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SCIENCE  AND  HUMAN 
AFFAIRS 

FROM  THE  VIEWPOINT  OF  BIOLOGY 


BY 

WINTERTON  C.  CURTIS,  PH.  D. 

PBOFESSOR   OP    ZOOLOGY   IN   THE    UNIVERSITY   OP   MISSOURI 


LONDON 

G.  BELL  AND  SONS,  L!l) 


COPYRIGHT,   1922,  BY 
HABCOURT,  BRACE  AND  COMPANY,  INC. 


Printed  in  the  U.  S.  A. 


TO  THE  MEMORY  OP  MY  FATHER 

WILLIAM  CONWAY  CURTIS 

WHO  THROUGHOUT  A  LONG  LIFE  EXEMPLIFIED  THE 
SPIRIT  OF  THE  OPEN  MIND 


PREFACE 

The  present  volume  sets  forth  certain  of  the  humanistic 
aspects  of  natural  science  with  illustrations  largely  from  the 
field  of  biology.  The  work  is  an  outcome  of  the  author's 
experience  as  a  teacher  of  zoology,  although  much  that  is 
here  contained  forms  no  part  of  routine  zoological  instruc- 
tion. The  interest  of  college  students  in  the  broader  aspects 
of  science,  as  viewed  by  the  biologist,  leads  him  to  believe 
that  the  matter  presented  may  interest  a  wider  audience. 
We  often  hear  the  statement  that  "we  live  in  a  scientific 
age."  But  what  does  this  mean  historically,  and  what  does 
it  imply  for  the  future?  Again,  it  is  said  that  the  present  is 
a  period  of  "readjustment."  Readjustment  to  what,  and 
because  of  what?  The  present  volume  seeks  in  a  modest 
way  to  answer  these  questions.  The  writer  has  also  found 
an  incentive  in  his  conviction  that  the  world  has  arrived  at 
an  age  of  science,  that  the  necessary  readjustments  have 
not  been  completed  and  that  the  future  belongs  to  the 
scientific  frame  of  mind. 

Acknowledgments  are  due  to  many  friends  and  associates 
who  have  consciously  or  unconsciously  contributed  to  the 
work  during  the  course  of  numerous  discussions.  Among 
my  fellow  zoologists,  who  have  read  extended  portions  of 
the  manuscript  and  made  valuable  suggestions,  are  Caswell 
Grave,  F.  B.  Isely,  the  late  W.  E.  Kellicott,  E.  G.  Conklin, 
S.  0.  Mast,  and  George  Lefevre.  I  am  particularly  indebted 
to  Professor  George  Twiss  of  the  Ohio  State  University,  and 
to  Professor  A.  H.  R.  Fairchild  of  the  University  of  Missouri, 
he  critical  reading  of  preliminary  drafts.  But  most  of 
all.  I  am  under  obligation  to  my  friend  and  colleague  Pro- 
fessor N.  M.  Trenholme  for  his  reading  of  earlier  and  later 
draft >  of  certain  chapters,  as  well  as  the  final  manuscript. 


vi  PREFACE 

His  constructive  criticism  of  all  phases  of  the  work  has  been 
of  inestimable  service.  Thanks  are  also  due  to  Mr.  George 
T.  Kline,  biological  artist  of  the  University  of  Missouri,  for 
the  drawing  of  Figs.  28,  29,  and  30,  and  for  assistance  with 
some  of  the  other  figures. 

Formal  acknowledgments  are  due  to  the  Scientific  Ameri- 
can for  Fig.  7;  to  the  Clarendon  Press  for  Fig.  8;  to  the 
Pierpont  Morgan  Library,  as  the  source  of  Fig.  9,  reproduced 
from  the  paper  by  W.  A.  Locy;  to  the  Macmillan  Company 
for  the  reproduction  of  Figs.  23  and  24,  and  for  the  quotation 
from  Metcalfs  " Organic  Evolution,"  as  it  appears  on  page 
61;  to  the  American  Museum  of  Natural  History  and  the 
F.  A.  Stokes  Company  for  Fig.  25;  and  to  Henry  Holt  and 
Company  for  the  tabulation  of  the  linked  characters  in 
Drosophila,  which  appears  on  page  133.  Lesser  quotations 
from  copyrighted  works  are  duly  acknowledged  in  the  foot- 
notes. 

W.  C.  C. 
University  of  Missouri, 

Nov.  10,  1921. 


CONTENTS 

PART  I 

The  History  and  Significance  of  Science 

CHAPTER  PAGE 

I.  THE  MEANING  OF  SCIENCE  TO  MANKIND 3 

II.  THE  ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD.  .  11 

III.  THE  DECLINE  OF  ANCIENT  LEARNING 42 

IV.  THE  EMERGENCE  OF  MODERN  SCIENCE 66 

V.  THE  FURTHER  GROWTH  OF  SCIENCE  .  .  94 


PART  II 

The  Science  of  Biology 

VI.  THE  BIOLOGICAL  SCIENCE  OF  THE  MODERN  PERIOD: 

THE  CELL-DOCTRINE 119 

VII.  THE  BIOLOGICAL  SCIENCE  OF  THE  MODERN  PERIOD: 

THE  THEORY  OF  ORGANIC  EVOLUTION 155 

VIII.  CURRENT  PROBLEMS  AND  METHODS  OF  ZOOLOGICAL 

SCIENCE 187 

PART  III 
The  Present  Importance  of  Science 

IX.  PHILOSOPHICAL    AND    PSYCHOLOGICAL    ASPECTS    OF 

SCIENCE 223 

\    THK  NATURE  AND  MEANING  OF  SCIENTIFIC  RESEARCH  242 
XL  Tun  ROLE  OF  SCIENCE  IN  THE  SOLUTION  OF  SOCIAL 

PROBLEMS 263 

XII.  THK  HIGHER  VALUES  OF  SCIENCE 290 

XIII.  MANKIND  AND  THE  FURTHER  PROGRESS  OF  SCIENCE    .  314 

INDEX  321 

vii 


PART  I 

THE  HISTORY  AND  SIGNIFICANCE  OF 

SCIENCE 


CHAPTER  I 
THE  MEANING  OF  SCIENCE  TO  MANKIND 

SCIENCE  is  the  product  of  human  reason  applied  to  the 
phenomena  of  nature.  It  is,  therefore,  as  old  as  rational 
thought.  The  straight-thinking  man  was  always  a  scientist. 
The  minor  facts  of  science,  which  arise  from  the  interpreta- 
tion of  simple  phenomena,  have  been  apprehended  from  the 
beginning,  though  not  subjected  to  critical  examination. 
The  major  facts  of  science,  which  are  called  scientific  laws, 
and  conscious  analysis  of  the  methods  by  which  such  laws 
are  discovered  have  been  acquired  within  the  period  of  re- 
corded history.  Comprehending  at  last  the  meaning  of 
natural  knowledge,  man  has  discovered  during  the  recent 
centuries,  the  network  of  relationships  which  constitutes 
modern  science.  But  the  foundations  of  science  have 
existed  since  the  dawn  of  rationality. 

Organized  science,  although  it  seems  so  recent  a  product  of 
the  human  understanding,  may  be  recognized  in  its  begin- 
nings at  an  earlier  time  than  is  commonly  supposed.  Reason 
is  constantly  striving  to  bring  order  out  of  seeming  chaos. 
This  undertaking  is  not  of  recent  origin.  Stripped  of  their 
purely  mythological  features,  primitive  cosmogonies  are 
comparable  to  the  larger  groupings  of  fact  which  characterize 
modern  scientific  knowledge.  Those  who  believed  the  earth 
to  be  flat  were  making  what  was  essentially  a  scientific 
generalization,  so  long  as  it  conformed  to  the  appearance  of 
things.  Among  the  Egyptians,  the  Babylonians,  and  related 
peoples,  the  germs  of  the  physical,  astronomical,  mathemat- 
ical, and  medical  sciences  made  their  appearance  at  an  early 
date.  Among  the  ancient  Greeks,  the  scientific  spirit  is 
discernible,  despite  the  limitations  imposed  by  ignorance, 
superstition,  and  unbridled  speculation.  Among  the  Euro- 

3 


4          HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

pean  peoples,  during  the  Middle  Ages,  science  was  obscured 
by  theological  dogma  and  by  the  loss  of  most  of  the  ancient 
learning.  During  the  Modern  Period,  which  might  be  termed 
the  Scientific  Period,  science  has  become  an  organized 
endeavor  of  overwhelming  importance.  It  has  entered  its 
growth-period  and  has  become,  with  amazing  rapidity,  the 
most  influential  factor  in  the  thought  and  action  of  the 
modern  world. 

The  dominant  influence  which  science  now  exercises  in 
western  culture  is  a  natural  outcome  of  the  spectacular 
changes  wrought  by  science  upon  the  environment  of  man. 
Within  less  than  two  hundred  years,  man  has  succeeded  in 
controlling  the  conditions  of  his  existence  to  an  extent  hith- 
erto unthinkable.  The  material  effects  of  this  new  power  are 
seen  wherever  "the  destroying  hand  of  economic  civiliza- 
tion" does  its  work.  It  is  this  deplorable  aspect  of  science 
which  has  captured  the  popular  imagination.  But  science 
has  gone  deeper.  Human  thinking  has  been  revolutionized 
by  scientific  knowledge  and  method.  It  is  this  spiritual 
aspect  of  modern  science  that  is  its  most  significant  feature. 
By  comparison,  the  material  aspect  is  insignificant.  So 
profound,  so  comprehensive,  and  so  rapid  have  been  the 
transformations  hi  human  thought  in  modern  times,  that 
even  scientists  have  been  forced  often  to  change  their  point 
of  view  over  night.  The  end  of  the  revolution,  which  has 
thus  been  forced  upon  the  world,  is  not  yet  apparent.  Its 
effects  are  spreading,  its  advance  shows  no  signs  of  abate- 
ment, its  ultimate  results  are  incalculable.  Extensive  as  the 
material  transformations  have  been,  thrilling  as  the  conquest 
of  physical  nature  has  been,  they  are  surpassed  in  importance 
by  the  changes  in  human  thought.  Modern  thought  is  the 
outcome  of  modern  science.  The  scientific  habit  of  mind  is 
the  unpredictable  factor  hi  the  life  of  mankind  to-day.  Its 
possibilities  for  the  future  defy  all  estimate  or  prophecy. 

The  spiritual  revolution  wrought  by  scientific  thought 
is  illustrated  in  the  changing  concept  of  authority.  SufB- 


THE  MEANING  OF  SCIENCE  TO  MANKIND         5 

cient  medievalism  survives  to  enable  us  to  appreciate  the 
intellectual  atmosphere  which  existed  in  Europe  from  the 
decline  of  the  Greco-Roman  culture  to  the  dawn  of  the 
Renaissance.  For  more  than  a  thousand  years,  the  final 
authority,  in  temporal  as  in  spiritual  matters,  was  scriptural 
phraseology  and  the  traditional  teachings  of  the  masters  of 
antiquity.  The  writings  of  Galen  were  law  in  human  anat- 
omy; the  Bible  was  regarded  as  a  trustworthy  textbook  in 
natural  history.  This  condition  of  mind  was  an  outcome  of 
the  enthronement  of  authoritative  statement  in  the  place  of 
critical  judgment.  It  reflected  the  theological  doctrine  of 
authority  inherent  in  every  phrase  of  a  Scripture  conceived 
to  be  inspired.  In  contrast  to  this  manner  of  thinking, 
science  recognizes  only  nature  as  the  ultimate  authority  in 
the  interpretation  of  nature.  Facts,  which  any  one  may 
verify  for  himself,  are  the  justifications  for  the  authoritative 
statements  of  science.  Insensibly,  the  popular  mind  is  reach- 
ing this  scientific  concept.  The  older  authority  may  stand, 
apparently  well  buttressed  and  secure,  but  in  reality  it  has 
been  undermined  by  the  progressive  recognition  of  the 
authority  of  nature. 

The  craftsman  of  the  Middle  Ages  never  doubted  the 
reality  of  the  universe  depicted  by  theology.  Performing  all 
the  labor  incident  to  the  creation  of  a  finished  product  out  of 
raw  material,  he  could  think  in  terms  of  a  Deity  who  had 
made  man  with  His  hands  and  who  arbitrarily  changed  the 
course  of  nature.  The  modern  industrial  worker,  who  per- 
forms a  small  part  of  the  process  incident  to  factory  output, 
and  whose  universe  is  the  universe  of  scientific  fact,  is  more 
likely  to  regard  himself  as  controlling  and  directing  forces  of 
nature  which  are  represented  in  his  machine.  This  latter 
point  of  view  has  its  limitations  and  calls  for  corrective 
treatment,  lest  the  individual  engaged  in  industry  come  to 
regard  himself  as  merely  a  cog  in  a  mechanism.  But  it  is 
accomplishing  one  beneficial  result.  It  is  instilling  into  the 
worker's  mind,  and  so  into  the  minds  of  all  mankind,  the 


6          HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

idea  of  natural  causation;  and  once  this  idea  becomes  a 
major  factor  in  human  thinking,  nature  will  become  for  all 
time  the  one  and  only  source  of  authority  in  explaining 
phenomena.  Even  unconsciously,  the  workman  feels  the 
worthlessnessof  authoritative  knowledge  of  the  older  sort,  and 
thus  stands  with  the  scientist,  who  regards  the  traditional 
explanations  as  negations  of  a  rational  explanation  of  the 
world. 

Recent  tendencies  in  education  further  illustrate  the 
influence  of  this  changing  concept  of  authority.  The  ascet- 
icism and  scholasticism  of  the  Middle  Ages  gave  way  before 
the  humanism  of  the  Renaissance.  The  new  ideal  found  its 
counterpart  in  the  thought  of  ancient  times.  The  literature 
of  Greece  and  Rome  was  ardently  studied  and  read  for  its 
humanistic  values.  Latin,  being  already  the  language  of  the 
learned,  became  one  vehicle  of  the  new  philosophy.  Greek, 
being  the  only  pathway  to  the  elder  source  of  European 
humanism,  assumed  a  corresponding  importance.  Thus 
Latin  and  Greek  became  associated  with  modern  human- 
istic philosophy,  a  union  which  has  been  maintained  until 
the  present  day.  The  teaching  of  the  Greek  and  Latin 
languages  per  se  assumed  a  commanding  position  in  the 
educational  scheme  of  western  Europe,  and  was  maintained 
therein  long  after  the  original  need  for  such  teaching  had 
disappeared.  But  the  authority  of  tradition,  voiced  by  the 
pronouncements  of  classical  scholars,  no  longer  convinces. 
The  public  in  general,  and  the  leaders  of  education  in  partic- 
ular, have  turned  from  the  authority  of  custom  to  that  of 
psychology,  of  pedagogy,  and  of  everyday  experience.  The 
claim  that  humanistic  values  inhere  within  the  very  lan- 
guages of  Greece  and  Rome  must  rest  upon  a  more  secure 
foundation  than  educational  tradition,  if  Greek  and  Latin 
continue  as  vital  elements  in  general  education. 

The  authority  in  education  from  now  on  must  be  scientific 
authority.  We  are  still  profoundly  ignorant  of  what  consti- 
tutes scientific  procedure  within  so  complex  a  field.  We 


THE  MEANING  OF  SCIENCE  TO  MANKIND         7 

shall  discover  this  procedure  only  by  long  and  painstaking 
study.  Merely  to  have  changed  time-honored  standards  is 
no  guarantee  that  the  new  ones  are  final.  If  analysis  of 
educational  experience  shows  that  the  only  road  to  an  under- 
standing of  the  ancient  humanism  lies  through  the  original 
languages,  and  if  it  appears,  as  a  further  result  of  scientific 
analysis,  that  herein  lies  the  greatest  reservoir  of  humanistic 
thought,  study  of  these  languages  will  continue  to  be  widely 
required.  If,  as  in  the  case  with  our  ethical  ideals,  the 
average  man  in  a  busy  world  can  secure  the  essence  of  this 
humanism  by  means  of  translations  and  interpretations,  the 
classical  languages  will  be  primarily  for  the  classical  scholar, 
and  not  for  those  who  merely  aspire  to  a  liberal  education. 
The  acid  of  the  scientific  method  is  being  applied  in  educa- 
tion. In  time  it  will  destroy  the  baser  metal,  not  alone  in  the 
teaching  of  the  classics  but  in  the  teaching  of  science  as  well. 
In  education,  as  in  other  fields,  the  day  of  passive  acceptance 
of  what  is  because  it  has  been  seems  gone  never  to  return. 
Here,  as  elsewhere,  an  appeal  to  the  facts  results  in  the  undo- 
ing of  traditional  authority  and  establishes  the  authority  of 
science.  The  changing  classical  requirements  in  modern 
education  illustrate  our  point,  although  such  changes  are 
insignificant  when  compared  with  the  possible  revolution  in 
education  as  a  whole. 

Recent  changes  in  religious  belief  may  be  cited  as  a  further 
example  of  the  influence  of  scientific  thought.  By  insensible 
degrees,  theology  has  been  losing  its  hold  upon  the  western 
mind.  The  early  Christian  cosmogony  has  long  been  dis- 
carded by  the  educated  laity,  and  is  not  taken  seriously  by 
many  of  the  clergy.  What  the  Copernican  Theory  did  to  the 
Heaven  and  Hell  of  an  earlier  period,  the  Higher  Criticism, 
which  consists  of  the  method  of  science  applied  to  the  study 
of  the  Old  and  New  Testaments,  is  doing  in  our  own  day  to 
belief  in  a  revealed  religion.  Facts!  Facts!  Facts  that  can- 
not be  denied  have  everywhere  rendered  ancient  beliefs  un- 
tenable. Wonderfully  interesting  legends  and  fables  the 


8         HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

Bible  stories  now  appear  to  be — records  of  attempted  solu- 
tions of  the  mysteries  of  life.  The  science  of  comparative 
mythology  is  fascinating  reading  and  is  of  even  more  than 
academic  interest,  because  it  explains  the  origin  of  many 
concepts  which  still  exercise  a  profound  influence  upon  the 
bulk  of  mankind.  Because  of  scientific  thinking,  theology  is 
being  recognized  as  a  barren  form  of  speculation  and  is 
rapidly  being  separated  from  what  may  be  termed  religion. 
The  latter  maintains  its  hold  upon  men  in  terms  of  the  hu- 
man sympathy  and  ethical  idealism  essential  in  man's 
nature,  without  which  social  cooperation  could  not  exist. 
Comparative  study  shows  the  various  religions  of  mankind  to 
have  their  foundations  in  these  fundamental  qualities  of  the 
human  mind.  The  religion  of  the  future  will  be  scientific 
in  that  it  will  be  all-comprehending. 

In  its  sifting  out  of  facts,  science  spares  nothing,  not  even 
the  most  sacred  of  traditions,  for  science  has  its  own  sacred 
tradition  of  the  open  mind.  One  cannot  view  dispassionately 
the  history  of  religious  belief  during  the  recent  centuries 
without  recognizing  the  changes  which  have  occurred.  And 
does  any  one  believe  that  these  changes  will  not  endure  or 
that  others  will  not  follow?  Will  not  religion  or  what  men 
will  call  religion  in  the  future  be  at  one  with  science,  be, 
indeed,  mainly  a  practical  application  of  the  ideas  and 
achievements  of  science;  and  will  not  the  scientific  habit  of 
mind  satisfy  the  ethical  and  philosophical  desires  which  have 
been  hitherto  formulated  as  religion  and  theology?  The 
influence  of  science  is  manifest.  Eventually,  it  will  recon- 
struct the  very  foundations  of  religious  thought. 

Again,  the  scientific  point  of  view  appears  hi  the  changing 
philosophy  of  life.  The  old  formulas,  by  which  man  long 
explained  the  riddles  of  existence,  have  failed  hi  the  light  of 
scientific  knowledge,  even  though  they  color  much  of  our 
thinking.  We  may  well  consider  the  possibility  of  a  life  to 
come,  but  our  immediate  concern  is  with  the  life  that  is  here 
and  now.  The  ignoring  of  temporal  affairs,  emphasized  so 


THE  MEANING  OF  SCIENCE  TO  MANKIND         9 

long  as  the  thoughts  of  men  were  directed  toward  another 
world,  has  left  an  historical  record  in  which  we  can  take 
little  pride.  The  humanistic  philosophy  of  life,  which 
flowered  in  Greece  and  which  has  blossomed  again,  is  not  the 
crude  materialistic  desire  to  eat,  drink,  and  be  merry.  It 
is  a  spiritual  joy  in  living  and  a  confidence  in  the  future, 
which  makes  this  life  a  thing  worthwhile.  The  otherworld- 
liness  of  the  Middle  Ages  does  not  satisfy  the  spiritual  de- 
mands of  modern  times. 

It  was  this  humanistic  ideal  which  strove  for  domination 
in  the  ancient  world  but  at  last  went  down  defeated  by  that 
fear  of  the  unknown  which  was  man's  heritage  from  savagery. 
The  Greek  ideal  of  life  declined,  despite  the  beginnings  of 
scientific  knowledge,  because  the  bulk  of  mankind  still  be- 
held in  nature  a  great  unknowable  filled  with  malignity 
toward  men.  Terror  of  the  dark  brought  victory  to  that 
philosophy  which  made  this  world  a  vale  of  tribulation 
wherein  man  prepared  himself  for  the  next.  From  primitive 
times,  blind  fear  swept  on,  unchecked  save  by  the  naked 
strength  of  the  Greek  mind.  When  Greece  and  Rome 
declined,  fear  chilled  the  hearts  of  men  until  in  modern 
times,  man  mastered  fear  by  scientific  knowledge.  To-day, 
men  can  face  the  unknown,  strong  in  their  conviction  that 
mankind  will  ultimately  comprehend  much  that  has  seemed 
unknowable.  Nature  now  appears  orderly,  not  capricious; 
causal,  not  magical.  For  those  who  come  after  us,  if  not  for 
ourselves,  the  life  that  now  is  will  possess  greater  possibilities 
than  those  ascribed  in  the  past  to  a  life  beyond  the  grave. 
We  have  ceased  to  look  upon  nature  with  the  dumb  terror  of 
the  savage  mind.  We  no  longer  grovel  before  her  as  an  un- 
n  power  whose  caprice  may  work  us  good  or  ill.  Be- 
cause of  modern  scientific  knowledge,  we  look  upon  a  world 
which  is  mainly,  perhaps  wholly,  organized  without  reference 
to  the  desires  of  individual  men,  a  universe  of  which  we  are  a 
part  and  whose  course  we  may  hope  to  influence,  if  only  to  an 
infinitesimal  degree.  Our  fate  may  be  "on  the  knees  of  the 


10        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

gods,"  but  the  gods  do  not  help  us  to  that  which  we  desire; 
we  help  ourselves,  by  understanding  nature  and  by  ordering 
our  lives  in  conformity  to  her  laws.  Courage  and  high  re- 
solve are  needed  thus  to  face  the  realities  of  life.  The  night 
of  fear  is  still  about  us,  though  we  face  the  new  day.  At 
times,  we  lose  all  hope  that  a  scientific  philosophy  of  life  can 
ever  prevail  within  the  hearts  of  men.  In  the  faith  that  it 
will  prevail,  we  lay  hold  upon  scientific  truth  as  we  see  it 
around  us,  believing  that  in  the  end  no  other  state  of  mind 
will  satisfy  as  well. 

As  a  final  illustration  of  the  part  played  by  science  in  this 
spiritual  revolution  which  is  the  distinctive  feature  of 
modern  times :  The  facts  of  biological  science  are  profoundly 
modifying  human  thought.  Their  effects  are  seen  in  the 
present;  and  such  facts  have  unbelievable  possibilities  for 
the  future,  because  they  deal  with  man's  relation  to  his 
environment  and  with  the  nature  of  human  personality. 
Biological  science  seeks  to  answer  the  question  whence  came 
man,  and  to  explain  what  man  is  at  the  present  time.  It  is 
also  concerned  with  the  whither  of  man  upon  this  earth;  it 
even  dreams  that  research  may  some  day  solve  the  mystery 
of  death.  To-day,  the  philosopher  recognizes  the  biological 
basis  of  philosophy,  the  theologian  the  biological  develop- 
ment of  theology,  the  historian  the  biological  background  of 
primitive  historical  events,  and  the  man  in  the  street  the 
biological  nature  of  his  own  existence.  Indeed,  biology 
occupies  a  pivotal  position  in  human  understanding. 

But  above  all  the  applications  of  particular  branches 
of  science,  man  must  apply  the  scientific  method  in  the 
solution  of  social  and  of  individual  problems,  lest  civilization 
perish  through  its  failure  to  progress.  Biology  in  partic- 
ular and  science  in  general  are  fundamentally  related  to  the 
welfare  of  mankind.  Human  life  itself  is  the  most  absorbing 
of  all  scientific  problems.  If  its  riddles  are  ever  to  be  solved 
it  must  be  primarily  through  science  and  in  the  terms  of 
science. 


CHAPTER  II 

THE  ORIGINS  OF  SCIENCE  IN  THE 
ANCIENT  WORLD 

HAVING  established  the  meaning  and  importance  of  science 
in  general,  the  next  step  is  to  examine  the  historical  origins  of 
scientific  thinking  and  knowledge,  as  a  further  introduction 
to  biological  science  in  particular.  In  such  an  inquiry, 
attention  may  be  confined  to  the  Near  East,  since  isola- 
tion rendered  India  and  China  unimportant  factors  in  the 
early  intellectual  development  of  the  Mediterranean  peoples. 
Commerce  is  known  to  have  existed  between  Egypt  and  the 
Indian  Peninsular  at  an  early  date.  There  were  contacts 
between  India  and  the  primitive  Mesopotamians.  But  the 
very  early  development  of  civilization  in  the  Nile  valley 
makes  it  probable  that  the  tide  of  cultural  influences  flowed 
from  west  to  east  and  not  in  the  reverse  direction. 

BEGINNINGS  OF  SCIENCE  IN  THE  VALLEY  OF  THE  NILE 

Beings  capable  of  fashioning  flint  implements  existed  in 
western  Europe  as  early  as  the  Third  Inter-Glacial  Period- 
estimated  as  some  125,000  years  before  our  era.1  Rock 
carvings  and  other  remains  indicate  that  cultural  levels 
similar  to,  although  not  necessarily  contemporaneous  with, 
reached  by  palaeolithic  races  of  Europe  were  also 
attained  by  implement  makers  who  inhabited  northern 

>O8born,  H.  F.,  "Men  of  the  Old  Stone  Age,"  p.  41.    This  estimate  is  a 

moderate  one,  as  some  other  authorities  place  the  appearance  of  the  Pre- 

Chellean  flint  workers  even  earlier  than  the  Glacial  IVriod.     Buttel-Reepen, 

Man  find    Hi*  Forerunners,"  p.   10.      In  the  table  given  by  J.  C. 

'  i".  Monthly,  p.  338,  Apl.,  1920,  no  time  estimate  appears,  but  the 

Paleolithic  Period  begins  with  the  Second  Glacial,  and  the  Eolithic  Period  ,* 

extended  well  b  !.«rtiary. 

11 


12       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

Africa  during  glacial  times.  The  Sahara  appears  to  have 
been  a  habitable  region  and  to  have  possessed  a  temperate 
climate,  at  least  during  the  earlier  periods  of  European 
glaciation.  With  the  close  of  the  Ice- Age  and  the  advent  of 
the  present  climate,  the  southern  shores  of  the  Mediter- 


FIQ.  1.  Map  of  Egypt.  Showing  outline  of  the  great  fault-rift, 
which  produced  the  Nile  Valley,  and  of  the  former  coast 
line.  (Adapted  from  Blanckenhorn.) 

ranean  were  populated  by  peoples  whose  cultural  level  was 
similar  to  that  attained  in  southwestern  Europe  only  in  later 
times.  It  is  not  improbable  that  similar  conditions  had  long 
prevailed  and  hence  that  a  truly  human  culture  emerged  in 
northern  Africa  far  earlier  than  in  Europe.  Egypt,  in  partic- 
ular, exhibits  not  only  the  record  of  an  indigenous  civiliza- 
tion, but  also  evidences  of  antecedent  neolithic  and  palaeo- 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    13 

lithic  cultures  that  extend  to  a  very  remote  period  in  the 
past,2 

The  geological  history  of  the  Nile  region  3  has  been  such 
that  we  may  determine  the  sequence  of  cultural  remains  in 
quite  a  definite  fashion.  Their  actual  age  is,  of  course,  sub- 
ject to  the  limitations  of  all  geological  estimates  of  time. 
An  exact  time  correlation  with  Europe  is  exceedingly  dif- 
ficult, if  not  impossible  with  our  present  data.  Nevertheless, 
these  remains  are  of  great  importance,  because  the  complete- 
ness of  the  record  is  hardly  duplicated  in  any  other  locality. 
The  Nile  valley  originated,  shortly  before  the  European 
Glacial  Age,  in  what  is  called  a  block  or  rift-fault.  As  shown 
by  Figs.  2  and  3,  a  narrow  section  or  fault-block  (a  a') 
of  the  Eocene  limestone,  extending  from  the  former  coastline 
near  Cairo  as  far  south  as  Coptos  (Fig.  1),  settled  eight 
hundred  or  more  feet  below  the  general  surface  of  the  plateau. 
Lesser  faults  extended  the  valley  southward  a  total  distance 
of  almost  four  hundred  and  fifty  miles  to  Gebelen.  The 
northern  end  of  this  rift,  as  shown  by  marine  fossils,  was  for 
a  time  occupied  by  a  fiord  of  the  sea  while  to  the  south  a 
fresh-water  lake  or  chain  of  lakes  existed  for  thousands  of 
years.  Later  the  fiord  also  became  converted  into  a  lake 
(Fig.  2).  Eventually,  this  series  of  waterways  became  the 
River  Nile,  which  in  its  early  history  carried  a  greater 
volume  of  water  than  at  the  present  time. 

Existence  of  the  lake  or  lakes  is  evidenced  by  the  extensive 
beds  of  lacustrine  deposits  which  still  appear  along  the  val- 
ley walls  (Fig.  3).  The  heavy  rainfall  of  earlier  times  swept 
quantities  of  sand  and  gravel  from  the  plateau.  Many  feet 
of  this  material  were  deposited  in  the  lake  upon  the  top  of 
the  fault-block  (Fig.  2).  After  the  river  was  established,  its 
erosion  cut  the  lake-beds  almost  to  their  bottom  before  the 

'Breasted,  J.  H.,  "The  Origins  of  Civilization,"  Sci.  Monthly,  Oct.,  1919, 
pp.  304-8. 

