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 which belong to you, and which you
might have used for yourself?" And what good reason have you to maintain
that Paul is bound to render this especial service gratuitously; that he
has no right to demand anything more in consequence of this requisition;
that the State ought to interfere to force him to submit? Is it not
incomprehensible that the economist, who preaches such a doctrine to the
people, can reconcile it with his principle of _the reciprocity of
services_? Here I have introduced cash; I have been led to do so by a
desire to place, side by side, two objects of exchange, of a perfect and
indisputable equality of value. I was anxious to be prepared for
objections; but, on the other hand, my demonstration would have been
more striking still, if I had illustrated my principle by an agreement
for exchanging the services or the productions themselves.

Suppose, for example, a house and a vessel of a value so perfectly equal
that their proprietors are disposed to exchange them even-handed,
without excess or abatement. In fact let the bargain be settled by a
lawyer. At the moment of each taking possession, the shipowner says to
the citizen, "Very well; the transaction is completed, and nothing can
prove its perfect equity better than our free and voluntary consent. Our
conditions thus fixed, I shall propose to you a little practical
modification. You shall let me have your house to-day, but I shall not