NATURE OF CAPITAL AND INCOME [Crae. III 
§ 2 
The desirability, then, of any particular goods, at any 
particular time, to any particular individual, under any 
particular conditions, is the strength or intensity of his de- 
sire for those goods at that time and under those conditions. 
What is here called desirability is identical with what has 
usually been called in economic writings “utility.” But 
utility, though not to be utterly displaced, is not the hap- 
piest term for our purpose. To say nothing of the mere 
awkwardness of its only antithetical term — “disutility ”’ 
— as compared with “undesirability,” it has fallen heir 
to so many different meanings that its use here is apt to 
be confusing. The term “useful,” for instance, in ordinary 
language is employed in opposition to “ornamental.” 
In this sense diamonds are said to be ornamental and not 
useful, though in economic science they are adjudged 
useful. Again, “utility” usually implies intrinsic merit, 
whereas, when we employ it in economic science, we are 
obliged to apply it to any noxious thing considered by its 
owner desirable, for instance, opium, alcohol, or degrad- 
ing literature. Finally, in the last few years, the word 
“utility” has come into a new and technical meaning as 
employed in the phrase “public utilities,” which desig- 
nates electric lighting plants, street railway systems, gas 
works, and many other things which are merely collections 
of wealth of a peculiar kind. 
In order to obviate these objections, Professor Pareto 
has proposed an entirely new term, “ophelimity.” This 
has both the advantages and the disadvantages of any 
newly invented technical term, and has thus far shared 
the fate which usually befalls the attempt to coin words. 
The word “utility” is still employed, and it is not likely 
that “desirability,” “ophelimity,” or any other term will 
soon displace it. In the present book we shall use both 
“utility” and “desirability,” but preferably the latter.