Value is the corner-stone of the economic edifice. The divine
artist who has intrusted us with the continuation of his work has
explained himself on this point to no one; but the few
indications given may serve as a basis of conjecture. Value, in
fact, presents two faces: one, which the economists call value in
USE, or intrinsic value; another, value in EXCHANGE, or of
opinion. The effects which are produced by value under this
double aspect, and which are very irregular so long as it is not
established,--or, to use a more philosophical expression, so long
as it is not constituted,--are changed totally by this
constitution.

Now, in what consists the correlation between USEFUL value and
value in EXCHANGE? What is meant by CONSTITUTED value, and by
what sudden change is this constitution effected? To answer
these questions is the object and end of political economy. I
beg the reader to give his whole attention to what is to follow,
this chapter being the only one in the work which will tax his
patience. For my part, I will endeavor to be more and more
simple and clear.

Everything which can be of any service to me is of value to me,
and the more abundant the useful thing is the richer I am: so
far there is no difficulty. Milk and flesh, fruits and grains,
wool, sugar, cotton, wine, metals, marble; in fact, land, water,
air, fire, and sunlight,-- are, relatively to me, values of use,
values by nature and function. If all the things which serve to
sustain my life were as abundant as certain of them are, light
for instance,--in other words, if the quantity of every valuable
thing was inexhaustible,--my welfare would be forever assured: I