silver, and shows himself an unquestioning bimetallist. He further
admits the necessity of some token money of small denominations, to be
composed of the baser metals. Having drawn attention to the transition
from the circulation of money, the value of which is recognised
solely by weight, to the circulation of that which is accepted for its
imprint or superscription, the author insists that the production of
such an imprinted coinage is essentially a matter for the sovereign
authority in the State. Oresme now comes to the central point of his
thesis. Although, he says, the prince has undoubtedly the power to
manufacture and control the coinage, he is by no means the owner of it
after it has passed into circulation, because money is a thing which
in its essence was invented and introduced in the interests of society
as a whole.

Oresme then proceeds to apply this central principle to the solution
of the question which he sets himself to answer, and concludes that,
as money is essentially a thing which exists for the public benefit,
it must not be tampered with, nor varied in value, except in cases of
absolute necessity, and in the presence of an uncontroverted general
utility. He bases his opposition to unnecessary monetary variation on
the perfectly sound ground that such variation is productive of loss
either to those who are bound to make or bound to receive fixed sums
in payment of obligations. The author then goes on to analyse the
various kinds of variation, which he says are five--_figurae_,
_proportionis_, _appellationis_, _ponderis_, and _materiae_. Changes
of form (_figurae_) are only justified when it is found that the
existing form is liable to increase the damage which the coins suffer
from the wear and tear of usage, or when the existing currency has
been degraded by widespread illegal coining; changes _proportionis_
are only allowable when the relative value of the different metals
constituting the coinage have themselves changed; simple changes of
name (_appellationis_), such as calling a mark a pound, are never
allowed. Changes of the weight of the coins (_ponderis_) are
pronounced by Oresme to be just as gross a fraud as the arbitrary
alteration of the weights or measures by which corn or wine are sold;
and changes of matter (_materiae_) are only to be tolerated when the
supply of the old metal has become insufficient. The debasement of the
coinage by the introduction of a cheaper alloy is condemned.