1  Blanckenhorn,  M.,  "Geschichte  des  Nil-Stroms,"  Zeitech.  der  Gesell.  fur 
Erdkundc,  1902. 


14       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

Plateau 


Plateau 


A1 


Possible    Fjiord-Lake    Surfaces 


Lake  Bottom  at  Final  Lake-Stage 


Beds  of  Lacustrine  Depo si ta  ^r^i^ 
~~~~~..  washed  in  from  Plateau^..i...T* 


Fault-Block 


Eocene 


Limestone 

Line  of  maximum 
erosion  of 
" lacustrine " 
deposits  _ 


Fia.  2.  Schematic  Cross-Section  of  the  Nile  Valley,  at  a  stage  when  the  fiord- 
lake  had  reached  its  maximum  development.  The  lacustrine  beds  are 
shown  filling  a  considerable  portion  of  the  rift  produced  by  sinking  of 
fault-block  a  a'  from  its  original  position  A  A'  B  E' .  The  downward 
displacement  of  the  fault-block  amounted  to  some  900  feet,  as  shown  by 
the  present  height  of  the  valley  walls.  The  distance  across  the  rift,  as  it 
now  exists,  varies  from  4  to  15  miles.  The  extent  to  which  the  lacustrine 
deposits  have  since  been  eroded  is  indicated  by  the  profile  of  the  present 
valley  which  is  outlined  as  in  Fig.  3.  The  vertical  dimension  is  greatly 
exaggerated.  Compare  with  Fig.  3.  (Adapted  from  Breasted  and  Blanck- 
enhorn.) 

dwindling  stream  became  converted  into  the  modern  Nile 
and  began  to  deposit  the  present  alluvium.  As  shown  by 
Fig.  3,  the  remains  of  the  old  lake-beds  are  exposed  along  the 
sides  of  the  great  rift.  Below  them  are  the  remains  of  two 
so-called  river  terraces,  marking  stages  during  which  the 
stream  maintained  its  volume  for  a  time  sufficient  to  estab- 
lish flood  planes  and  lay  down  alluvial  terraces  that  have 
since  been  washed  down  to  rounded  contours. 

The  peculiar  features  of  the  foregoing  geological  events 
enable  us  to  trace  the  cultural  record  in  a  definite  manner. 
The  numbers  on  the  right  hand  side  of  Fig.  3  indicate  the 
location  of  the  items  which  may  now  be  enumerated  in  the 
order  of  their  antiquity. 

1.  Many  implements  and  flint  workings,  similar  to  palaeolithic 
remains  elsewhere  in  Northern  Africa,  are  found  scattered  over 
the  plateau. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD     15 

Plateau  _  I 


Remains  of  Lacustrine 
Deposits 


Lower  Terrace  and  Present 
Alluvium 


FIG.  3.  Schematic  Cross-Section  of  the  Nile  Valley  at  Present  Day.  Showing 
remains  of  lacustrine  deposits  and  of  two  river  terraces.  The  alluvium  of 
the  modern  valley  floor  and  the  present  Nile  appear  below.  Vertical 
dimension  is  exaggerated.  Compare  with  Fig.  2.  Location  of  human 
artifacts  is  indicated  by  figures  on  the  right  hand  side  as  explained  in 
text.  (Adapted  from  Breasted  and  Blanckenhorn.) 

2.  Implements  similar  to  (1),  but  found  embedded  at  various 
levels  in  the  lake  deposits,  are  believed  to  have  been  washed  in  from 
the  plateau,  since  this  was  the  source  of  the  material  composing 
the  lake  deposits.    Hence  some  at  least  of  the  plateau  implements 
antedate  the  formation  of  the  lake  deposits. 

3.  Many  implements  are  found  embedded  within  the  upper 
river  terrace.    These  are  similar  to  (1)  and  (2).    The  material  of 
this  terrace  was  derived  by  washings  from  the  older  lake  deposits 
or  from  the  plateau. 

4.  Implements  on  any  undisturbed  surface  of  this  terrace  are 
of  later  origin  than  (3). 

4a.  Prehistoric  cliff  pictures  of  game  animals,  primitive  boats, 
and  the-  like,  now  found  upon  the  upper  cliffs  are  believed  to  be 
nporaneous  with  (4). 

.">.  Implements  within  the  lower  terrace  would  be  regarded  as 
more  recent  than  (4),  or  as  washed  down  from  the  earlier  forma- 
above,  since  tin-  material  of  this  terrace  had  such  an  origin. 

6.  Implements  upon  any  undisturbed  surface  of  this  lo\\«-r  ter- 
race would  be?  later  than  (5). 

7  Implements,  fragments  of  pottery,  etc..  have  been  found 
deeplv  IMI. \.t-t\t  led  in  the  present  alluvial  plain.  The  transition 


16        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

from  a  palaeolithic  culture  to  a  dawning  civilization  would  be  looked 
for  in  these  deposits,  reading  from  the  bottom  upward. 

8.  The  archaeological  and  early  historic  record  of  Ancient  Egypt 
is  found  upon  the  surface  and  within  the  upper  layers  of  the 
alluvium. 

Assuming  that  the  foregoing  geological  interpretations  are 
correct,  the  record  is  tolerably  complete  from  the  times  when 
flint-working  beings  inhabited  the  plateau  and  lived  along 
the  precipitous  shores  of  the  fiord  and  lakes,  through  the 
diminishing  stages  of  the  river  to  the  period  in  which  a  prim- 
itive civilization  made  its  appearance  among  the  dwellers  of 
the  modern  valley.  If  the  lacustrine  deposits  are  correctly 
placed  in  the  late  Pliocene  and  First  Glacial  periods  and  if 
the  presence  of  flint  artifacts  within  these  lake  deposits  and 
upon  the  plateau  has  been  correctly  interpreted,  beings 
capable  of  producing  rough  stone  implements  existed  in 
Egypt  even  as  early  as  the  First  Glacial  Period  of  Europe, 
which  may  be  conservatively  estimated  as  some  500,000 
years  from  the  present  time.  Only  the  most  extreme  placing 
of  the  earliest  European  flint  workers  (Pre-Chellean)  would 
take  us  so  far  into  the  past.4 

Perhaps  the  age  of  the  lake  deposits,  by  which  the  age  of 
the  plateau  implements  is  determined,  has  been  overesti- 
mated. The  interpretation  of  the  lacustrine  flints  as 
washed  in  from  the  plateau  may  be  incorrect.  But  in  any 
case  it  appears  that  implement-making  beings  existed  in 
northeastern  Africa  at  a  very  remote  period.  It  is  generally 
accepted  that  the  Pre-Chellean  flint  workers  entered  Europe 
from  another  continent.  The  region  of  southeastern  Asia 
has  been  most  commonly  looked  to  as  their  point  of  origin. 
In  view  of  the  geological  and  cultural  records  of  the  Nile 
valley  we  may  well  entertain  the  hypothesis  that  the  im- 
mediate migration  into  Europe  may  have  been  from  Africa. 

4  The  vexed  question  of  the  so-called  eoliths  is  disregarded,  since  the  flints 
of  the  lake-beds  and  the  plateau  are  comparable  with  the  Chellean  and  Pre- 
Chellean  implements  of  western  Europe. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD     17 

Further  search  for  palaeolithic  remains  in  northern  Africa  and 
correlation  with  those  of  western  Europe  seems  highly 
desirable. 

Whatever  the  period  of  the  beings  who  produced  the 
flints  now  found  upon  the  plateau  and  within  the  lake 
deposits,  the  implement  record  within  the  valley  itself  is 
complete,  beginning  with  the  oldest  river  terraces.  The 
earliest  known  archaeological  remains  are  comparatively 
recent,  appearing  within  the  present  valley  floor,  and  are 
estimated  as  belonging  to  a  period  about  15,000  B.  c.5  They 
have  been  obtained  by  borings  in  the  alluvium  and  consist 
of  fragments  of  pottery.  Elsewhere,  pottery  is  character- 
istic of  an  early  neolithic  stage  of  development.  Between 
15,000  B.  c.  and  5000  B.  c.,  the  inhabitants  of  the  Nile  valley 
advanced  through  a  neolithic  culture  to  a  primitive  civiliza- 
tion. The  earliest  known  burials  are  placed  at  approximate- 
ly 4000  B.  c.  and  show,  in  addition  to  pottery  and  flint  im- 
plements of  remarkable  perfection,  hand-bored  vessels  of 
stone,  implements  and  ornaments  of  ivory,  and  occasional 
articles  of  copper.  Barley,  millet,  wheat,  and  flax  were 
under  cultivation,  as  shown  by  the  contents  of  the  pottery 
jars  found  in  the  graves.  Some  of  the  bodies  are  wrapped  in 
linen  which  exhibits  considerable  textile  skill.  Sheep,  goats, 
long-horned  cattle,  and  donkeys  are  pictured  as  domesticated 
animals.  It  is  a  fair  presumption  that  the  domestication  of 
the  animal  and  plant  life  here  represented  consumed  many 
centuries.  The  development  of  pottery-making  as  early  as 
15,000  B.  c.  take  us  still  further  into  the  past.  We  see 
stretching  back  of  the  dawning  age  of  metal,  as  shown  by  the 
burials  (4000  B.  c.),  a  period  of  life  on  the  alluvium,  begin- 
ning perhaps  as  early  as  20,000  years  before  our  era.  Future 
investigations  will  probably  make  the  record  complete,  both 
palseontologically  and  archaeologically,  from  the  original 
occupation  of  the  valley  by  the  flint  workers  of  the  plateau, 
perhaps  200,000  years  or  more  ago,  to  the  earliest  fixed  date 

•  Breasted,  J.  H.,  loc.  ctt. 


18       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 


in  history  (4241  B.  c.),  as  established  by  the  Egyptian  calen- 
dar with  its  year  of  twelve  months  and  three  hundred  and 
sixty-five  days. 

What  is  known  concerning  earliest  civilized  Egypt,  there- 
fore, pictures  a  society  in  which  the  rudiments  of  the  practi- 
cal sciences  were  well  es- 
tablished not  later  than 
4500  B.  c.  If  it  is  true 
that  Egyptian  civilization 
antedates  that  of  Meso- 
potamia, the  latter,  al- 
though o  f  independent 
origin,  probably  received 
from  Egypt  more  than  it 
gave.  Most  authorities 
maintain  that  civilization 
had  its  earliest  beginnings 
in  Egypt.  It  may  have 

FIG.  4.  Profile  of  a  Pre-historic  Egyptian.  arisen     independently     in 
Restored    by  Elliot  Smith   from   an  Mesopotamia   and    in    the 
early   pre-dynastic    skull.      (Rediawn  Far  Eagt   at  ft  lftter  J^ 
from  Breasted.) 

But  with  our  present  data 

we  must  look  to  the  Nile  valley  for  the  earliest  known  transi- 
tion from  palaeolithic  and  neolithic  men  to  those  whose  ac- 
complishments mark  the  earliest  beginnings  of  extensive 
scientific  knowledge.  There  seems  to  exist  in  northern 
Africa,  a  continuity  through  the  palaeolithic  savagery 
and  the  neolithic  barbarism  of  the  Ice-Age,  to  a  cultural 
level  which  was  the  forerunner  of  the  Greco-Roman,  and 
hence  of  our  own  western  civilization. 

It  appears  that  Egyptian  craf tmanship  was  of  the  greatest 
significance  to  the  Greeks,  who  received  their  earliest  models 
largely  from  this  source.  The  civilization  of  Greece,  which 
was  the  first  emergence  of  a  strictly  European  people  from 
barbarism,  now  appears  to  have  been  initiated  by  contact 
with  the  Egyptian  and  Mesopotamian  cultures  through  the 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD     19 

Phoenicians.  The  ^Egeans,  whom  the  Greeks  conquered, 
were  highly  civilized,  but  their  culture  seems  to  have  been 
obliterated  rather  than  absorbed.  The  Greek  alphabet 
arose  through  imitation  of  the  Phoenician,  mathematical 
concepts  were  received  from  Mesopotamia,  Greek  architec- 


FIG.  5.  Hornless  Breed  of  Egyptian  Cattle.     From  a  tomb  relief 
at  Gizeh,  29th  century  B.  C.    (Redrawn  from  Breasted.) 

ture,  as  shown  by  the  derivation  of  the  colonnaded  Greek 
temple  and  many  lesser  features,  had  its  prototypes  in 
Egypt.  In  like  manner,  many  of  the  earliest  intellectual  and 
mechanical  accomplishments  of  the  Hellenic  race  are  trace- 
able to  what  existed  in  the  civilizations  previously  established 
at  the  eastern  end  of  the  Mediterranean. 

The  scientific  achievements  of  the  Egyptians  during  the 
thirty-five  centuries  preceding  1000  B.  c.  may  now  be  sum- 
marized, without  too  great  emphasis  upon  the  exact  dates, 
since  it  is  our  purpose  merely  to  indicate  the  total  legacy  of 
natural  knowledge  which  passed  from  Egypt  to  Europe  by 
way  of  Greece.  Extensive  archaeological  records  appear 
after  4500  B.  c.  A  steady  though  slow  development  may  be 


20       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 


noted  during  the  millenium  which  follows.  Fire,  implements, 
and  finally  domesticated  animals  and  plants  had  been  the 
great  achievements  of  the  human  race  during  the  ages  of 
stone.  Metals,  writing,  and  government  were  the  more  im- 
portant achievements  in  the  early  advance  of  the  Egyptians 
toward  civilization.  The  extensive  domestication  and 
specialization  of  a  wide  range  of  animal 
and  plant  life  are  examples  of  a  prac- 
tical knowledge  which  was  the  begin- 
ning of  biological  science.  In  medi- 
cine, the  Egyptians  excelled  all  other 
ancient  peoples.  Only  the  study  and 
treatment  of  mental  diseases  seem  to 
have  been  neglected.  The  earliest 
known  machine  is  an  Egyptian  crank- 
drill  invented  before  3000  B.  c.  (Fig. 
6).  The  potter's  wheel  was  of  similar 
early  origin.  The  ox-drawn  plow  arose 
as  a  modification  of  the  peasant's  hoe. 
For  a  long  time  the  advance  was 
gradual.  But  with  the  opening  of  the 
Pyramid  Age  (3000-2500  B.  c.)  there 
appears  a  single  century,  which,  alone 

FIG.  6.  The  Earhest  Known     **  .   J ' 

Machine.  An  Egyptian  of  all  the  centuries,  is  comparable  to 
crank  drill,  about  3400  our  nineteenth  century  in  its  mechani- 

to  3000   B.    C.     (Re-       11-  T      one  A 

drawn  from  a  figure  by  cal  achievement.  In  3050  B.  c.,  the 
Borchardt  in  Breast-  first  stone  masonry  had  not  been  laid. 
Less  than  one  hundred  and  fifty  years 
fater  the  great  pyramid  of  Gizeh  was  under  construction. 
The  transition  from  barbarism  thus  culminated  suddenly  hi 
this  " Wonderful  Century"  of  the  ancient  world.  The  pyra- 
mids and  other  architectural  productions  of  the  Egyptians  are 
important  as  indications  of  the  perfection  of  their  mechanical 
skill.  A  marvelous  manual  dexterity  is  exhibited,  alike  by 
their  sculpture,  their  architecture,  and  their  craftsmanship. 
The  earliest  sea-going  ships  appear  hi  the  30th  century  B.  c. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    21 

The  laying  out  of  buildings  and  the  construction  of  irrigation 
ditches  are  examples  of  engineering  feats  which  excite  ad- 
miration. Perhaps  the  most  remarkable  of  all  is  the  record- 
ing of  the  levels  of  the  Nile  in  all  latitudes,  which  resulted  in 
a  line  being  carried  in  one  plane  around  all  the  bends  of  the 
river  for  some  seven  hundred  miles.  Although  in  the  same 
plane  throughout  its  length,  this  line  is  not  exactly  parallel  to 
the  flood  slope  for  the  entire  distance.  But  when  it  was  later 
extended  some  two  hundred  miles  up  the  river  the  plane  and 
the  flood  slope  became  more  closely  parallel.6 

If,  as  some  maintain,  there  exists  a  correlation  between 
climatic  conditions  and  the  character  of  a  civilization,  a 
parallel  may  be  drawn  in  ancient  Egypt.  The  climate  of  the 
Nile  valley  offered  an  appropriate  setting  for  a  civilization 
which  was  intensely  material,  but  at  the  same  time  peaceful 
and  benign.  But  the  Egyptian,  despite  his  practical  accom- 
plishment, exhibits  certain  mental  crudities.7  In  abstract 
thinking,  there  seems  to  have  been  much  confusion  of 
thought.  There  is  no  clear  evidence  of  a  conspicuous  ability 
to  generalize,  and  with  this  may  perhaps  be  correlated  a 
certain  planlessness  in  architecture  and  an  inaccuracy  of 
artistic  representation.  If  these  were  characteristics  of 
Egyptian  thought,  we  can  the  better  understand  their 
scientific  limitations.  Wonderful  in  their  grasp  of  mechan- 
ical processes,  in  the  confidence  with  which  they  undertook 
great  enterprises  like  the  building  of  the  pyramids,  and  in 
their  governmental  organization,  they  give  no  evidence  of 
the  transcendent  imagination  which  led  the  Greek  in  his 
quest  for  natural  causation.  No  other  people  in  history  ever 
-ted  for  so  long  a  period  without  external  invasion  or 
serious  internal  revolution.  Their  material  foundation  was 
early  assured.  Yet  the  Egyptians  seem  never  to  have 
passed  beyond  the  more  immediate  problems  of  science  and 
philosophy.  It  is  this  failure  to  progress  which  constitutes 

•  Breasted,  J.  H.,  loc.  cit. 

1  Taylor,  H.  O.,  "Ancient  Ideals,"  p.  12. 


22        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

the  strongest  suggestion  of  their  mental  limitations.  We 
cannot  ascribe  to  them,  as  to  certain  of  the  Greeks,  the  intel- 
lectual qualities  of  the  modern  scientific  mind.  Neverthe- 
less, the  classical  tradition  of  the  debt  to  Greco-Roman 
culture  should  not  conceal  the  fact  that  many  of  the  mechan- 
ical and  artistic  elements  of  western  civilization  originated  in 
the  valley  of  the  Nile,  and  were  merely  passed  over  to 
western  Europe  by  the  Greco-Roman  world. 

DEVELOPMENT  OF  SCIENCE  AMONG  THE  PEOPLES 
OF  MESOPOTAMIA 

The  climatic  and  racial  background  of  ancient  Mesopo- 
tamian  culture  is  in  marked  contrast  with  that  of  Egypt.  In 
the  Nile  valley  we  see  a  homogeneous  people,  apparently  of 
a  stock  similar  to  the  Mediterranean  race  of  a  later  period, 
living  in  a  land  well  protected  by  natural  barriers  and  with 
agricultural  conditions  of  great  stability.  The  Mesopo- 
tamian  plain  was,  by  contrast,  the  meeting  place  of  con- 
flicting races  from  the  desert  to  the  south  and  west  and  from 
the  mountains  to  the  north.  From  the  period  of  the  Sume- 
rian  peoples,  whose  documentary  record  begins  about  3000 
B.  c.,  we  find  a  recurring  struggle  between  established 
civilizations  and  barbarian  invaders.  Moreover,  agricul- 
tural conditions  were  less  stable  than  in  Egypt. 

The  absence  of  an  abundant  supply  of  stone  led  to  the  use 
of  brick  for  most  building  purposes.  Hence  the  record  is  less 
extensive  in  certain  lines.  The  sun-dried  bricks  have  crum- 
bled to  rums,  but  the  records  upon  the  baked  cylinders  and 
tablets  have  proved  almost  indestructible  and  whole  li- 
braries have  been  preserved.  In  the  main,  the  civilization 
thus  depicted  appears  to  have  originated  independently  in 
Mesopotamia,  despite  extensive  trade,  and  consequently 
exchange  of  ideas,  with  Egypt  after  2500  B.  c.  That  one 
item,  at  least,  was  actually  derived  from  Egypt  is  indicated 
by  the  fact  that  split-wheat  was  called  by  its  Egyptian  name. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    23 

Many  elementary  facts  of  mathematical  and  physical 
science  were  established  as  early  as  the  third  millennium 
B.  c.  In  Babylon,  we  find  standard  measures  of  length, 
weight,  and  capacity  issued  by  governmental  authority. 
Our  own  unit  of  weight,  the  pound,  has  descended  from  the 
Sumerian  mina.  Our  tune  unit  sixty  had  a  similar  origin. 
The  earliest  writing  which  was  exclusively  alphabetic  was 
that  of  the  Aramean  Syrians,  in  contact  with  Mesopotamia 
to  the  north  and  west.  The  multiplication  table,  tables  of 
squares  and  cubes,  a  duodecimal  and  a  decimal  system 
appear  in  the  sculptured  records,  bearing  testimony  to  the 
intelligence  which  made  so  admirable  a  beginning  in  the 
basic  sciences.8  The  elements  of  geometry  arose,  apparently 
in  connection  with  the  measurement  of  land.  A  calendar 
was  developed  to  meet  the  demands  of  Agriculture.  Among 
the  items  of  modern  life,  illustrative  of  applied  science  and 
independently  originated  by  the  Mesopotamians  or  through 
them  transmitted  to  Europe,  may  be  enumerated :  the  wheel, 
as  a  burden-bearing  device  (3000  B.  c.);  cotton,  derived 
from  India  at  an  early  date;  the  domestic  horse,  coming  to 
Babylonia  from  the  north  about  2100  B.  c.;  and  iron,  which 
was  first  extensively  used  by  the  armies  of  Assyria.  The 
beginnings  of  a  postal  system  under  Sennacherib  (700  B.  c.) 
may  also  be  mentioned.9 

The  record  of  the  Chaldean  civilizations,  as  drawn  from 
the  inscriptions  on  temple  and  palace  walls  and  on  the 
cylinders  and  tablets  of  clay,  is  tolerably  complete.  It 
tells  us  of  civilizations  in  which  astronomy,  mensuration, 

8  The  original  discovery  of  what  might  be  called  the  properties  of  the  various 
numbers  must  have  been  a  wonderful  experience  for  the  human  mind.  It  is 
not  surprising  that  merit  and  demerit  were  ascribed  to  numbers  which  be- 
haved so  differently  in  computation.  For  an  interesting  discussion  along  this 
line  see:  Slocum,  S.  E.,  "The  Romantic  Aspect  of  Numbers,"  Scientific 
Monthly,  July,  1918. 

:n,  W.  C.  D.,  and  C.  D.,  "Science  and  the  Human  Mind."    Draper, 
History  of  the  Conflict  between  Religion  and  Science."    Sedgwick, 
W.  T.,  and  Tyl.-r.  II.  W.,  "A  Short  History  of  Science." 


24       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

arithmetic,  agriculture,  and  the  calendar  were  recognized  as 
worthy  the  attention  of  priest  and  administrator.  Thus  the 
first  astronomers  were  probably  the  Chaldean  astrologer- 
priests,  whose  vigils  in  the  clear  atmosphere  of  an  arid  region 
led  them  to  watch  the  stars  and  to  recognize  order  and  law 
in  the  heavens.  Astrology  was  their  dominant  motive.  But 
astronomical  events  were  carefully  observed  and  are  recorded 
in  the  inscriptions  as  early  as  2000  B.  c.  Subsequently,  these 
early  astronomers  were  able  to  predict  the  eclipses  of  the 
moon.  Our  present  names  for  the  signs  of  the  zodiac — the 
Crab,  the  Scorpion,  and  the  like — are  lineal  descendants  of 
the  Chaldean  astronomy,  in  which  the  sky  was  mapped  and 
the  names  of  animals,  symbolic  of  gods,  given  to  the  several 
divisions.  Intermingled  with  religious  beliefs,  this  modicum 
of  knowledge  became  a  system  by  which  it  was  claimed  that 
future  events  and  the  fates  of  men  could  be  foretold.  The 
sorcery  and  magic  of  Chaldea,  along  with  its  astrology, 
spread  westward,  exerting  its  influence,  first  upon  Greek  and 
Roman  thought,  and  later  upon  that  of  western  Europe. 
Thus,  the  idea  of  the  virtues  inherent  in  certain  numbers,  so 
potent  throughout  the  Middle  Ages,  appears  to  have  orig- 
inated in  Mesopotamia  and  even  to-day  fortune  tellers 
claim  for  their  art  descent  from  the  soothsayers  of  Chaldea 
and  Babylonia. 

Speculative  science  and  rational  philosophy  might  have 
arisen  from  the  practical  scientific  knowledge  which  thus 
came  into  being.  That  such  was  not  the  case  is  perhaps  ex- 
plained by  the  fact  that  the  gods  of  the  Mesopotamian 
peoples  were  regarded  as  hostile  and  ever  in  need  of  propitia- 
tion. Fate  hung  heavy  on  the  human  mind  and  men's 
thoughts  were  always  seeking  to  avert  its  decrees.  "  Strange 
mingled  streams  of  foolishness  and  knowledge"  arose  in 
Mesopotamia  and  flowed  west,  north,  and  perhaps  east.10 
Religious  beliefs  were  hopelessly  intermingled  with  scientific 
and  philosophical  thought.  The  Hebrew  story  of  the 

10  Taylor,  H.  O.,  loc.  tit.,  p.  13,  Vol.  I. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    25 

Temptation  of  Eve,  which  was  of  Babylonian  origin,  and  in 
which  the  acquirement  of  knowledge  was  a  form  of  sacrilege, 
is  an  echo  of  a  conception  of  the  universe  unfavorable  to  the 
development  of  scientific  thinking.  The  tumultuous  exist- 
ence of  these  peoples  of  Mesopotamia  throughout  many  cen- 
turies, during  which  one  conqueror  followed  another,  may 
have  emphasized  the  concept  of  unfriendly  gods,  while  the 
peace  of  Egypt  may  have  been  largely  responsible  for  gods 
who  smiled  on  men.11  The  practical  scientific  achievements 
of  these  Near-Eastern  peoples,  before  the  advent  of  any 
European  civilization,  constitute  the  first  great  advance  of 
science.  If  there  remained  for  the  Greeks  the  first  important 
advance  toward  a  theoretical  explanation  of  the  universe,  the 
material  accomplishments  of  the  Near  East  should  not  be 
disregarded.  The  orientalist  has  done  an  inestimable 
service  in  showing  the  foundations  upon  which  the  first 
strictly  European  civilization  was  reared. 

CONTRIBUTION   OF   GREECE    TO    THE   ADVANCE 
OF   SCIENCE 

In  Greece,  the  seeds  of  scientific  thought,  which  had 
germinated  among  the  earlier  peoples  of  the  Eastern  Med- 
iterranean, reached  their  full  fruition  in  the  ancient  world. 
We  have  been  taught  to  regard  the  rise  of  Hellenic  civiliza- 
tion as  a  social  and  intellectual  phenomenon  unparalleled  in 
:  y.  How  Greece  so  suddenly  came  to  her  glory  was  long 
a  mystery.  But  the  archaeological  investigations  of  recent 
years  have  established  certain  facts  of  continuity,  previously 
unknown.  Investigations  in  Crete  have  shown  the  existence 
of  the  so-called  Minoan  civilization,  originating  from  an 
indigenous  neolithic  foundation,  which  can  be  followed  in 
tin-  lower  strata  of  the  hill  of  Cnossus,  back  to  a  period 
perhaps  as  early  as  7000  B.  c.  This  neolithic  culture  artic- 

11  Jastrow,  J.,  " Aspects  of  Religious  Belief  and  Practice  in  Babylonia  and 
A«yna." 


26        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

ulates  on  the  one  hand  with  the  late  palaeolithic  of  western 
Europe  and  northern  Africa  and  on  the  other  is  transformed 
into  the  early  Minoan  about  3400  B.  c.  Subsequently,  the 
Minoan  civilization  was  in  intimate  contact,  first  with 
Egypt,  and  later,  with  Mesopotamia,  although  never  wholly 
dominated  by  either.12 

The  indigenous  origin  in  Crete  of  this  ^Egean  culture  is  of 
prime  importance.  Egypt,  Mesopotamia,  and  Crete,  al- 
though interacting  at  a  subsequent  period,  appear  to  be 
three  separate  lines  of  evolution  connecting  the  barbarism  of 
the  Late  Stone  Age  with  the  civilization  of  later  Europe. 
The  first  towns  upon  the  European  continent  were  the 
settlements  of  the  ^Egeans  at  Mycense,  Tiryns  and  elsewhere 
upon  the  mainland  of  Greece.  The  cultural  level  estab- 
lished upon  the  shores  of  the  ^Egean  Sea  constitutes  a  third 
great  civilization  of  independent  origin  in  the  near-eastern 
world.  After  2500  B.  c.,  the  contact  of  the  ^Egeans  with 
Egypt  was  increasingly  intimate.  Crete  became  a  depend- 
ency of  Egypt  following  the  development  of  Egyptian  naval 
power.  Cretan  envoys  bringing  tribute  are  recorded  during 
the  fifteenth  century  B.  c.  By  the  beginning  of  the  second 
millennium  the  ^Egeans  upon  the  island  of  Crete  were  highly 
civilized,  their  "Grand  Age"  being  the  sixteenth  century 
B.  c.  Later,  this  high  civilization  spread  to  the  mainland  of 
Greece.  These  facts  are  important  in  determining  the 
period  of  the  actual  dominance  of  the  Greeks  in  the  JSgean 
region,  which  began  about  the  twelfth  century  before  our 
era.13 

12  Evans,  Sir  Arthur,  "New  Archaeological  Lights  on  the  Origins  of  Civiliza- 
tion in  Europe."    Address  of  the  President  of  the  British  Association  for  the 
Advancement  of  Science,  1916.    Reprinted  in  Science,  Sept.  22,  1916.    See 
also:  Baikie,  J.,  "The  Sea  Kings  of  Crete";  and  Hawes,  C.  H.,  and  H.  B., 
"Crete  the  Forerunner  of  Greece." 

13  One  of  the  most  specific  intimations  of  the  ejection  of  the  ^Egeans,  by 
the  incoming  Greeks,  is  found  in  the  record  of  a  naval  battle  pictured  on  the 
wall  of  a  temple  at  Thebes.    The  conflict,  which  took  place  off  the  coast  of 
Syria,  was  between  Cretan  fugitives  and  Egyptians.    Breasted,  J.  H.,  Scientific 
Monthly,  Feb.,  1920,  p.  206. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    27 

Thus,  some  two  thousand  years  before  our  era  there 
existed  upon  the  shores  and  islands  of  the  JEgean  Sea  a 
civilization  which  had  already  attained  a  high  level.  The 
ethnic  stock  of  these  ^Egean  folk  was  the  long-headed,  dark 
complexioned,  delicately  molded  Mediterranean  race  made 
familiar  through  studies  upon  European  anthropology. 
During  the  early  centuries  of  this  second  millennium  there 
came  from  the  north,  by  way  of  the  Black  Sea  and  the 
Balkans,  a  flood  of  barbarians.  It  is  clear  from  the  references 
to  their  stature,  their  blue  eyes,  and  their  tawny  hair,  as 
well  as  from  their  cultural  traditions  and  the  anatomical 
evidence  derived  from  skeletal  remains,  that  this  invading 
people  was  of  the  Northern  European  or  Nordic  stock. 
Their  use  of  the  funeral  pyre,  as  described  in  Homer,  is  one 
custom  among  many  which  differentiates  them  sharply  from 
the  ^Egeans.  The  Homeric  tales  are,  presumably,  founded 
upon  certain  of  their  early  exploits,  just  as  the  fabuluous 
stories  of  King  Arthur  have  some  sort  of  an  historical  foun- 
dation. The  original  Hellenes  were  perhaps  in  possession  of 
the  mainland  for  centuries,  before  they  learned  to  build 
ships  and  voyage  to  the  islands.  The  period  of  their  original 
invasion  is  uncertain,  since  they  possessed  no  written  lan- 
guage until  a  much  later  period.  But  their  occupation  of  the 
Peloponnesus  can  be  placed  in  the  eleventh  century  B.  c. 

Following  the  Hellenic  conquests,  the  ^Egeans  in  Crete 
and  on  the  mainland  survived  in  large  part  as  a  subject 
population.  In  the  course  of  centuries,  the  stock  of  the 
original  invaders,  and  others  who  doubtless  followed  them, 
must  have  become  somewhat  intermingled  with  that  of  the 
conquered  jEgeans.  The  Greek  population  some  four  or 
'•enturies  later,  at  the  dawn  of  its  written  history,  was 
of  double  origin.  The  extent  to  which  the  two  elements 
had  then  fused  together  is,  of  course,  impossible  to  ascer- 
tain.14 It  is  fair  to  surmise  that  for  many  centuries  a  land- 

'•«  fact  that  the  Philistines  of  Biblical  times  are  known  to  hav.-  orig- 
inated from  a  group  of  Cretan*,  who  fled  before  their  conquerors  shows  that 


28       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

holding  aristocracy  of  Nordic  origin  was  superimposed  upon 
a  larger  group  of  dependents  which  was  almost  wholly 
^Egean.  For  example,  in  Sparta  and  Crete  the  citizens 
were  virtually  military  garrisons  commanding  a  hostile 
population.  The  helots  or  serfs  were  controlled  with  dif- 
ficulty. Gradually  the  conquering  stock  died  out  or  mingled 
with  the  conquered  as  the  two  intermarried  and  the  more 
competent  ^Egean  strains  came  to  the  fore.  It  is  not  clear  to 
what  extent  the  Nordic  element  existed  throughout  Greece 
at  a  later  date,  but  there  is  evidence  that  the  ^Egean  strain 
was  more  extensive  among  the  Athenians  than  in  many 
other  communities.  We  know  that  there  was  present  every- 
where a  relatively  large  population  of  slaves.  The  modern 
student  of  racial  heredity  finds  even  these  meager  facts  of 
interest  as  a  clue  to  the  Hellenic  genius.  Some  critics  have 
believed  that  there  exists  a  causal  connection  between  the 
dilution  of  the  northern  blood  and  the  final  decline  of  the 
Greek  states.  The  attainments  of  the  ^Egeans  before  the 
advent  of  the  invading  Hellenes  renders  such  a  belief  less 
plausible. 

Continuity  between  the  culture  of  Hellas  and  the  three 
preceding  civilizations  of  Egypt,  Mesopotamia,  and  Crete 
has  thus  been  established.  It  does  not  appear  that  the 
northern  conquerors  brought  to  their  new  home  a  culture 
which  nearly  approached  that  of  the  ^Egeans.  Civilization 
was,  for  the  time  being,  obliterated  and  barbarism  prevailed. 
The  original  invaders  were  still  in  a  neolithic  stage.  They 
did  not  bring  civilization  with  them,  but  only  strong  bodies, 
and  minds  capable  of  assimilating  some  measure  of  the  cul- 
ture they  trampled  upon.  The  ^Egean  civilization  was 
crushed,  but  some  influence  must  have  remained.  In  the 
course  of  time  there  was  increasing  contact,  through  the 
Phoenician  traders,  with  Egypt  and  Mesopotamia.  Greek 
civilization  was,  therefore,  not  a  spontaneous  product,  as 

there  was  a  certain  amount  of  forced  emigration  eastward  and  southward. 
But  the  majority  of  the  ^Egeans  no  doubt  remained  as  serfs  and  slaves. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    29 

was  long  supposed  to  be  the  case.  Its  most  unique  feature 
was  the  receptivity  of  the  primitive  Hellene  to  the  legacy  of 
the  ancient  East  and  his  capacity  to  make  this  legacy  his 
own.15 

The  distinctive  accomplishments  of  the  three  antecedent 
civilizations  had  been  practical  and  materialistic.  Despite 
their  diversified  attainments,  the  analytical  quality  appears 
to  have  been  lacking  in  both  Egypt  and  Mesopotamia.  Of 
the  Minoan  culture  we  know  little  in  this  regard,  because  the 
inscriptions  are,  as  yet,  mainly  undecipherable.  The  im- 
portance of  the  Hellenic  culture  in  relation  to  science  lies  hi 
its  philosophical  analysis  of  natural  phenomena,  including 
those  of  human  social  organization.  Explanation  of  the 
physical  universe,  which  is  now  the  function  of  natural 
science,  was  first  seriously  attempted  by  the  Greek  philos- 
ophers. Their  intellectual  superiority  lay  in  their  ability  to 
generalize  and  to  abstract.  Hard  thinking  and  close  reason- 
ing were  distinctive  traits.  These  appear  in  their  art,  their 
literature,  their  philosophy  and  their  science.  They  general- 
ized and  grasped  the  principles  that  lie  behind  the  products 
of  human  eyes  and  hands.  They  showed  an  ability  to 
separate  meaning  from  existence.  Nothing  approaching 
their  capacity  for  abstraction  appears  in  the  records  of  ante- 
cedent civilizations,  unless  the  monotheism  of  the  Hebrews 
can  be  taken  as  an  example  of  a  similar  capacity  within  the 
ethical  field.  In  any  history  of  science,  the  Greek  is  of  over- 
shadowing importance  because  of  his  scientific  turn  of  mind.16 

<;  aeem  to  see  a  race  suddenly  coming  to  its  own — "False,  boastful  and 

