CHAPTER  III
 

               THEORY  OF  UTILITY



                Definition of Terms.

Pleasure  and pain  are undoubtedly the  ultimate

objects of the Calculus of Economics.  To satisfy our

wants to the utmost with the least effort—to procure

the greatest amount  of what is  desirable at the

expense  of the least  that  is  undesirable—in  other

words, to  maximise  pleasure,  is  the  problem   of

Economics.   But it  is  convenient  to transfer our

attention as soon  as possible to the physical objects  or

actions which are the source to  us of pleasures and

pains.  A very large  part of the labour of any com¬

munity is spent upon the production of the  ordinary

necessaries and conveniences of life, such  as  food,

clothing, buildings, utensils, furniture, ornaments, etc.;

and the  aggregate  of these  things, therefore,  is the

immediate object  of our attention.

   It is  desirable to introduce at once, and to define,

some  terms  which facilitate the   expression of the

Principles  of Economics.  By  a commodity  we shall