Src. 3] UTILITY 43 
In proposing that economists substitute so far as possible 
the term “desirability” for “utility,” the author is simply 
following the example of Professor Gide! and Professor 
Marshall. 
§ 3 
If the term “utility” is to be used at all, we must dis- 
tinguish the utility of goods from the use of the goods. 
As has been pointed out, the uses or services of goods are 
the desirable events which occur by their means, Utility, 
on the other hand, is not these desirable events, but their 
desirability. 
Again, the desirability or utility of goods must not be 
confused with the pleasure which may be ultimately ob- 
tained from those goods. Here our second concept is 
involved, for pleasure is not the desire, but the satisfac- 
tion of the desire. It is an experience in time, and requires 
duration of time for its existence. Desirability, which 
means the intensity of desire of an individual under certain 
conditions, merely indicates a state of mind at a particular 
point of time, namely, the point of time at which he mentally 
weighs and measures the desirability of any contemplated 
service, property, or wealth. We may speak of the de- 
sirability of a fruit orchard to a particular person on Janu- 
ary 1, 1905; but the pleasure derivable from that orchard 
is only to be experienced during future years, as it bears 
fruit and the fruit gives enjoyment to those who eat it. 
Thus we have two concepts: utility or desirability, — a 
state of mind at a point of time; and pleasure or satisfac- 
tion, — an experience of mind through a period of time. 
These two concepts are closely related; for the desirability 
of goods is simply the present esteem in which the future 
1 Gide’s Principles of Political Economy, 2d American ed, 1904, 
Pp. 48. See also the present writer’s “ Mathematical Investigations in the 
Theory of Value and Prices,” Transactions of the Connecticut Academy, 
1892, p. 23.