Accordingly,  if  by  quantity  of  hfe  we  mean  the  amount  of
physical  energy  developed  or  the  amount  of  physical  work
done,  all  the  requirements  of  breadth  of  life  are  fully  included
in  the  requirement  of  length  alone.
But  this  is  not  what  we  commonly  mean  by  '  breadth  of  life.'
When  we  speak  of  one  form  of  existence  as  being  broader  than
another,  we  use  *  breadth '  in  its  second  possible  meaning
in  which  it  refers  not  to  amount  but  to  variety  and
co7npkxity  of  activity.  And  this  is  evidently  what  Mr.  Spencer
means  by  'the  more  multiplied  and  varied  adjustments  of
acts   to  ends.'      But,  of  course,  breadth  of  life  is  not    mere


SCIENTIFIC   HEDONISM  67

variety  and  complexity.  We  do  not  conceive  a  life  to  be
broader  merely  because  one's  energies  are  more  scattered ;
nor,  again,  because  being  scattered,  their  mutual  relations  are
more  complicated  and  more  difficult  of  statement.  A  broader
life,  in  the  popular  and  desirable  sense,  is  a  life  so  organised
as  to  contain  more  of  what  is  humanly  interesting.  But
(assuming  that  we  have  rejected  length  of  life  as  a  sole  crite-
rion) we  have  no  quantitative  conception  for  the  measure  of
what  is  interesting.  The  term  *  breadth  '  is  a  mere  metaphor.
Multiplying  the  length  of  a  hfe  into  its  breadth  is  like  multiply-
ing the  height  of  a  building  by  its  architectural  beauty.  It  is
multiplying  a  number  of  years  into  an  interesting  quality,  a
quantity  into  something  which  is  not  a  quantity.  This  is  evi-
dently an  impossible  mathematical  operation.