•us  perhaps,  but  with  a  sense  of  beauty,  a  confident  joy  in  life,  a  warmth 
of  affection  that  bespeak  a  gallant,  vigorous,  open-minded,  conquering  people, 
a  people  of  extraordinarily  brilliant  ori^iniil  intellectual  endowment,  tempered 
and  purified  by  the  rigors  of  the  North,  and  then  placed  in  a  land  of  glorious 
beauty,  where  the  wine-dark  sea  brought  the  trade  and  knowledge  of  the 
world  to  their  doors,  where  the  climate  smiled  upon  their  fortified  homesteads, 

Abundant  slaves  made  life  easy,  and  gave  leisure  for  the  growth  of  the 
highest  forms  of  philosophy,  literature  and  art."  Whetham,  loc.  cit.,  p.  33. 

-hafTy,  J.  I'.,  "What  Have  the  Greeks  Done  for  Modern  Civilisation?", 
Chap  VIII. 


30        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

The  origin  of  democratic  institutions  in  Greece  is  no  doubt 
to  be  correlated  with  the  type  of  mind  above  described.  The 
Oriental  had  acquiesced  in  a  subjection  of  mind  and  body  to 
political  and  religious  tradition.  Democracy  in  any  sense 
was  unknown.  Corporate  and  class  spirit  was  characteristic 
of  ancient  oriental  society.  The  Greeks  developed  the  idea 
of  the  individual  and  his  intellectual  worth  and  so  gave  scope 
to  genius.  They  enthroned  the  citizen  above  the  king,  as 
well  as  natural  law  above  the  gods.  The  wonder  is  not  that 
in  the  end  they  failed  to  conquer  the  world  but  that  they 
wrought  so  well.  Man  rather  than  nature  was,  however, 
then-  culminating  concern.  "Know  thyself"  is  a  phrase 
significant  as  a  clue  to  an  underlying  philosophy.  In  this 
respect  our  present  age  may  well  profit  by  the  Greek  spirit, 
which  at  its  best  was  too  well  balanced  to  subordinate  human 
aspiration  to  the  materialities  of  existence. 

We  are  more  particularly  concerned  with  the  place  of 
science  among  this  many-sided  race.  But  this  cannot  be 
discussed  aside  from  their  philosophy  and  their  religion.  In 
the  religion  of  Greece  is  seen  reflected  the  Greek  mind  with 
its  joy  in  living.  In  the  main,  the  gods  smiled  on  men  and 
stood  ready  to  help  them.  There  was  no  established  church 
or  priesthood,  tending  towards  the  crystallization  of  current 
doctrines  into  dogmatic  beliefs.  As  tune  went  on,  the  idea  of 
a  single  God,  the  supreme  and  righteous  Zeus,  was  developed 
among  the  more  advanced  thinkers.  As  with  the  Hebrews, 
this  conception  arose  by  gradual  stages,  finding  its  culmina- 
tion hi  Plato's  reconstruction  of  religion  and  hi  the  mysticism 
that  was  taken  over  from  Platonic  thought  by  the  early 
Christian  theologians.  In  general,  Hellenic  monotheism 
was  intellectual  rather  than  ethical.  It,  therefore,  tended  to 
supply  the  deficiencies  hi  the  Hebrew  system  when  the 
latter  was  taken  over  by  Christianity.17 

Philosophy,  distinct  from  religion  hi  name  as  well  as  in 

17  Dickinson,  G.  Lowes,  "The  Greek  View  of  Life."  Also:  Farnell,  L.  R., 
."The  Higher  Aspects  of  Greek  Religion." 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    31 

spirit,  is  here  first  recognizable.  Inquiry  did  not  stop  with 
everyday  experience,  but  leaped  beyond  to  theories  of  the 
universe  and  of  ultimate  reality.  "All  things  have  arisen 
from  water  and  will  return  to  water,"  not  water  but  " air  or 
fire  or  the  four  original  elements  or  atoms  are  the  universal 
principles  of  reality,"  are  examples  of  Greek  speculative 
thought.  The  intellectual  failure  of  the  Greek  was  his 
inability  to  see  the  point  at  which  philosophic  speculation  so 
far  outruns  fact  as  to  become  unprofitable.  That  his  specu- 
lations on  the  evolution  of  life  and  on  the  atomic  nature  of 
matter  are  in  line  with  the  facts  established  by  modern 
science  is  not  mere  coincidence.  It  is  rather  the  insight  of 
master  minds  groping  towards  the  truth  without  sufficient 
factual  knowledge.  The  Greek  hi  his  theorizing  had  the 
advantage  of  a  rationalistic  point  of  departure,  since  the 
Greek  religion  offered  no  compelling  philosophical  system  as 
did  Christianity  at  a  later  day.  Deductive  logic  was  form- 
ally organized,  while  the  inductive  method  was  practiced,  if 
not  clearly  apprehended.18  The  concept  of  physical  causa- 
tion was  apprehended.  Thus  the  Greek  perceived  the  gen- 
eral in  the  midst  of  the  particular  more  truly  than  did  any 
other  ancient  people.  Moreover,  the  part  played  by  intellect 
was  for  the  first  time,  consciously  recognized. 

It  is  unsafe  to  generalize  regarding  racial  traits  even 
among  our  contemporaries.  But  the  capacity  of  certain  of  the 
Greeks  for  abstract  and  analytical  thinking  marks  them  as 
the  intellectual  forebears  of  modern  scientific  thought. 
The  Greek  mind  showed  its  ability  to  grasp  the  scientific 

"  The  following  example  of  the  inductive  method  is  cited  by  Sedgwick  and 
Tyler,  "A  Short  History  of  Science,"  p.  54:  "We  may  recognize  here  the  char- 
:iH«-ri.--tir  Clements  of  the  inductive  method,  first,  observation  of  the  par- 
ticular fact  that  in  a  certain  right  triangle,  with  sides,  3,  4,  and  5,  the  sum  of 
the  squares  on  the  two  sides  is  equal  to  that  on  the  hypotenuse;  second,  the 
formation  of  the  hy(>othcsis  that  this  may  be  true  also  for  right  triangles  in 
general;  third,  the  verification  of  the  hypothesis  in  other  particular  cases. 
Then  follows  the  deductive  confirmation  of  the  hypothesis  as  a  law  for  all 
right  triangles." 


32       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

spirit  of  truth  by  the  work  of  Hippocrates  and  his  school 
(c.  400  B.  c.)  in  medicine,  by  that  of  Archimedes  (287-212 
B.  c.)  in  mechanics,  and  of  Aristarchus  (c.  270  B.  c.)  in  his 
heliocentric  theory  of  the  universe.19  But  everywhere 
speculation  outran  ascertained  fact.  Although  Greek 
philosophy  permeated  the  theology  of  Christendom  for 
many  centuries,  and  although  the  science  of  Hippocrates, 
of  Archimedes,  and  of  Aristarchus,  and  the  great  Aristotelian 
tradition  flowed  into  Europe  through  Rome  and  Constanti- 
nople, only  to  be  fully  acknowledged  as  Greek  in  origin  in  the 
period  of  the  Renaissance,  the  birthplace  of  modern  science 
was  not  Greece  but  western  Europe.  In  Hellenic  thought, 
science  was  as  a  rising  tide,  while  philosophy  was  at  the  flood. 
Among  the  causes  for  the  decline  of  Greek  civilization  may 
have  been  the  failure  to  appreciate  the  solid  ground  of 
scientific  fact  upon  which  has  been  founded  the  material  and 
spiritual  progress  of  modern  tunes. 

The  Greek  did  not  sufficiently  acknowledge  science,  with 
its  demand  for  sure  even  though  slow  progress,  as  distinct 
from  the  speculations  of  philosophy.  Nor  can  one  consider 
the  science  of  Greece  apart  from  its  philosophy,  since  the 
Greeks  were  philosophical  scientists  to  a  degree  which  even 
philosophers  have  not  surpassed  in  later  days.  Of  all  the 
speculations,  non-scientific  at  the  time  but  since  brought 
within  the  realm  of  science,  those  concerning  the  nature  of 
matter  and  the  origin  of  life  are  of  most  interest  at  the 
present  day.  The  very  existence  of  such  speculations  indi- 
cates a  remarkable  advance  in  thought.  When  indulging  in 
them,  these  philosopher-scientists  were  reflecting  upon  and 
offering  hypotheses  for  problems  which  twenty  centuries 
later  became  subject  matter  for  exact  science.  Empedocles 
separated  energy  from  matter,  and  Democritus  developed  a 

19Libby,  Walter,  "An  Introduction  to  the  History  of  Science."  Also: 
Sedgwick,  W.  T.,  and  Tyler,  H.  W.,  "A  Short  History  of  Science";  and 
Browne,  C.  A.,  "Four  Anniversaries  in  the  History  of  Greek  Philosophy," 
The  Open  Court,  Dec.,  1915. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    33 

theory  of  all  matter  as  composed  of  atoms — theories  which 
failed  to  establish  themselves  because  they  lacked  observa- 
tional and  experimental  support.  But  what  a  contrast  to  the 
mental  attitude  of  earlier  peoples  and  to  that  of  early  Chris- 
tendom is  here  presented ! 

Speculations  concerning  the  origin  of  life  proceeded  along 
two  lines — the  origin  of  the  individual  and  the  origin  of  the 
race.  These  two  problems,  which  have  so  concerned  the 
biologist  of  modern  times,  were  not  always  clearly  separated. 
They  have,  of  course,  certain  features  in  common.  The 
speculations  of  the  earlier  Greek  philosophers  culminated  in 
the  doctrine  of  Aristotle  that  living  things  originated  from 
germs,  composed  of  soft  masses  of  matter,  or,  in  the  case 
of  higher  forms,  sprang  directly  from  the  earth.  We  find 
here  the  beginnings  of  the  controversy  over  spontaneous 
fition,  which  was  not  settled  until  the  third  quarter  of 
the  nineteenth  century.  The  explanation  of  racial  origins— 
what  we  now  term  evolution — was  developed  among  the 
Greeks  as  an  outgrowth  of  their  observation  that  nature  was 
in  a  state  of  constant  change.  Seeing  the  apparent  flux  of 
all  material  things,  the  Greek  philosopher  speculated,  not 
only  upon  the  existence  of  a  permanent  element  in  nature, 
but  also  upon  the  nature  of  the  change  that  was  forever  in 
progress.  Thus  arose  the  idea  of  living  things  as  changing; 
and,  finally,  the  concept  of  a  succession  of  animal  types,  and 
of  descent  with  modification,  was  vaguely  expressed.  Again, 
the  concept  of  a  survival  of  the  fittest  was  dimly  recognized  by 
Empedocles;  and  Aristotle  clearly  stated  the  problem,  if  not 
the  solution,  of  the  phenomenon  of  adaptation  in  organic 
nature.  As  a  result  of  these  speculations,  the  Greeks,  as  one 
writer  expresses  it,  "left  the  later  world  face  to  face  with  the 
problem  of  Causation  in  three  forms:  first,  whether  Intelli- 
Design  is  constantly  operating  in  Nature;  second, 
her  Nature  is  under  the  operation  of  natural  causes 
originally  implanted  by  Intelligent  Design;  and  third, 
whether  Nature  is  under  the  operation  of  natural  causes  due 


34        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

from  the  beginning  to  the  laws  of  chance,  and  containing  no 
evidences  of  design,  even  hi  their  origin. "  20 

Aristotle,  the  greatest  of  all  the  Greek  philosopher- 
scientists,  is  especially  interesting  to  the  biologist,  because 
he  has  been  called  the  father  of  zoological  science.  Taken  as  a 
whole,  his  work  represents  the  culmination  of  the  scientific 
genius  of  the  Hellenic  race.  He  was  the  first  individual  of 
whom  it  is  recorded  that  he  took  notes  and  collected  books, 
with  a  view  to  an  encyclopaedic  organization  of  existing  knowl- 
edge; he  was  also  the  first  to  definitely  formulate  the  princi- 
ples of  deductive  logic.  He  was  the  greatest  systematizer 
of  knowledge  that  the  ancient  world  produced,  and  was  in 
general  the  founder  of  most  of  the  sciences  which  originated 
in  the  ancient  world.  This  in  part  accounts  for  the  fact  that 
his  works  were  looked  upon  as  authoritative  in  science  and 
philosophy  until  modern  tunes.  It  is  no  wonder  that  Dante 
designated  him  as  "the  master  of  them  that  know."  But 
more  than  this,  Aristotle  possessed  the  mind  of  scientific 
genius. 

Aristotelian  philosophy,  in  opposition  to  the  supernatural- 
ism  of  Plato,  was  the  philosophy  of  the  concrete  and  partic- 
ular substance  or  thing;  and  was,  despite  its  coloring  of 
Platonic  supernaturalism,  the  logical  antecedent  of  modern 
scientific  realism.  In  his  scientific  conclusions,  Aristotle 
was  influenced  by  his  philosophical  preconceptions,  but  the 
fact  that  his  dominant  philosophy  was  realistic  rendered  this 
influence  of  less  significance.  In  biological  science,  he  seems 
to  have  been  familiar  with  a  large  number  of  animals  by 
actual  dissection,  and  to  have  possessed  a  factual  knowledge 
greater  than  any  student  of  animal  life  until  the  period  of  the 
Renaissance.  He  illustrates  the  Hellenic  genius,  on  its 
intellectual  side,  more  completely  than  any  one  individual. 
His  works,  in  garbled  and  fragmentary  form,  constitute  the 
greatest  single  item  in  the  philosophical  and  scientific  legacy 
inherited  from  the  ancient  world.  In  him  was  epitomized 

20  Osborn,  H.  F.,  "From  the  Greeks  to  Darwin,"  p.  68. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    35 

the  genius  for  generalization  so  characteristic  of  the  Greek 
mind. 

But  the  attainments  of  the  Hellenic  mind  can  be  illustrated 
by  institutions  as  well  as  by  individuals.  The  conspicuous 
example,  in  science,  is  the  Museum  at  Alexandria.  Here, 
the  Macedonian  rulers  brought  together  the  literature  of 
the  ancient  world  in  a  great  library  and,  by  attracting  schol- 
ars from  the  entire  Mediterranean  region,  created  what 
more  nearly  approaches  the  great  university  of  the  present 
day  than  any  other  institution  of  ancient  times.  The  Mu- 
seum was  the  institutional  culmination  of  the  intellectual 
genius  of  the  Greeks  as  Aristotle  was  the  personal.  Stimu- 
lated no  doubt  by  the  older  civilizations  with  which  the 
conquests  of  Alexander  had  made  them  familiar,  the  Greeks 
in  this  cosmopolitan  city  of  the  Ptolemies  assumed  the 
intellectual  leadership  of  the  ancient  world.  Founded  about 
300  B.  c.,  the  Museum  continued  in  existence  for  some  700 
years.  The  three-fold  object  of  this  ancient  university  was 
the  perpetuation,  increase,  and  diffusion  of  knowledge. 
We  shall  comment  only  upon  its  encouragement  of  natural 
science. 

Fortunately,  the  Aristotelian  doctrine  of  factual  knowl- 
edge and  inductive  reasoning  were  dominant  at  the  outset. 
To  observation,  there  was  added  an  increasing  amount  of 
experimentation.  We  find  here  the  beginnings  of  the  method 
which  has  yielded  such  important  results  at  the  hands  of  the 
physical  scientist  during  the  Modern  Period.  Archimedes 
and  Ptolemy  were  the  intellectual  forebears  of  Galileo  and 
Copernicus.  Here  Ctesibius  and  Hero  invented  the  fire 
engine;  and  the  first  steam  engine  was  produced.  In  geo- 
graphical science,  the  technique  of  map  making  and  survey- 
ing were  examined,  and  the  circumnavigation  of  Africa  was 
proposed.  The  globular  nature  of  the  earth  was  accepted, 
and  attempts  were  made  to  determine  its  circumference. 
In  the  field  of  geological  science,  the  submergence  and  the 
elevation  of  land  masses,  and  such  problems  as  the  origin 


36       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

of  a  strait,  like  that  of  Gibraltar  or  the  Dardanelles,  were 
considered  in  terms  of  the  rationalistic  explanations  of  the 
present  day.  The  attempts  to  discover  an  elixir  of  life  were 
a  foreshadowing  of  the  work  of  the  later  alchemists  from 
which  our  modern  chemistry  arose.  Biological  science  was 
not  neglected,  for  the  medical  traditions  of  Hippocrates  were 
known  in  Alexandria  and  there  mingled  with  those  of  ancient 
Egypt.  The  examination  of  the  human  body  was  permitted, 
and  the  dissecting  room  of  the  Museum  was  the  earliest 
anatomical  laboratory.  The  existence  of  zoological  and 
botanical  gardens  is  also  recorded. 

For  the  purposes  of  this  discussion,  these  particular  items 
are  of  interest,  but  it  is  of  more  importance  that  the  Alex- 
andrian Museum  represents  the  earliest  institutional  at- 
tempt at  the  systematic  organization  and  extension  of 
scientific  knowledge.  Moreover,  the  science  of  Alexandria 
did  not  restrict  itself  to  observation,  but  relied  also  upon 
experiment.  Although  the  great  days  were  gone  centuries 
before  the  Mohammedan  conquest,  it  is  not  without  sig- 
nificance that  the  Arabs  became  proficient  in  the  same  fields 
of  knowledge  which  had  been  highly  developed  in  Alexandria 
at  an  earlier  period.21 

In  the  hands  of  a  race  politically  and  morally  dominant, 
these  material  and  spiritual  attainments  of  the  ancient 
Greeks  might  have  conquered  the  world.  But  in  Alexandria, 
even  before  the  Roman  conquest,  the  government  was 
insecure.  Dissipation  was  rife;  and  the  paralysis  born  of 
moral  skepticism  had  become  almost  universal  among  the 
upper  classes  with  the  decay  of  paganism.  In  the  technical 
operations  of  science,  there  were  certain  limitations  that  were 
not  removed  until  long  after  the  period  in  question.  For 
example,  physical  science  was  handicapped  by  the  lack  of 

21  Draper,  J.  W.,  "History  of  the  Intellectual  Development  of  Europe." 
An  excellent  account  of  the  Alexandrian  Museum  will  be  found  in  Chapter  VI. 
See  also:  Browne,  C.  A.,  loc.  ait.;  and  Mahaffy,  J.  P.,  "The  Progress  of  Hel- 
lenism in  Alexander's  Empire." 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    37 

accurate  and  convenient  instruments  for  the  recording  of 
both  time  and  of  temperature.  Another  deficiency  was  in 
the  means  and  method  of  arithmetical  computation.  We 
can  appreciate  the  clumsiness  of  the  Roman  numerals  in 
this  particular,  but  these  were  superior  as  a  means  of  com- 
putation to  the  numerals  of  the  Greeks.  Only  one  who  has 
followed  the  history  of  mathematics  in  relation  to  physical 
science  can  appreciate  the  advances  in  knowledge  which 
have  been  made  possible  by  the  introduction  of  the  decimal 
point  and  the  figure  zero  of  our  present  Arabic  numerals. 

Greek  thought  thus  stamped  itself  upon  the  ancient 
world,  through  Macedonian  imperialism,  despite  the  failure 
of  the  Greek  city-states  to  unite  into  a  great  nation.  During 
the  three  centuries  which  preceded  the  Christian  Era,  Hel- 
lenic culture  came  to  dominate  the  peoples  of  the  entire 
region  about  the  middle  and  eastern  Mediterranean,  and 
was  influential  even  to  Gibraltar  and  to  the  shores  of  the 
Indian  Ocean.  This  Hellenistic  Age  (323-23  B.  c.)  estab- 
li>hcd  the  cultural  inheritance  of  the  Roman  Empire.  The 
learning  of  the  Roman  Period  was  the  learning  of  Greece. 
Having  survived  the  attacks  of  the  barbarians  from  the  east, 
Greece  was  overthrown  politically  by  internal  strife  and  by 
the  barbarism  of  early  Rome.  But  she  set  her  mark  upon 
her  conqueror.  Hellenic  philosophy,  at  its  best,  had  ban- 
ished the  fear  of  malevolent  natural  forces.  The  finer  spirits 
among  the  Greeks  had  lived  in  a  harmony  with  the  world 
\\hich  we  of  the  present  can  well  afford  to  envy.  Although 
thi>  harmony  proved  only  a  temporary  solution  of  the  prob- 
lem, it  is  the  hope  of  modern  life  that  mankind  will  eventu- 
ally establish,  through  science,  a  harmony  which  shall  rest 
upon  a  surer  foundation. 

UTILIZATION   OF   SCIENCE    BY   ROME 

The  racial  sources  of  the  original  Romans  are  not  so 
clearly  traceable  as  those  of  the  Greeks.  There  seems 


38        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

again  to  have  been  superposition  of  a  Nordic  element  upon 
a  Mediterranean  one.  But  the  fusion  was  more  complete. 
The  sunny  shores  of  the  Middle  Sea  attracted  the  barbarian 
long  before  the  centuries  during  which  Roman  legions  held 
back  the  northern  hordes.  A  transition  occurred  in  Italy  as 
well  as  in  Greece  from  the  simple  unimaginative  standards 
of  neolithic  culture  to  the  luxurious  and  thoughtful  tastes 
of  civilization,  under  the  influence  of  Egypt,  Mesopotamia, 
and  Crete.  Later,  the  Hellenic  culture  became  dominant 
in  the  intellectual  life  of  Rome. 

In  contrast  to  the  Greeks,  the  Romans  were  active  in  the 
practical  application  of  science  rather  than  its  theoretical 
extension.  Their  cultural  contribution  was  government  and 
the  internationalizing  of  civilization.  Rome  was,  however, 
a  bulwark  against  the  barbarians,  and  thus  made  possible 
a  further  development  of  science  hi  Alexandria  and  in  the 
lesser  centers  which  preserved  the  Greek  tradition.  Again 
there  occurred  a  great  advance  in  the  material  aspects  of 
civilized  life,  this  time  in  the  means  of  communication  and 
transportation  and  in  the  stabilizing  of  the  entire  civilized 
world.  But  through  it  all,  the  Roman  was  not  distinguished 
for  originality  in  science  or  philosophy.  Interest  in  nature 
seems  to  have  consisted  mainly  in  the  practical  applications 
of  principles  already  ascertained.  After  two  centuries  of 
peace,  following  the  conquests,  Roman  genius  was  still 
imitative  in  speculative  science. 

Energy  and  fortitude,  prudence,  endurance  of  long  and 
arduous  labor  for  the  sake  of  ultimate  gain,  and  hence  an 
unremitting  toil,  practical  sense,  and  capacity  to  profit  by 
experience  were  distinctive  Roman  characteristics.  The 
Greek  ideal  of  a  noble  enjoyment  of  leisure  and  the  pursuit 
of  knowledge  was  but  superficially  comprehended  by  the 
majority  of  cultured  Romans.22  The  influence  of  racial 
traits  is  a  possible  key  to  the  situation.  The  Roman  by 
nature  was  practical  and  utilitarian  rather  than  philosophical 

"Taylor,  H.  O.,  "Ancient  Ideals,"  Chap.  XII. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD     39 

and  speculative.  Mechanical  inventions  were  developed  in 
many  instances,  but  Rome  more  and  more  neglected  the 
aspects  of  Hellenic  learning  which  might  have  advanced 
science.  Compendiums  were  produced  during  the  later 
empire,  containing  information  regarding  arithmetic,  geom- 
etry, astronomy,  and  the  like.  The  knowledge  of  nature, 
accumulated  in  Greece,  passed  over  into  Italy  and  through- 
out the  Roman  Empire.  But  the  creative  scientific  spirit 
did  not  flourish.  The  elder  Pliny  illustrates  the  Roman 
mind  in  its  scientific  development.  His  work  upon  natural 
history  exhibits  a  lively  interest  in  biological  nature,  but  also 
the  borrowing  by  which  the  intellectual  life  of  Rome  sus- 
tained itself  from  that  of  Greece. 

Many  individuals,  who  attained  distinction  in  intellectual 
lines  during  the  Roman  Period,  were  not  of  Roman  stock. 
Galen  the  Roman  physician,  whose  knowledge  of  human 
anatomy  dominated  Europe  throughout  the  Middle  Ages, 
was  a  Greek  by  birth  and  not  a  Roman,  although  resident 
in  Rome  during  his  later  years.  He  was,  moreover,  trained 
to  dissection  at  Alexandria  and  in  the  rival  center  of  medical 
learning  at  Pergamum,  a  Greek  city  of  Asia  Minor.  He 
became  a  worthy  successor  to  Hippocrates.  Ptolemy  of 
Alexandria  (c.  127-151  A.  D.),  also  a  Greek  rather  than  a 
Roman,  became  an  authority  in  astronomy  and  geography, 
whose  hold  was  only  loosened  by  the  Copernican  Theory 
and  by  the  voyages  of  discovery.  We  have  already  described 
the  Museum  of  Alexandria,  founded  before  the  Roman 
conquest  and  continuing  in  existence  during  the  first  four 
centuries  of  the  present  era.  The  inception  and  later  con- 
tinuation of  this  institution  were  alike  the  product  of  Greek 
and  not  of  Roman  genius,  although  its  progress  was  not 
uraged  by  the  Roman  culture.  Its  domination  by 
scholars  of  Greek  descent,  illustrates  the  persistence  of 
Hellenic  influences. 

The  practical  scientific  accomplishments  of  the  Romans 
are  seen  in  their  adaptation  and  development  of  practical 


40       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

inventions  and  in  their  scientific  organization  of  military 
affairs.  Bridge  and  road  building  proceeded  in  a  systematic 
fashion  not  unlike  modern  engineering.  The  construction  of 
aqueducts  and  other  public  works,  if  less  arduous  than 
pyramid  building,  nevertheless  exhibits  greater  aptitude  in 
the  application  of  scientific  principles.  The  mechanical 
devices  of  the  Hellenistic  Age  were  improved  and  widely 
applied. 

The  writings  of  Titus  Lucretius  Carus  (96-55  B.  c.)  23 
represent  the  highest  level  of  Roman  genius  as  applied  in 
synthetic  and  speculative  thought.  Lucretius  seems  to  have 
derived  his  initial  inspiration  from  Greek  sources.  In  his 
famous  didactic  poem  "De  Rerum  Natura,"  he  elaborates 
the  ideas  of  Democritus  regarding  the  origin  of  the  cosmos 
from  atoms  in  motion.  But  he  becomes  more  definite.  The 
progressive  development  of  life  from  mother  earth  by  spon- 
taneous generation,  and  the  origin  of  man  from  brutish 
ancestry  are  proposed.  The  origin  of  language  from  animal 
sounds  and  of  religious  ideas  from  dreams  is  conjectured. 
The  idea  of  selection  in  a  struggle  for  existence  is  vaguely  sug- 
gested. Above  all,  Lucretius  is  notable  for  his  grasp  of 
speculative  ideas  and  their  application  to  human  life  and 
nature.  His  great  aim  was  the  liberation  of  mankind  from 
superstition  and  from  the  fear  of  death.  He  was  not  atheis- 
tic and  Epicurean  in  the  sense  often  supposed.  Happiness 
through  self-control  and  a  feeling  for  the  dignity  of  human 
life  were  his  ideals.  His  attempt  to  synthesize  knowledge  and 
establish  a  sound  philosophy  of  life  represents  the  most  com- 
prehensive effort  of  the  Greco-Roman  world  in  this  direction. 
By  a  refinement  of  the  Epicurean  philosophy,  he  believed 
that  man  could  find  an  harmonious  solution  to  the  problem 
of  existence.  Despite  the  limitations  of  ignorance,  his 
interpretations  of  human  life  and  of  nature  resemble  those  of 
modern  science.  His  mind  runs  in  the  scientific  channel. 
The  conflict  between  superstition  and  the  laws  of  nature  is 

23  "Lucretius  on  the  Nature  of  Things,"  translation  by  H.  A.  J.  Munro. 


ORIGINS  OF  SCIENCE  IN  THE  ANCIENT  WORLD    41 

clearly  presented.  He  has  been  maligned  as  a  pagan,  but  his 
ideas  find  a  sympathetic  response  at  the  present  day.  Thus 
the  Christian  Era  dawned  upon  a  world  in  which  science  had 
made  a  noble  beginning,  although  the  ancient  learning  had 
begun  its  decline. 


CHAPTER  III 
THE  DECLINE  OF  ANCIENT  LEARNING 

WHATEVER  the  causes  for  its  decline,  the  scientific  spirit, 
which  had  made  a  favorable  beginning  in  the  ancient  world, 
gradually  disappeared  with  the  oncoming  of  the  Medieval 
Period.  From  the  time  when  the  pagan  schools  were  finally 
closed  until  the  Renaissance  in  Italy,  the  history  of  science 
is  largely  a  blank  among  the  Christian  nations,  in  so  far  as 
the  production  and  promulgation  of  new  ideas  is  concerned. 
On  the  scientific  side  the  Middle  Ages  are  at  their  worst. 
From  a  scientific  point  of  view  the  period  may  be  fitly  called 
the  "Dark  Ages. "  It  is  not  surprising  that  the  scientist  has 
been  harsh  in  his  criticism  of  the  mental  attitude  of  mankind 
during  a  period  which  was  everywhere  dominated  by  blind 
faith  and  by  ignorant  prostration  before  the  authority  of  the 
Church.  But  the  artistic  and  literary  accomplishment  of 
these  centuries  and  their  final  issue  in  the  Modern  Period 
should  not  be  disregarded. 

DECLINE    OF    SCIENCE    DURING    THE    EARLY    CENTURIES    OF 
THE  CHRISTIAN  ERA 

The  religious  beliefs  of  a  people  exert  a  far-reaching  in- 
fluence upon  their  philosophy  and  their  science.  Since  the 
decline  of  science  in  the  ancient  world  corresponds  to  the 
expansion  of  Christianity,  we  may  ask  whether  there  is 
evidence  of  a  causal  connection  between  these  two  historical 
events,  whether  there  were  not  elements  in  the  early  Chris- 
tian religion  inimical  to  the  growth  of  science  or  which  has- 
tened a  decline  already  begun.  Just  as  the  freedom  of  the 
Greek  religion  favored  scientific  speculation,  and  the  gloomy 

42 


THE  DECLINE  OF  ANCIENT  LEARNING  43 

religious  atmosphere  of  Babylonia  retarded  its  growth,  so  the 
religious  beliefs  and  practices  of  the  early  Christian  cen- 
turies may  have  possessed  qualities  unfavorable  or  even 
hostile  to  the  scientific  spirit. 

It  has  been  widely  believed,  among  those  interested  in 
science,  that  the  advent  of  Christian  dogma  was  mainly 
responsible  for  the  decline  of  the  ancient  spirit  of  investiga- 
tion. It  is  certainly  true  that  the  intellectual  atmosphere, 
which  came  into  existence  during  the  first  centuries  of  our 
era  and  which  culminated  in  the  Dark  Ages,  was  one  in  which 
the  rational  analysis  of  natural  phenomena  became  almost 
an  impossibility.  But  there  were  many  factors  involved. 
Fundamental  social  changes  were  in  progress,  in  the  face  of 
which  the  decline  of  science  cannot  have  been  solely  due  to 
dogmatic  theology.  The  internal  decay  of  the  Roman  Em- 
pire, the  gradual  change  in  the  population  from  Roman  and 
classical  to  Teutonic  and  Christian,  were  important  factors 
in  addition  to  the  antagonism  of  Christianity  to  pagan  cul- 
ture. The  barbarian  invasions  of  the  fifth  and  sixth  cen- 
turies tended  to  obliterate  the  heritage  of  ancient  learning. 
The  intellectual  backwardness  of  the  Teutonic  invaders, 
reinforced  by  the  animosity  of  the  Church,  but  gave  the 
death  blow  to  a  culture  which  had  already  lost  its  initial 
inspiration  and  vitality.1 

The  decline  of  science  was  but  one  aspect  of  the  collapse  of 
the  Roman  world.  The  entire  social  and  economic  situation 
must  be  taken  into  account.  The  period  of  the  Hannibalic 
or  Second  Punic  War  (218-202  B.  c.)  may  be  regarded  as  the 
summit  of  Rome's  spiritual  achievement.  Conquest  and 
material  greatness  came  in  the  centuries  which  followed. 
But  the  seeds  of  an  internal  decay  had  germinated  before  the 
opening  century  of  the  Christian  Era.  As  we  have  seen,  the 
Romans  made  no  important  additions  to  the  intellectual 
legacy  which  they  derived  from  the  earlier  civilizations, 

'UM:  ,-•   Corifl.ri    of  C'lin  .,th    Heathenism."      Al«o: 

mi-  «>f  i  l.c  Middle  Ages." 


44        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

excepting  only  along  lines  of  government  and  law.  The 
intellectual  decline  of  Greece  began  with  the  collapse  of  her 
political  influence,  despite  the  extension  of  Greek  culture 
during  the  Hellenistic  Age.  The  apex  of  the  curve  had  been 
reached  by  the  ancient  learning  before  the  first  century 
A.  D.  Christendom  inherited  from  Greece  and  Rome  a 
philosophy  already  divorced  from  the  sure  ground  of  science. 
We  have  seen  how  the  cultural,  and  perhaps  racial,  traits  of 
the  Romans  prevented  the  complete  assimilation  of  the  Greek 
spirit  of  investigation.  It  is  important  that  this  replace- 
ment of  the  scientific  spirit  by  the  ignorance  and  supersti- 
tion, which  culminated  in  the  Dark  Ages,  was  in  progress 
during  the  two  centuries  that  preceded  the  Christian  era. 
At  the  most,  Christianity  but  hastened  what  was  already 
begun. 

The  causes  of  the  disintegration  of  the  Roman  Empire, 
while  the  subject  of  much  controversy,  have  become  toler- 
ably clear  to  the  historian.2  Notable  among  them  was  the 
failure  of  Rome  to  use  and  to  extend  scientific  knowledge. 
In  her  feats  of  engineering  and  architecture,  she  did  indeed 
utilize  and  develop  the  knowledge  of  an  earlier  day.  But  in 
agriculture  and  in  the  more  difficult  field  of  social  phenomena 
she  failed  to  establish  an  enduring  civilization.  The  scien- 
tist of  to-day  is  particularly  interested  in  some  of  the  biologi- 
cal factors  which  seem  to  have  been  involved.  From  the 
standpoint  of  heredity  there  are  signs  of  a  physical  degenera- 
tion resulting  from  the  elimination  of  the  more  competent 
human  strains  by  war,  by  the  administration  of  distant 
provinces,  and  by  the  race-suicide  and  general  deterioration 

2  The  terrible  picture  of  the  degenerate  spiritual  life  of  the  capital  is  pic- 
tured by  Uhlhorn,  Chap.  II,  loc.  cit.  Specific  evidence  of  physical  degeneration 
is  suggested  by  the  fact  that  portrait  busts  and  statues  of  the  last  centuries  of 
pagan  Rome,  which  are  still  extant,  "  display  an  increasing  ugliness.  Their 
forms  look  unhealthy,  either  bloated  or  shrunken,"  p.  313.  Also:  Adams,  G.  B., 
"Civilization  during  the  Middle  Age,"  77-88,  for  a  well  considered  resume"  of 
the  complex  of  factors  involved  in  the  decline  of  this  race  which  was  the  strong- 
est the  world  had  then  produced. 


THE  DECLINE  OF  ANCIENT  LEARNING  45 

incident  to  a  luxurious  standard  of  living.  Disease,  partic- 
ularly malaria,3  and  soil-exhaustion,  along  with  the  unwhole- 
some economic  conditions  of  slavery  and  of  an  over-devel- 
oped urban  life,  were  environmental  factors  that  contrib- 
uted to  the  decadence  alike  of  ideals  and  of  physical  vigor.4 
Rome  squandered  the  accumulated  savings  of  the  earlier 
Mediterranean  civilizations,  and  when  the  bank  was  empty 
she  possessed  neither  the  racial  stamina  nor  the  material 
resources  to  longer  resist  the  barbarians.  Appreciation  of 
the  significance  of  scientific  knowledge  in  the  perpetuation 
of  any  civilization  might  have  saved  the  day.  But  if  we  of 
the  twentieth  century  fail  to  appreciate  the  possibilities 
involved  in  man's  squandering  of  the  resources  accumulated 
by  nature  during  millions  of  years,  and  also  the  signs  of  our 
own  deterioration,  we  need  not  marvel  that  Rome  did  not 
appreciate  the  possibilities  inherent  in  the  scientific  achieve- 
ments of  the  ancient  world.5 

