﻿A. 
  INTRODUCTION 
  

   LECTURE 
  I 
  

  

  DESCENT 
  : 
  THEORIES 
  OF 
  EVOLUTION, 
  AND 
  METHODS 
  

  

  OF 
  INVESTIGATION 
  

  

  Newton 
  convinced 
  his 
  contemporaries 
  that 
  

   natural 
  laws 
  rule 
  the 
  whole 
  universe. 
  Lyell 
  

   showed, 
  by 
  his 
  principle 
  of 
  slow 
  and 
  gradual 
  

   evolution, 
  that 
  natural 
  laws 
  have 
  reigned 
  since 
  

   the 
  beginning 
  of 
  time. 
  To 
  Darwin 
  we 
  owe 
  the 
  

   almost 
  universal 
  acceptance 
  of 
  the 
  theory 
  of 
  

   descent. 
  

  

  This 
  doctrine 
  is 
  one 
  of 
  the 
  most 
  noted 
  land- 
  

   marks 
  in 
  the 
  advance 
  of 
  science. 
  It 
  teaches 
  the 
  

   validity 
  of 
  natural 
  laws 
  of 
  life 
  in 
  its 
  broadest 
  

  

  / 
  

  

  sense, 
  and 
  crowns 
  the 
  philosophy 
  founded 
  by 
  

   Newton 
  and 
  Lyell. 
  

  

  Lamarck 
  proposed 
  the 
  hypothesis 
  of 
  a 
  com- 
  

   mon 
  origin 
  of 
  all 
  living 
  beings 
  and 
  this 
  ingenious 
  

   and 
  thoroughly 
  philosophical 
  conception 
  was 
  

   warmly 
  welcomed 
  by 
  his 
  partisans, 
  but 
  was 
  not 
  

   widely 
  accepted 
  owing 
  to 
  lack 
  of 
  supporting 
  evi- 
  

   dence. 
  To 
  Darwin 
  was 
  reserved 
  the 
  task 
  of 
  

  

  i 
  

  

  