﻿LECTURE 
  III. 
  

   THE 
  CRITERIA 
  OF 
  LIVINGNESS. 
  

  

  1. 
  Living 
  and 
  Not-living. 
  2. 
  The 
  Essential 
  Characteristics 
  of 
  

   Living 
  Organisms. 
  3. 
  Persistence 
  of 
  a 
  Complex 
  Specific 
  

   Metabolism 
  and 
  of 
  a 
  Corresponding 
  Specific 
  Organisation. 
  4. 
  

   The 
  Capacity 
  of 
  Growth, 
  Reproduction, 
  and 
  Development. 
  

   5. 
  Effective 
  Behaviour, 
  Registration 
  of 
  Experience, 
  and 
  

   Variability. 
  

  

  1. 
  Living 
  and 
  Not-living. 
  

  

  IF 
  we 
  are 
  to 
  reach 
  a 
  coherent 
  view 
  of 
  Nature, 
  such 
  as 
  

   could 
  be 
  included 
  in 
  a 
  philosophy, 
  we 
  must 
  arrive 
  at 
  some 
  

   discernment 
  of 
  the 
  characteristics 
  which 
  mark 
  off 
  living 
  

   organisms 
  from 
  their 
  not-living 
  surroundings. 
  In 
  the 
  pres- 
  

   ent 
  state 
  of 
  science 
  a 
  definition 
  of 
  the 
  organism 
  cannot 
  be 
  

   more 
  than 
  tentative, 
  but 
  it 
  must 
  be 
  continually 
  attempted. 
  

  

  When 
  we 
  pass 
  from 
  watching 
  a 
  flowing 
  stream 
  or 
  the 
  

   wind-swept 
  clouds, 
  to 
  look 
  at 
  the 
  bees 
  visiting 
  the 
  flowers, 
  

   or 
  the 
  swallows 
  building 
  their 
  nest, 
  we 
  feel 
  that 
  we 
  are 
  

   facing 
  something 
  new 
  living. 
  What 
  we 
  see 
  is 
  not, 
  indeed, 
  

   in 
  every 
  respect 
  new 
  as 
  compared 
  with 
  the 
  inorganic, 
  for 
  

   gravity 
  acts 
  on 
  animals 
  just 
  as 
  on 
  drops 
  of 
  rain, 
  and 
  living 
  

   creatures 
  never 
  disobey, 
  so 
  far 
  as 
  we 
  know, 
  the 
  ordinary 
  

   laws 
  of 
  physics 
  and 
  chemistry 
  which 
  sum 
  up 
  the 
  routine 
  

   of 
  our 
  analytic 
  experience 
  of 
  the 
  not-living. 
  On 
  the 
  whole, 
  

   however, 
  especially 
  if 
  we 
  look 
  at 
  animals 
  rather 
  than 
  plants, 
  

   the 
  differences 
  impress 
  us 
  more 
  than 
  the 
  resemblances, 
  

   we 
  feel 
  rightly 
  that 
  we 
  are 
  in 
  the 
  presence 
  of 
  something 
  

   new. 
  Organisms 
  show 
  characteristics 
  which 
  mark 
  them 
  off 
  

  

  