pretend to offer to the world, or a novelty that we bring into
science, any more than the division of labor was an unheard-of
thing when Adam Smith explained its marvels. The proportionality
of products is, as we might prove easily by innumerable
quotations, a common idea running through the works on political
economy, but to which no one as yet has dreamed of attributing
its rightful importance: and this is the task which we undertake
today. We feel bound, for the rest, to make this declaration in
order to reassure the reader concerning our pretensions to
originality, and to satisfy those minds whose timidity leads them
to look with little favor upon new ideas.

The economists seem always to have understood by the measure of
value only a standard, a sort of original unit, existing by
itself, and applicable to all sorts of merchandise, as the yard
is applicable to all lengths. Consequently, many have thought
that such a standard is furnished by the precious metals. But
the theory of money has proved that, far from being the measure
of values, specie is only their arithmetic, and a conventional
arithmetic at that. Gold and silver are to value what the
thermometer is to heat. The thermometer, with its arbitrarily
graduated scale, indicates clearly when there is a loss or an
increase of heat: but what the laws of heat-equilibrium are; what
is its proportion in various bodies; what amount is necessary to
cause a rise of ten, fifteen, or twenty degrees in the
thermometer,--the thermometer does not tell us; it is not certain
even that the degrees of the scale, equal to each other,
correspond to equal additions of heat.

The idea that has been entertained hitherto of the measure of