Having  thus  recognized  the  decline  of  science  as  an  inci- 
dent in  the  collapse  of  the  Greco-Roman  culture  and  not 
primarily  due  to  the  advent  of  a  new  religion,  the  specific 
influence  of  Christianity  may  be  considered.  The  fact  to  be 
grasped  at  the  outset  is  that  the  actual  teachings  of  Jesus 
were  ethical,  not  theological.  What  we  have  long  designated 
as  Christianity  is  in  many  respects  a  direct  inheritance  from 
paganism.  The  spread  of  its  initial  doctrines  was  due  to 
their  ethical  idealism  and  to  the  appeal  which  the  promise  of 
a  future  life  made  to  the  afflicted  and  oppressed.  Reorgani- 
zation of  society  was  proposed.  Slavery  was  to  be  abolished, 
charity  was  created,  self-sacrifice  was  inculcated.  The 
brotherhood  of  all  mankind  was  proclaimed.  The  unifica- 

ics,  W.  H.  S.,  "Malaria:  A  Neglected  Factor  in  the  History  of  Greece 
and  Rome." 

,  Guglielmo,  "The  Greatness  and  Decline  of  Rome."    The  evils 

ne's  excessive  urbanization  are  here  set  forth  at  length. 

rrero,  Guglielmo,  "Ancient  Rome  and  Modern  America."  The  parallel 
between  the  urbanization  in  Rome  and  in  the  United  States  of  America  is 
here  discussed  in  an  interesting,  if  not  wholly  convincing,  manner. 


46       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

tion  of  the  civilized  world  in  the  Roman  Empire  and  also  the 
moral  dissolution  of  Rome  facilitated  the  rapid  development 
to  a  position  of  power.  Christianity  was  at  the  outset 
strictly  a  religion.  In  the  first  century  A.  D.,  men  said  "See 
how  these  Christians  love  one  another."  But  theological 
controversy  soon  intervened,  and  hi  the  fourth  century,  it 
was  said  "There  are  no  wild  beasts  so  ferocious  as  Christians 
who  differ  concerning  their  faith. "  6  After  the  third  century, 
the  new  faith  became  largely  a  set  of  intellectual  proposi- 
tions. The  victory  in  matters  temporal  was  a  triumph  of 
paganism  as  well;  for  it  consisted  in  an  accession  to  pagan 
power  and  in  an  absorption  of  heathen  beliefs  and  customs 
of  ancient  origin.  Thus,  Mariolatry,  the  Doctrine  of  the 
Trinity,  Image  Worship,  and  other  widely  accepted  aspects 
of  later  Christianity  can  be  traced  to  pagan  origins  which  far 
antedate  the  Christian  Era.  It  is  important  for  Christianity 
in  our  own  day  that  we  distinguish  between  the  doctrine 
which  Jesus  seems  actually  to  have  taught  his  disciples  and 
the  heterogeneous  mass  of  pagan  traditions  with  which  the 
original  nucleus  soon  became  encrusted  and  which  many 
still  regard  as  essential  features  in  the  religion  of  the 
Occident. 

The  decline  of  the  scientific  spirit  during  the  early  Chris- 
tian Era  was  due,  primarily,  not  to  prohibitions  of  the 
theologians,  but  rather  to  a  change  in  mental  attitude  of  the 
Mediterranean  population,  and  to  the  intellectual  backward- 
ness of  barbarian  peoples  from  the  north  and  west.  In 
correlation  with  this  changing  point  of  view  we  find :  philos- 
ophy becoming  a  part  of  religion,  and  hence  intolerant  of 
changes  in  the  established  system;  salvation,  in  another 
world,  coming  to  be  regarded  as  the  chief  end  of  man;  the 
second  coming  of  Christ  and  the  end  of  the  world  being  ex- 
pected at  any  time,  and  hence  a  failing  interest  in  the  visible 
universe.  "To  discuss  the  nature  and  position  of  the  earth, " 
says  St.  Ambrose,  "does  not  help  us  in  our  hope  of  the  life  to 

6  Leeky,  W.  E.,  "History  of  Rationalism  in  Europe." 


THE  DECLINE  OF  ANCIENT  LEARNING  47 

come."  "It  is  not  through  ignorance,  but  through  con- 
tempt of  such  useless  labor  that  we  think  little  of  these 
matters  and  turn  our  souls  to  better  things,"  writes  Eusebius. 
"It  is  a  matter  of  no  interest  to  us, "  writes  Basil,  "whether 
the  earth  is  a  sphere  or  a  cylinder  or  a  disc."  These  and 
many  similar  pronouncements  are  representative  of  pre- 
vailing convictions  that  were  unfavorable  to  scientific 
progress. 

As  time  went  on,  the  dogma  that  the  Scriptures  were  the 
direct  word  of  God  to  man,  to  be  interpreted  as  literally  true 
in  all  respects,  led  to  the  doctrine  that  anything  in  conflict 
with  Biblical  statements  was  sinful;  and  further,  that 
promulgation  of  such  an  error  should  be  punished.  The 
famous  saying  of  St.  Augustine,  "Nothing  is  to  be  accepted 
save  on  authority  of  Scripture,  since  greater  is  that  authority 
than  all  the  powers  of  the  human  mind,"  came  to  be  the 
basis  of  faith;  and  in  this  atmosphere  of  blind  belief  it  is 
small  wonder  that  ignorance  reigned.  The  idea  of  God's 
will  as  the  source  of  all  causation  was  fostered  by  the  doc- 
trine of  the  inscrutability  of  God's  ways  to  man,  while 
always  and  everywhere  there  was  a  tendency  to  warp 
facts  to  fit  theological  conceptions.  In  brief,  the  Scriptures, 
and  not  the  book  of  nature,  became  the  authority  in  the 
interpretation  of  natural  phenomena,  while  the  existence  and 
overwhelming  importance  of  supernatural  phenomena  were 
;  >ted  as  a  matter  of  course.7 

following  pagan  characterization  of  the  Christian  view  of  knowledge 
illustrates  the  existence  of  a  measure  of  active  hostility  to  knowledge:  "The 
Christians  passed  with  the  heathen  as  a  race  averse  to  all  that  is  great,  fair 

M<-  in  our  humanity,  as  even  hostile  to  it,  and  haters  of  mankind.    In 
its  origin  their  religion  was  barbarian:  they  despised  all  science.    This  is  the 

d  down  l»y  them,  writes  Celsus: '  Let  no  one  come  to  us  who  has  been 
educated,  or  who  is  wise  or  prudent,  for  such  qualifications  are  deemed  evil 
by  us;  but  if  there  be  any  ignorant,  or  uncultivated,  or  unintelligent,  or  foolish 
person,  let  him  come  with  confidence.'  Their  tr.-ichers  he  affirms,  say:  "See 
that  none  of  you  lay  hold  of  knowledge1  Knowledge  is  an  evil.  Knowledge 
causes  men  to  low  their  soundne^  «>!  mind;  they  perish  through  wisdom 
riilhorn.  (',  .  fo  J29. 


48       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

In  such  an  environment  it  was  inevitable  that  science  and 
rational  philosophy  should  languish,  and  steadily  decline 
with  the  extension  of  the  spiritual  and  temporal  power  of  the 
medieval  Church.8 

It  is  interesting  to  find  that  this  mental  attitude  was  not 
universal.  The  ideas  of  Origen  (c.  185-253  A.  D.),  a  Greek 
Christian  of  Alexandria,  bear  some  resemblance  to  those  of 
modern  Higher  Criticism,  in  that  he  denied  the  exact  and 
literal  meaning  of  certain  passages  of  the  Scriptures.  He 
was,  moreover,  opposed  to  the  doctrine  of  damnation  and  hell. 
But  these  beliefs  brought  persecution  during  the  lifetime  of 
Origen  and  were  anathematized  in  553.  Had  they  triumphed, 
in  the  absence  of  the  allegorical  interpretations  to  which 
Origen  gave  credence  and  which  were  later  extended  to  a 
ridiculous  degree,  the  evolution  of  Christianity  might  have 
taken  a  different  course.  Synesius,  a  pupil  of  Hypatia  of 
Alexandria  and  who  afterwards  became  Bishop  of  Cyrene, 
although  accepting  Christianity,  declines  to  surrender  his 
freedom  of  thought.  In  a  statement  of  his  difficulties  in 
accepting  the  appointment  of  bishop,  he  writes  as  follows: 
"I  must  insist  upon  one  other  point,  beside  which  all  other 
obstacles  are  as  nothing.  It  is  difficult,  if  not  altogether  im- 
possible, to  eradicate  from  one's  soul  those  convictions  which 
have  been  gained  by  means  of  science.  You  know  that 
philosophy  rejects  many  of  those  dogmas  which  are  generally 
accepted  as  true.  I  could  never  persuade  myself,  for  ex- 
ample, that  the  soul  was  of  later  origin  than  the  body;  nor 
would  I  ever  say  that  the  world  or  any  of  its  parts  is  doomed 
to  destruction;  the  resurrection,  an  object  of  common  be- 
lief, is  for  me  only  a  sacred  allegory  and  I  am  far  from 
accepting  the  views  which  are  ordinarily  held."9  This 
declaration  was  like  a  dying  challenge  of  Greek  thought  to 
the  gathering  spirit  of  blind  belief  and  superstition.  The 
murder  of  Hypatia,  by  a  rabble  of  fanatics  (415),  was  one  of 

8  White,  A.  D.,  "A  History  of  the  Warfare  of  Science  with  Theology." 

9  Quoted  from  the  article  by  C.  A.  Browne,  cited  in  the  preceding  chapter. 


THE  DECLINE  OF  ANCIENT  LEARNING         49 

the  final  steps  in  the  obliteration  of  the  ancient  spirit  of 
rationalism.  There  are  also  instances  of  opposition,  by 
whole  groups  of  individuals,  to  this  spread  of  blind  faith 
with  its  consequent  ignorance.  Gnosticism,  although  not, 
as  is  often  erroneously  supposed  because  of  its  name,  a 
creed  of  the  efficacy  of  natural  knowledge,  was  nevertheless 
more  acceptable  than  Christianity  to  individuals  of  scientific 
mind,  in  Alexandria  and  elsewhere.  But  eventually  these 
opposing  beliefs  seem  only  to  have  hastened  the  consolida- 
tion of  doctrines  which  triumphed  as  the  Christianity  of 
Rome  and  of  Constantinople.  Thus  it  appears  that  early 
Christian  theology  was  antagonistic  to  scientific  thought  and 
knowledge  and,  while  not  the  sole  cause  of  the  decline  of 
science,  helped  to  bring  about  an  age  of  ignorance. 

THE   DARK  AGES   OF   SCIENCE 

The  period  from  the  close  of  the  fifth  century  to  the  begin- 
ning of  the  Renaissance  in  Italy  was  one  of  gradual  assimila- 
tion into  the  life  of  western  Europe  of  new  forces  and 
factors.  The  Teutonic  invaders,  who  had  overrun  the 
western  portion  of  the  Roman  Empire,  were  on  a  cultural 
level  not  much  above  the  best  of  the  North  American 
aborigines.  They  and  their  culture  became,  for  the  time 
being,  the  dominant  factor  in  the  western  world.  Greece  and 
Rome,  Christianity  and  the  Teutonic  barbarians  were  the 
immediate  sources  of  our  western  civilization.  The  impor- 
tant service  of  the  Church,  which  is  not  always  recognized, 
was  her  influence  upon  the  barbarians.  Christianity  became 
t  h<-  int  ollectual  power  of  the  world.  The  Church  was  mainly 
responsible,  despite  other  influences,  for  the  gradual  re- 
ruction  of  society,  which  made  possible  the  return  to 
scientific  thinking.  "To  make  out  of  the  barbarized  sixth 
century,  stagnant  and  fragmentary,  with  little  common  life, 
>ut  ideals  or  enthusiasms,  the  fifteenth  century  in  full 
possession  again  of  a  common  world  civilization,  keen, 


50       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

pushing,  and  enthusiastic.   This  was  what  the  Middle  Ages 
had  to  do,  and  this  was  what  they  did."  10 

It  is  difficult  for  the  scientist  to  understand  the  intellec- 
tual outlook  of  the  Middle  Ages.  Society  was  dominated, 
during  the  greater  portion  of  the  period,  by  theological  ideas. 
Interest  in  secular  studies  had  been  obliterated.  Belief  in 
the  Bible,  as  the  direct  word  of  God  to  man,  gave  rise  on  the 
one  hand  to  allegorical  and  on  the  other  to  intensely  literal 
interpretations  of  the  Scriptures.  Obsessed  with  the  belief 
in  allegories,  men  sought  for  occult  meanings  in  nature,  as 
well  as  in  the  Biblical  phraseology.  The  habits  of  animals, 
the  characteristics  of  birds,  reptiles,  plants,  and  various 
natural  objects  such  as  stones  and  minerals  were  supposed  to 
possess  a  spiritual  significance  and  to  carry  with  them 
lessons  in  conduct  or  morality.  The  people  were  credulous, 
and  stories  of  weird  animals,  like  the  phoenix  and  the  unicorn 
together  with  even  stranger  stories  of  real  animals,  were 
received  without  question.11  In  biological  science,  the 
accounts  of  animals  appearing  in  the  "Physiologi"  or 
" Bestiaries"  are  further  examples  of  these  forced  interpre- 
tations.12 Even  when  the  scriptural  statements  were 
matter-of-fact  and  easy  to  understand,  allegorical  explana- 
tions were  often  employed,  or,  if  a  natural  explanation  was 
used,  the  application  to  current  events  was  frequently  made 
with  a  literalness  that  now  seems  absurd.  This  state  of 

10  Adams,  G.  B.,  "Civilization  During  the  Middle  Ages,"  p.  11. 

11  The  subsequent  medical  doctrine  of  signatures,  by  which  the  fancied  re- 
semblances in  shape  or  color  between  objects  in  nature  and  the  parts  of  the 
human  body  were  held  to  be  divine  indications  of  the  medicinal  values  of 
certain  plants  or  minerals,  was  an  outgrowth  of  this  belief  in  the  allegorical 
significance  discoverable  in  the  works  of  the  Creator. 

12  The  writings  generally  known  under  the  title  "Physiologus"  or  "Bestia- 
rius"  were  the  most  important  source  of  knowledge  concerning  animals  during 
the  Medieval  Period.     They  seem  to  have  originated  in  the  utilization  of 
natural  history  as  a  means  of  enforcing  Christian  doctrines.     For  almost  a 
thousand  years  these  mystical  and  symbolic  interpretations  of  animals  men- 
tioned in  the  Bible  and  others  of  a  purely  mythical  character  continued  as  an 
authoritative  source  of  information.     See:  Cams,  J.   V.,   "Geschichte  der 
Zoologie,"  Munich,  1872. 


THE  DECLINE  OF  ANCIENT  LEARNING  51 

mind,  which  was  so  well  established  during  the  early  cen- 
turies of  the  Medieval  Period,  has  not  become  extinct  even 
hi  our  own  times.13 

The  work  of  Cosmas  (c.  535  A.  D.),  entitled  "  Christian 
Opinion  Concerning  the  World,"  well  illustrates  this  medieval 
attitude  in  the  interpretation  of  nature  and  also  the  existing 
state  of  geographical  and  astronomical  knowledge.  Cosmas 
set  out  to  refute,  among  other  heresies,  the  existence  of  the 
Antipodes.  But  his  work  was  of  a  comprehensive  nature  and 
proclaimed  itself  "a  Christian  topography  of  the  universe, 
established  by  demonstrations  from  Divine  Scripture,  con- 
cerning which  it  is  not  lawful  for  a  Christian  to  doubt." 
His  conclusions  regarding  the  said  topography  are  interest- 
ing, as  summarizing  the  ideas  then  current.14  But  his 

11 A  nineteenth  century  example  of  this  manner  of  reasoning,  cited  in  Lecky's 
"History  of  Rationalism,"  runs  as  follows:  "a  geologist  deeply  impressed  with 
the  mystery  of  baptism — that  mystery  by  which  a  new  creature  is  formed  by 
means  of  water  and  fire — would  never  have  fallen  into  the  absurdities  of  ac- 
counting for  the  formation  of  the  globe  solely  by  water  or  solely  by  fire.  He 
would  have  suspected  that  the  truth  lay  in  the  union  of  both."  Modern  geol- 
ogy, of  course,  acknowledges  both  fire  and  water  and  also  other  agencies  as 
causes  in  the  evolution  of  the  earth's  surface,  but  not  on  grounds  of  allegorical 
mysticism. 

'"According  to  Cosmas,  the  world  is  a  flat  parallelogram.  Its  length, 
which  should  be  measured  from  west  to  east,  is  the  double  of  its  breadth, 
which  should  be  measured  from  north  to  south.  In  the  centre  is  the  earth  we 
inhabit,  which  is  surrounded  by  the  ocean,  and  this  again  is  encircled  by 
another  earth,  in  which  men  lived  before  the  deluge,  and  from  which  Noah 
was  transported  in  the  ark.  To  the  north  of  the  world  is  a  high  conical  moun- 
tain, around  which  the  sun  and  moon  continually  revolve.  When  the  sun  is 
hid  behind  the  mountain,  it  is  night;  when  it  is  on  our  side  of  the  mountain, 
it  is  day.  To  the  edges  of  the  outer  earth  the  sky  is  glued.  It  consists  of  four 
high  walls  rising  to  a  great  height  and  then  meeting  in  a  vast  concave  roof, 
thus  forming  an  immense  edifice  of  which  our  world  is  the  floor.  This  edifice 
w  divided  into  two  stories  by  the  firmament  which  is  placed  between  the  earth 
and  the  roof  of  the  sky.  A  great  ocean  is  inserted  in  the  side  of  the  firma- 
ment remote  from  the  earth.  This  is  what  is  signified  by  the  waters  that 
•re  above  the  firmament.  The  space  from  these  waters  to  the  roof  of  the 
oky  Is  allotted  to  the  blest;  that  from  the  firmament  to  our  earth  to  the  angels, 
in  their  character  of  ministering  spirits."  Lecky,  W.  E.  H .,  History  of  Ra- 
tionalism in  Europe."  The  diagram  of  the  universe  as  conceived  by  Hebrew 
thought  (Fig.  22,  in  the  present  volume)  may  be  referred  to  in  this  connection. 


52       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

method  of  reasoning,  by  the  adroit  manipulation  of  phrase- 
ology and  by  an  appeal  to  mysticism  and  allegory,  is  of 
greater  importance  for  our  present  purpose  as  a  key  to  the 
medieval  state  of  mind.  Cosmas  reprimands  those  who  are 
misled  by  Greek  fables  or  the  deceit  of  human  science  and 
who  forget  that  the  intimations  of  the  nature  of  the  universe 
contained  in  Scripture  have  far  greater  value  and  authority 
than  anything  which  man  can  attain  through  his  now  un- 
aided reason.  He  tells  us  that  he  would  appeal  "to  the  law 
and  the  testimony"  and  not  to  the  writings  of  pagans.  He 
disposes  of  the  question  of  the  Antipodes  by  strictly  Biblical 
arguments,  such  as  St.  Paul's  words  that  all  men  are  made 
to  live  upon  "the  face  of  the  earth,"  and  therefore,  could 
not  live  upon  more  faces  than  one  or  upon  the  back.  Having 
such  proof  as  this,  a  true  Christian  should  not  "even  speak  of 
the  Antipodes. "  In  discussing  the  structure  of  the  universe, 
he  takes  the  tabernacle  of  Moses  as  the  model,  because  St. 
Paul  refers  to  the  earth  as  a  tabernacle.  Other  examples 
need  not  be  cited.  His  argument  throughout  is  along  these 
general  lines. 

The  scientist  does  not  profess  to  a  sympathetic  treatment 
of  the  Middle  Ages,15  although  he  recognizes  the  value  to 
mankind  of  mental  attitudes  which  are  unscientific.  Some 
of  the  specific  traits  of  medieval  man  which  impress  us  as 
significant  in  relation  to  science  are:  his  ideas  regarding  the 
taint  of  sin,  that  was  assumed  to  be  inherent  in  nature;  the 
belief  in  the  damnation  of  the  unbeliever,  and  its  outcome  in 
persecution  and  the  suppression  of  all  spirit  of  criticism;  the 
constant  suggestion  of  the  infinite,  not  in  terms  of  the  un- 
fathomed  depths  of  science  but  in  terms  of  mysticism;  the 
dominance  of  emotionalism  over  rationalism;  and  the 
development  of  asceticism.16 

16  Taylor,  H.  O.,  "The  Medieval  Mind." 

16  The  asceticism  of  the  Middle  Ages  has  been  characterized  as  follows: 
"Beauty  is  a  snare,  pleasure  is  a  sin,  the  world  a  fleeting  show,  man  fallen 
and  lost,  death  the  only  certainty,  judgment  inevitable,  hell  everlasting,  heaven 
hard  to  win,  ignorance  acceptable  to  God  as  a  proof  of  faith  and  submission, 


THE  DECLINE  OF  ANCIENT  LEARNING  53 

Despite  all  this,  it  is  unfair  to  this  important  period  of 
European  history  to  suppose  that  its  science  amounted  to 
nothing  more  than  what  could  be  gleaned  from  tradition  and 
later  an  infusion  from  the  Arab  learning.  The  scientific 
knowledge  of  the  past  often  seems  curious  and  amusing  in 
the  light  of  the  present.  We  forget  how  knowledge  grows 
from  half  truths  and  sometimes  from  positive  errors.  For 
example,  it  is  now  universally  acknowledged  among  intelli- 
gent persons  that  it  is  idle  to  regard  the  Scriptures  as  a 
source  of  scientific  information.  Nevertheless  the  most 
interesting  and  original  constructive  work  of  the  Middle 
Ages,  in  the  field  of  science,  was  done  on  the  basis  of  evidence 
furnished  by  the  Bible.  This  may  be  illustrated  by  the 
work  of  Cosmas  to  which  we  have  previously  alluded.  The 
point  is,  that  the  men  who  desired  to  know  something  of 
natural  phenomena,  turned  to  the  supposed  source  of  wisdom 
in  the  Written  Word.  The  efforts  of  the  medieval  scholar 
who  struggled  under  the  cloud  of  supernaturalism  are  pa- 
thetic and  not  ridiculous.  In  spite  of  the  prevailing  doctrine, 
the  Middle  Ages  produced  a  number  of  enlightened  scien- 
tific thinkers  as  well  as  sane  men  who  condemned  the  popu- 
lar errors  and  beliefs. 

Occasional  men  and  events  prove  that  there  was  intellec- 
tual progress  in  spite  of  persecution  and  a  stifling  mental 
atmosphere.  St.  Augustine  (354-430),  with  all  his  ortho- 
doxy, seems  to  have  doubted  some  of  the  current  beliefs;  for 
he  explicitly  declared  that  neither  good  nor  evil  neces- 
sarily flowed  from  the  conjunction  of  the  planets;  and  from 
time  to  tune  men  of  real  scientific  attainments  came  to  the 
Charlemagne's  reformation  of  the  Church  was  a 
period  of  intellectual  culture  which  has  been  characterized 
as  an  "Earlier  Renaissance."  17  Agobard  (779-840),  an 

abstinence  and  mortification  the  only  safe  rules  of  life:  These  were  the  fixed 
ideas  of  the  ascetic  medieval  church."    Symonds,  J.  A.,  "Renaissance  in 
Italy." 
17  Burckhardt,  Jacob,  "The  Civilization  of  the  Renaissance  in  Italy." 


54        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

archbishop  of  Lyons,  attacked  popular  superstitions  such  as 
belief  in  witchcraft  and  the  ordeal  of  fire.  His  point  of  view 
was  theological  rather  than  scientific,  but  he  exhibits  a  clear 
intellect  and  an  independent  judgment.  Gerbert  of  Rheims 
(940-1003),  afterwards  Pope  Silvester  II,  was  a  master  of  the 
knowledge  of  his  day,  and  was  reputed  to  be  the  ablest 
mathematician  and  mechanician  of  his  time.  Educated  in 
the  science  of  the  Arabs  in  Spain,  he  became  the  head  of  a 
famous  school  at  Rheims.  He  obtained  great  reputation  as 
a  scientist,  but  because  his  science  was  rationalistic  in 
character  and  because  his  knowledge  was  so  far  in  advance 
of  his  associates  he  was  suspected  of  being  in  league  with  the 
Evil  One.  He  was  the  first  to  use  the  Arabic  numerals  and  he 
also  invented  a  timepiece  which  was  regarded  as  wonderful 
in  its  day.  But  to  the  Middle  Ages  he  was  a  magician  and  a 
sorcerer  whose  tomb  grew  moist  and  whose  bones  clattered 
whenever  a  pope  was  about  to  die.  The  mystic,  Joachim  of 
Flora  (1145-1202)  seems  to  have  caught  a  glimpse  of  a  better 
future  for  mankind  on  this  earth  when  he  proclaimed  that 
"the  Gospel  of  the  Father  was  past,  the  Gospel  of  the  Son 
was  passing,  the  Gospel  of  the  Spirit  was  to  be,"  although 
his  Age  of  the  Spirit  was  to  be  one  of  contemplation  rather 
than  action.  Abelard  (1079-1142)  protested  against  the 
state  of  mind  which  ascribed  too  great  significance  to  mere 
words. 

But  the  isolated  individual  had  little  influence  upon  the 
current  of  the  times.  Minds  no  doubt  rebelled  of  whom  we 
have  no  record.  The  effect  of  the  persecutions  must  have 
been  frightfully  selective  both  as  to  rational  ideas  and  as  to 
individuals  capable  of  developing  them.  The  Middle  Ages 
fulfilled  their  task  of  the  cultural  unification  of  Europe,  but, 
as  Burckhardt  puts  it,  "if  those  elegaic  natures  which  long  to 
see  them  return  could  pass  but  one  hour  in  the  midst  of 
them,  they  would  gasp  to  be  back  in  modern  air."  Self- 
confidence  was  lacking,  life  was  hard  and  there  was  scant  joy 
in  living.  The  terrors  of  another  world  beyond  were  added 


THE  DECLINE  OF  ANCIENT  LEARNING  55 

to  those  of  the  present.  Men  lived  with  no  extensive  knowl- 
edge of  the  past  and  with  no  conception  of  the  possibilities 
held  in  store  by  the  future. 

A  constructive  side  of  the  period,  in  relation  to  science,  is 
seen  in  the  preservation  of  the  older  learning  and  in  the  pro- 
tection afforded  to  scholars  by  the  monasteries.  Knowledge 
of  the  ancient  world  descended  in  manuscripts  that  were 
preserved  by  the  Church,  though  not  widely  known  until 
the  Revival  of  Learning.  This  service  of  conservation  was 
of  inestimable  value,  despite  the  pious  frauds  of  the  copyists 
which  cast  suspicion  upon  the  accuracy  of  many  of  the 
writings  transmitted.  As  to  the  protection  of  scholars,  it 
appears  that  the  monasteries  and  cathedrals  were  the  only 
places,  hi  which  there  was  opportunity  for  the  practice  of 
scholarly  pursuits,  during  the  welter  of  social  and  economic 
unrest  of  the  five  centuries  that  followed  the  year  500 
A.  D.,  since  they  offered  the  first  opportunity  for  an  intellec- 
tual life  protected  from  the  turmoil  of  the  world.  The 
celibacy  of  the  clergy  was  unfortunate,  in  so  far  as  it  tended 
to  check  the  reproduction  of  minds  capable  of  intellectual 
attainment.  But  the  intellectual  and  ethical  idealism  of  the 
monastic  life,  when  at  its  best,  was  a  potent  factor  in  the 
eventual  development  of  a  greater  measure  of  intellectual 
activity.  The  universities  of  Europe  arose  in  intimate  union 
with  the  scholarly  activities  of  the  Church  and  clergy.  In 
biological  science,  the  knowledge  of  medicine  was  trans- 
mitted, if  not  extended,  because  of  the  service  of  religion  to 
the  afflicted.  In  these  respects,  the  Middle  Ages  appear  as 
the  conserver  of  the  older  learning  and  to  some  extent  the 
protector  of  the  new. 

INFLUENCE   OF  THE   ARAB   CIVILIZATION 

Leaving  Europe,  we  now  turn  to  another  continent  and  to 
another  race  which  inherited  and  extended  the  ancient 
learning  in  science.  The  Arabs,  during  their  century  of  con- 


56        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

quest  (650-750  A.  D.),  had  expanded  their  empire,  not  only 
throughout  the  Mesopotamian  region,  but  to  India  on  the 
east  and  westward  along  the  southern  shores  of  the  Medi- 
terranean until  they  occupied  Spain.  In  the  East,  they  came 
into  contact  with  the  tradition  of  Greek  science  in  Asia 
Minor  and  at  Alexandria,  and  with  the  mathematical 
science  of  the  Hindus  in  India.  In  the  West,  they  threat- 
ened to  overrun  Europe  both  in  Spain  and  at  Constantinople. 
In  contrast  to  the  intellectual  backwardness  of  the  northern 
barbarians,  who  conquered  the  Roman  empire,  the  Arabs 
showed  an  immediate  aptitude  for  the  older  learning.  Their 
civilization  exhibited  an  intellectual  quality,  particularly 
along  scientific  lines.  At  a  time  when  science  seemed  hope- 
lessly lost  in  Christendom,  they  quickly  assimilated  the 
learning  of  the  ancient  world,  and  also  received  with  enthu- 
siasm suggestions  from  other  sources.  In  Spain,  the  Moorish 
Kingdom  attained  a  cultural  and  material  level  above  any- 
thing that  existed  in  Europe  before  the  Italian  Renaissance. 
Paved  and  lighted  streets,  running  water,  architecture  of 
wonderful  grace,  public  libraries,  the  encouragement  of 
literature  and  science,  and  a  spirit  of  toleration  were  the 
marks  of  a  civilization  that  was  remarkable  for  its  intellec- 
tual superiority. 

In  their  earlier  conquests  the  Arabs  exhibited  the  spirit  of 
the  barbarian.  They  destroyed  libraries  and  other  works  of 
civilization.18  But  within  a  century  they  were  establishing 
colleges  and  collecting  manuscripts.  The  court  of  the 
Khalifate  of  Al-Mamun  (813-833  A.  D.)  at  Bagdad  became 
an  intellectual  center  rivaling  ancient  Alexandria.  Schools 
were  attached  to  the  mosques  throughout  the  empire.  At 
Bagdad  and  elsewhere  there  were  colleges  for  the  higher 
branches.  A  surprising  toleration  prevailed,  as  shown  by  the 

18  The  Khalif  Omar  is  said  to  have  replied,  to  a  request  that  he  spare  the 
remnant  of  the  great  Alexandrian  library,  "If  the  books  agree  with  the  Koran, 
the  Word  of  God,  they  are  useless,  and  need  not  be  preserved;  if  they  dis- 
agree with  it,  they  are  pernicious.  Let  them  be  destroyed."  And  the  story 
is  that  the  books  were  distributed  as  fuel  to  the  baths  of  the  city. 


THE  DECLINE  OF  ANCIENT  LEARNING  57 

frequent  commission  of  the  superintendence  of  these  schools 
to  Nestorian  Christians  or  to  Jews.  "It  mattered  not  in 
what  country  a  man  was  born,  nor  what  were  his  religious 
opinions;  his  attainment  hi  learning  was  the  only  thing  to  be 
considered."  19  The  medical  colleges  at  Cairo  hi  Egypt  and 
at  Salerno  in  Italy,  and  the  astronomical  observatories  in 
Spain  were  centers  from  which  a  quickening  influence  ex- 
tended to  Europe.  The  Arabs  for  a  tune  succeeded,  where 
the  Greeks  had  failed,  by  recognizing  the  sure  ground  of 
generalization  based  upon  observation  and  experiment  as 
opposed  to  speculation.  Their  work  in  many  lines  exhibits  a 
surprising  aptitude  for  scientific  investigation.  While  not 
making  revolutionary  discoveries,  they  performed  inestim- 
able service  in  preserving  and  consolidating  the  ancient 
knowledge  in  scientific  lines.  The  ancient  learning,  in- 
herited at  Alexandria  and  elsewhere,  was  passed  over  to 
Europe  in  far  better  condition  than  when  the  Arabs  re- 
ceived it  at  the  eastern  end  of  the  Mediterranean. 

The  Arab  predilection  for  experimentation  appears  in  the 
fact  that  his  conclusions  were  almost  invariably  based  upon 
an  experiment  or  an  instrumental  observation.  Thus  the 
foundations  of  modern  chemistry  were  laid;  while  in  astron- 
omy and  physical  science  instruments  and  apparatus  were 
developed.  The  adoption  of  the  Indian  numeration  in 
arithmetic  greatly  facilitated  calculation  and  surprising 
progress  was  made  in  the  mathematical  sciences,  particularly 
in  algebra,  which  was  received  from  the  Hindus  but  was 
elaborated  by  the  Arabs  into  its  present  form.  Astronomical 
tables  of  eclipses  and  the  like  were  extensively  developed. 
The  forerunners  of  modern  surveying  instruments  were  in- 
vented. The  specific  weights  of  many  chemical  elements 

l>  The  Khalif  Al-Mamun  declared  that  scholars  were  "the  elect  of  God,  his 
best  and  most  useful  servants,  whose  lives  were  devoted  to  the  improvement 
r  rational  faculties;  that  the  teachers  of  wisdom  are  the  true  luminaries 
and  legislators  of  the  world,  \\hirh,  without  their  aid,  would  again  sink  into 
ignorance  .M  rism."    Quoted  from:  Draper,  J.  W.,  "History  of  the 

Conflict  between  Religion  and  Science." 


58       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

were  approximately  ascertained.  Methods  of  distillation, 
filtration,  and  crystallization  were  elaborated.  The  cir- 
cumference of  the  earth  was  calculated  after  several  meas- 
urements of  the  arc  of  a  degree  on  the  surface.  The  principal 
of  position  in  numbers  and  the  idea  of  infinite  series  were  re- 
ceived, like  Algebra,  from  the  Hindus;  and  the  so-called 
arable  numerals  were  likewise  passed  on  to  Europe,  where 
they  quickly  superseded  the  clumsy  Roman  notation.  The 
mariner's  compass  and  gunpowder  appear  also  to  have 
reached  Europe  through  Arab  channels. 

Among  their  great  teachers,  Avicenna  (980-1037)  wrote 
on  medicine  and  became  an  authority  in  European  schools 
for  centuries;  while  Averroes  (1126-1198),  who  was  so  largely 
instrumental  in  making  known  to  Europe  the  works  of 
Aristotle,  became  the  greatest  philosopher  of  the  later  Mid- 
dle Ages.  Anticipating  the  Renaissance,  the  Arab  seemed  to 
catch  the  Greek  spirit  of  the  individual  as  opposed  to  the 
horde  composing  the  race,  and  to  grasp  the  subjective  in  the 
midst  of  the  objective.  It  is,  doubtless,  indicative  of  an  un- 
recorded survival  of  the  ancient  learning  in  Alexandria,  after 
the  destruction  of  the  Museum,  that  Arab  science  advanced 
along  the  very  lines  that  were  highly  developed  by  the 
Museum  during  the  Hellenistic  Age  and  the  early  centuries 
of  the  Christian  Era. 

The  turning  point  in  the  intellectual  development  of 
Europe  came  about  the  year  1200.  It  is  significant  that 
Arab  science  began  its  more  intimate  contact  with  Europe 
during  the  preceding  centuries.  In  general,  the  Arab  culture 
was  much  more  important  in  southern  Europe  during  the 
Middle  Ages  than  during  the  Renaissance.  It  appears  that 
most  of  the  scientific  ideas  of  the  later  Middle  Ages,  of  any 
value  in  mathematics,  astronomy,  geography,  medicine,  and 
natural  history,  are  traceable  directly  or  indirectly  to  the 
Arab  learning.  Men  like  Gerbert  of  Rheims  and  Roger 
Bacon  seem  to  have  owed  their  initial  knowledge  and  inspira- 
tion to  tfiis  source.  Despite  their  superstitious  quests  for 


THE  DECLINE  OF  ANCIENT  LEARNING  59 

the  elixir  of  life  and  the  philosopher's  stone,  the  Arabs  built 
up  a  fairly  solid  body  of  scientific  knowledge  upon  the 
foundation  acquired  from  the  ancient  world.  Arab  science 
must,  therefore,  be  regarded  as  the  most  important  bond  of 
continuity  between  the  science  of  antiquity  and  that  of 
modern  times.  In  this  account  of  the  services  of  an  alien 
race  to  the  development  of  European  science,  may  also  be 
mentioned  the  services  of  the  Jews,  who  were  the  chief  inter- 
preters to  Europe  of  the  Arab  learning.  They  seem  to  have 
been  second  only  to  the  Moors  of  Spain  in  their  cultivation  of 
natural  science.  But  this  may  have  been  due  merely  to  the 
fact  that  the  Arab  learning  was  more  accessible  to  the  Jews 
because  of  their  commercial  activities.20 

The  Arabs,  with  their  dawning  appreciation  of  science, 
might  have  won  to  power  throughout  Europe,  had  not  inter- 
nal dissensions  produced  a  division  of  their  Empire  and  had 
