We  have  touchstones  for  all  this,  and  every  one
makes  use  of  them  before  making  known  the  fruits  of
his  labors.  The  attempt  to  maintain  any  proposition
by  lawyer's  tricks,  or  the  intention  to  make  others  be-
lieve anything  that  cannot  be  proven,  are  immediately
wrecked  by  the  ethics  of  science."

Not  so  in  other  fields,  where  concrete  and  material
things  are  left  behind  and  abstract,  so-called  philoso-
phical, matters  are  taken  up,  as,  for  instance,  questions
of  general  conceptions  of  the  world  and  of  life,  of  be-
ginning and  end,  of  the  semblance  and  the  essence  of
things,  of  cause  and  effect,  of  matter  and  force,  of
might  and  right,  of  wisdom  of  life,  of  morality,  relig-
ion, and  politics.  Here  we  find,  instead  of  irrefutable
proofs,  mere  "lawyer's  tricks,"  an  absence  of  reliable
knowledge,  a  mere  groping  amid  contradictory  opin-
ions.
And  it  is  precisely  the  prominent  authorities  of
natural  science  who  show  by  their  disagreements  on
such  matters  that  they  are  mere  tyros  in  philosophy.
It  follows,  then,  that  the  socalled  ethics  of  science,  the


50  THE   NATURE  OF  HUMAN   BRAIN   WORK

touchstones  of  which  the  boast  is  made  that  they
never  fail  in  determining  what  is  knowledge  and  what
is  mere  conjecture,  are  based  on  a  purely  instinctive
practice,  not  on  a  conscious  theory  of  understanding.
