26 
ON THE NATURE 
the direct assertion, that ‘although money 
may increase inits power of purchasing, it does 
not necessarily increase in value*” If Mr. 
Malthus thus abandons his own definition; what 
other will he put in its place ? 
I have already shown, that the power of pur- 
chasing, or the power of commanding other 
objects in exchange, can be expressed only by 
quantity. In other words, the value of one 
commodity can be expressed only by the quan- 
tity of some other object for which it will ex- 
change. When a hat is said to be twenty 
shillings in value, it is obvious that the value of 
the hat is expressed by the quantity of silver: 
when a yard of cloth is said to be worth two 
bushels of wheat, the value of the cloth is ex- 
pressed by the quantity of wheat. It is im- 
possible to designate, or express the value of 
a commodity, except by a quantity of some 
other commodity. 
The power of purchasing, or the value of an 
object in relation vo some other object, admits 
* Pace 62.