in the theory of value and prices.
23
§14.
Utility as defined in the preceding sections does not involve theeconomist in controversy as to the laws of the subjective states ofpleasure and pain, the influence of their anticipation as connectedwith their probabilities,* the vexed questions whether they differ inquality as well as in intensity and duration,! whether duty can orcannot exist as a motive independently of pleasure,!; etc -
It does not follow that these discussions have no meaning or im-portance. Doubtless pleasure and pain are connected with desireand doubtless they have an important biological and sociologicalfunction as registering “healthful” or "pathological” conditions.!But the economist need not envelop his own science in the hazes ofethics, psychology, biology and metaphysics.
Perhaps utility is an unfortunate word to express the magnitudeintended. Desirability|| would be less misleading, and its opposite,undesirability is certainly preferable to dis-utility. “ Utility ” is theheritage of Bentham and his theory of pleasures and pains. For ushis word is the more acceptable, the less it is entangled with histheory.
§ 15.
This chapter may be thus summarized:Postidate : Each individual acts as he desires.
(2) and (1)
( 3 )
( 4 )
( 5 )
Definitions of utility.
ut. of A ^ ut. of B
if the given indiv. at the given timeprefers A to B or neither.
ut. of dAut. of c?B — n
if ut. of t£A=ut. of ndM. (M total)
and ut. of <ZB=rut. of d'M (M also total).
<*U , r . ,
~~t~i = Marginal utility.
= Unit of utility (util.) (A being given).