not  the  accession  to  power  of  barbarian  Turks  and  Berbers 
hi  the  East  interposed  a  final  check  upon  their  scientific 
progress.  The  influence  of  Arab  culture  upon  the  intel- 
lectual life  of  Christendom  was  more  lasting  than  its  in- 
fluence upon  the  life  of  Islam.  Contact  with  Arab  civiliza- 
tion, through  the  Crusades,  through  the  commerce  of  the 
Mediterranean,  and  more  directly  in  Spain  and  at  Con- 
stantinople, aroused  in  Europe  a  zeal  for  the  science  and 
literature  of  antiquity.  Arab  science  was,  therefore,  one  of 
the  most  important  cultural  influences  during  the  later 
Middle  Ages. 

THE   APPROACH   TO   MODERN   SCIENCE 

It  is  a  mistake  to  suppose  that  the  Renaissance,  which 
is  now  recognized  as  the  period  at  which  modern  science 

»  The  history  of  the  Arab  and  the  Jew  in  relation  to  the  origins  of  modern 

scientific  ideas  seems  never  to  have  been  adequately  studied  by  the  historian. 

Enough  is  known  of  the  facts  to  indicate  the  importance  of  the  contributions 

thus  made,  but  further  historical  investigation  would  doubtless  yield  many 

'•sting  details. 


60       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

began  to  be  firmly  established,  was  either  a  mere  revival  of 
the  ancient  science  or  a  miraculous  development  of  the  new. 
We  find  in  the  Renaissance  many  survivals  of  medieval 
superstitions  and  we  likewise  find  in  the  late  Middle  Ages 
the  mental  stirrings  which  presage  the  Renaissance.  It  is  a 
truism  to  say  that  every  age  has  its  roots  in  the  past,  but  in 
the  face  of  striking  cultural  changes,  the  antecedent  factors 
are  not  always  clear.  Because  of  these  indications  of  the 
new  day,  which  appear  during  the  last  two  centuries  of  the 
Medieval  Period,  the  dawn  of  modern  science  is  coming  to 
be  set  about  the  year  1200,  instead  of  during  the  Renais- 
sance or  at  an  even  later  date,  as  is  done  by  those  who  as- 
sume that  nothing  important  was  accomplished  before  the 
nineteenth  century.  We  have  considered  some  of  the  scat- 
tered indications  of  a  more  scientific  attitude  during  the 
Middle  Ages  and  also  the  nature  and  influence  of  the  Arab 
learning.  We  may  now  consider  certain  men  and  events 
that  evidence  the  dawn  of  science  during  the  thirteenth  and 
fourteenth  centuries. 

By  the  opening  of  the  thirteenth  century,  certain  elements 
of  stability  had  appeared  in  Europe  which  had  not  been 
in  existence  since  the  period  of  the  Roman  Empire,  although 
the  Empire  of  Charlemagne  came  near  to  their  realization. 
The  northern  barbarians  had  been  finally  checked  and  in 
part  absorbed,  the  Christian  nations  had  been  unified  by 
the  influence  of  the  Church  of  Rome,  and  the  governments 
of  the  existing  European  states  had  become  sufficiently 
strong  to  preserve  order.  The  irrational  state  of  mind  char- 
acteristic of  the  Middle  Ages  was  still  dominant,  but  the 
influence  of  Arab  science  was  being  felt  and  individuals  who 
struggled  against  the  prevailing  current  became  more  nu- 
merous. Thus  Albertus  Magnus  (1193-1280)  appears  as  the 
earliest  botanist.  In  addition  to  other  botanical  studies, 
he  examined  the  artificial  propagation  of  plants  in  a  hothouse 
attached  to  his  convent  garden.  He  also  made  numerous 
chemical  experiments  and  first  used  the  chemical  term  a/- 


THE  DECLINE  OF  ANCIENT  LEARNING  61 

finity  in  its  modern  scientific  sense.  In  the  field  of  natural 
history,  he  dissented  from  the  then  accepted  belief  "that 
certain  birds  spring  from  trees  and  are  nourished  by  the  sap, 
and  also  from  the  theory  that  some  are  generated  in  the  sea 
from  decaying  wood."  2l  His  studies  on  the  influence  of 
geographical  features  upon  races  and  his  position  in  opposi- 
tion to  those  who  ridiculed  the  existence  of  the  Antipodes 
entitle  him  to  a  place  as  one  of  the  founders  of  geographical 

»  White,  A.  D.,  loc.  tit.,  Vol.  I,  p.  37. 

The  name  goose-barnacle,  which  survives  in  modern  zoology,  arose  in  con- 
nection with  this  belief. 

For  example,  Sylvester  Giraldus,  in  his  "Relations  concerning  Ireland," 
(1187)  writes  as  follows:  "Chapt.  II,  Of  Barnacles  which  grew  from  fir  timber 
and  their  nature." 

"There  are  likewise  here  (in  Ireland)  many  birds  called  barnacles,  which 
nature  produces  in  a  wonderful  manner,  out  of  her  ordinary  course.  They 
resemble  the  marsh  geese,  but  are  smaller.  Being  at  first  gummy  excrescences 
from  pinebeams  floating  on  the  water,  and  then  enclosed  in  shells  to  secure 
their  free  growth,  they  hang  by  their  beaks,  like  seaweeds  attached  to  the 
timber.  Being  in  process  of  time  well  covered  with  feathers,  they  either  fall 
into  the  water  or  take  their  flight  into  the  free  air,  their  nourishment  and 
growth  being  supplied,  while  they  are  bred  in  this  very  unaccountable  and 
curious  manner,  from  the  juices  of  the  wood  in  the  water.  I  have  often  seen 
with  my  own  eyes  more  than  a  thousand  minute  embryos  of  birds  of  this 
species  on  the  sea-shore,  hanging  from  one  piece  of  timber,  covered  with  shells, 
and  already  formed.  No  eggs  are  laid  by  these  birds  .  .  .;  the  hen  never 
sits  on  eggs  in  order  to  hatch  them;  in  no  corner  of  the  world  are  they  seen 
either  to  pair,  or  build  nests.  Hence,  in  some  parts  of  Ireland,  bishops  and 
men  of  religion  make  no  scruple  of  eating  these  birds  on  fasting  days,  as  not 
being  flesh,  because  they  are  not  born  of  flesh,  but  these  men  are  curiously 
drawn  into  error.  For,  if  any  one  had  eaten  part  of  the  thigh  of  our  first  par- 
ent, whifh  was  really  flesh,  although  not  born  of  flesh,  I  should  think  him 
not  guiltless  of  having  eaten  flesh.  Repent,  O  unhappy  Jew." 

As  late  as  1676  this  same  belief  was  seriously  maintained,  when  Sir  Robert 
Murray  reported  his  observations  to  the  Royal  Society  of  England:  "In  many 
shells  I  opened,  I  found  a  perfect  Sea-Fowl;  the  little  Bill  like  that  of  a  Goose; 
the  Eyes  marked;  the  Head,  Neck,  Breast,  Wings,  Tail,  and  Feet,  formed; 
athers  everywhere  perfectly  Shaped,  and  Blackish  colored;  and  the 
Feet  like  those  of  other  Water-Fowl,  to  my  best  Rememberance.  The  biggest 
I  found  upon  the  Tree,  was  but  about  the  size  of  the  Figure  (an  inch  long); 
nor  did  I  ever  see  any  of  the  little  Birds  alive,  nor  meet  with  any  Body  that 
did;  only  some  credible  Persons  have  assured  me  that  they  have  seen  some 
as  big  as  their  Fist."  (Quoted  from  Metcalfe,  M.  M.,  "Organic  Evolution," 
published  by  the  Macmillan  Co.  Reprinted  by  permission.) 


62       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

science.  Like  Gerbert  of  Rheims,  he  was  regarded  as  in 
league  with  the  Devil,  but  his  ecclesiastical  standing  saved 
him  from  persecution. 

The  greatest  of  medieval  scientists  was  Roger  Bacon,  born 
about  the  year  1214  and  known  as  the  "  Admirable  Doc- 
tor. "  Familiar  with  Latin,  Greek,  Hebrew,  and  Arabic, 
Bacon  was  well  versed  in  the  older  learning,  but  more  than 
this  he  was  a  man  of  new  ideas.  He  seems  to  have  practiced 
in  the  thirteenth  century  what  Francis  Bacon  advocated  in 
the  seventeenth,  proclaiming  that  man  by  the  use  of  science 
could  do  all  things.  Realizing  the  danger  of  reliance  upon 
traditional  authority,  he  advocated  the  scientific  method  of 
critical  observation  and  experimentation,  and  he  shows 
throughout  his  work  an  insight  into  the  spirit  of  modern 
science  which  is  remarkable.  Bacon  placed  mathematics 
first  among  the  sciences.  He  was  one  of  the  first  real  astron- 
omers in  western  Europe  and  his  recommendation  to  Pope 
Clement  II  to  rectify  the  calendar,  as  was  done  three  cen- 
turies later,  shows  how  far  he  was  in  advance  of  his  time. 
He  discovered  the  use  of  spectacles,  described  the  use  of  the 
telescope  and  microscope,  and  foresaw  the  application  of 
various  optical  devices  to  instruments  for  the  measurement 
of  angles.  In  a  wonderful  letter  that  has  come  down  to  us 
he  practically  foretells  the  steamship,  the  steam  engine, 
the  automobile,  the  suspension  bridge,  and  the  flying  ma- 
chine. His  scientific  imagination  was  great  enough  to  rise 
above  the  practical  limitations  of  his  time  and  see  into  the 
future.  Yet  his  greatest  contribution  was  his  insistence 
upon  real  reasoning  and  upon  experiment  and  research  into 
the  workings  of  nature  rather  than  subtilizing  on  empty 
propositions  and  fruitless  study  of  Aristotle. 

But  the  spirit  of  the  times  was  averse  to  these  ideas. 
Bacon  was  so  much  in  advance  of  his  age,  that  his  inventions 
were  regarded  as  " suspicious  novelties."  The  leaders  in 
church  and  state  accused  him  of  magical  practices  and  of 
being  in  league  with  Satan.  The  ignorant  minds  of  the  age 


THE  DECLINE  OF  ANCIENT  LEARNING  63 

could  not  sustain  new  truths  which  were  in  opposition  to  the 
Bible  and  dogmatic  theology.  They  cried  " Atheist!", 
"  Infidel ! "  and  "  Magician ! " ;  and  thus  won  the  day.  To  his 
critics  Bacon  replied  that  "  because  these  things  are  beyond 
your  comprehension,  you  call  them  the  works  of  the  Devil, 
your  theologians  and  canonists  abhor  them  as  the  produc- 
tion of  magic,  regarding  them  as  unworthy  of  a  Christian." 

Bacon's  attempt  to  show  that  much  which  was  ascribed 
to  demons  resulted  from  natural  means  merely  added  to  the 
flame;  for  to  limit  the  power  of  Satan  was  deemed  hardly 
less  impious  than  to  limit  the  power  of  God.  When  he 
attempted  to  perform  a  few  simple  experiments  before  a 
select  audience  at  Oxford  the  whole  city  arose  in  horror  and 
alarm.  A  riot  was  precipitated;  for  all  believed  that  Satan 
was  to  be  summoned  to  appear.  The  news  spread  like  wild- 
fire and  from  every  house  rushed  priests,  lecturers,  students, 
and  townspeople  crying  "Down  with  the  magician. "  When 
Clement  IV,  Bacon's  friend  and  protector,  died,  Bacon  was 
persecuted  by  the  Church  for  his  free  views  and  finally 
thrown  into  prison  where  he  spent  over  ten  years,  being 
released  shortly  before  his  death  in  1294.  Tradition  has  it 
that  almost  his  last  words  were  "would  that  I  had  not  given 
myself  so  much  trouble  for  the  love  of  science."  Europe 
was  not  to  see  such  a  true  man  of  science  for  two  centuries, 
at  least,  and  no  better  criticism  of  the  narrowness  of  medieval 
theology  and  the  domination  of  irrational  superstition 
can  be  cited  than  the  treatment  he  received  in  his  own  life 
and  by  posterity  which  long  failed  to  recognize  his  greatness 
in  the  intellectual  history  of  Europe.22 

The  recovery  of  the  complete  works  of  Aristotle  occurred 
during  the  second  decade  of  the  thirteenth  century,  first  in 
Arabic  translations  and  later  in  the  original  Greek.  Dur- 
ing the  Middle  Ages  these  writings  had  been  known  only  in  a 

"Taylor,  H.  O.f  "The  Medieval  Mind,"  I,  Chapter  on  Roger  Bacon.    White, 
\    !> ,  ioc.  of.,  1,  pp.  387-391.    Draper,  J.  W.,  "The  Intellectual  Dov.-lop- 
of  Kuropr."  II,  pp.  163-56. 


64       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

fragmentary  form.  Being  eagerly  devoured  by  the  school- 
men, they  at  once  became  a  part  of  the  traditional  teachings, 
rather  than  a  stimulus  to  a  renewal  of  the  Greek  spirit  of 
investigation.  It  is  for  this  reason  that  the  Ptolemaic 
astronomy  and  the  science  of  Aristotle  were  looked  upon 
with  suspicion  by  many  of  the  scholars  of  the  Renaissance. 
The  Arab  influence  is  seen  throughout  these  closing  decades 
of  the  Middle  Ages.  Those  who  struggled  against  the  es- 
tablished authority  seem  continually  to  have  drawn  inspira- 
tion from  this  source  rather  than  from  the  ancient  masters  as 
interpreted  by  Europe.  The  philosophical  aspects  of  the 
Aristotelian  doctrines  were  set  forth  by  the  Spanish- Arabian 
scholar  Averroes  (1126-1198)  and  assumed  such  importance 
that  the  Church  was  at  great  pains  to  counteract  them. 
Despite  these  attacks,  the  intellectual  vistas  that  were 
being  opened  to  Europe  continued  to  unfold. 

The  union  of  science  and  theology,  which  had  been 
criticized  by  Averroes,  was  further  protested  by  Duns 
Scotus  (1265-1308)  and  by  William  of  Occam  (d.  1347),  the 
latter  denying  that  theological  doctrines  were  rationally 
demonstrable  and  showing  the  irrational  nature  of  many  of 
the  current  teachings.23  Thomas  Aquinas  (1227-1274), 
although  a  defender  of  orthodox  theology,  shows  a  more 
scientific  spirit  than  many  of  his  contemporaries,  when  he 
declares  that  "the  object  of  the  study  of  philosophy  is  not  to 
learn  what  men  have  thought  but  what  is  the  real  truth  of 
the  matter. "  But  Aquinas  represents  the  spirit  of  Scholasti- 
cism rather  than  the  spirit  of  science.  He  is  admired  at  the 
present  day  as  an  earnest  seeker  after  truth,  possessed  of 
great  intellectual  acumen  but  dominated  by  the  prejudices 
of  his  age,  rather  than  one  whose  ideas  were  hi  line  with 
modern  thought. 

The  culmination  of  distinctively  medieval  ideas  is  seen  in 
the  scholasticism  of  the  thirteenth  and  fourteenth  centuries. 

28  Whetham,  W.  C.  D.,  and  C.  D.,  "Science  and  the  Human  Mind."  Also: 
Taylor,  H.  O.,  "  The  Medieval  Mind,"  Chap.  XLII. 


THE  DECLINE  OF  ANCIENT  LEARNING  65 

Scholasticism  is  of  interest  to  science  as  a  sign  of  an  intense 
intellectual  activity  and  not  because  of  its  accomplishments. 
The  harbingers  of  the  modern  spirit  were  not  the  theologians, 
but  Roger  Bacon,  and  the  other  scientist-philosophers  of  the 
thirteenth  and  fourteenth  centuries,  who  seem  to  have 
drawn  their  knowledge  and  inspiration  so  largely  from  the 
Arab  sources.  As  was  emphasized  at  the  beginning  of  the 
present  chapter,  the  Middle  Ages  are  not  to  be  judged  by 
their  scientific  accomplishment,  but  rather  by  their  unifica- 
tion of  a  discordant  world  in  preparation  for  the  reestablish- 
ment  and  extension  of  the  scientific  spirit  of  antiquity.  These 
centuries  were  always  lacking  in  the  modern  rationalistic 
spirit,  being  dominated  by  supernaturalism.  Reasoning  was 
taught  and  practiced  as  a  form  of  mental  gymnastics.  The 
preeminence  of  theology  attracted  to  theological  studies 
minds  that  might  better  have  been  employed  in  science. 
The  dominant  thought  at  the  close  of  the  period  was  still 
without  any  clear  conception  of  scientific  reasoning.  The 
true  and  the  false  were  hopelessly  intermingled.  Facts 
"that  would  not  be  denied"  were  at  length  the  means  by 
which  the  rationalism  of  modern  times  triumphed  over 
supernaturalism. 


CHAPTER  IV 
THE  EMERGENCE  OF  MODERN  SCIENCE 

WE  think  too  much  of  the  Renaissance  as  mainly  character- 
ized by  literary  and  artistic  revival  and  achievement. 
The  history  of  science  shows  that  the  period  was  one  of 
diversified  activity  and  that  its  scientific  achievements 
were  even  more  important  than  those  in  other  lines.  It  was 
during  the  Renaissance  that  science  became  securely  estab- 
lished; and  the  scientific  spirit  of  the  modern  world  is  but 
a  continuation  of  the  spirit  which  appeared  in  southern  and 
western  Europe  during  the  fourteenth,  fifteenth,  and  six- 
teenth centuries.  The  limits  of  such  an  historical  period,  of 
course,  are  arbitrary.  In  literature  and  art,  the  time  at 
which  the  Renaissance  culminates  is  recognized  as  differing 
hi  different  countries.  Considering  science  alone  and  the 
western  world  as  a  whole,  we  may  apply  the  term  to  a 
period  (1350-1700)  which  includes  both  the  century  of  the 
awakening  in  Italy  and  also  the  centuries  during  which 
science  became  strongly  established  within  the  nations  that 
succeeded  Italy  hi  the  intellectual  domination  of  Europe. 
During  the  Renaissance  a  thoroughly  scientific  spirit  appears 
for  the  first  time  in  history.  For  not  only  was  the  older 
learning  recovered  and  rated  at  its  true  value,  but  there  also 
occurred  a  new  development  of  natural  knowledge,  which  has 
brought  forth  the  science  of  the  present  time. 

MEDIEVAL   ANTECEDENTS    OF   THE    RENAISSANCE    IN    SCIENCE 

The  culture  of  the  Renaissance,  like  that  of  ancient 
Hellas,  was  formerly  regarded  as  a  spontaneous  develop- 
ment. But  investigation  has  told  us  more  of  its  origins. 

66 


THE  EMERGENCE  OF  MODERN  SCIENCE         67 

Like  other  historic  cultures,  it  now  appears  as  a  natural 
outgrowth  from  preceding  centuries.  The  Middle  Ages 
culminated  in  the  Renaissance  by  a  natural  process,  and  this 
historical  fact  puts  a  better  face  upon  the  Middle  Ages.  The 
Crusades,  which  were  so  distinctively  a  product  of  the 
medieval  frame  of  mind,  are  now  recognized  as  the  precur- 
sors of  the  intellectual  awakening  of  Europe.  Beginning  as 
a  response  to  what  was  believed  to  be  the  call  of  God,  they 
eventuated  in  developments  that  were  of  far-reaching  im- 
portance along  intellectual  lines. 

Such,  for  example,  was  the  commercial  development  of 
the  Italian  cities,  initiated  by  the  transportation  of  the 
crusaders,  and  the  consequent  rise  of  an  industrial  aristoc- 
racy possessed  of  wealth  and  leisure.  Contact  with  the  in- 
fidels brought  respect  for  their  courage,  their  morality,  and 
their  learning.  Mohammedan  learning,  which,  as  we  have 
seen,  had  been  filtering  into  Europe  during  the  preceding  cen- 
turies, became  the  basis  for  a  renewed  growth  of  science, 
although  its  influence  was  not  generally  acknowledged.  The 
secularization  of  many  activities  tended  toward  greater  in- 
tellectual freedom.  New  vistas  were  opened  to  the  human 
mind,  not  only  by  the  partial  recovery  of  the  ancient  learning 
but  also  by  geographical  discoveries  and  by  the  renewed 
incursions  within  the  field  of  natural  knowledge.  The  mari- 
time experiences  of  the  Italians  and  their  sudden  economic 
advancement,  along  with  the  intellectual  leadership  of  the 
Church  at  Rome,  made  the  Italian  peninsula  the  starting 
point  from  which  the  awakening  spread  westward  and  north- 
ward. We  have  seen  that  the  dawn  of  European  science 
dates  from  Roger  Bacon  and  the  thirteenth  century.  By  the 
opening  years  of  the  fourteenth  century,  the  spirit  most 
typical  of  the  Middle  Ages  had  disappeared  in  the  more 
progressive  centers  of  the  western  world,  and  the  time  was 
ripe  for  the  re-birth  that  was  to  follow.1 

>  Adams,  G.  B.,  "Civilization  during  the  Middle  Ages,"  Chapters  XI  and 
XII. 


68       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

Even  scholasticism,  the  traditional  spirit  of  which  was  so 
repellent  to  that  of  science,  was  a  sign  of  the  renewal  of  in- 
tellectual activity.  The  story  of  its  development  is  a  revela- 
tion of  how  human  ability  may  be  perverted  and  misdirected 
through  limited  knowledge.  The  schoolmen  give  evidence  of 
great  intellectual  acumen,  although  so  largely  ignorant  of  the 
older  learning  and  so  mistaken  in  their  concept  of  authority. 
Beginning  in  the  abortive  revival  of  the  schools  under 
Charlemagne,  scholasticism  culminated  during  the  thirteenth 
century  hi  a  broader  outlook,  but  still  in  conflict  with  the 
spirit  which  soon  prevailed.  The  complete  works  of  Aris- 
totle became  known  between  1210  and  1225  and  proved  a 
wonderful  stimulus.  But  the  schoolmen  were  mainly  con- 
tent with  the  authority  of  Aristotle  and  the  Scriptures  in 
matters  of  natural  knowledge.  Only  rare  individuals  among 
them,  like  Roger  Bacon,  recognized  the  authority  of  nature. 
Nevertheless,  if  their  conclusions  were  false  their  systems  of 
thought  were  comprehensive,  and  often  scientific  save  for 
their  premises.  Many  of  their  discussions  revolved  upon 
important  problems  hi  speculative  philosophy  which  even 
to-day  can  be  attacked  only  through  speculation.  Again, 
the  older  universities  of  Europe  were  established  under  the 
stimulus  of  scholasticism.  When  we  understand  that  the 
great  century  of  the  schoolmen  (1200-1300)  was  one  of  the 
most  intellectual  periods  in  all  history,  we  recognize  hi 
scholasticism  a  prediction  and  an  introduction  of  the  age  of 
new  thought  which  followed. 

The  greater  social  stability,  which  appeared  in  western 
Europe  during  the  twelfth  and  thirteenth  centuries,  the 
decline  of  papal  authority,  incident  to  the  failure  of  the 
Crusades,  the  rise  of  national  states,  and  the  growing  politi- 
cal freedom  of  the  Italian  cities  were  additional  factors. 
When  the  whole  situation  is  taken  into  consideration,  there 
is  abundant  evidence  of  a  changing  outlook,  during  the  final 
century  of  the  Middle  Ages.  The  spirit  of  other-worldliness 
was  beginning  to  wane  and  the  bonds  of  traditional  authority 


THE  EMERGENCE  OF  MODERN  SCIENCE         69 

were  already  loosened.  Thus,  the  Renaissance  appears  as  a 
product  of  the  Middle  Ages,  and  not  merely  as  the  ancient 
spirit  restored  to  power. 

It  was  necessary  for  the  men  of  the  Renaissance  to  become 
masters  of  the  old.  But  the  re-birth  was  not  merely  a  revival 
of  learning,  it  was  a  new  creation  as  well.  In  science,  at 
least,  the  Renaissance  began  where  the  older  knowledge  had 
reached  the  limits  of  its  understanding.  Here,  for  the  first 
time,  science  found  itself,  came  to  take  the  ancient  learning 
at  its  true  value,  and  began  to  shape  new  courses.  Philos- 
ophy became  distinct,  on  the  one  hand  from  science  and  on 
the  other  from  current  theology.  The  authority  of  nature 
came  to  be  acknowledged,  and  the  rationalistic  point  of 
view  was  established  in  a  manner  distinctive  of  modern 
thought.  During  the  first  century  of  the  Renaissance 
(1350-1450),  many  of  the  older  beliefs  and  superstitions 
survived,  and  even  flourished  with  renewed  vigor,  like  the 
false  sciences  of  alchemy  and  astrology.  But  with  the 
growth  of  skepticism,  rationalism  more  and  more  prevailed. 
Thus,  through  a  critical  attitude  toward  the  old  knowledge, 
the  way  was  prepared  for  the  development  of  more  positive 
and  constructive  thinking  after  the  middle  of  the  fifteenth 
century. 

DISTINCTIVE  FEATURES  OF  THE  SCIENCE  OF  THE  RENAISSANCE 

The  terms  Revival  of  Learning  and  Renaissance,  which 
are  both  applied  to  this  great  period  of  European  history,  are 
descriptive  of  its  best  known  features — the  restoration  of  the 
older  knowledge  and  the  rebirth  of  its  spirit.  The  ancient 
culture  was  restored  to  Europe  in  part  by  its  survivals  in 
Italy  and  Constantinople,2  and  by  transfer  from  the  Arab 

•The  Greek  tradition  had  survived  continuously  in  Constantinople,  but 
the  limited  means  of  communication  during  the  Middle  Ages  and  the  lack  of 
intellectual  interest  on  the  p.trt  of  western  Europeans  rendered  its  influence 
unavailing.  The  fall  of  Constantinople  in  1453  is  an  overrated  event  from 
the  point  of  view  of  culture,  as  the  revival  of  the  classics  had  already  taken 


70       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

civilization.  The  Greek  language  had  practically  disappeared 
in  Italy  during  the  darkest  centuries,  but  was  recovered 
toward  the  close  of  the  scholastic  period.  This  revival  of  the 
older  learning,  which  was  effected  mainly  during  the  four- 
teenth and  early  fifteenth  centuries,  was  a  point  of  departure, 
but  the  distinctive  feature  of  the  Renaissance  in  science  was 
the  acquisition  of  factual  knowledge  that  was  wholly  new  and 
the  change  of  spiritual  outlook  which  this  knowledge 
gradually  forced  upon  mankind. 

A  feature  of  the  Renaissance  which  is  of  more  vital  signifi- 
cance is  that  its  intellectual  development  falls  into  two 
periods  which  form  a  natural  sequence  but  which  are  rather 
clearly  separated.  From  the  early  fourteenth  to  the  middle 
fifteenth  century  the  spirit  was  one  of  skepticism  toward 
traditional  explanations  and  a  growing  rationalism  regarding 
scientific  questions.  After  1450  constructive  thought  was 
increasingly  evident.  During  the  earlier  period  many 
medieval  superstitions  survived  and  false  sciences  like 
astrology  continued  to  flourish.  During  the  later  period 
these  hindrances  were  removed  by  the  increase  of  factual 
knowledge.  By  the  close  of  the  seventeenth  century  the 
calm  and  consciously  rational  spirit  of  science  is  seen  among 
progressive  thinkers,  and  thus  the  characteristic  feature  of 
the  modern  mind  becomes  established. 

But  the  most  distinctive  aspect  of  the  period  under  dis- 
cussion was  the  widening  of  intellectual  horizon  and  the 
resultant  effects  upon  imagination.  The  science  of  the 
Renaissance  is,  therefore,  hi  contrast  with  that  of  our  own 
day  which  has  been  distinguished  by  its  material  achieve- 
ments. During  the  Renaissance,  man  came  for  the  first  time 
to  know  himself  and  to  know  the  world.  The  horizon  of 
human  experience  became  suddenly  extended  to  an  un- 
dreamed of  distance.  This  spiritual  influence  of  the  new 
learning  may  be  visualized  by  an  exhibition,  in  tabular  form, 

place.  However,  it  did  bring  to  western  Europe  a  number  of  scholars  and 
some  new  manuscripts. 


THE  EMERGENCE  OF  MODERN  SCIENCE         71 

of  the  more  important  factors  which  thus  influenced  the 
mind  of  Europe.  In  the  tabulation,  as  given,  the  names  of 
individuals  commonly  associated  with  particular  factors  ap- 
pear to  the  left,  while  to  the  right  is  a  phrase  characterizing 
the  factor  in  question. 


FACTORS  INFLUENTIAL  IN  WIDENING  OF  INTELLECTUAL 
HORIZON  DURING  RENAISSANCE  OF  SCIENCE  (1350-1700) 


IN  GEOGRAPHICAL  SCIENCE 

Paolo  Toscanelli 
(1397-1482) 

Making  of  Map  used  by  Explorers 

Prince  Henry,  the  "Navigator" 
(1394-1460) 

Exploration  of  African  Coasts,  Discovery 
of  Madeira  and  the  Azores 

Bartholomew  Dias 
(1445-1500) 

Rounding  Cape  of  Good  Hope 

Christopher  Columbus 
(1446-1506) 

Discovery  of  America  (1492) 

Amerigo  Vespucci 
(1452-1512) 

Naming  and  better  Knowledge  of  America 

Vasco  da  Gama 
(1469-1524) 

Discovery  of  Sea-Route  to  India 

Ferdinand  Magellan 
(1480-1521) 

Circumnavigation  of  Globe  (1519-21),  Es- 
tablishment  of   Earth's   Sphericity   by 
means  of  Geographical  Evidence 

Gerhard  Kramer,  "Mercator" 
(1512-1594) 

More    Accurate     Map-Making    of    New 
World,  Introduction  of  Mercator's  Pro- 
jection 

Gillx-rt  of  Colchester 
(1540-1603) 

Studies    in    Magnetism    and    Electricity, 
Adoption  and  Development  of  Mariner's 
Compass 

Numerous  Explorers  and 
Geographers  (1,500-1700) 

Detailed    Exploration    and    Mapping    of 
Globe 

72       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 


IN  THE  MATHEMATICAL,  ASTRONOMICAL,  PHYSICAL,  AND 
CHEMICAL  SCIENCES 


Lucas  Pacioli 
(1450-?) 

Rapid  Development  of  Mathematical 
Science  following  Adoption  of  Arabic 
Numerals 

Albrecht  Diirer 
(1471-1528) 

Geometrical  Theory  of  Perspective  De- 
veloped in  Connection  with  Artistic 
Representation 

Nicolas  Copernicus 
(1473-1543) 

Heliocentric  Theory  revived  with  Evidence 
in  its  Favor 

Tycho  Brahe 
(1546-1601) 
Stevinus  of  Bruges 
(1548-1620) 
Galileo  Galilei 
(1564-1642) 

Confirmation  of  Copernican  Theory  by 
Telescope  and  Intensive  Work  upon 
Mathematico-Physical  Problems,  with 
Accumulation  of  Adequate  Data 

Johann  Kepler 
(1571-1630) 

Laws  Describing  Movements  of  the  Heav- 
enly Bodies,  Founded  on  Calculation 

Isaac  Newton 
(1642-1727) 

Discovery  of  Gravitation  as  the  Law  of 
the  Heavens 

Robert  Boyle 
(1627-1691) 
Georg  Ernst  Stahl 
(1660-1734) 

Beginnings  of  Chemical  Science 

THE  EMERGENCE  OF  MODERN  SCIENCE         73 


IN  THE  BIOLOGICAL  SCIENCES 


The  Medical  Humanists 
(1450-1550) 

Revival  of  Writings  of  Hippocrates  and 
Galen 

Philippus  von  Hohenheim, 
"Paracelsus"  (1493-1541) 

Teaching  in  Common  Tongue,  Increasing 
Reliance  upon  Direct  Observation, 
Chemical  Medicine 

Andreas  Vesalius 
(1514-1564) 

Establishment  of  Human  Anatomy  as  a 
Science,  First  Modern  Textbook 

Conrad  von  Gesner 
(1516-1565) 

Knowledge  of  Strange  Animals  and  Plants 
Collected  from  Remote  Regions 

William  Harvey 
(1578-1657) 

Discovery  of  Circulation  of  the  Blood, 
Growth  of  Physiological  and  Embryo- 
logical  Knowledge 

Francesco  Redi 
(1626-1698) 

Disproof  of  Spontaneous  Generation  in  all 
but  Microscopic  Forms 

John  Hay 
(1628-1705) 

Preliminary  Steps  toward  Modern  Classi- 
fication of  Plants  and  Animals 

Marcello  Malpighi 
(1628-1694) 

Increasing  Knowledge  of  Animals  and 
Plants  both  Gross  and  Microscopic 

Anthony  van  Leeuwenhoek 
(1632-1723) 
Jan  Swammerdam 
(1637-1680) 

Introduction  of  Microscope  and  Study  of 
Microorganisms 

74        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 


MISCELLANEOUS  FACTORS 


Laurens  Coster 
(1370-1440) 
Johannes  Gutenberg 
(1397-1468) 

Introduction  of  Printing  from  Movable 
Type  (c.  1440) 

Leone  Battista  Albert! 
(1404-1472) 
Leonardo  da  Vinci 
(1452-1519) 
Giovanni  Pico  della  Mirandola 
(1463-1494) 

Stimulus  of  Individuals  of  Universal  Genius 

Giordano  Bruno 
(1548-1600) 

Open  Criticism  of  Dogmas  of  the  Church, 
culminating  in  the  Religious  Toleration 
of  Present  Time 

(1500-1700) 

Economic  Development  stimulated  by  Be- 
ginning of  Trade  with  World  and  con- 
tinuing to  the  Present 

Michel  Montaigne 
(1533-1592) 

Outspoken  Skepticism  concerning  Many 
Traditional  Beliefs 

Francis  Bacon 
(1561-1626) 

Widely  Advertised  Formulation  of  Steps 
Necessary  for  Man's  Control  of  Nature 

Thomas  Hobbes 
(1588-1679) 

Growth  of  Rationalism 

Rene"  Descartes 
(1596-1650) 

Development  of  Mathematics  in  Relation 
to  Philosophy 

Blaise  Pascal 
(1623-1662) 

Foundation  of  Theory  of  Probability,  im- 
portant as  a  Rationalistic  Explanation 
of  Many  Complex  Phenomena 

John  Locke 
(1632-1704) 
Baruch  Spinoza 
(1632-1677) 
Gottfried  Leibnitz 
(1646-1716) 

Profound  Changes  in  Theological  and  Phil- 
osophical Thought,  Separation  of  Philos- 
ophy from  Theology  and  Establishment 
of  the  Former  upon  a  more  Rationalistic 
Basis 

THE  EMERGENCE  OF  MODERN  SCIENCE         75 

Within  the  period  covered  by  the  foregoing  table  the 
universe  was  literally  made  anew.  For  the  primitive  ideas 
regarding  geography  and  astronomy,  surviving  since  the 
dawn  of  history  about  the  shores  of  the  Mediterranean  and 
essentially  like  those  of  savage  peoples  the  world  over,  were 
cast  aside.  Only  the  establishment  of  the  evolutionary 
theory  during  the  nineteenth  century  can  compare  with  the 
revolution  in  human  thinking  thus  produced.  But  evolution 
made  its  way  in  a  more  tolerant  age  when  freedom  had  been 
won  and  its  story  is  less  dramatic.  As  one  writer  says, 
"  There  came,  one  after  the  other,  five  of  the  greatest  men 
our  race  has  produced — Copernicus,  Kepler,  Galileo,  Des- 
cartes, and  Newton — and  when  their  work  was  done  the  old 
theological  conception  of  the  Universe  was  gone.  'The 
spacious  firmament  on  high' — 'the  crystalline  spheres '- 
the  Almighty  enthroned  upon  'the  circle  of  the  heavens, '  and 
with  his  own  hands,  or  with  angels  as  his  agents,  keeping  sun, 
moon  and  planets  in  motion  for  the  benefit  of  the  earth, 
opening  and  closing  the  'windows  of  heaven/  letting  down 
upon  the  earth  the  '  waters  above  the  firmament, '  setting  his 
bow  in  the  cloud,  hanging  out  'signs  and  wonders/  hurling 
comets,  'casting  forth  lightnings'  to  scare  the  wicked,  and 
'shaking  the  earth'  in  his  wrath:  all  this  had  disappeared. "  3 
And  with  its  disappearance  came  the  knowledge  of  a  new 
heaven  and  a  new  earth.  Truth  had  begun  to  triumph  over 
ignorance.  An  age  of  Science  was  replacing  an  age  of 
Superstition. 

GROWTH  OF  SCIENTIFIC  AND  RATIONALISTIC  KNOWLEDGE 

The  appearance  of  individuals  of  genius  and  the  occurrence 

ents  of  revolutionary  import  are  indicative  of  the  dawn 

of  a  new  age.    It  was  so  with  the  Renaissance.    The  great 

Italian  national   poet,   Dante  Alighieri   (1265-1321)  is  in 

'Whit*-,   A     I),       \    History  of  (he  Warfare  of  Science  with  Theology," 
Vd  I,  p.  15. 


76        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

many  respects  a  medieval  figure  but  in  others  he  is  of  the 
Renaissance.  His  science  and  theology  were  those  of 
Thomas  Aquinas,  but  his  independence  of  judgment,  his  con- 
ception of  the  worth  of  the  individual,  and  his  appreciation 
of  beauty  are  signs  of  the  awakening.  The  existence  of  a 
rising  skepticism  toward  the  traditional  teachings  is  sug- 
gested by  the  language  of  orthodoxy  throughout  the  later 
years  of  the  thirteenth  century.  The  most  conspicuous  ex- 
ample of  an  individual  who  is  known  to  have  questioned  the 
accepted  doctrines  is  Peter  of  Apono  (1260-1316),  a  disciple 
of  Averroes  and  influential  in  the  promulgation  of  Averroism 
in  Italy.  He  seems  to  have  denied  the  existence  of  demons 
and  of  miracles,  although  his  beliefs  were  tainted  by  astrolog- 
ical superstitions.  In  his  old  age  he  was  imprisoned  by  the 
Church  on  the  charge  of  magic  and  intercourse  with  spirits, 
