We must remark, also, that the constant appearance of money in every exchange has overturned and misled all our ideas:  men have ended in thinking that money was true riches, and that to multiply it was to multiply services and products.  Hence the prohibitory system; hence paper money; hence the celebrated aphorism, “What one gains the other loses;” and all the errors which have ruined the earth, and embrued it with blood.[2] After much research it has been found, that in order to make the two services exchanged of equivalent value, and in order to render the exchange equitable, the best means was to allow it to be free.  However plausible, at first sight, the intervention of the State might be, it was soon perceived that it is always oppressive to one or other of the contracting parties.  When we look into these subjects, 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