, we
are always compelled to reason upon this maxim, that _equal value_
results from liberty. We have, in fact, no other means of knowing
whether, at a given moment, two services are of the same value, but that
of examining whether they can be readily and freely exchanged. Allow the
State, which is the same thing as force, to interfere on one side or the
other, and from that moment all the means of appreciation will be
complicated and entangled, instead of becoming clear. It ought to be
the part of the State to prevent, and, above all, to repress artifice
and fraud; that is, to secure liberty, and not to violate it. I have
enlarged a little upon exchange, although loan is my principal object:
my excuse is, that I conceive that there is in a loan an actual
exchange, an actual service rendered by the lender, and which makes the
borrower liable to an equivalent service,--two services, whose
comparative value can only be appreciated, like that of all possible
services, by freedom. Now, if it is so, the perfect lawfulness of what
is called house-rent, farm-rent, interest, will be explained and
justified. Let us consider the case of _loan_.

Suppose two men exchange two services or two objects, whose equal value
is beyond all dispute. Suppose, for example, Peter says to Paul, "Give
me ten sixpences, I will give you a five-shilling piece." We cannot
imagine an equal value more unquestionable. When the bargain is made,
neither party has any claim upon the other. The exchanged services are
equal. Thus it follows, that if one of the parties wishes to introduce
into the bargain an additional clause, advantageous to himself, but
unfavourable to the other party, he must agree to a second clause, which
shall re-establish the equilibrium, and the law of justice. It would be
absurd to deny the justice of a second clause of compensation. This
granted, we will suppose that Peter, after having said to Paul, "Give me
ten sixpences, I will give you a crown," adds, "You shall give me the
ten sixpences _now_, and I will give you the crown-piece _in a year_;"
it is very evident that this new proposition alters the claims and
advantages of the bargain; that it alters the proportion of the two
services. Does it not appear plainly enough, in fact, that Peter asks of
Paul a new and an additional service; one of a different kind? Is it not
as if he had said, "Render me the service of allowing me to use for my
profit, for a year, five shillings whic