but  as  he  died  before  sentence  was  pronounced  the  inquisitors 
could  only  burn  him  in  effigy.  Like  Roger  Bacon  he  de- 
scended to  posterity  as  one  of  the  greatest  magicians  of  the 
time.4 

Francesco  Petrarca  or  Petrarch  (1304-1374)  is  fully  rep- 
resentative of  the  early  Renaissance.  His  humanism  was 
that  blending  of  the  old  and  the  new  which  is  character- 
istic of  modern  thought.  Although  a  literary  man  and  in  no 
sense  a  scientist,  Petrarch  exhibits  a  rebellion  against  the 
traditional  authority  and  a  critical  attitude  indicative  of  the 
scientific  spirit.  He  well  represents  the  state  of  mind  that 
characterized  the  Renaissance  before  the  period  of  construc- 
tive thought.  Petrarch  contributed  to  the  advancement  of 
science  by  denouncing  the  astrologers  as  charlatans  and 
rogues.  The  medical  men  of  the  tune  he  regarded  as  no 
better,  but  he  forecast  the  way  to  a  science  of  health  and 
disease  which  was  later  exemplified  in  modern  medicine  and 
surgery.  He  ridiculed  the  pious  beliefs  regarding  animals 
inherited  from  the  Bestiaries  as  childish  superstitions,  and  of 
no  value  to  man.  In  common  with  all  humanists  or  men  of 

4  Lecky,  loc.  tit.,  Vol.  I,  p.  103. 


THE  EMERGENCE  OF  MODERN  SCIENCE          77 

the  new  learning,  he  abhorred  the  teachings  of  scholasticism 
and  scoffed  at  the  authority  of  Aristotle.  He  was  the  first 
great  figure  in  the  valiant  battle,  waged  against  make- 
believe  and  superstition,  by  the  rationalists  of  the  fourteenth, 
fifteenth,  and  sixteenth  centuries. 

Neither  the  reputation  which  is  popularly  attached  to 
Giovanni  Boccaccio  (1313-1375),  and  others  of  the  human- 
ists who  are  known  chiefly  by  the  laxness,  from  a  modern 
viewpoint,  of  their  standards  of  morality,5  nor  prejudice 
toward  the  classical  requirements  that  have  hitherto  dom- 
inated western  education  should  conceal  the  fact  that 
these  men  occupy  an  important  place  in  the  transition  from 
medieval  to  modern  scientific  thought.  Humanism  may 
have  acted  as  a  temporary  check  upon  the  development  of 
interest  in  the  natural  sciences.  But  the  study  of  ancient 
literature  was  the  most  important  single  factor  in  the  libera- 
tion of  the  intellect.  Humanism  did  yeoman  service  in  the 
advancement  of  the  critical  frame  of  mind  which  was  a 
necessary  preliminary  to  the  constructive  rationalism  of 
modern  science.  In  view  of  their  limited  knowledge  of  facts, 
it  is  remarkable  that  the  humanists  wrought  so  well. 

By  the  year  1450  the  recovery  of  the  ancient  learning 
was  almost  complete  and  the  essentially  modern  culture  of 
the  humanists  was  fast  displacing  the  gloom  of  the  Middle 
Ages.  As  we  have  seen,  the  first  century  of  the  Renaissance 
(1350-1450)  was  an  age  of  increasing  skepticism  and  negation 
while  the  positive  and  constructive  activities  of  the  period 
were  later  accomplishments.  After  1450  the  study  of  nature 
assumed  increasing  importance.  Facts  began  to  accumulate 
and  men  awoke  to  the  obvious  truths  of  natural  science,  so 
that  rapid  advances  in  scientific  knowledge  became  possible. 

More  than  any  other  individual  Leonardo  da  Vinci  (1452- 

*  The  significance  of  the  literary  work  of  Boccaccio  is  not  to  be  estimated  by 
the  salaciousness  of  the  Decameron,  but  on  the  basis  that,  in  opposition  to  the 
asceticism  of  the  medieval  spirit,  he  "proclaimed  the  beauty  of  the  world,  the 
••«  of  youth  and  strength  and  love,  unterrified  by  hell,  unappalled  by  the 
of  impending  death."    Symonds,  J.  A.,  "The  Renaissance  in  Italy." 


78       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

1519)  embodies  the  spirit  of  the  period.  Whether  one  man 
can  ever  again  grasp  the  learning  of  his  day  as  Leonardo  did 
is  doubtful,  in  view  of  the  present  extension  of  knowledge. 
But  in  any  era  such  a  man  would  exert  widespread  influence. 
Known  mainly  as  an  artist,  he  was  preeminent  also  as  a  man 
of  science,  an  architect,  and  an  engineer.  For  us,  his  im- 
portance lies  in  his  apprehension  of  the  scientific  method  and 
in  his  unique  personality.  Of  him  it  has  been  well  said,  "He 
was  not  a  scholastic,  and  neither  was  he  a  blind  follower  of 
classical  authority,  as  were  many  of  the  men  of  the  Renais- 
sance. To  him,  observation  of  nature  and  experiment  were 
the  only  true  methods  of  science.  Knowledge  of  the  ancient 
writers,  useful  as  a  starting  point,  could  never  be  conclu- 
sive." He  grasped  the  fundamental  concept  that  true  science 
begins  with  observation.  "Those  sciences  are  vain  and  full 
of  errors,  he  tells  us,  which  are  not  born  from  experience, 
the  mother  of  all  certainty,  and  which  do  not  end  with 
one  clear  experiment.  Science  gives  certainty,  and  science 
gives  power.  Those  who  rely  on  practice  without  science 
are  like  sailors  without  rudder  or  compass."  Could  there 
be  a  clearer  statement  of  the  nature  and  value  of  science 
even  in  the  twentieth  century? 

As  indicative  of  his  grasp  of  fundamentals  hi  scientific 
method  and  fact,  may  be  cited  his  understanding  of  the 
nature  of  fossils  and  of  the  changes  by  which  mountains  have 
been  upraised,  together  with  the  effects  of  erosion.  For 
example,  he  says  that  the  Po  will  eventually  lay  dry  land  in 
the  Adriatic  as  in  the  past  it  has  deposited  a  great  part  of 
Lombardy.  For  Leonardo,  nature  was  devoid  of  magic 
and  subject  to  immutable  necessity.  If  his  fragmentary 
notes,  apparently  taken  with  a  view  to  publication  in  ency- 
clopaedic form  had  become  accessible,  it  is  hard  to  tell  what 
force  they  might  not  have  exerted  in  the  advancement  of 
science.6  It  is  of  interest,  in  view  of  his  renown  as  an  artist, 

8  Among  many  remarkable  passages  is  the  following  upon  the  saltness  of  the 
sea.    After  considering  various  explanations  notably  those  of  Pliny,  Leonardo 


THE  EMERGENCE  OF  MODERN  SCIENCE         79 

that  Leonardo's  reputation  in  this  field  rests  not  alone  upon 
his  creation  of  a  few  great  paintings  but  upon  the  fact  that 
he  possessed  so  wide  a  perception  of  the  possibilities  of  this 
form  of  artistic  expression.  He  has  been  characterized  as 
"not  so  much  a  painter  as  a  great  inventor  in  painting." 
Corot,  for  example,  proclaimed  him,  "The  creator  of  modern 
landscape/'  although  the  landscape  feature  in  Leonardo's 
paintings  is  seemingly  an  insignificant  part.  His  attitude  as 
an  artist  was  rather  that  of  the  man  of  science  than  that  of 
the  traditional  man  of  art.  For  him,  reality  and  perfection 
were  the  same.  This  explains  the  seemingly  incongruous 
union  of  the  artist  and  the  scientist.  The  list  of  the  mechan- 
ical devices  to  which  he  devoted  intensive  study,  is  amazing 
in  its  extent  and  diversity.  Some  of  the  more  interesting 
cases  are  the  following:  He  was  the  real  pioneer  worker  hi 
aviation,  as  a  science  in  which  air  currents,  specific  gravity, 
the  flight  of  birds,  and  the  like  were  studied,  along  with  the 
production  of  a  heavier-than-air  flying-machine  (Fig.  7). 
He  seems  to  have  made  as  much  speculative  and  observa- 
tional progress  with  the  problem  as  was  possible  before  the 
creation  of  modern  machinery  and  the  invention  of  internal 
combustion  engines.  He  devised  a  variety  of  machine  guns 
and  other  similar  mechanisms,  a  machine  for  excavating 

concludes  "that  the  salt  ness  of  the  sea  is  due  to  the  numerous  springs  of 
water,  which,  in  penetrating  the  earth,  find  the  salt  mines,  and  dissolving  parts 
of  these  carry  them  away  with  them  to  the  ocean  and  to  the  other  seas,  from 
whence  they  are  never  lifted  by  the  clouds  which  produce  the  rivers.  So  the 
sea  would  be  more  salt  in  our  times  than  it  has  ever  been  at  any  time  pre- 
viously;  and  if  it  were  argued  by  the  adversary  that  in  an  infinite  course  of 
tune  the  sea  would  either  become  dried  up  or  congealed  into  salt,  to  this  I 
hat  the  salt  is  restored  to  the  earth  by  the  setting  free  of  the  earth  which 
is  raised  up  together  with  the  salt  it  has  acquired,  and  the  rivers  restore  it  to 
the  earth  over  which  they  flow."  His  arguments  against  the  explanation  of 
marine  shells  of  fossil  deposits  as  having  been  left  by  the  Noachian  deluge  dis- 
play a  knowledge  of  geological  fact  and  method  which  did  not  become  common 
information  until  after  the  work  of  James  Hutton  toward  the  close  of  the 
eighteenth  century  Numerous  quotations  from  his  scientific  writings  are 
easily  accessible  in  th<-  volum*-  < -untied:  "Leonardo  da  Vinci's  Note  Booko," 
by  Edward  McCurdy  9ec  I  '  \\-  tlum,  toe.  tit. 


80       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

canals,  a  large  number  of  hydraulic  devices,  a  smelting 
furnace,  and  so  on  through  a  list  of  unbelievable  length.    He 


FIG.  7.  Sketches  Relating  to  Flying  Machines.     From  the  note  books  of 
Leonardo  da  Vinci.     (Courtesy  of  Scientific  American.) 

forecast  the  coming  of  steam  engines  and  steam  navigation. 
He  drew  plans  of  model  towns  and  cities  and  was  thus  the 
originator  of  the  modern  concept  of  the  city  beautiful.  His 


THE  EMERGENCE  OF  MODERN  SCIENCE 


81 


manuscript  notes  describe  a  modern  system  of  factory  ef- 
ficiency.   More  than  any  other  individual  who  has  lived, 
Leonardo  seems  the  superman  of  human  intelligence. 
Leonardo  was  not  entirely  alone,  although  he  is  clearly 


Fio.  8.  Leonardo's  use  of  Cross-Sections  to  illustrate 
Anatomy.  From  the  note  books  of  Leonardo  da 
Vinci.  (Reproduced  from  a  Figure  in  Singer  after 
Hopstock.) 

the  greatest  among  the  men  of  genius  developed  by  the 
Italian  Renaissance.  Giovani  Pico  della  Mirandolla  (1463- 
1494)  possessed  the  most  catholic  view  of  learning  and  schol- 
p  of  any  man  of  his  time.  His  most  important  service 
to  science  was  his  refutation  of  astrology,  which  accomplished 


82        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

the  final  overthrow  of  this  false  view  of  astronomy.  Leone 
Battista  Alberti  (1404-1472),  an  earlier  contemporary,  had 
for  his  motto  "Men  can  do  all  things  if  they  will."  His 
interest  in  science  together  with  his  proficiency  in  physics 
and  mathematics  greatly  aided  the  forward  movement  of 
enlightenment  which  so  aroused  his  enthusiasm.  Modern  ex- 
perimental science  begins  with  Galileo  in  the  sixteenth 
century.  But  the  services  of  the  humanists,  and  of  the 
workers  and  thinkers  from  Peter  of  Apono  to  Leonardo  da 
Vinci,  were  an  essential  part  in  the  development  from  the 
supernaturalism,  still  dominant  in  the  thirteenth  century, 
to  the  established  rationalism  of  sixteenth  and  seventeenth 
century  science. 

The  scientific  methods  of  observation  and  comparison 
were  first  applied  by  the  Renaissance  in  the  field  of  literary 
and  historical  criticism.  They  appear  in  Petrarch  and  others 
of  the  humanists  who  applied  the  principles  of  textual  criti- 
cism to  historical  documents.7  This  spirit  of  literary  criticism 
was  not  without  importance  for  the  Reformation,  although 
the  later  Protestant  orthodoxy  was  not  well  disposed  toward 
the  extension  of  critical  study.  The  publication  of  the  work 
of  Copernicus  in  1543  was  the  climax  in  this  development  of 
observational  and  descriptive  science.  The  older  geo-centric 
theory  of  Ptolemy,  promulgated  in  Alexandria  during  the 
second  century  of  the  Christian  Era,  had  become  an  in- 
tegral part  of  Christian  theology.  The  Copernican  system 
proposed  what  was  literally  a  new  universe.  The  story  of 
the  controversy  which  was  thus  precipitated  is  familiar  to 
all.  We  have  alluded  to  its  significance  in  a  previous  section. 

The  Renaissance  did  more  than  extend  the  scientific 
methods  of  observation  and  comparison.  Its  claim  to  be  the 
period  in  which  modern  science  became  established  is  based 

7  The  case  of  Laurentius  Valla  may  be  cited  in  illustration.  "At  the  request 
of  King  Alfonso  of  Naples  he  subjected  the  so-called  Donation  of  Constantino 
to  the  tests  of  the  new  criticism  and  showed  its  historical  impossibility  to  the 
conviction  of  the  world,  thus  depriving  the  papacy  of  one  source  of  argument 
in  support  of  its  pretensions."  Adams,  G.  B.,  loc.  til. 


THE  EMERGENCE  OF  MODERN  SCIENCE         83 

primarily  upon  the  development  of  experimental  and 
analytical  methods.  While  the  spirit  and  appreciation  of 
science  appear  in  da  Vinci,  the  modern  intensive  attack 
appears  first  in  the  investigations  of  Galileo  (1564-1642). 
Building  upon  the  work  of  Copernicus,  Galileo  continued  the 
advance  in  astronomy  despite  theological  opposition.  By 
the  year  1700,  Descartes  (1596-1650)  and  Pascal  (1623- 
1662),  by  establishing  the  theory  of  probability  had  elimi- 
nated evil  spirits  from  many  hitherto  inexplicable  phenom- 
ena on  the  earth,  while  Kepler  (1571-1630)  and  Newton 
(1642-1727)  had  enthroned  natural  law  in  the  heavens. 

Geographical  and  astronomical  science  were  established  by 
the  voyages  of  discovery,  and  by  the  scientific  work  of 
Copernicus  and  Galileo.  Chemistry,  which  had  existed  as 
alchemy  since  the  early  Christian  Era  and  which  had  been 
defined  during  the  eleventh  century  as  "the  preparation  of 
silver  and  gold,"  received  an  impetus  through  the  chemical 
medicine  of  Paracelsus  (1493-1541);  while  the  foundation 
of  modern  chemistry  was  laid  by  Boyle  (1627-1691)  who 
defined  chemistry  as  "the  composition  of  substances,"  and 
emphasized  the  methods  of  experimentation  and  inductive 
reasoning.  Boyle  defined  the  elements  as  substances  in- 
capable of  decomposition,  and  the  compounds  as  substances 
composed  of  elements,  but  the  development  of  this  general- 
ization was  subsequently  held  in  abeyance  by  the  promulga- 
tion of  the  erroneous  Phlogiston-Theory? 

Within  the  field  of  physical  and  mathematical  sciences, 
Galileo  had  established  the  science  of  dynamics  by  his  ex- 
periments with  falling  bodies.  His  laws  of  motion  had  made 
possible  the  explanation  of  the  continuous  movement  of  the 
planets,  but  their  orbital  movement  remained  unexplained. 
Newton  applied  to  the  heavens  the  simple,  though  even  now 
inexplicable,  phenomenon  of  gravitation;  and  calculated  the 
sweep  of  the  planets  in  the  same  terms  as  the  fall  of  a  stone. 
His  emotional  excitement  during  the  conclusion  of  his  cal- 

•  See:  note,  p.  97  of  the  present  volume. 


84        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

culations  is  said  to  have  been  "so  great  that  he  could  hardly 
see  his  figures";  and  certain  it  is  that  of  all  the  generaliza- 
tions of  science  none  is  more  marvelous  than  the  theoretical 
extension  of  the  simple  phenomena  of  motion  and  gravita- 
tion, observed  on  the  surface  of  the  earth,  to  the  farthest  star. 

Mathematical  science  was  keeping  pace.  Indeed  the  work 
above  indicated  would  have  been  impossible  at  an  earlier 
period,  when  methods  of  calculation  were  little  developed. 
Space  will  not  permit  a  further  elaboration  of  the  progress 
of  science  along  these  mathematical-physical  lines  during 
the  period  under  discussion.  We  may  emphasize,  in  con- 
clusion, the  growing  significance  of  the  philosophical  aspects 
of  mathematics  and  physics,  hi  addition  to  their  value  as 
practical  tools  of  science. 

In  the  biological  sciences,  the  Middle  Ages  had,  as  we  have 
seen,  produced  little  beyond  a  garbled  and  childish  account 
of  some  of  the  ancient  knowledge  of  Aristotle  and  Galen. 
Gradually  the  study  of  human  anatomy  by  dissection  be- 
came possible.  In  1315,  da  Luzzi  had  published  a  manual 
of  anatomy,  based  not  upon  Galen  but  upon  actual  dissec- 
tion. Vesalius  (1514-1564)  now  laid  bare  the  secrets  of  the 
human  frame  and  overthrew  many  traditional  errors. 
Harvey  (1578-1657)  not  only  discovered  the  circulation  of 
the  blood  but  also  established  the  experimental  method 
which  has  since  dominated  the  science  of  physiology.  Bot- 
any was  widely  cultivated  through  the  search  for  herbs  of 
medicinal  value.  The  first  Botanical  Gardens  came  into 
existence  for  the  cultivation  of  rare  and  interesting  plants. 
Stimulated  by  medical  science  and  by  the  general  awakening, 
the  biological  sciences  were  proceeding  along  two  great  lines: 
knowledge  of  the  number  and  kinds  of  animals  and  plants- 
Natural  History;  and  knowledge  of  minute  structures  and 
organisms — Microscopy.  The  microscope  did  not  come  into 
use  as  an  instrument  of  biological  investigation  until  the 
latter  half  of  the  seventeenth  century,  but  the  more  general 
facts  of  microscopic  structure,  aside  from  the  cell-theory,  had 


THE  EMERGENCE  OF  MODERN  SCIENCE         85 

been  ascertained  before  the  year  1700.  The  bacteria,  the 
protozoa,  and  a  host  of  minute  organisms  were  discovered  by 
Swammerdam  (1637-1680),  Leeuwenhoek  (1632-1723),  and 
their  contemporaries.  Redi,  in  1668,  disproved  spontaneous 
generation  in  macroscopic  forms;  but  the  mode  of  generation 
in  the  microorganisms  was  not  entirely  established  until  the 
nineteenth  century.  Malpighi  (1628-1694)  made  known  the 
facts  of  microscopic  anatomy.9 

A  work  which  illustrates  the  transition  from  medieval  to 
modern  concepts  in  natural  history  is  the  "Puch  der  Na- 
ture" by  Conrad  von  Megenberg.  Although  first  printed  in 
1475,  this  volume  dates  from  an  earlier  period,  for  it  was  a 
German  translation,  with  some  changes,  from  the  Latin 
"De  Naturis  Rerum"  completed  by  Thomas  of  Cantimpre* 
about  1248.  It  is,  therefore,  truly  medieval  but  a  great  ad- 
vance upon  the  Physiologus.  The  figures  are  crude,  yet 
they  give  some  internal  evidence  of  having  been  drawn  from 
nature  and  being  specially  prepared  for  the  volume  in  ques- 
tion (Fig.  9).  The  popular  interest  in  such  works  is  attested 
by  the  fact  that  the  volume  passed  through  numerous 
editions  and  was  followed  by  others  which  were  the  first 
crude  beginnings  of  modern  studies  in  natural  history. 
Interest  in  first-hand  knowledge  of  animals  is  thus  evidenced 
during  the  later  Middle  Ages.10 

The  collection  of  animals  and  plants  in  zoological  and 
botanical  gardens  further  illustrates  the  advancing  knowl- 
edge and  interest  in  natural  history.  This  custom  originated 
in  Italy  with  the  increase  of  wealth  and  economic  stability. 
Botanical  gardens  were  attached  to  large  estates  and  to 
public  establishments.  Collections  of  animals  from  foreign 
countries  became  popular  among  the  wealthy.  These  not 

•  Further  elaboration  of  these  advances  in  the  study  of  microscopic  struc- 
tures and  microorganisms  is  omitted  here,  since  the  subject  has  been  used  as 
an  illustration  in  a  subsequent  chapter.  See:  pp.  246-250  of  the  present  vol- 


"Locy,  W.  A.,  "The  Earliest  Printed  Illustrations  of  Natural  History," 
Scientific  Monthly,  Sept.,  1921. 


86        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

only  served  the  same  purpose  as  the  modern  menageries  and 
zoological  gardens,  by  gratifying  curiosity,  but  served  also 
the  higher  purpose  of  observation  and  experiment.  The  im- 


Fia.  9.  Four  Figures  of  Quadrupeds.  Traced  from  a  plate  of  twelve  fig- 
ures in  "Das  Puch  der  Nature"  by  von  Megenberg.  Although 
printed  in  1475  and  showing  figures  some  of  which  bear  internal  evi- 
dence of  having  been  drawn  from  nature,  this  work  was  based  mainly 
upon  the  earlier  manuscript  and  figures  of  the  truly  medieval  volume 
"De  Naturis  Rerum"  by  Thomas  Cantimpre"  about  1248.  Contrast 
with  the  more  accurate  and  artistic  figure  from  Gesner  (Fig.  10). 
(Reproduced  from  Locy,  Scientific  Monthly,  Sept.,  1921.) 

portation  of  strange  animals  from  distant  regions  was  not 
difficult  because  of  the  geographical  situation  of  the  Italian 
peninsular  and  because  the  mild  climate  rendered  possible 
the  keeping  of  animals  from  warmer  latitudes.  Lions  were 


THE  EMERGENCE  OF  MODERN  SCIENCE         87 

especially  numerous,  because  of  their  symbolic  interest  and 
because  of  the  excellent  way  in  which  they  stood  captivity. 
They  were  used  at  times  as  executioners  and  their  presence 
near  the  palace  of  an  Italian  tyrant  had  doubtless  a  measure 
of  political  and  social  effectiveness.  A  present  of  lion  cubs  is 
frequently  mentioned  in  diplomatic  documents.  The  city  of 
Florence  also  kept  leopards  and  other  wild  beasts,  employing 
a  special  keeper. 

By  the  close  of  the  fifteenth  century  large  menageries  were 
hi  existence.  Matarazzo,  the  chronicler  of  Perugia,  tells  us 
that:  "It  belongs  to  the  position  of  the  great  to  keep  horses, 
dogs,  falcons,  and  other  birds,  court  jesters,  singers  and 
foreign  animals."  The  point  for  our  purpose  is  that  the 
presence  of  elephants,  giraffes,  zebras  and  other  strange 
animals  helped  to  open  men's  minds  to  the  wonders  of 
animate  nature  and  to  acquaint  them  with  the  various  sorts 
of  animal  life.  True  it  is  that  no  attempt  was  made  to  im- 
prove on  the  Aristotelian  system  of  zoological  classification, 
but  at  the  same  time  a  more  rational  and  scientific  attitude 
toward  animal  life  developed.  People  no  longer  believed  in 
the  ridiculous  myths  and  fables  of  the  medieval  bestiaries  or 
natural  history  treatises.  There  are,  moreover,  interesting 
evidences  of  successful  efforts  towards  scientific  breeding 
and  improvement  of  stock  in  connection  with  the  stud  of 
Francesco  Gonzaga,  duke  of  Mantua,  and  along  this  special 
line  considerable  advances  were  undoubtedly  made.11 

The  Swiss,  Conrad  von  Gesner  (1516-1565),  must  have 
been  aided  in  his  studies  on  natural  history  by  the  existence 
of  these  zoological  gardens.  His  great  work,  "Historia  Ani- 
malium, "  is  indicative  of  the  decline  of  the  medieval  absurd- 
ities, and  proved  of  great  educational  value  hi  the  populariz- 
ing of  scientific  facts  concerning  the  larger  animals  (Fig.  10). 
But  there  was  no  immediate  advance  toward  a  more  scien- 
tific classification,  even  with  the  work  of  Gesner.  In  contrast 

11  Burckhardt,  J.,  loc.  tit.     The  further  account  of  an  anthropological 
given  by  this  author  is  of  interest  in  this  connection. 


88       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

to  the  dramatic  discoveries  attendant  upon  the  advent  of  the 
microscope,  the  study  of  natural  history  was  distinguished, 
during  the  seventeenth  century,  by  the  slow  and  laborious 
collection  of  facts  regarding  the  number  and  kinds  of  animals 


FIG.  10.  Representative  Illustration  from  Gesner. 
Photographic  reproduction  of  one  of  the  orig- 
inal woodcuts.  (Reproduced  from  Brooks, 
Popular  Science  Monthly,  May,  1895.) 

and  plants.  Upon  this  foundation,  John  Ray  (1628-1705) 
established  the  first  exact  concept  of  a  species;  and  Lin- 
naeus, in  the  succeeding  century,  set  forth  the  first  universal 
classification. 

The  numerous  societies  and  academies,  which  arose  first 
in  Italy  and  Southern  France,  are  indicative  of  the  intellec- 
tual activity  of  the  period.  The  older  universities  were 
founded  during  the  twelfth  and  early  thirteenth  centuries 
and  hence  were  a  product  of  scholasticism.  To  the  early 


THE  EMERGENCE  OF  MODERN  SCIENCE         89 

reformers  of  the  Renaissance,  the  universities  appeared  as 
strongholds  of  the  old  order.  They  were,  according  to 
Petrarch,  " nests  of  gloomy  ignorance."  Even  later,  the 
humanists  were  grudgingly  received  within  the  schools;  and 
not  infrequently,  when  the  humanistic  learning  had  been 
assimilated,  it  was  rendered  sterile  by  the  erection  of  the 
ancient  masters  to  a  place  of  authority,  not  in  harmony  with 
the  spirit  that  had  developed  with  the  advance  of  critical 
scholarship.  Under  these  circumstances,  the  more  independ- 
ent spirits  sought  their  inspiration  in  organizations  outside 
the  established  intellectual  institutions,  where  freedom  of 
thought  was  unhampered.12  These  early  scientific  societies 
were  reproductions  of  similar  organizations  which  had 
formerly  existed  among  the  Moors,  in  Grenada  and  Cordova. 
Some  of  them,  like  the  Academy  of  Toulouse,  founded  in 
1345,  have  survived  to  the  present  day.  As  the  Renaissance 
spreads  northward,  the  same  tendency  is  apparent.  The 
Royal  Society  of  London  was  incorporated  in  1662  and  has 
survived  through  a  long  and  illustrious  career.  In  the 
beginning,  it  was  accused  of  "  destroying  the  established 
religion,  of  injuring  the  universities,  and  of  upsetting  ancient 
and  solid  learning. "  13  Eventually,  there  was  not  a  capital 
in  Europe  without  these  organizations  which  were  thus  inde- 
pendent of  the  formal  educational  system.  Thus  ended  the 
isolation  of  the  workers  in  science.  Moreover,  the  academies 
gave  the  scientists  a  degree  of  solidarity,  and  encouraged  all 
who  opposed  the  traditional  doctrines. 

""The  Accademia  del  Cimento,  established  at  Florence,  1657,  held  its 

£s  in  the  ducal  palace.    It  lasted  ten  years,  and  was  then  suppressed 

nee  of  the  papal  government;  as  an  equivalent,  the  brother  of  the 

grand-duke  was  made  a  cardinal.     It  numbered  many  great  men,  such  as 

Torricelli  and  Castelli,  among  its  members.    The  condition  of  admission  into 

it  was  an  abjuration  of  all  faith,  and  a  resolution  to  inquire  into  the  truth." 

Draper,  J.  V.  r\  .  .f  1 !,«•  Conflict  between  Religion  and  Science."  p.  300. 

11  Draper,  loc.  cit.,  pp.  307-310. 


90        HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 


POSITION  OF  SCIENCE  AS  ESTABLISHED   BY  THE  RENAISSANCE 

In  the  foregoing  sections,  the  scientific  awakening  of 
Europe  has  been  traced  from  its  beginnings  in  the  later 
Middle  Ages  to  its  culmination  during  the  sixteenth  and 
seventeenth  centuries.  In  such  a  complex  of  men  and  events 
it  is  difficult  to  keep  hi  mind  the  larger  changes.  We  shall, 
therefore,  enumerate  the  broader  features  of  this  momentous 
step  in  human  development  by  a  brief  characterization  of 
particular  periods.  In  this,  one  must  remember  that  dates 
are  arbitrary,  that  round  numbers  have  no  meaning  as  such, 
and  that  such  an  outline  necessarily  disregards  the  over- 
lapping which  is  so  important  a  factor  in  the  growth  of  ideas. 
With  these  reservations,  the  intellectual  development  con- 
sidered in  the  preceding  pages  may  be  summarized  as  follows: 

750-800      Revival  of  the  schools  under  Charlemagne. 

Evidence  of  an  abundance  of  intellectual  ability. 
800-1150    Failure  of  the  schools,  because  of  unstable  political 

conditions. 

Glimmerings  of  intellectual  progress  in  isolated  in- 
dividuals. 

Influence  of  the  Arab  science  during  this  period. 
1 150-1200    Intense  intellectual  eagerness  culminating  in  scholasti- 
cism. 

1200-1300    The  century  of  scholasticism — a  great  intellectual 
period,  although  its  point  of  view  was  not  in  line 
with  subsequent  developments. 
The  dawn  of  European  science  is  seen  in  the  cumu- 
lative influence  of  the  Arab  science,  and  in  the 
scientific  insight  and  vision  of  Roger  Bacon. 
1300-1350    Disappearance  in  the  progressive  centers  of  Europe 
of  the  frame  of  mind  most  distinctive  of    the 
Middle  Ages. 

Growing  skepticism  regarding  traditional  authority. 
1350-1450    Period  of  destructive  criticism  and  growing  rational- 
ism which  prepared  the  way  for  the  constructive 
scientific  work  of  the  later  Renaissance. 


THE  EMERGENCE  OF  MODERN  SCIENCE         91 

1450-1500    Beginnings,  in  Italy,  of  the  constructive  period  of  the 

scientific  Renaissance. 
1500-1600    Rapid  accumulation  of  facts  and  development  of 

rationalistic  explanations  of  natural  phenomena. 
1600-1700    Dawning  concept  of  the  rational  explanation  of  all 

natural  phenomena. 

Not  only  were  the  broader  facts  of  modern  science  made 
apparent  by  the  workers  of  the  Renaissance,  but  also  the 
significance  of  science  began  to  be  appreciated  in  its  relation 
to  civilized  life.  What  Roger  Bacon  had  foreseen  with 
prophetic  vision,  and  what  was  beyond  the  comprehension 
of  his  contemporaries,  his  more  superficial  namesake, 
Francis  Bacon  (1561-1626),  helped  to  establish  in  the 
popular  imagination.  While  the  latter  was  given  too  high  a 
position,  when  he  was  called  the  father  of  the  inductive  sciences, 
he  undoubtedly  deserves  the  credit  of  giving  publicity  to  the 
failure  of  the  deductive  scholastic  reasoning  and  of  having 
formulated,  in  such  a  manner  as  to  secure  its  general  accept- 
ance, the  claim  that  the  scientific  method  possesses  unbe- 
lievable possibilities.  During  the  seventeenth  century  men 
began  to  be  persuaded  that  there  must  be  natural  solutions 
to  problems,  although  they  were  unable  to  discover  them. 
And  the  fact  that  this  attitude  of  mind  has  become  almost 
an  obsession  in  modern  times  illustrates  better  than  almost 
anything  else  how  far  we  have  departed  from  the  super- 
naturalism  of  the  Middle  Ages. 

The  Renaissance,  taken  as  a  whole,  marks  the  intellectual 
awakening  of  the  western  world.  If  we  have  seemed  to  in- 
clude too  much  under  the  head  of  Science  in  the  Renais- 
sance, it  Ls  not  because  we  would  claim  all  for  science  but 
because  the  manifestations  of  science  are  everywhere  present. 
The  Renaissance  in  its  broadest  meaning  marks  the  begin- 
nin^  of  modern  culture.  It  was  not  alone  the  revival  of  the 
old  it  was  also  a  creation  of  the  new,  first  by  the  Italian 
people  and  later  by  the  other  western  nations.  The  Protes- 
t.'int  Reformation  and  the  English  and  French  Revolutions 


92       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

were  the  natural  extensions  of  the  scientific  and  rationalistic 
developments  which  had  then-  beginnings  in  Italy  during  the 
fourteenth  and  fifteenth  centuries.  These  religious  and 
political  revolutions  were  a  contribution  by  the  northern 
peoples  to  the  larger  movement.  We  must  have  in  mind  the 
whole  social  complex,  material  as  well  as  intellectual,  if  we 
are  to  reach  a  proper  evaluation  of  the  Renaissance  in  rela- 
tion to  science  and  human  affairs. 

The  two  outstanding  features  of  the  period  were  the  dis- 
covery of  the  human  mind  and  the  discovery  of  the  world 
of  nature.  Knowledge  of  antiquity  was  important,  because 
it  helped  the  humanist  to  discover  himself  and  to  feel  his 
kinship  with  the  minds  of  other  days;  knowledge  of  nature, 
because  it  brought  into  being  the  modern  scientific  spirit. 
Once  set  in  motion,  these  factors  and  many  others  became 
inextricably  interwoven.  In  art,  the  human  body  was  re- 
discovered as  a  thing  of  beauty,  while  nature  lost  its  "taint 
of  sin"  and  became  again  beautiful  to  the  eyes  of  man. 
Having  passed  that  painful  period  in  which  doubt  is  not  yet 
regarded  as  innocent  and  having  undergone  the  sufferings  of 
suspended  judgment,  the  human  mind  was  liberated  as  from 
a  dungeon  during  this  wonderful  intellectual  outpouring 
that  was,  as  Symonds  puts  it,  "the  first  transcendent 
spring-tide  of  the  modern  world."  A  sense  of  human 
dignity  appeared,  different  from  anything  in  evidence  during 
the  Middle  Ages  and  on  an  even  higher  level  than  the  sense 
of  human  worth  of  ancient  times.  Excessive  individualism 
and  worldliness  were  vices  of  the  period,  but  were  not 
necessary  adjuncts  of  the  new  and  scientific  humanism. 
The  distinctive  feature  was  not  the  recovery  of  the  older  arts 
and  inventions  nor  the  discovery  of  the  new,  but  "the 
attainment  of  self-conscious  freedom  by  the  European 
peoples."  In  science,  we  may  catalogue  the  specific  dis- 
coveries of  these  centuries  of  the  awakening,  but  the  more 
important  factor  was  the  establishment  of  the  modern 
scientific  spirit.  Freedom  and  self -consciousness  found  ex- 


THE  EMERGENCE  OF  MODERN  SCIENCE         93 

pression  in  science;  and  the  spirit  thus  generated  continues, 
dominant  throughout  the  western  world.  Not  alone  hi 
science  but  hi  the  whole  sweep  of  our  activities,  we  of  the 
present  are  carrying  forward  that  which  the  men  of  the 
Italian  Renaissance  began. 


CHAPTER  V 
THE  FURTHER  GROWTH  OF  SCIENCE 

THE  year  1700  is  chosen  as  the  beginning  of  the  modern 
scientific  period,  because  the  theoretical  and  practical 
applications  of  science  began  to  be  widely  comprehended 
during  the  eighteenth  century.  Many  important  facts  in 
astronomy,  in  geography,  and  even  in  biological  science  were, 
indeed,  ascertained  before  this  time.  The  scientific  method 
was  recognized  by  certain  individuals.  But  the  great  ex- 
tensions of  detailed  knowledge  and  appreciation  of  the 
meaning  of  many  scientific  facts  had  not  taken  place.  By 
the  middle  of  the  eighteenth  century  scientific  thinking  had 
