﻿MAR. 
  19, 
  1922 
  troland: 
  psychophysics 
  the 
  key 
  of 
  physics, 
  etc. 
  145 
  

  

  for 
  a 
  philosophically 
  uncritical 
  physicist 
  prior 
  to 
  the 
  advent 
  of 
  rela- 
  

   tivity 
  theory 
  to 
  regard 
  his 
  subject 
  matter 
  as 
  an 
  actual 
  abstraction 
  

   from 
  immediate 
  experience. 
  I 
  say 
  "philosophically 
  uncritical" 
  be- 
  

   cause 
  even 
  before 
  the 
  advent 
  of 
  the 
  Einsteinian 
  theory 
  a 
  very 
  close 
  

   scrutiny 
  of 
  the 
  relations 
  obtaining 
  between 
  physical 
  ideas 
  and 
  the 
  

   actual 
  data 
  of 
  consciousness 
  would 
  have 
  revealed 
  serious 
  difficulties 
  

   in 
  their 
  identification 
  at 
  any 
  point. 
  These 
  difficulties 
  were 
  manifest 
  

   to 
  Bishop 
  Berkeley, 
  several 
  centuries 
  ago, 
  when 
  he 
  wrote 
  his 
  essay 
  

   on 
  A 
  New 
  Theory 
  of 
  Vision 
  and 
  maintained 
  that 
  the 
  primary 
  as 
  well 
  

   as 
  the 
  secondary 
  qualities 
  of 
  external 
  experience 
  could 
  not 
  be 
  regarded, 
  

   as 
  required 
  by 
  the 
  physicist's 
  formula, 
  as 
  being 
  independent 
  of 
  the 
  

   observing 
  individual. 
  If 
  the 
  structures 
  and 
  the 
  changes 
  of 
  physics 
  

   differ 
  ever 
  so 
  minutely 
  from 
  those 
  which 
  occur 
  in 
  the 
  experience 
  of 
  

   the 
  observer 
  they 
  cannot 
  be 
  identical 
  with 
  the 
  latter, 
  and 
  must 
  there- 
  

   fore 
  be 
  conceived 
  as 
  comprising 
  a 
  separate 
  though 
  possibly 
  a 
  very 
  

   similar 
  system 
  of 
  things. 
  It 
  is 
  doubtful 
  whether 
  even 
  with 
  the 
  assis- 
  

   tance 
  of 
  the 
  notion 
  of 
  universals, 
  or 
  of 
  platonic 
  ideas, 
  we 
  can 
  legiti- 
  

   mately 
  conceive 
  even 
  absolutely 
  similar 
  structures 
  as 
  being 
  numerically 
  

   identical, 
  if 
  the 
  substances 
  which 
  enter 
  into 
  these 
  structures 
  are 
  differ- 
  

   ent 
  in 
  kind. 
  The 
  fact 
  that 
  our 
  perceptions 
  of 
  spacial, 
  massive, 
  and 
  

   temporal 
  relationships 
  are 
  conditioned, 
  as 
  was 
  emphasized 
  in 
  Berke- 
  

   ley's 
  classical 
  monograph, 
  upon 
  physiological 
  processes 
  is 
  not 
  in 
  itself 
  

   proof 
  that 
  these 
  perceptions 
  do 
  not 
  actually 
  include 
  portions 
  of 
  the 
  

   physical 
  universe. 
  However, 
  the 
  neo-realistic 
  philosophies 
  which 
  

   explicitly 
  assume 
  this 
  possibility 
  have 
  not 
  as 
  yet 
  succeeded 
  in 
  develop- 
  

   ing 
  an 
  explanation 
  of 
  the 
  universe 
  which 
  is 
  either 
  simple 
  or 
  plausible. 
  

   The 
  acceptance 
  of 
  the 
  principle 
  of 
  relativity 
  settles 
  this 
  dispute 
  

   within 
  the 
  domain 
  of 
  physical 
  methods 
  alone 
  by 
  admitting 
  that 
  

   measurements 
  within 
  all 
  three 
  of 
  the 
  fundamental 
  dimensions 
  of 
  

   physics 
  are 
  conditional 
  for 
  their 
  objective 
  significance 
  upon 
  the 
  con- 
  

   ditions 
  of 
  observation. 
  In 
  accordance 
  with 
  the 
  Einsteinian 
  scheme, 
  

   two 
  observers 
  can 
  make 
  measurements 
  upon 
  what 
  purports 
  to 
  be 
  a 
  

   single 
  object 
  or 
  system 
  and 
  these 
  measurements 
  may 
  be 
  quite 
  dis- 
  

   crepant 
  without 
  either 
  set 
  of 
  evaluations 
  constituting 
  evidence 
  su- 
  

   perior 
  to 
  the 
  other; 
  in 
  other 
  words, 
  what 
  any 
  individual 
  observer 
  

   empirically 
  finds, 
  using 
  the 
  most 
  refined 
  methods 
  of 
  physical 
  analysis 
  

   and 
  restricting 
  himself 
  to 
  the 
  domain 
  of 
  space, 
  mass 
  and 
  time, 
  is 
  still 
  

   dependent 
  upon 
  his 
  own 
  standpoint 
  and 
  does 
  not 
  comprise 
  the 
  only 
  

   true 
  description 
  of 
  external 
  realities. 
  Whether 
  an 
  object 
  is 
  long 
  

  

  