DEMAND 
37 
enlarged income is not accompanied by a 
proportional access of utility may be called the 
law of the diminishing utility of income. 
Our first step in analysis having been com 
pleted, we may now pass on to inquire whether 
any propositions can be laid down connecting 
the utility of individual things with the quan 
tity of them that a person possesses. It will be 
discerned at once that this enquiry can be con 
ducted on three different assumptions. It may 
be supposed (1) that the person’s possession of 
other things remains as before ; (2) that the 
person’s income remains as before, except 
for the addition of further increments of the 
article in question, but that the person is at 
liberty to rearrange the expenditure of his 
income laid out on other things if he so desire, 
or (3) that his income and the way in which 
it is spent may vary. 
In the first case it is unquestionable that the 
utility enjoyed by the person can only increase, 
if it increases at all, at a diminishing rate very 
soon after consumption begins. Minute sup 
plies of a thing might at first simply whet 
the individual’s appetite if they had any 
effect at all, but as supplies increased they 
would take from the keenness of its edge. 
' The same conclusion holds of the second case. 
But about the third case there is some doubt.