become  emancipated  from  superstition  and  started  on  its 
own  path  of  unprejudiced  observation  and  experimentation. 
During  the  latter  half  of  the  century  there  was  rapid 
advancement  in  many  lines.  In  the  biological  sciences, 
foundations  were  being  laid  for  the  later  Cell-Theory,  and 
the  first  definite  statement  of  Organic  Evolution  was  being 
promulgated;  while  comprehension  of  physiological  proc- 
esses was  opening  the  way  to  a  science  of  medicine.  In 
astronomy  and  the  physical  sciences,  the  concept  of  a 
dynamic  as  opposed  to  a  static  universe  came  to  be  recog- 
nized as  a  scientific  fact,  and  the  theories  of  Conservation  of 
Energy  and  of  Chemical  Combination  began  to  assume 
definitive  form.  In  the  field  now  designated  as  that  of 
political  and  social  science,  the  secularization  of  many 
activities,  the  progress  of  individualism,  of  rationalism,  and 
of  toleration  indicate  a  growing  scientific  temper.  The 
attempts  to  apply  scientific  fact  and  method  in  the  solution 
of  larger  social  problems  indicate  the  hold  which  science  had 
obtained  upon  mankind  by  the  close  of  this  first  century  of 

94 


THE  FURTHER  GROWTH  OF  SCIENCE  95 

modern  scientific  times.  In  the  material  applications  of 
science,  the  later  decades  of  the  century  witnessed  the 
beginnings  of  the  Industrial  Revolution.  The  rise  of  modern 
industry  and  the  rise  of  modern  democracy  were  almost 
simultaneous.  The  scientific  frame  of  mind  developed 
during  the  Renaissance  was  mainly  responsible  for  these 
momentous  changes  as  well  as  for  the  technical  progress 
of  eighteenth  century  science. 

FOUNDATIONS   OF   THE   MODERN   SCIENCES 

The  history  of  natural  science  during  the  seventeenth  and 
the  early  eighteenth  centuries  is  characterized  by  the  rapid 
accumulation  of  minor  facts.  Just  as  the  manifold  details 
were  added  to  the  outline  of  geographical  knowledge  fur- 
nished by  the  earlier  centuries  of  discovery,  so  astronomical 
and  other  branches  of  science  became  increasingly  compre- 
hensive. Biological  knowledge,  for  instance,  received  an 
impetus  during  the  latter  half  of  the  seventeenth  century  by 
the  serious  use  of  the  microscope  in  scientific  investigation. 
The  discovery  of  microorganisms  immediately  followed,  and 
the  minute  anatomy  of  larger  forms  was  made  known.  In 
studies  with  the  microscope,  as  well  as  in  natural  history, 
examination  of  new  kinds  of  animals  and  plants  presented 
seemingly  endless  fields  for  discovery.  Hence  the  broader 
biological  problems  were  commonly  disregarded.  Neverthe- 
less, the  generalizations  of  present-day  biology  were  rooted 
in  the  detailed  knowledge  thus  acquired.  A  similar  situation 
exi-ted  in  other  scientific  fields.  The  knowledge  of  scientific 
fact  and  method,  then  acquired  by  the  popular  mind,  marks 
the  beginning  of  a  persistent  inclination  toward  scientific  ex- 
planations, which  had  far-reaching  consequences  even  during 
the  eighteenth  century.1 

1  The  dilletantism  of  many  individuals,  who  posed  as  savants  at  this  time, 
tends  to  obscure  the  situation  which  actually  existed.    The  underlying  stim- 
ulus to  such  pretensions  among  tin-  upper  classes  was  the  position  of  u 
edented  esteem  in  which  scientific  men  were  held. 


96       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

In  geographical  science,  to  cite  further  examples,  the 
nature  and  extent  of  the  earth  had  become  known  among  the 
educated  and  traveled  classes.  This  popular  knowledge  of 
geography  did  not,  of  course,  lead  to  scientific  generaliza- 
tions, but  proved  influential  along  social  and  political  lines. 
The  peoples  of  western  Europe  became  conscious  of  their 
position  in  the  world  and  of  the  coexistence  of  other  peoples 
in  all  the  stages  from  barbarism  to  civilization.  Foundations 
were  being  laid  for  a  science  of  human  society. 

In  astronomical  science,  the  nature  of  the  solar  system 
had  been  ascertained  by  Copernicus  and  Galileo  and  the 
laws  of  motion  and  gravitation  had  been  extended  to  the 
heavens  by  Newton.  It  remained  to  set  forth  the  way  in 
which  the  heavenly  bodies  had  reached  their  present  form. 
Cosmic  Evolution,  with  its  implication  of  a  dynamic  uni- 
verse, found  definite  expression  in  the  Nebular  Hypothesis 
of  Laplace  (1796).2  By  this  hypothesis,  the  laws  of  mass  and 
motion,  as  applied  by  Newton  to  the  present  solar  system, 
were  extended  to  the  past.  The  existing  system  was  con- 
ceived as  having  reached  its  present  state  through  the 
action  of  natural  forces.  The  nebular  hypothesis  is  not  the 
only  theory,  of  the  origin  of  solar  systems,  maintained  by 
astronomers  at  the  present  day.  But  the  idea  of  our  own  and 
other  solar  systems  as  having  undergone  evolutionary 
modification,  is  to-day  the  accepted  historical  generalization 
of  astronomy.  Laplace  and  his  associates  among  the 
French  Encyclopaedists  believed  they  were  on  the  threshold 
of  an  explanation  of  the  universe  in  terms  of  matter  and 
motion.  If  their  generalizations  were  premature,  they  were 
nevertheless  in  agreement  with  the  explanations  since 
established  by  science.  The  concept  of  cosmic  evolution, 
which  the  nebular  hypothesis  implies,  is  now  accepted  as  a 
matter  of  course. 

2  The  prevailing  statement  that  the  Nebular  Hypothesis  originated  with 
Kant  seems  to  be  incorrect.  Lovejoy,  A.  O.,  "Kant  and  Evolution,"  Popular 
Scientific  Monthly,  Dec.,  1910. 


THE  FURTHER  GROWTH  OF  SCIENCE  97 

Again,  the  later  years  of  the  eighteenth  century  were  im- 
portant in  the  history  of  chemistry  and  physics.  Such 
generalizations  as  the  Atomic  Theory,  and  the  theories  of 
Chemical  Combination,  Conservation  of  Energy,  and  Inde- 
structibility of  Matter  were  at  least  tentatively  established. 
When  the  nature  of  elements,  compounds,  and  solutions 
became  sufficiently  clear,  chemistry  could  progress.  When 
the  distinction  between  matter  and  energy  was  recognized, 
the  great  advance  made  by  physical  science  during  the 
nineteenth  century  became  possible.3 

The  development  of  the  atomic  theory  is  an  example  of 
how  the  theories  of  science  may  have  their  beginnings  and 
may  reach  their  existing  limits  in  philosophical  speculation. 
The  doctrine  that  matter  consists  of  invisible  and  indivisible 
particles  between  which  is  a  void  appears  in  Hindu  philos- 
ophy at  a  remote  period.  Among  the  Greco-Roman  philos- 
ophers, Democritus  and  Lucretius  were  its  ardent  exponents. 
During  the  Middle  Ages  theological  beliefs  sufficed.  In  the 
seventeenth  century  Boyle  and  also  Newton  recognized  its 
advantages.  The  former  had  even  grasped  the  idea  of 
permanent  elements  and  changeable  compounds,  and  had 
defined  chemistry  as  "the  composition  of  substances." 
But  the  Phlogiston-Theory  intervened.4 

1  These  generalizations  have  persisted  as  the  foundations  of  modern  physico- 
chemical  theory,  although  the  structure  and  possible  divisibility  of  the  atom 
is  a  subject  of  present-day  investigation.  The  facts  discovered  in  connection 
with  radium  h:ive  made  the  chemist  skeptical  regarding  the  permanency  of 
unchanging  elements.  The  theory  of  the  conservation  of  energy  is,  of  course, 
baaed  upon  experimentation  within  limited  fields.  Nevertheless,  these  funda- 
mental hypotheses,  which  made  their  appearance  toward  the  close  of  the 
eighteenth  century,  have  constituted  the  point  of  departure  for  subsequent 
o-chemical  investigation. 

4  Robert  Boyle  (1627-1691)  stated  the  principle  that  only  tangible  and 
ponderable  substances  should  be  recognized  as  elements,  a  chemical  element 
being  a  substance  from  which  other  substances  could  be  made.  Georg  Stahl 
(1660-1734)  developed  the  Phlogiston-Theory.  Phlogiston  was  "the  principle 
of  corn  and  was  considered  as  a  definite  I »«>«!>•  ami  hence  material. 

All  <  homical  action  was  explained  an  <lu«  to  the  presence  of  this  all-important 
substance.  This  concept  delayed  the  estal.li-hnirnt  of  tho  atomic  theory,  but 


98       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

The  advance  of  biological  science  during  the  century  under 
discussion  was  mainly  important  as  a  preparation.  The 
Cell-Theory  was  not  formulated  until  the  second  quarter  of 
the  nineteenth  century.  Organic  Evolution  was  not  gener- 
ally accepted  until  the  publication  of  Darwin's  "  Origin  of 
Species"  (1859).  The  development  of  biological  science 
during  the  closing  centuries  of  the  Renaissance  has  already 
been  summarized.  During  the  eighteenth  century,  the  facts 
regarding  the  number  and  kinds  of  animals  and  plants  were 
organized  by  Linnaeus  (1707-1778).  His  was  the  first  system 
of  classification  which  pretended  to  an  arrangement  of  all  the 
known  forms  of  life.  If  Linnaeus  did  not  originate  the 
binomial  nomenclature,5  by  which  each  kind  of  animal  is 
given  a  double  name,  he  may  be  said  to  have  established  its 
use.  His  general  scheme,  of  species,  genera,  and  families 
exists  at  the  present  day,  despite  the  progressive  changes  in 
the  larger  groupings  and  the  wholly  new  concept  of  classifi- 
cation which  was  necessitated  by  the  doctrine  of  evolution. 
Linnaeus  introduced  order  into  the  study  of  animal  life,  and 

it  was  a  good  theory  for  the  time  being  and  did  not  hamper  chemical  progress 
in  many  lines.  It  was  finally  overthrown  when  Lavoisier  (1743-1794)  showed, 
by  means  of  the  balance,  that  combustion  was  a  process  and  not  a  substance, 
since  it  possessed  no  weight.  The  way  was  then  open  for  the  establishment  of 
the  atomic  theory  through  the  work  of  Dalton  (1808).  At  the  present  time 
physicists  speak  of  the  structure  of  the  atom,  of  the  continuous  ether,  and  of 
all  matter  as  energy,  and  even  challenge  the  philosophers  with  interesting 
theories  of  ultimate  reality.  But  despite  modifications,  the  atomic  theory 
with  its  concept  of  relatively  indivisible  atoms,  which  combine  into  molecules, 
is  the  working  assumption  of  physico-chemical  science.  The  atoms  and  the 
void,  now  called  the  ether,  have  never  been  seen.  Belief  in  their  existence, 
despite  the  fact  that  it  explains  visible  phenomena,  is  a  theoretical  generaliza- 
tion which  is  useful  because  it  gives  a  summary  basis  for  the  explanation  of 
tangible  facts. 

6  Here,  as  elsewhere,  use  of  a  second  or  even  a  third  name  had  been 
made  as  a  matter  of  course.  It  now  became  universal  in  biological  science. 
Its  value  lies  in  the  fact  that  the  naming  can  be  more  definite  the  greater  the 
number  of  names  applied.  But  more  than  two  is  cumbersome.  Thus  we 
speak  of  the  Smiths,  and  to  be  specific,  of  John  Smith;  going  further,  of  John 
Henri/  Smith:  just  as  we  designate  the  cats,  Felis,  and  the  domestic  cat,  Felis 
domestica. 


THE  FURTHER  GROWTH  OF  SCIENCE  99 

though  he  is  not  known  to  have  favored  the  evolutionary 
theories  promulgated  during  his  lifetime,  he  made  an  im- 
portant contribution  in  this  direction  by  so  classifying 
plants  and  animals  that  men  could  visualize  the  resemblances 
and  differences  now  explained  in  terms  of  evolution. 

The  discussion  of  a  generalization  so  important  as  the 
theory  of  organic  evolution  must  be  deferred.  For  the 
purpose  here,  it  is  only  necessary  to  state  that  the  doctrine 
of  descent  with  modification  was  first  promulgated  in 
scientific  terms  by  Buff  on  (1707-1788)  and  his  contempo- 
raries. It  is  important,  in  considering  the  eighteenth  century 
as  a  period  during  which  the  larger  generalizations  of  modern 
science  were  being  formed,  that  the  theory  of  evolution  was 
then  proposed  upon  a  scientific  basis.  Many  significant 
facts  hi  anatomy,  embryology,  heredity,  and  variation,  had 
been  established.  Attention  was  directed  to  the  close 
anatomical  resemblance  between  man  and  the  apes.  More- 
over, evolution  or  the  Theory  of  Transmutation,  as  it  was 
then  called,  was  openly  and  widely  discussed  in  intellectual 
circles.6  This  early  attempt  to  formulate  organic  evolution 
in  terms  of  science  culminated  hi  the  Lamarckian  theories 
during  the  first  quarter  of  the  nineteenth  century.  The 
temporary  failure  of  the  evolutionary  hypothesis  was  due  to 
insufficient  knowledge  and  to  prejudice  in  favor  of  an  ex- 
planation of  organic  nature  in  terms  of  the  Biblical  account 
of  creation.  The  Transmutationists  of  the  later  eighteenth 
century  were  expressing  the  spirit  of  their  day  when  they 
attempted  to  organize  the  facts  of  biological  science  into  a 
fundamental  theory  of  the  origin  and  development  of  all 
living  things. 

The  phrase  origin  of  life  may  be  used  in  a  twofold  sense. 
It  may  refer  either  to  the  origin  of  the  species  (evolution)  or 
to  the  origin  of  the  individual.  The  latter  problem  appears 
in  the  eighteenth  century  controversies  over  the  theory  of 

•Lovcjoy,  A.  O.f  "Some  Eighteenth  Century  Evolutionists,"  Popular 
Science  Monthly,  July,  1904. 


100      HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

Spontaneous  Generation.  This  theory,  although  restricted 
to  the  origin  of  microscopic  organisms,  was  actively  cham- 
pioned. Redi  had  show  (1668)  that  insect  larvae,  which  had 
been  supposed  to  arise  spontaneously  in  decaying  flesh, 
actually  arose  from  the  eggs  of  parent  forms,  as  did  larger 
animals  like  the  birds  and  reptiles  whose  eggs  are  of  con- 
spicuous size.  It  was,  of  course,  recognized  that  the  higher 
plants  developed  from  seeds.  The  discovery  of  microorgan- 
isms (c.  1675)  reopened  a  question  which  might  otherwise 
have  been  regarded  as  settled.  Admitting  that  larger  ani- 
mals and  plants  arose  from  parents,  and  not  by  a  process 
of  spontaneous  generation,  it  might  still  be  maintained  that 
simpler  and  microscopic  types  originated  without  the  inter- 
vention of  living  matter.  The  early  investigators  beheld 
their  infusions  teeming  with  microscopic  organisms  that 
appeared  literally  over  night.  Some  naturally  believed 
there  could  be  no  other  explanation  of  this  sudden  appear- 
ance but  that  of  spontaneous  generation.  Although  the 
work  of  Spallanzani  (1775)  and  others  during  the  eighteenth 
century  produced  evidence  against  this  spontaneous  origin 
of  living  bodies,  it  was  impossible  to  secure  a  conclusive 
verdict  until  the  cell-theory  was  established  and  until  com- 
plete life-cycles  for  representative  microscopic  forms  were 
made  known  toward  the  middle  of  the  nineteenth  century. 
The  later  eighteenth  century  was  concerned  with  this 
problem,  as  it  was  with  the  broader  generalizations  in  other 
scientific  lines.  In  view  of  the  absence  of  a  cell-theory,  it  is 
perhaps  remarkable  that  the  advocates  of  spontaneous 
generation  were  not  more  numerous. 

In  medicine,  the  final  steps,  which  divorced  the  treatment 
of  disease  from  superstitions  such  as  belief  hi  demoniacal 
possession  and  in  the  visitations  of  Providence,  were  taken 
during  the  eighteenth  century.  This  happened  in  spite  of 
popular  survivals  of  such  beliefs.  Disease  was  increasingly 
acknowledged  to  be  an  abnormal  bodily  state,  and  as  such  to 
be  subject  to  investigation  by  science.  Jenner's  discovery  of 


THE  FURTHER  GROWTH  OF  SCIENCE          101 

vaccination  against  smallpox  (1796)  was  the  precursor  of  the 
vaccinations  of  the  present  time.  The  Germ-Theory  of 
disease  was  forecast  by  the  increasing  emphasis  upon  the 
analogy  between  the  spread  of  disease  and  the  spread  of 
living  organisms.  But  the  generalizations,  which  ushered  in 
the  existing  science  of  medicine,  were  made  possible  only  by 
further  extensions  of  biological  knowledge  in  the  early  nine- 
teenth century. 

Other  examples  might  be  cited.  The  foregoing  suffice 
to  show  that  the  great  generalizations  in  the  older  sciences 
began  to  assume  their  present  form  during  the  eighteenth 
century.  Some  of  these,  like  the  theory  of  the  transmutation 
of  species,  were  unable  to  maintain  themselves.  Acceptance 
was  delayed  until  a  later  time.  In  other  cases,  such  as  the 
cell-theory,  the  eighteenth  century  failed  to  discover  the 
thread  of  common  meaning.  Yet  to  a  surprising  degree  the 
men  of  this  early  modern  period  arrived  at  generalizations 
that  were  points  of  departure  for  scientific  progress  during 
the  century  which  followed. 

In  brief,  the  larger  regions  of  science  were  mapped  and 
charted,  and  the  scientific  method  was  acknowledged  as  the 
correct  procedure  within  the  realm  of  nature.  There  was 
still  confusion  over  what  constituted  natural  knowledge. 
Important  fields,  such  as  the  mental  phenomena  since 
claimed  by  the  psychologists,  were  excluded  from  the 
scientific  domain.  But  even  to-day  non-scientific  explana- 
tions are  offered  for  phenomena  which  may  eventually  be 
explained  in  terms  of  science.  Toward  the  close  of  the 
century  the  distinction  between  science  and  philosophy 
attained  wider  recognition;  while  supernaturalism  began  to 
receive  its  present  valuation.  It  should  again  be  empha- 
sized that  any  separation  between  the  Scientific  Renaissance 
and  modern  times  is  arbitrary,  for  since  the  days  of  Leonardo 
and  Galileo  science  has  gone  forward  with  increasing  mo- 
mentum. 


102      HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

APPLICATIONS   OF  SCIENCE   TO   MODERN   INDUSTRY 

The  value  of  science  in  modern  industry,  commerce,  and 
agriculture  is  so  generally  appreciated  that  any  lengthy  dis- 
cussion is  quite  unnecessary.  Exploitation  of  nature  by 
means  of  scientific  knowledge  is  the  most  conspicuous 
feature  in  the  history  of  civilization  during  the  past  two 
hundred  years.  Since  the  middle  of  the  eighteenth  century, 
the  western  world  has  undergone  almost  as  complete  a 
metamorphosis  as  it  did  in  the  thousand  years  during  which 
the  Teutonic  barbarians  were  changed  into  the  civilized 
peoples  of  the  Renaissance.  The  steps  in  this  profound  re- 
organization, which  has  produced  a  culture  based  upon 
science,  must  be  considered,  if  we  would  understand  the 
place  of  any  particular  science  in  the  twentieth  century. 

In  the  past,  commercial  intercourse  has  brought  exchange 
of  ideas  as  well  as  goods;  and  as  a  result,  civilizations  have 
been  made  anew.  Ideas,  like  diseases,  follow  the  routes  of 
trade.  The  Phencecians  were  the  earliest  common  carriers 
of  the  world;  through  them  the  influence  of  the  Egyptian 
and  of  the  Mesopotamian  cultures  was  extended  along  the 
shores  of  the  Mediterranean  until  it  quickened  western 
Europe.  Later,  the  commerce  of  Greece  was  the  initial 
impulse  to  the  establishment  of  Greek  colonies  in  Sicily  and 
southern  Italy  and  to  the  westward  spread  of  Hellenic 
civilization.  During  the  Medieval  Period,  commerce  with 
the  countries  about  the  eastern  end  of  the  Mediterranean 
was  an  important  factor  in  preserving  the  tradition  of  an 
ancient  learning  commensurate  with  the  majestic  ruins  of 
the  Roman  world  which  Europe  beheld  in  Italy,  France,  and 
Spain.  We  have  referred  earlier  to  the  development  of  an 
industrial  aristocracy,  founded  upon  the  trade  of  the  Italian 
cities  with  the  Orient,  and  its  relation  to  the  intellectual 
awakening  of  the  Renaissance.  The  Mediterranean  was  the 
great  trade-route  of  the  world  before  the  geographical  dis- 
coveries of  the  fifteenth  and  sixteenth  centuries.  Until  the 


THE  FURTHER  GROWTH  OF  SCIENCE  103 

opening  of  the  Modern  Period,  the  Near  East  was  the 
principal  source  of  ideas,  as  well  as  the  finer  products  of 
industry,  both  of  which  were  transmitted  mainly  by  follow- 
ing established  routes  of  trade. 

The  discovery  of  a  broader  world  by  the  Portuguese  and 
Spanish  navigators  was  the  first  step  in  the  commercial 
supremacy  of  western  Europe.  The  Mediterranean  became 
insignificant,  as  a  means  of  communication  with  the  East, 
upon  the  discovery  of  the  sea-route  to  India  and  upon  the 
domination  by  the  Turks  of  the  caravan  routes  from  the 
Red  Sea  and  Persian  Gulf.  The  wealth  of  the  western 
hemisphere  and  of  the  Orient  tempted  both  merchant  and 
adventurer.  And  thus  the  Europeanization  of  the  world, 
which  has  been  characterized  as  "one  of  the  most  fateful 
events  of  all  history,"  was  set  in  motion.  Dissemination  of 
knowledge  concerning  the  world  and  its  peoples  has  been 
rightly  regarded  as  one  of  the  major  influences  in  the  broad- 
ening of  the  mental  horizon  that  was  distinctive  of  the 
Renaissance.  Much  of  this  dissemination  was  due  to  the 
intercourse  of  commerce  and  to  the  increased  wealth  and 
leisure  which  was  thus  brought  to  western  nations. 

While  Arab  civilization  and  later  the  Revival  of  Learning 
were  leavening  the  mind  of  Europe,  the  trade  of  the  Italian 
cities  was  producing  a  more  tolerant  and  matter-of-fact 
spirit  which  was  further  developed  by  the  centuries  of  dis- 
covery. Contact  with  peoples  beyond  the  European  pale, 
even  though  they  were  regarded  as  inferior  to  Christians, 
showed  that  Christendom  contained  the  lesser  portion  of  the 
human  race.  Innovations  became  more  easy  when  new  and 
strange  customs  had  been  observed  elsewhere.  The  pirate- 
adventurers,  who  harried  the  Spanish  Main  and  brought 
home  booty  to  Elizabethan  England,  laid  the  foundation 
for  the  extension  of  English  trade  and  colonization  in  India 
and  America  during  the  century  which  followed.  But  more 
than  this,  they  opened  the  way  for  new  ideas.  Knowledge 
of  the  new  geography  was  brought  to  Europe  mainly  as  the 


104       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

result  of  commercial  activities.  What  the  Mediterranean 
was,  in  the  dissemination  of  culture  during  ancient  times, 
the  " Seven  Seas"  became  during  the  transition  from  the 
Renaissance  to  the  Modern  Period.  The  Industrial  Revolu- 
tion, which  began  in  England  about  the  middle  of  the 
eighteenth  century,  was  a  natural  sequence  to  the  develop- 
ment of  trade  during  the  period  between  1600  and  1750. 
The  modern  appreciation  of  scientific  knowledge  in  relation 
to  practical  life  was  an  inevitable  product  of  the  Industrial 
Revolution. 

Thus  the  relation  of  commercial  intercourse  to  the  ad- 
vancement of  science  was  at  first  incidental.  Under  the 
liberalizing  influence  of  trade,  new  ideas  were  able  to  take 
root.  The  leisure  incident  to  increasing  wealth  gave  op- 
portunity for  intellectual  development.  Even  with  the 
advent  of  the  Factory  System,  the  influence  upon  scientific 
progress  was  still  indirect.  Only  in  the  nineteenth  century 
did  industry  grow  conscious  of  its  dependence  upon  scien- 
tific knowledge  and  thus  become  the  most  effective  means  of 
making  widely  known  the  facts  and  methods  of  science. 

Modern  industry  arose  in  England  during  the  latter  half 
of  the  eighteenth  century.  The  replacement  of  hand  labor 
by  steam  and  water-power,  together  with  the  development 
of  a  remarkable  series  of  practical  inventions,  gave  rise  to 
the  Factory  System  and  to  the  industrial  expansion  of  the 
modern  era.  It  may  be  observed  that  these  first  steps  in  the 
direction  of  scientific  industry  were  taken  by  men  of  practical 
bent,  who  were,  in  the  main,  ignorant  of  scientific  theory. 
It  was  found  immensely  profitable  to  manufacture  for  ex- 
portation, and  under  this  impetus  the  initial  steps  of  indus- 
trial development  were  quickly  taken.  The  medieval  dis- 
like of  innovation  having  been  removed,  the  practical 
Englishman  entered  upon  his  period  of  industrial  supremacy 
to  be  checked  only  toward  the  close  of  the  nineteenth  century 
by  the  growth  of  more  scientific  methods  among  his  later 
commercial  rivals. 


THE  FURTHER  GROWTH  OF  SCIENCE  105 

Water-power,  which  had  come  into  general  use  in  England 
after  1770,  was  gradually  replaced  by  steam.  The  crude 
steam  engine,  invented  by  Savery  (1698)  and  improved  by 
Newcomen  (1707),  was  used  for  pumping  water  from  mines 
as  early  as  the  first  decade  of  the  eighteenth  century.  But 
although  this  steam  pump  doubled  the  depth  at  which  coal 
could  be  mined,  steam  power  was  not  feasible  for  general 
purposes  until  after  the  invention  of  the  first  real  steam 
engine  by  James  Watt  (1769).7  In  the  cloth-making  indus- 
tries, Kay's  flying  shuttle  (1733)  and  Hargreave's  spinning 
jenny  (1764)  revolutionized  weaving.  Arkwright's  so-called 
water-frame  (1769)  was  an  improvement  upon  the  spinning 
jenny.  Compton  combined  the  jenny  and  the  water-frame 
in  his  mide  or  muslin-wheel  (1779),  and  Cartwright's  power- 
loom  (1785)  increased  the  demand  for  power  and  power- 
driven  machines.  The  history  of  weaving  is  duplicated  in 
many  lines  of  manufactory.  Invention  followed  invention 
hi  rapid  succession.  Improvements  in  the  iron  industry 
made  easier  the  construction  of  machinery.  Commerce 
demanded  better  means  of  transportation.  Bridges,  break- 
waters, and  dams  became  common.  Road  building  pro- 
gressed rapidly,  and  canal  building  linked  together  the 
growing  industrial  centers,  enabling  cities  like  Manchester 
and  Liverpool  to  attain  an  unprecedented  prosperity.  The 
steamboat  (1807)  and  the  steam  locomotive  (1825)  were  the 
final  triumphs  of  steam  as  applied  to  industrial  and  com- 
mercial activities.8 

This  Industrial  Revolution  began  in  England  during  the 
later  eighteenth  century.  Early  in  the  following  century 

7  A  machine,  which  revolved  by  means  of  steam  on  the  same  principle  as 
the  modern  turbine,  is  recorded  as  having  been  produced  by  Hero  of  Alexandria 
about  130  B.  c.  But  this  earliest  recorded  steam  engine,  like;  another  machine 
1  l.v  II'  ro  and  driven  by  the  expansive  power  of  heated  air,  was  used 
only  for  trivial  purposes.  Ewing,  I  A  ,  KM-  lint  Article  on  "Steam  Engine." 
Cf.  p.  35  of  the  present  volume 

i  r   I     W.t  "A  Social  and  Industrial  History  of  England,"  Chap. 
XXXVI. 


106      HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

it  spread  throughout  western  Europe  and  to  the  New  World. 
Not  only  were  all  the  old  lines  of  industry  remade,  but 
wholly  new  industries  were  created  just  as  in  our  own  times. 
This  involved  a  complete  social  reorganization,  the  effects 
of  which  have  extended  to  the  present  day  and  the  adjust- 
ment to  which  is  not  yet  complete.  There  are  also  many 
points  of  interest  in  the  revolution  in  methods  of  agricul- 
ture which  proceeded  side  by  side  with  that  of  industry. 
This  was  stimulated  both  by  the  increasing  urban  popula- 
tions, with  their  demands  for  food,  and  by  the  correspond- 
ing reduction  of  the  available  farm  labor.  As  is  the  case 
with  the  industrial  situation,  betterment  of  agricultural 
methods  and  the  social  adjustments  entailed  by  excessive 
urbanization  are  problems  which  have  continued  to  the 
twentieth  century.  Viewing  the  entire  situation,  two  fea- 
tures are  in  evidence:  The  Industrial  Revolution  has  pro- 
ceeded with  unbroken  continuity  from  its  beginning  in  the 
eighteenth  century;  and  this  revolution  was  initiated  almost 
exclusively  by  practical  inventors,  who  harnessed  the  forces 
of  nature  that  they  might  secure  wealth  for  themselves.  The 
eighteenth  century  was  not  lacking  in  men  who  understood 
the  visions  of  Roger  Bacon,  of  Leonardo,  and  of  Francis 
Bacon,  each  of  whom  had  foreseen  the  possibilities  in  man's 
control  over  nature.  But  it  was  reserved  for  the  nineteenth 
century  to  develop  an  appreciation  of  scientific  theory  in 
relation  to  industry.  So  long  as  the  relatively  easy  and 
simple  things  remained  undone,  the  inventor  was  the  dom- 
inant figure.  He  still  retains  his  place  in  the  adaptation  of 
established  principles  to  new  combinations  of  circumstances. 
But  the  situation  at  the  present  day  has  become  vastly 
more  complicated. 

The  material  progress  of  the  nineteenth  century,  based 
upon  this  harnessing  of  the  forces  of  nature,  is  a  familiar 
story.  The  steam  engine  came  to  perform  the  labor  of  mil- 
lions of  men  and  made  possible  a  production,  and  hence  a 
consumption,  of  goods  which  was  previously  inconceivable. 


THE  FURTHER  GROWTH  OF  SCIENCE  107 

By  its  application  to  transportation,  steam  made  distance 
insignificant  and  thus  increased  the  content  of  individual 
experience.  The  possibility  of  better  living  conditions  was 
created,  although  in  the  rush  for  luxuries  the  sum  total  of 
human  toil  may  not  have  been  lessened.  A  similar  revolu- 
tionary advance,  is  occurring  in  the  present  generation, 
through  the  medium  of  the  electric  generator  and  the  gas 
engine.  The  bearing  of  this  material  progress  upon  the 
ultimate  welfare  of  humanity,  and  the  disastrous  effects 
of  these  human  activities  upon  the  exhaustible  resources  of 
our  planet  need  not  be  considered  here.  Practical  men 
believe  this  kind  of  advancement  worth  while,  and  the  desire 
for  physical  comforts,  is  likely  to  countenance  the  exploita- 
tion of  nature  so  long  as  it  continues  easy  and  profitable. 

Material  progress  during  the  past  one  hundred  and  fifty 
years  has  been  founded  upon  a  progressive  control  of  the 
forces  of  physical  nature.  This  control  has  been  made  pos- 
sible by  the  knowledge  of  nature  called  science.  Assuming 
that  our  ant-like  activities  are  worth  while,  the  question 
is  no  longer  whether  this  practical  side  of  scientific  knowledge 
is  to  be  desired,  but  whether  progress  in  those  branches  of 
science  which  are  not  obviously  utilitarian  is  necessary  for 
human  welfare.  Whether  pure  science  as  well  as  applied 
science  is  a  necessity  rather  than  a  luxury.  This  question 
is  being  answered  for  the  mass  of  mankind  by  the  researches 
in  pure  science,  which  are  becoming  increasingly  significant 
in  connection  with  industry  and  agriculture.  Commercial 
enterprise  finds  itself  confronted  with  problems  which  are 
beyond  the  powers  of  the  inventor  of  an  earlier  generation 
and  which  can  be  solved  only  by  trained  scientists.  The 
technical  investigator  in  the  industrial  research  establish- 
ment is  confronted  with  problems  in  abstract  science  which 
formerly  exhibited  no  seeming  relation  to  practical  life, 
same  situation  obtains  in  institutions  established  for 
the  investigation  of  practical  problems  in  agriculture.  It  is 
becoming  a  commonplace  to  say  that  the  nation  which  does 


108       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

not  base  its  industry  and  its  agriculture  upon  an  advancing 
knowledge  of  science  is  doomed. 

The  sublime  confidence  in  the  knowledge  of  the  practical 
man,  which  distinguished  British  and  also  American  industry 
throughout  the  nineteenth  century,  was  doubtless  bred  of 
the  fact  that  practical,  self-made  men  were  mainly  instru- 
mental in  giving  England,  and  later  America,  their  initial 
positions  as  industrial  nations.  It  was  German  scientists 
and  German  industrial  laboratories,  more  than  German 
commercial  aptitude  that  challenged  British  supremacy 
in  world-trade  during  the  closing  decades  of  the  nineteenth 
century.  There  is  a  oneness,  to  scientific  knowledge,  which 
makes  the  distinction  between  the  practical  and  the  theoret- 
ical of  no  avail,  and  this  fact  is  gradually  becoming  acknowl- 
edged even  among  hardheaded  men  of  affairs.  In  the  future, 
new  industries  are  likely  to  be  created  by  advances  in  pure 
science,  such  as  the  discovery  of  radio-activity  or  of  new 
methods  of  electrical  transmission,  rather  than  by  rule-of- 
thumb  inventions. 

Thus,  the  outstanding  feature  of  modern  industrial  prog- 
ress has  been  the  control  of  nature  by  means  of  scientific 
knowledge.  This  was  and  is  the  general  formula  for  the 
material  prosperity  of  western  nations.  In  the  physical 
sciences,  we  have  reached  a  point  where  this  formula  is 
patent  to  all  thinking  men,  who  recognize  that  the  evolution 
of  mechanical  devices  and  of  industry  begins  and  ends  with 
scientific  knowledge.  There  has  even  grown  up  a  popular 
faith  that  inventors,  like  Edison  and  Marconi,  who  for  the 
man  in  the  street  are  the  great  scientists,  can  accomplish 
anything  if  given  time.  This  belief  may  not  be  warranted, 
but  the  material  progress  effected  through  science  during 
the  recent  centuries  has  been  so  continuous  that  such  a 
belief  is  not  unnatural. 

The  western  world  has  developed  a  culture  that  is  ob- 
sessed with  the  idea  of  science  as  an  instrument  of  material 
progress,  because  the  practical  and  theoretical  phases  of 


THE  FURTHER  GROWTH  OF  SCIENCE  109 

scientific  knowledge  have  so  impressed  the  occidental  mind. 
We  shall  not  dwell  at  greater  length  upon  this  aspect  of 
modern  science  nor  describe  its  material  achievements  of 
civilization,  save  as  they  explain  the  manner  in  which  the 
