2. Benthamism was so much in the air, both in
England and on the Continent, that (with the notable
exception of Carl Menger) the early writers on utility
followed Bentham's hedonism and equated utility with
the pleasure experienced by an individual during the
act of consumption. This is especially true of Gossen
and Edgeworth and, to some extent, of Jevons. It is
from this position that Edgeworth, with whom hedo-
nism reached its apogee in economics, was able to
defend the cardinal measurability of utility by invoking
the law of sensations enunciated by G. T. Fechner and
E. H. Weber in 1860. Utility is measurable, he con-
tended, because an actual pleasure may be measured
in terms of its “atoms,” i.e., in terms of “just percep-
tible increments” (Mathematical Psychics, 1881). And,
even though not quite in the same vein as Bentham,
Edgeworth expressed his belief in the eventual con-
struction of a hedonimeter for measuring actual pleas-
ures.
But economics could not go on indefinitely with a
notion of utility which implies that the consumer de-
cides whether or not to buy more coffee while drinking
coffee. The modern notion of utility embodies an idea
laboriously outlined by Richard Jennings in an essay
that received hardly any attention at the time (1855).
Utility (Jennings used “value”) is the expression of the
expected pleasure at which the individual arrives on
the basis of his past actual pleasures. However, it is
the unique, yet totally ignored, merit of Gossen to have
perceived that one can go deeper than that. Indeed,
Gossen alone saw that actual pleasure is governed by
a second diminishing principle: Any pleasure dimin-
ishes in intensity and duration with its repetition, and
the sooner the repetition, the greater the diminution.
When all is said and done and utility is taken in
Jennings' sense, the fact that milk tastes better if con-
sumed less frequently has more to do with the Principle
of Decreasing Marginal Utility than the fact that the
intensity of the pleasure of drinking milk decreases as
one is drinking milk.
