﻿ORGANISM 
  AND 
  MECHANISM 
  137 
  

  

  it 
  fails 
  all 
  along 
  the 
  line 
  in 
  thoroughness 
  of 
  description, 
  

   and 
  that 
  it 
  does 
  not 
  give 
  us 
  the 
  kind 
  of 
  answer 
  that 
  as 
  

   biologists 
  we 
  want. 
  Xo 
  student 
  of 
  science 
  could 
  have 
  any- 
  

   thing 
  but 
  delight 
  in 
  learning 
  that 
  the 
  contraction 
  of 
  a 
  muscle, 
  

   or 
  a 
  reflex 
  action, 
  or 
  the 
  movements 
  of 
  an 
  Amoeba 
  had 
  been 
  

   satisfactorily 
  described 
  in 
  terms 
  of 
  chemistry 
  and 
  physics. 
  

   But 
  it 
  has 
  not 
  been 
  done 
  as 
  yet 
  in 
  the 
  case 
  of 
  any 
  single 
  

   vital 
  activity. 
  Diffusion 
  plays 
  its 
  part 
  in 
  the 
  interchange 
  of 
  

   gases 
  in 
  the 
  lungs, 
  but 
  the 
  lining 
  epithelium 
  of 
  the 
  air-sacs 
  be- 
  

   haves, 
  Dr. 
  J. 
  S. 
  Haldane 
  tells 
  us, 
  in 
  a 
  way 
  which 
  modifies 
  

   diffusion 
  processes, 
  and 
  that 
  elusive 
  modification 
  keeps 
  us 
  

   alive. 
  In 
  the 
  second 
  place, 
  the 
  mechanistic 
  description, 
  even 
  

   if 
  it 
  attained 
  to 
  the 
  completeness 
  of 
  a 
  ledger 
  of 
  all 
  the 
  chem- 
  

   ical 
  and 
  physical 
  processes 
  in 
  a 
  piece 
  of 
  behaviour, 
  would 
  

   not 
  thereby 
  give 
  us 
  a 
  natural 
  history 
  description 
  of 
  the 
  

   behaviour. 
  We 
  need 
  historical 
  or 
  genetic 
  concepts. 
  So 
  we 
  

   do 
  not 
  propose 
  to 
  sum 
  up 
  the 
  ways 
  of 
  a 
  starfish 
  as 
  those 
  

   of 
  a 
  physico-chemical 
  machine. 
  

  

  (d) 
  The 
  distinctively 
  biological 
  position 
  admits 
  that 
  phys- 
  

   ical 
  and 
  chemical 
  formulae, 
  concepts, 
  or 
  ' 
  categories 
  ' 
  are 
  

   applicable 
  to 
  organisms, 
  but 
  argues 
  that 
  they 
  are 
  inadequate, 
  

   notably, 
  for 
  instance, 
  because 
  life 
  is 
  always 
  in 
  a 
  sense 
  his- 
  

   tory. 
  But 
  has 
  not 
  the 
  line 
  of 
  physiological 
  progress 
  been 
  

   mechanistic? 
  The 
  answer 
  is 
  that 
  it 
  is 
  part 
  of 
  the 
  method 
  

   of 
  science 
  to 
  ' 
  abstract 
  ', 
  and 
  that 
  it 
  has 
  been 
  of 
  great 
  service 
  

   to 
  corner 
  off 
  and 
  analyse 
  physical 
  and 
  chemical 
  operations 
  

   which 
  occur 
  in 
  organisms. 
  But 
  the 
  success 
  that 
  has 
  attended 
  

   the" 
  study 
  of 
  the 
  chemistry 
  of 
  the 
  blood 
  or 
  the 
  study 
  of 
  the 
  

   optics 
  of 
  the 
  eye, 
  does 
  not 
  prove 
  that 
  the 
  physico-chemical 
  

   description 
  of 
  a 
  living 
  creature 
  is 
  or 
  can 
  be 
  adequate. 
  

  

  (e) 
  A 
  thoroughly 
  sound 
  criticism 
  is, 
  that 
  the 
  concepts 
  of 
  

   physics 
  and 
  chemistry 
  are 
  not 
  stationary 
  but 
  in 
  process 
  of 
  

  

  