to other commodities.The exchange process of commodities is the real relation that exists between them.This is a social process which is carried on by individuals independently of one another,but they take part in it only as commodity-owners;they exist for one another only insofar as their commodities exist;they thus appear to be in fact the conscious representatives of the exchange process.
The commodity is a use-value,wheat,linen,a diamond,machinery,etc.,but as a commodity it is simultaneously not a use-value.It would not be a commodity,if it were a use-value for its owner,that is a direct means for the satisfaction of his own needs.For its owner it is on the contrary a non-use-value ,that is merely the physical depository of exchange-value,or simply a means of exchange .Use-value as an active carrier of exchange-value becomes a means of exchange.The commodity is a use-value for its owner only so far as it is an exchange-value.
[It is in this sense that Aristotle speaks of exchange-value (see the passage quoted at the beginning of this chapter).]The commodity therefore has still to become a use-value,in the first place a use-value for others.Since it is not a use-value to its owner,it must be a use-value to owners of other commodities.If this is not the case,then the labour expended on it was useless ;labour and the result accordingly is not a commodity.The commodity must,on the other hand,become a use-value for its owner ,since his means of existence exist outside it,in the use-values of other people's commodities.To become a use-value,the commodity must encounter the particular need which it can satisfy.Thus the use-values of commodities become use-values by a mutual exchange of places:they pass from the hands of those for whom they were means of exchange into the hands of those for whom they serve as consumer goods.Only as a result of this universal alienation of commodities does the labour contained in them become useful labour.Commodities do not acquire a new economic form in the course of mutual relations as use-values.On the contrary,the specific form which distinguished them as commodities disappears.Bread,for instance,in passing from the baker to the consumer does not change its character as bread.It is rather that the consumer treats it as a use-value,as a particular foodstuff,whereas so long as it was in the hands of the baker it was simply representative of an economic relation,a concrete and at the same time an abstract thing.The only transformation therefore that commodities experience in the course of becoming use-values is the cessation of their formal existence in which they were non-use-values for their owner,and use-values for their non-owner.To become use-values commodities must be altogether alienated;they must enter into the exchange process;exchange however is concerned merely with their aspect as exchange-values.
Hence,only be being realized as exchange-values can they be realized as use-values.
The individual commodity as a use-value was originally regarded as something independent,while as an exchange-value it was from the outset regarded in its relation to all other commodities But this was merely a theoretical,hypothetical,relation.It realises itself only in the process of exchange.
