31. Rise of Commerce. Principle of the valuation of
commercial things.
Reciprocal wants first introduced exchanges of what we
possessed, for what we stood in need of one species of provision
was bartered for another, or for, labour. In exchanging, it is
necessary that each party is convinced of the quality and
quantity of every thing exchanged. In this agreement it is
natural that every one should desire to receive as much as he
can, and to give as little; and both being equally masters of
what they have to barter, it is in a man's own breast to balance
the attachment he has to the thing he gives, with the desire he
feels to possess that which he is willing to receive, and
consequently to fix the quantity of each of the exchanged things.
If the two persons do not agree, they must relax a little on one
side or the other, either by offering more or being content with
less. I will suppose that one is want of corn and the other of
wine; and that they agree to exchange a bushel of corn for six
pints of wine. It is evident that by both of them, one bushel of
corn and six pints of wine are looked upon as exactly equivalent,
and that in this particular exchange, the price of a bushel of
corn is six pints of wine, and the price of six pints of wine is
one bushel of corn. But in another exchange between other men,
this price will be different, accordingly as one or the other of
them shall have a more or less pressing want of one commodity or
the other; and a bushel of corn may be exchanged against eight
pints of wine, while another bushel shall be bartered for four
pints only.) Now it is evident, that not one of these three
prices can be looked on as the true price of a bushel of corn,
rather than the others; to each of the dealers, the wine he has
received was equivalent to the corn he had given. In a word, so
long as we consider each exchange independent of any other, the
value of each thing exchanged has no other measure than the wants
or desires of one party weighed with those of the other, and is
fixed only by their agreement.
