consequently interests to rise.

3rd. The anecdote I have just related enables you to explain this
apparently singular phenomenon, which is termed the duration or
perpetuity of interest. Since, in lending his plane, James has been
able, very lawfully, to make it a condition that it should be returned
to him, at the end of a year, in the same state in which it was when he
lent it, is it not evident that he may, at the expiration of the term,
lend it again on the same conditions? If he resolves upon the latter
plan, the plane will return to him at the end of every year, and that
without end. James will then be in a condition to lend it without end;
that is, he may derive from it a perpetual interest. It will be said,
that the plane will be worn out. That is true; but it will be worn out
by the hand and for the profit of the borrower. The latter has taken
into account this gradual wear, and taken upon himself, as he ought, the
consequences. He has reckoned that he shall derive from this tool an
advantage, which will allow him to restore it in its original condition,
after having realised a profit from it. As long as James does not use
this capital himself, or for his own advantage--as long as he renounces
the advantages which allow it to be restored to its original
condition--he will have an incontestable right to have it restored, and
that independently of interest.

Observe, besides, that if, as I believe I have shown, James, far from
doing any harm to William, has done him a _service_ in lending him his
plane for a year; for the same reason, he will do no harm to a second, a
third, a fourth borrower, in the subsequent periods. Hence you may
understand that the interest of a capital is as natural, as lawful, as
useful, in the thousandth year, as in the first. We may go still
further. It may happen that James lends more than a single plane. It is