﻿144 
  JOURNAL 
  OF 
  THE 
  WASHINGTON 
  ACADEMY 
  OF 
  SCIENCES 
  VOL. 
  12, 
  NO. 
  6 
  

  

  surfaces 
  for 
  instance 
  are 
  to 
  be 
  regarded 
  as 
  concatenations 
  of 
  color 
  

   elements, 
  which 
  latter 
  in 
  themselves 
  cannot 
  constitute 
  any 
  surface, 
  

   however 
  small. 
  On 
  the 
  other 
  hand, 
  the 
  impression 
  of 
  empty 
  space 
  

   separating 
  the 
  eye 
  from 
  the 
  color 
  surface 
  must 
  be 
  regarded 
  as 
  

   involving 
  a 
  distinctive 
  visual 
  element 
  of 
  depth, 
  which 
  cannot 
  be 
  

   identified 
  with 
  color; 
  these 
  depth 
  elements, 
  however, 
  are 
  in 
  them- 
  

   selves 
  non-structural 
  and 
  must 
  be 
  arranged 
  into 
  a 
  structure 
  in 
  

   order 
  to 
  present 
  an 
  experience 
  of 
  distance 
  or 
  of 
  volume. 
  Now, 
  it 
  

   is 
  clearly 
  the 
  structural 
  rather 
  than 
  the 
  substantial 
  aspect 
  of 
  spacial 
  

   experience 
  which 
  physics 
  considers. 
  The 
  physicist 
  arranges 
  his 
  units 
  

   of 
  mass 
  in 
  imagination 
  into 
  a 
  three-dimensional 
  pattern 
  which 
  is 
  struc- 
  

   turally 
  similar 
  to 
  the 
  arrangements 
  of 
  qualities, 
  such 
  as 
  color 
  or 
  touch 
  

   sensations 
  which 
  he 
  finds 
  in 
  immediate 
  experience. 
  The 
  similarity 
  

   however, 
  is 
  not 
  complete, 
  since 
  none 
  of 
  the 
  spaces, 
  visual, 
  tactual 
  

   or 
  auditory, 
  of 
  our 
  consciousness 
  are 
  strictly 
  Euclidean 
  in 
  character. 
  

   They 
  are 
  all 
  more 
  or 
  less 
  anisotropic 
  or 
  possessed 
  of 
  different 
  properties 
  

   in 
  different 
  directions, 
  and 
  they 
  are 
  obviously 
  very 
  imperfect 
  and 
  

   incomplete 
  in 
  relation 
  to 
  the 
  totality 
  of 
  the 
  universe. 
  

  

  The 
  category 
  of 
  time, 
  again, 
  is 
  psychologically 
  quite 
  distinct 
  in 
  

   nature 
  from 
  those 
  of 
  mass 
  or 
  of 
  space. 
  Time 
  is 
  not 
  qualitative, 
  

   neither 
  is 
  it 
  structural, 
  for 
  it 
  concerns 
  quite 
  another 
  aspect 
  of 
  exper- 
  

   ience, 
  namely 
  its 
  liability 
  to 
  change. 
  The 
  idea 
  of 
  time 
  is 
  inflexibly 
  

   bound 
  up 
  with 
  the 
  fact 
  that 
  experience 
  is 
  a 
  process 
  or 
  a 
  flux. 
  This 
  

   flux 
  consists 
  in 
  the 
  replacement 
  of 
  one 
  form 
  of 
  consciousness 
  by 
  a 
  

   different 
  one. 
  Within 
  consciousness 
  or 
  experience 
  in 
  concrete 
  form 
  

   such 
  processes 
  involve 
  transmutations 
  not 
  only 
  of 
  structures 
  but 
  

   of 
  qualities. 
  Physics, 
  however, 
  having 
  eliminated 
  the 
  latter, 
  must 
  

   confine 
  itself 
  to 
  changes 
  in 
  spacial 
  structure, 
  or 
  to 
  motion. 
  Time, 
  

   for 
  physics, 
  thus 
  becomes 
  a 
  conception 
  of 
  the 
  relation 
  between 
  motion 
  

   and 
  the 
  thing 
  which 
  moves 
  ; 
  in 
  any 
  single 
  instance 
  it 
  is 
  measured 
  by 
  

   the 
  ratio 
  of 
  a 
  distance 
  to 
  a 
  velocity, 
  a 
  definition 
  which 
  must 
  be 
  supple- 
  

   mented 
  in 
  situations 
  involving 
  a 
  multiplicity 
  of 
  concurrent 
  motions, 
  

   by 
  a 
  definition 
  of 
  simultaneity. 
  Time, 
  both 
  from 
  a 
  psychological 
  

   and 
  from 
  a 
  physical 
  or 
  mathematical 
  point 
  of 
  view, 
  is 
  a 
  complex 
  

   conception 
  based 
  upon 
  two 
  ultimate 
  facts: 
  those 
  of 
  change 
  and 
  of 
  

   the 
  interdependency 
  of 
  concurrent 
  changes. 
  

  

  Although 
  the 
  relations 
  between 
  the 
  space, 
  mass 
  and 
  time 
  concepts 
  

   of 
  physics 
  and 
  the 
  corresponding 
  conceptions 
  relating 
  to 
  immediate 
  

   experience 
  are 
  clearly 
  somewhat 
  involved, 
  it 
  was 
  nevertheless 
  possible 
  

  

  