SUPPLY  AND  DEMAND

89

delicately  adjusted  economic  system  by  the
marginal  cost  of  any  normal  business  which
was  in  a  position  of  perfect  equilibrium.  In
Chapter  VII  we  shall  meet  again  with  the
differentiation  of  business  experience  in  the
matter  of  business  organisation  and  of  the
action  of  the  law  of  equi-marginal  returns  in
settling  it  ;  and,  since  the  analogies  between
the  laws  of  demand  and  supply  have  been
touched  upon,  it  may  further  be  remarked
here  that  we  shall  find  in  Chapter  IX  that
the  marginal  method  discloses  on  the  supply
side  of  value  a  surplus  analogous  to  that  on
the  demand  side  known  as  consumer’s  surplus.
To  conclude  this  chapter  a  few  remarks  may
be  made  as  regards  the  agents  in  production.
Production  consists  in  making  utilities  out  of
the  material  and  forces  at  our  disposal—
utilities  being  defined  as  laid  down  in  the
previous  chapter.  The  agents  are  commonly
classified  as  land,  labour,  capital  and  organising. ­
  Land  means  not  only  land  but  all  the
forces  of  nature  (apart  from  human  nature)
which  are  an  aid  to  man’s  productive  activities, ­
  including  animal  life  and  winds  and  rivers
and  seas.  Organising  and  labour  are  of  the
same  general  class,  and  to  a  large  extent  they
interpenetrate  one  another,  but  for  purposes