ommodity is an object, external to ourselves, which by its properties
in some way satisfies human wants. The utility of a thing constitutes
its use-value. Use-values of commodities form the substance of all
wealth, and also become the material repositories of exchange-value. The
magnitude of the value of any article is determined by the labour-time
socially necessary for its production. So the value of a commodity would
remain constant if the labour-time required for its production also
remained constant. But the latter varies with every variation in the
productiveness of labour.

An article may have use-value, and yet be without value, if its utility
is not due to labour, as in the case of air, or virgin soil, or natural
meadows. If a thing be useless, so is the labour contained in it, for,
as the labour does not count as such, it therefore creates no value. A
coat is worth twice as much as ten yards of linen, because the linen
contains only half as much labour as the coat. All labour is the
expenditure of human labour-power in a special form and with a definite
aim, and in this, its character of concrete useful labour, it produces
use-values.

Everyone knows, if he knows nothing else, that commodities have a value
form common to them all, and presenting a marked contrast with the
varied bodily forms of their use-values. I mean their money form.

Every owner of a commodity wishes to part with it in exchange for other
commodities, but only those whose use-value satisfies some want of his.
To the owner of a commodity, every other commodity is, in regard to his
own, a particular equivalent. Consequently his own commodity is the
universal equivalent for all others. But, since this applies to every
owner, there is, in fact, no commodity acting as a universal equivalent.
It was soon seen that a particular commodity would not become the
universal equivalent except by a social act. The social action,
therefore, has set apart the particular commodity in which all values
are represented, and the bodily form of this commodity has become the
form of the socially recognised universal equivalent--money.

The first chief function of money is to supply commodities with the
material for the expression of their values. It thus serves as a
universal measure of value, and only by virtue of this function does
gold, the commodity _par excellence_, become money. But money itself has
no price. As the measure of value and the standard of pr