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 desire
 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 happiest
 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 degrading
 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 designates
 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.