scientific  habit  of  mind  has  assumed  its  present  eminence. 
Science  has  won  recognition  by  its  material  accomplish- 
ment in  matters  of  everyday  life,  and  hence  the  scientific 
spirit  has  appeared  in  places  where  it  would  not  otherwise 
have  come  into  being.  For  this  reason,  the  history  of  in- 
dustry and  of  common  labor  is  second  only  to  the  history 
of  knowledge  in  an  understanding  of  the  relation  of  science 
to  the  affairs  of  men. 


INFLUENCES   AND   IMPLICATIONS   OF   SCIENCE 

The  more  general  and  indirect  effects  of  science  during  the 
eighteenth  century  may  now  be  considered.  Among  other 
evidences  of  the  influence  of  scientific  knowledge,  was  the 
rapid  decline  of  the  spirit  of  persecution  that  occurred  in 
Europe  during  the  seventeenth  century.  Men  had  long 
been  taught  that  credulity  was  a  virtue  and  doubt  a  sin. 
The  new  learning  enforced  the  doctrine  that  belief  must 
rest  upon  evidence  that  was  open  to  examination.  To  per- 
secute successfully,  one  must  be  sure  he  has  the  truth. 
What  science  implies  is  not  so  much  the  importance  of  any 
particular  truth  as  the  right  to  seek  truth  and  extend  it 
unhampered  by  restrictions.  Particular  beliefs  can  survive 
only  so  long  as  they  justify  themselves  against  opposition. 
It  is  the  essence  of  the  spirit  of  persecution  to  be  unfair  and 
to  assume  that  the  doctrines  of  the  persecutors  need  no 
justification.  The  scientific  advances  of  the  Renaissance 
set  up  standards  of  thinking  which  made  persecution  no 
part  of  righteousness.  The  spirit  of  intolerance  did  not  dis- 
appear, but  it  became  increasingly  difficult  to  justify  such  a 
spirit  upon  grounds  of  morality. 

Waning  bo  lief  in  the   material   efficacy  of  supernatural 


110       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

agencies  was  another  outcome  of  scientific  knowledge.  Men 
came  to  assume  that  natural  explanations  must  exist  even  in 
cases  where  none  had  been  discovered.  The  concept  of  natural 
law  gradually  replaced  that  of  supernatural  interference. 
The  decline  in  the  sense  of  the  miraculous,  which  is  so  dis- 
tinctive a  feature  of  modern  times,  had  set  in  during  the 
sixteenth  century.  Many  old  beliefs  had  perished  by  in- 
difference, and  the  secularization  of  intellectual  activity  was 
much  in  evidence  even  before  the  seventeenth  century.  The 
Italian  genius  had  borne  the  brunt  of  the  initial  advance 
from  the  intellectual  servitude  of  an  earlier  period.  But  a 
succession  of  wars  and  disasters,  during  which  the  Church  of 
Rome  set  itself  against  intellectual  progress  and  Italy  be- 
came the  battle  ground  of  nations,  together  with  the  malign 
influences  of  the  Counter  Reformation,  won  the  day.  The 
intellectual  emancipation  of  Europe,  through  the  develop- 
ment of  a  scientific  spirit,  was  thenceforth  carried  forward  by 
the  northern  and  western  nations. 

We  have  seen  that,  with  the  decline  of  the  ancient  learn- 
ing, philosophical  thinking  became  merely  an  adjunct  to 
the  dominant  theology  and  that  this  situation  culminated 
in  the  scholastic  philosophy  of  Thomas  Aquinas.  The 
story  of  the  emancipation  from  this  intellectual  bondage  is 
the  history  of  the  rise  of  modern  rationalism  and  of  the  im- 
plications drawn  from  the  facts  of  modern  science.  The 
larger  movements  proceeded  somewhat  as  follows:  The 
Reformation,  despite  its  intolerance,  emphasized  the  value 
of  individual  opinion.  Rationalistic  tendencies  were  much 
hi  evidence  during  the  seventeenth  century,  as  shown  by 
the  contentions  of  the  protestant  clergy  in  their  conflict 
with  Rome  and  by  the  philosophy  of  Descartes.  The  Deists 
of  the  late  seventeenth  and  early  eighteenth  century  in 
England  were  not  a  powerful  company  intellectually,  and 
their  attempt  to  formulate  a  natural  religion  gained  scant 
recognition;  but  they  were  a  sign  of  the  times.  The  more 
significant  fact  is  the  extent  to  which  their  essential  doctrines 


THE  FURTHER  GROWTH  OF  SCIENCE          111 

gradually  permeated  the  thought  of  orthodoxy.  In  England, 
for  example,  there  existed  during  the  eighteenth  century  a 
surprising  amount  of  rationalism,  as  an  outcome  of  the  tacit 
acceptance  of  deistic  teachings.9  Despite  a  pathetic  lack  of 
knowledge  concerning  many  details  of  scientific  fact,  eight- 
eenth century  thinkers  perceived  the  implications  of  science 
to  an  extent  for  which  mankind  is  even  now  scarce  prepared. 
As  a  result,  rationalistic  systems  of  thinking  established  their 
right  to  existence. 

But  if  science  has  been  important  in  the  foundation  of 
modern  philosophy,  the  role  of  the  philosopher  and  of  the 
man  of  letters  has  been  no  less  significant  in  the  extension  of 
science.  The  scientist  is  often  unmindful  of  the  broader 
significance  and  of  the  popular  acceptance  of  scientific  doc- 
trines. The  philosopher,  on  the  other  hand,  is  interested  in 
the  implications  of  science  and  frequently  extends  these 
implications  to  fields  where  science  is  not  established,  but 
where  popular  interest  may  be  acute.  Science  advances 
through  the  general  acceptance  of  its  teaching  as  much  as 
by  additions  to  knowledge.  The  thinker,  who  pursues  its 
implications  and  who  induces  others  to  follow  his  lead,  is  no 
less  important  in  scientific  progress  than  he  who  contributes 
to  the  establishment  of  technical  generalizations. 

The  importance  of  Francis  Bacon  (1561-1626)  is  due 
mainly  to  his  understanding  of  the  implications  of  science. 
Although  dethroned  from  the  place  he  long  occupied  as 
father  of  the  science  of  physics  and  of  inductive  philosophy, 
Bacon  deserves  a  prominent  position,  because  he  appre- 
hended, at  an  early  period,  the  steps  by  which  man  might 
cease  to  be  the  plaything  of  blind  forces  and  become  the 
controller  of  his  environment.  In  his  attempt  to  "  extend 
more  widely  the  power  and  greatness  of  man,"  Bacon  gave 
publicity  to  the  concept  of  man's  relation  to  nature  which 
has  since  become  the  creed  of  science.  He  did  not  originate 

•Stephen,  Leslie,  "History  of  Knglish  Thought  in  the  Eighteenth 
Century." 


112       HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

this  concept,  for  Roger  Bacon  and  Leonardo  were  before 
him.  But  more  than  any  man  of  his  day  he  gave  impetus  to 
the  doctrine  that  in  science  rests  the  progress  of  the  future.10 

What  Francis  Bacon  accomplished  hi  the  popular  mind 
Ren6  Descartes  (1596-1650)  accomplished  in  philosophical 
thought.  The  full  significance  of  the  scientific  discoveries 
of  the  Renaissance  would  have  remained  unappreciated,  had 
it  not  been  for  the  extension  of  the  method  of  science  which 
was  begun  by  Descartes.  The  scholastic  system  of  thought 
was  doomed  by  the  discovery  of  scientific  facts,  but  it  was 
not  overthrown  until  it  could  be  replaced  by  a  system  based 
upon  the  new  knowledge.  Descartes  produced  the  first 
great  philosophy  which  was  independent  of  scholastic  tradi- 
tion and  in  agreement  with  the  science  of  the  period.  More 
than  any  other  he  may  be  regarded  as  the  founder  of  modern 
philosophical  thinking;  since  he  gave  the  necessary  impetus 
to  the  scientific  method  by  his  insistence  upon  the  subjec- 
tion of  every  opinion  to  critical  examination.  The  Cartesian 
doubt  is  nothing  more  than  scientific  skepticism  regarding 
traditional  assumptions.  The  mechanistic  conception  of 
nature,  which  Descartes  set  forth  as  the  necessary  condition 
of  scientific  study,  is  the  underlying  assumption  of  all  mod- 
ern investigation  in  the  exact  sciences.11 

The  critical  examination  by  John  Locke  (1632-1704) 
of  the  limits  of  the  human  understanding  was  a  further  step 
in  the  development  of  a  scientific  philosophy.  It  was  also 
the  forerunner  of  eighteenth  century  thinking  as  exempli- 
fied by  David  Hume  (1711-1776)  and  Immanuel  Kant 

10  This  belief  has  since  been  often  and  clearly  stated.    Among  recent  writers, 
it  is  vividly  set  forth  by  E.  Ray  Lankester,  in  the  opening  chapter  of  a  volume 
entitled:  "The  Kingdom  of  Man,"  where,  under  the  heading  "Nature's  In- 
surgent Son,"  man  is  pictured  as  an  insurgent  who  has  rebelled  against  nature 
and  gone  so  far  in  his  rebellion  there  can  be  no  turning  back. 

11  An  excellent  summary  of  the  nature  and  significance  of  the  thought  of 
Descartes  may  be  found  in  the  familiar  essay  by  T.  H.  Huxley,  entitled:  "On 
Descartes'  Discourse  touching  the  method  of  using  one's  reason  rightly  and  of 
seeking  scientific  truth,"  Vol.  I,  "Collected  Essays." 


THE  FURTHER  GROWTH  OF  SCIENCE  113 

(1724-1804).  Descartes,  Locke,  Hume,  and  Kant  were 
largely  responsible  for  the  replacing  of  the  scholastic  system 
by  forms  of  thought  compatible  with  scientific  knowledge. 
In  the  course  of  this  change  in  philosophical  theory,  the 
facts  of  science  became  permanently  established  as  the 
starting  point  in  the  analysis  of  objective  phenomena;  while 
the  critical  methods  of  science  were  applied  by  the  philoso- 
pher within  the  subjective  field.  Science  gave  philosophy 
a  suitable  point  of  departure  for  its  speculations  concerning 
ultimate  reality,  while  philosophy  extended  and  gave  more 
concrete  form  to  the  methods  of  science. 

But  philosophical  theories  of  reality  and  of  the  nature  of 
knowledge  are  not  so  obviously  important  for  mankind  as 
the  philosophical  interpretations  of  everyday  affairs,  al- 
though we  may  believe  that  it  is  the  activity  of  the  great 
philosophical  intellects  which  hi  the  long  run  stimulates 
every  real  advancement.  The  line  of  thought  which  leads 
through  Montaigne,  Descartes,  Bayle,  and  Voltaire  is  more 
immediately  significant  hi  its  influence,  because  the  thought 
of  these  writers  so  quickly  pervaded  the  literature  of  the 
period.  Montaigne  (1533-1592)  was  the  first  popular  repre- 
sentative of  secular  and  rationalistic  thought  among  the 
northern  races.  Skepticism  regarding  prevailing  beliefs, 
which  had  developed  toward  the  close  of  the  Italian  Renais- 
sance, is  further  exemplified  by  his  writings.  He  "  ventured 
to  judge  all  questions  by  a  secular  standard,  by  the  light  of 
common  sense,  and  by  the  measure  of  probability  which  is 
furnished  by  daily  experience."  12  In  other  words,  he  ac- 
cepted the  method  of  science.  His  essays  upon  the  individ- 
uals and  the  society  of  his  day  emphasized  the  harmlessness 
of  error  in  contrast  with  the  evils  of  persecution,  in  a  man- 
ner characteristic  of  the  scientific  temper.  The  growing 
acceptance  of  this  point  of  view  prepared  the  way  for  the 
ideas  of  Descartes,  who  recognized  doubt  as  the  beginning 
of  wisdom. 

"Lccky,  \V.  I     II       II,  -MV  of  Rationalism  in  Europe,"  Vol.  I,  p.  11J 


114      HISTORY  AND  SIGNIFICANCE  OF  SCIENCE 

The  volume  by  Bayle  (1647-1706),  entitled  "Compel 
them  to  Enter  in,"  shows  that  its  author  began  with  skep- 
ticism and  proceeded  from  thence  to  toleration.  Intellec- 
tual liberty  was  Bayle's  passion,  and  his  critical  examination 
of  existing  beliefs  was  an  important  step  hi  the  initial  estab- 
lishment of  modern  rationalism.  The  spirit  of  toleration 
which  flamed  forth  in  the  writings  of  Voltaire  (1694-1778) 
was  the  natural  culmination  of  this  trend  of  thought.  It 
has  been  remarked  that  Voltaire's  genius  lay  in  the  fact  that 
he  said  what  everyone  thought  at  the  tune.  If  eighteenth 
century  toleration  condoned  many  excesses  and  proved  a 
cloak  for  immorality,  it  was  none  the  less  a  welcome  change 
from  the  spirit  of  persecution  which  had  prevailed.  In- 
dividualism had  freer  play,  and  the  spread  of  a  truthful 
spirit  outweighed  the  license  which  was  often  the  first  ex- 
pression of  growing  liberalism.  The  spirit  which  appeared 
in  literature  is,  therefore,  an  example  of  the  implications 
drawn  from  scientific  knowledge  and  brought  to  a  focus 
by  their  application  to  the  affairs  of  common  life.  Mon- 
taigne, Descartes,  Bayle,  and  Voltaire  exemplified  and 
extended  the  scientific  spirit,  hi  that  they  warred  against 
prejudice  and  encouraged  mankind  to  examine  the  founda- 
tions of  belief. 

In  regard  to  the  broader  influence  of  science,  the  eight- 
eenth century,  therefore,  marks  the  final  transition  from 
the  Renaissance  to  our  own  times.  The  philosophical  import 
of  scientific  fact  and  method  began  to  assume  its  present 
importance.  What  may  be  termed  the  implications  of 
science  assumed  definitive  form.  Science  for  the  first  tune 
attained  self-consciousness  and  self-determination.  During 
the  eighteenth  century  men  began  to  realize  that  the  scientific 
point  of  view  could  be  extended  beyond  the  boundaries  of 
what  had  been  called  the  natural  world.  The  political, 
economic,  and  theological  fields  of  thought  were  subjected 
to  scientific  examination,  if  not  to  exact  analysis.  Science 
began  to  exert  a  profound  influence  upon  the  thought  of 


THE  FURTHER  GROWTH  OF  SCIENCE  115 

mankind,  although  the  relationship  between  science  and  the 
changing  frame  of  mind  was  not  always  appreciated.  The 
pursuit  of  these  implications  has  been  greatly  extended  dur- 
ing the  last  hundred  years.  Their  first  general  extensions 
occurred  during  the  eighteenth  century. 

In  this  regard,  the  eighteenth  century  closed  in  failure. 
The  first  half  of  the  nineteenth  century  was,  in  many  re- 
spects, stagnant  and  negative.  Technically  speaking, 
science  was  making  rapid  progress,  but  its  implications  were 
not  comprehended,  hi  what  were  regarded  as  non-scientific 
fields.  Mankind  may  never  again  witness  such  confident 
predictions  of  an  approaching  Age  of  Reason  as  were  made 
during  the  later  eighteenth  century.  The  world  may  seem 
to  have  been  living  ever  since  in  a  period  of  retrogression. 
Yet  science  has  done  its  work,  and  no  future  period  of  re- 
action can  bring  back  the  habits  of  thought  that  existed 
before  the  culmination  of  the  Renaissance  in  this  first  cen- 
tury of  the  Modern  Period. 


PART  II 
THE  SCIENCE  OF  BIOLOGY 


CHAPTER  VI 

THE   BIOLOGICAL    SCIENCE    OF   THE    MODERN 
PERIOD:  THE  CELL-DOCTRINE 

HAVING  outlined  the  historical  significance  of  science  in 
general  and  of  biological  science  hi  particular,  representative 
features  of  modern  biology  may  now  be  considered.  In 
common  with  all  branches  of  science,  modern  biological 
science  is  more  significant  hi  human  affairs  through  its 
influence  upon  the  point  of  view  than  for  its  material  achieve- 
ments. Biology  touches  human  life  at  so  many  angles  that 
it  is  particularly  adapted  to  illustrate  the  place  now  occupied 
by  science  in  general  within  the  lives  of  men.  The  biological 
sciences  occupy  a  position  intermediate  between  the  sciences 
of  inanimate  matter  and  the  less  exact  social  sciences  that 
deal  with  human  behavior.  An  exhaustive  survey  of  the 
biological  field  will  not  be  attempted,  but  rather  an  outline 
of  its  broader  features  by  means  of  concrete  illustrations. 
The  development  of  biological  science  1  during  modern 
times  has  been  so  diversified  that  we  are  first  impressed 

1  The  term  biological  science  may  be  used  broadly  to  include  all  fields  of 
knowledge  which  are  mainly  concerned  with  the  activities  of  living  bodies 
whether  of  unicellular  organisms  or  of  men.  In  the  more  restricted  sense, 
however,  the  term  includes  zoology,  botany,  the  medical,  agricultural,  and 
similar  sciences  which  depend  most  directly  upon  a  knowledge  of  animals  and 
plants.  In  the  present  chapter  the  term  is  used  in  its  restricted  meaning 
unless  otherwise  explained.  Classification  of  science  is,  of  course,  arbitrary. 
There  are  no  sharp  distinctions  in  nature  such  as  have  come  to  exist  within 
our  minds.  The  same  physical  and  chemical  changes  are  found  within  the 
living  body  as  in  non-living  matter.  But  since  the  phenomena  of  life  still 
seem  unique  in  many  respects,  we  may,  for  convenience,  make  the  broad 
distinction  between  the  Physical  Sciences,  such  as  Chemistry,  Physics,  Astron- 
omy, and  the  like,  and  the  Biological  Sciences,  such  as  Botany,  Zoology, 
\Krnn ilt  uro,  and  their  subdivisions.  The  Social  Sciences  might  be 
placed  in  a  third  category,  although,  biologically  speaking,  they  may  be  re- 
garded as  a  form  of  Animal  Behavior. 

110 


120  THE  SCIENCE  OF  BIOLOGY 

by  the  coming  into  existence  of  a  host  of  new  sciences  having 
little  in  common.  But  looking  closer,  these  multitudinous 
developments  may  all  be  correlated  with  one  or  the  other  of 
two  major  hypotheses — the  Theory  of  Organic  Evolution  and 
the  Theory  of  Cells.  Such  sciences  as  Pathology,  Bacteri- 
ology, Histology,  Taxonomy,  Ecology,  and  the  like,  may 
not  have  arisen  in  conscious  correlation  with  either  of  the 
major  theories.  But  having  arrived,  they  arrange  them- 
selves quite  naturally  in  relation  to  the  broader  generaliza- 
tions. Pathology  is  the  problem  of  abnormalities  in  cells, 
Taxonomy  the  problem  of  classifying  animals  and  plants 
according  to  their  evolutionary  affinities.  The  others  can 
be  similarly  aligned.  Moreover,  the  general  biological 
problems,  distinctive  of  recent  progress,  allow  of  the  same 
classification.  Questions  regarding  the  origin  of  living  sub- 
stance find  their  answers  hi  the  cells.  The  nature  of  vital 
processes,  whether  mechanistic  or  vitalistic,  is  a  cell  problem. 
The  fundamental  identity  of  vital  phenomena  is  explained 
by  the  essentially  identical  structure  and  functioning  of 
cells  in  all  animals  and  plants.  The  nature  of  embryological 
development,  the  mechanism  of  heredity,  the  relation  of  liv- 
ing and  lifeless  matter,  in  short,  the  answers  to  "all  ultimate 
biological  problems  must,  in  the  last  analysis,  be  sought  in 
the  cell."  Its  structures  and  activities  give  clues  to  the  rid- 
dles of  living  matter.2  The  theory  of  organic  evolution  is 
no  less  inclusive.  The  progress  of  modern  biology  is  sum- 
marized by  the  story  of  these  two  greatest  of  biological 
generalizations. 

THE   CELL-THEORY   IN   ZOOLOGY 

The  doctrine  termed  the  Cell-Theory  postulates  that  the 
living  substance  exists,  almost  without  exception,  in  the 
form  of  microscopic  units  known  as  cells.  This  cellular 
structure  was  discovered  in  plants  by  the  microscopists  of  the 

2  Wilson,  E.  B.,  "The  Cell  in  Development  and  Inheritance,"  p.  1. 


THE  CELL-DOCTRINE  121 

seventeenth  century.  Hooke,  Leeuwenhoek,  Grew,  and  Mal- 
pighi  recorded  the  presence  of  cells  without  recognizing 
them  as  universal.  The  simplest  organisms,  which  consist  of 
but  a  single  cell,  were  studied  for  more  than  a  century  and  a 
half  before  their  cellular  nature  was  recognized.  Cells  and 
their  nuclei  were  described  in  many  plants  and  in  a  few  ani- 
mals, during  the  first  third  of  the  nineteenth  century.  But 
it  was  not  until  1838  that  a  cell-theory  was  promulgated  for 
the  animal  body  by  Theodor  Schwann,  and,  in  the  following 
year,  for  the  plant  body  by  Matthias  Schleiden.  The  value 
of  this  generalization  was  at  once  apparent.  It  unified  and 
explained  observations  of  the  most  diverse  sort  throughout 
organic  nature,  giving  an  explanation,  first,  of  microscopic 
structure  and,  second,  of  embryological  development. 

Since  its  universal  acceptance  toward  the  middle  of  the 
nineteenth  century,  the  theory  has  found  confirmation  in 
whatever  direction  the  microscope  has  been  turned.  The 
cell  is  now  recognized  as  the  unit  of  structure,  and  so  of 
function,  throughout  the  organic  world.  The  problems  of 
embryology,  of  physiology,  of  pathology,  and  even  of 
heredity  are,  in  the  last  analysis,  cell  problems.  The  domain 
of  cellular  biology  has  steadily  expanded,  until  there  exists  an 
apparently  inexhaustible  field  of  investigation  in  cell  chem- 
istry and  physics,  as  well  as  the  structural  features,  which 
remain  unexplored. 

Cells  were  originally  observed  in  the  form  of  walled  com- 
partments, to  which  the  term  cell  was  fittingly  applied.  It 
was  soon  realized,  however,  that  the  walls,  which  had  seemed 
the  important  feature,  were  not  universal.  The  earlier  con- 
cept of  a  series  of  minute  cavities  was  displaced  before  the 
middle  of  the  nineteenth  century  by  the  discovery  that  the 
protoplasm,  or  semi-fluid  material  enclosed  within  the  wall, 
and  not  the  wall  itself,  constituted  the  living  stuff.  More- 
it  was  found  that  the  walls,  particularly  in  animal  cells, 
were  frequently  represented  by  membranes  so  delicate  as 
to  seem  non-existent.  A  "mass  of  protoplasm  containing  a 


122 


THE  SCIENCE  OF  BIOLOGY 


cc. 


nucleus"  came  to  be  recognized  as  the  fundamental  unit,  and 
the  inappropriateness  of  calling  such  a  body  a  cell  was 
acknowledged  (Fig.  11).  But  the  word  had  become  so 
firmly  established  in  terminology,  that  it  has  successfully 

resisted  both  earlier  and 
later  efforts  directed  toward 
the  substitution  of  a  more 
suitable  term. 

The  idea  of  animal  and 
plant  bodies  being  made  of 
many  independent,  but  at 
the  same  tune  interdepend- 
ent,  units,  known  as  cells, 
thus  came  into  existence. 
The  simplest  organisms 
were  found  to  be  composed 

FIG.  11.  Diagrammatic  Figure  of  a  Cell.  of  -f^ip  rpiiq       jn    o-pnpml 

Ce,  centrosome;  chn,  chondriosome;  ]  ^'      lr 

chr,    chromatin;    mb,    metaplasmic  it  was  established  that  cells, 

body;  nu,  nucleus;  pi,  plasmosome;  ]fce    the    bricks    of  a    wall, 
cy,  cytoplasm. 

make  up  the  whole  living 

structure.  It  was  evident,  therefore,  that  cell  activities, 
collectively  or  individually,  formed  the  basis  for  the  activi- 
ties of  any  living  organism.  All  functions  of  organisms 
were  seen  to  be  cell  functions  in  the  ultimate  analysis. 
Such  a  generalization  laid  new  foundations  for  biological 
science. 

As  the  universality  of  cells  became  apparent,  their  mode 
of  origin  was  recognized  as  a  problem  demanding  solution. 
The  formulators  of  the  cell-theory  had  supposed  that  cells 
arose  by  differentiation  from  a  formative  substance.  Within 
a  few  years  it  was  proved  that  cells  arise  only  from  pre- 
existing cells  by  a  process  of  cell  division.  Later,  it  was  dis- 
covered that  nucleus  arises  from  nucleus  in  a  similar  manner. 
Following  this,  it  was  shown,  that  ovum  and  spermatozoon 
are  merely  specialized  cells.  Finally,  it  was  ascertained 
(1875)  that  fertilization  consists  in  the  union  of  a  single 


THE  CELL-DOCTRINE  123 

spermatozoon  with  a  single  ovum,  and,  more  important 
still,  in  the  union  of  nucleus  with  nucleus.  The  continuity 
between  generations  was  thus  proved  to  be  a  continuity  of 
cells. 

The  foregoing  facts  constitute  the  foundation  for  the 
modern  concept  of  development.  The  material  basis  of 
ontogeny,  and  so  of  heredity,  is  cellular.  All  present  theories 
of  differentiation,  growth,  heredity,  and  the  like,  rest  upon 
the  broader  hypothesis  of  cellular  organization.  Like  the 
evolutionary  theory,  the  cell-theory  became  at  once  a  great 
unifying  generalization.  The  biologist  recognized  the  cells, 
not  only  as  units  of  structure  and  function  in  the  existing 
organism,  but  as  a  key  to  the  past.  The  living  substance 
was  revealed  as  a  continuous,  never-dying  stuff,  which  could 
be  traced  back  through  many  cell  divisions  to  egg  and 
spermatozoon,  and  thence  to  preceding  generations.  These 
facts  led  to  the  inference  that  the  protoplasm  had  persisted 
through  an  infinitude  of  cell  divisions  since  its  first  cell 
organization  in  the  remote  past.  Thus  it  consists  of  the 
mortal  body-cells,  which  constitute  the  adult  bodies  exist- 
ing at  any  given  moment,  and  of  the  potentially  immortal 
ova  and  spermatozoa.  The  origin  and  nature  of  these  germ- 
cells,  their  union  in  fertilization,  and  the  processes  of  cell 
division  and  differentiation  by  which  the  adult  organism 
arises  from  the  single  cell  formed  by  their  union,  are  all  parts 
of  the  cell-theory  as  developed  during  the  last  fifty  years. 
Cellular  phenomena  will  probably  remain  an  outstanding 
feature  of  the  developmental  process  for  all  time. 

The  establishment  of  a  cellular  continuity  between  suc- 
cessive generations  was  a  final  blow  to  the  recurrent  theory 
of  spontaneous  generation.  The  results  obtained  by  Spal- 
lanzani  (1777),  by  Franz  Schultze  (1836),  and  later  by 

ann  and  others,  who  found  that  life  came  only  from  pre- 
existing life,  were  for  the  first  tune  fully  explained.    It  was 

a  that  the  living  substance  was  composed  exclusively 
of  cells  and  that  it  arose  solely  by  division  of  antecedent 


124 


THE  SCIENCE  OF  BIOLOGY 


cells.  The  fact  that  living  organisms  arise  only  from  parent 
organisms  was  explained,  when  the  bodies  of  animals  and 
plants  were  shown  to  consist  of  living  cells  which  arose  by 
cell  division.  The  inherent  falsity  of  spontaneous  generation 
was  thus  shown  as  the  cell-theory  became  extended  to  the 
entire  field  of  development. 


FIG.  12.  Development  of  the  Frog.  Showing  probable  relations  of  axes  of  egg 
to  axes  of  adult  body.  A,  the  egg  or  ovum  at  time  of  fertilization  by 
spermatozoon  (s);  B,  entrance  of  sperm;  C,  differentiation  of  certain 
portions  of  adult  body  (c,  en,  n,  and  m),  and  approach  of  male  and  female 
nuclei;  D,  two  cell  stage;  E,  eight  cell  stage,  F,  early  blastula;  G,  early 


THE  CELL-DOCTRINE 


125 


TOO 


gastrula;  //,  early  embryo;  7,  late  embryo  with  dotted  outline  of  an  early 
tadpole  stage.  The  arrow  passing  through  the  vertical  axis  and  polar 
bodies  of  the  egg  in  A  and  B  is  drawn  in  same  position  with  reference  to 
parts  of  egg  and  embryo  in  G,  H,  and  7.  The  poles  of  the  unfertilized  egg 
can  thus  be  traced  to  regions  of  the  embryo  and  thence  to  the  adult. 
A  and  P,  D  and  V,  in  A  and  /  show  the  anterior-posterior  and  dorso-ventral 
areas  appearing  in  egg  and  tadpole  respectively.  Note  rotation  of  egg 
axis  which  occurs  in  stages  represented  by  H,  bringing  dorsal  surface  to 
its  definitive  position  in  7.  Bp,  blastopore  (opening  to  primitive  gut 
cavity);  c,  notochord  (primitive  backbone);  e,  enteron  (gut  cavity);  en, 
endodenn  (lining  of  gut  cavity);  ra,  mesoderm;  mo,  mouth;  n,  nervous 
system;  n  cf  and  n  9,  male  and  female  pronuclei  of  odsperm;  s,  sper- 
matozofin  (nucleus  entering  egg,  flagellum  remaining  outside);  sc,  seg- 
mentation or  blastula  cavity.  (Redrawn  with  modifications  from  Conklin, 
"Heredity  and  Environment.") 

During  the  last  fifty  years,  the  cellular  basis  of  develop- 
ment and  hence  of  heredity  has  been  ascertained  in  mar- 
velous detail.  The  adult  features  of  animals  have  been 
traced  back  to  their  origin  in  a  few  cells  or  even  in  single 
cells.  The  e^-cell  has  been  studied  before  and  after  fertili- 
zation; and  the  cell-lineage  of  the  adult  parts  has  been  made 
knnwn.  In  the  frog,  for  example,  the  unfertilized  egg  ex- 


126  THE  SCIENCE  OF  BIOLOGY 

hibits  no  foreshadowing  of  the  adult  body  (Fig.  12  A). 
When,  however,  the  spermatozoon  has  entered  (in  this 
instance  the  entrance  occurs  at  some  point  on  the  equator) 
differentiation  begins.  Stimulated  by  the  entrance  of  the 
sperm,  the  protoplasm  changes  its  appearance  to  such  a 
degree  that  the  axes  and  certain  regions  of  the  adult  body 
can  now  be  recognized  (Fig.  12  B).  Portions  of  the  egg 
which  later  form  the  anterior,  posterior,  dorsal,  and  ventral 
areas,  are  discernible  and  may  be  referred  to  the  earlier 
stage  (Fig.  12  A).  Areas  from  which  are  to  be  formed  the 
nervous  system  (n),  primitive  backbone  (c),  and  germ-layers  of 
the  early  embryo  appear  within  the  egg,  even  before  the 
male  and  female  nuclei  have  completed  their  union.  Thus, 
before  any  division  of  the  egg-cell  has  occurred  the  general 
regions  of  the  adult  body  have  been  delineated  (Fig.  12  A-I). 
The  cell  divisions  which  ensue  parcel  out  these  predestined 
regions  to  groups  of  cells  which  develop  into  the  adult  parts. 
In  some  cases  a  few  cells  or  portions  of  cells  represent  for  the 
time  being  an  entire  organ  or  group  of  organs  (Fig.  12  E 
and  F).  But  this  is  not  remarkable  since  the  original 
fertilized  egg-cell  or  oosperm  represents  the  entire  adult 
body.  What  is  of  interest  for  the  present  illustration  is 
that  the  steps  from  single-celled  oosperm  to  many-celled 
adult  have  been  followed  with  such  completeness.  The 
cellular  continuity  between  generations  is  known  to  these 
finest  details.  Embryological  problems  have,  therefore, 
been  reduced  to  cell  problems. 

But  analysis  of  the  cellular  basis  of  development,  and  thus 
of  heredity,  has  been  extended  to  structures  and  activities 
within  the  individual  cell.  The  basal  fact  of  development 
is  that  the  many-celled  adult  arises  from  a  single  cell  formed 
by  the  union  of  ovum  and  spermatozoon.  These  germ-cells 
are  the  most  wonderful  of  cells,  because  of  their  potential- 
ities. They  are,  as  it  were,  vehicles  of  inheritance,  by  which 
the  characteristics  of  one  generation  pass  to  another. 
Naturally  enough,  their  structure  and  mode  of  origin  has 


THE  CELL-DOCTRINE  127 

been  searchingly  examined.  The  question  has  been  asked 
whether  any  one  portion  of  the  germ-cell  is  more  important 
than  another.  The  answer  is  surprisingly  definite.  The 
material  composing  the  nucleus  rather  than  the  cytoplasm 
seems  the  primary  agency  in  development  (Fig.  11).  And 
within  the  nucleoplasm  a  stainable  substance,  the  chromatin, 
is  the  more  important.  In  the  intervals  between  cell  divi- 
sions the  chromatin  appears  to  exist  in  the  form  of  stainable 
granules.  But  with  the  onset  of  cell  division  it  takes  the 
form  of  definite  bodies,  the  chromosomes  (Fig.  13  B,  C,  D). 
Although  the  chromosomes  have  been  traced  through  the 
non-dividing  period  in  only  a  few  instances,  there  are 
theoretical  reasons  for  believing  that  their  individual  exist- 
ence is  always  preserved  during  these  intervals  when  they 
cannot  be  readily  recognized  as  chromosomes  (Fig.  13  A 
and  F).  Chromatin,  at  least,  persists  and  from  it  chromo- 
somes are  formed  at  every  period  of  division.  What  is 
termed  the  Chromosome  Theory  of  heredity  has  been  devel- 
oped, because  the  behavior  of  the  chromosomes  is  correlated 
with  end  results  in  inheritance. 

The  more  general  evidence,  which  points  to  the  chromo- 
somes as  the  bearers  of  the  heritage,  can  be  appreciated 
upon  brief  explanation.  When  fully  matured,  the  male  and 
female  germ-cells  are  very  dissimilar  in  appearance.  The 
ovum  is,  save  for  the  presence  of  non-living  food  material 
called  yolk,  a  very  typical  cell  (Fig.  12  A).  The  spermato- 
zoon on  the  other  hand  is  a  most  atypical  cell  (Fig.  14  A, 
B,  and  D).  It  consists  of  a  mass  of  condensed  nuclear 
material,  almost  wholly  chromatin,  and  a  relatively  small 
amount  of  cytoplasm.  At  the  time  of  fertilization,  the  so- 
called  head  and  the  middle-piece  of  the  spermatozoon  enter 
the  egg,  while  the  tail  or  flagellum  usually  remains  on  the 
outside  playing  no  further  part  in  development  (Fig.  12 
B  and  C).  While  the  middle-piece  almost  invariably  enters 
the  ovum  along  with  the  head  or  nucleus,  this  seems  un- 
necessary even  where  it  normally  occurs.  The  essential 


128 


THE  SCIENCE  OF  BIOLOGY 


FIG.  13.  Mitotic  or  Indirect  Cell  Division.  A,  cell  with  nucleus  in  resting 
phase;  B,  prophase,  chromosomes  appearing  and  two  centrosomes  that 
have  arisen  by  division  of  the  single  centrosome  in  A  now  separating  with 
formation  of  spindle;  C,  metaphase,  chromosomes  at  equator  of  fully 
developed  spindle  are  now  split  lengthwise;  D,  anaphase,  the  separation  of 
the  two  daughter  groups  of  chromosomes;  E,  telophase,  massing  of  two 
daughter  groups  and  division  of  the  cytoplasm;  F,  completion  of  the 
process  with  return  of  nucleus  to  resting  phase.  (Redrawn  with  modifica- 
tions from  figures  by  Agar,  "Cytology.") 


THE  CELL-DOCTRINE 


129 


aes. 


acs. 


FIG.  14.  Spermatozoa.  A  and  B,  human  spermatozoon,  two  views  showing 
flattening  of  head  (nucleus) ;  C,  stage  in  development  of  spermatozoon  of 
guinea-pig,  showing  what  is  more  obviously  a  cell;  D,  diagrammatic 
figure  of  fully  formed  spermatozoon  of  guinea-pig.  Acs,  acrosome;  a  /., 
axial  filament;  cy,  cytoplasm;./?,  flagellum,  n,  nucleus;  ra.  p.,  middle  piece. 
(A  and  B  after  Retzius;  C  and  D  redrawn  from  Agar  after  Meves.) 

item  in  fertilization  is  the  entrance  of  a  sperm-nucleus  and 
its  union  with  the  nucleus  of  the  ovum. 

At  first  glance  the  nuclei  of  ovum  and  spermatozoon  ap- 
pear disproportionate  in  size.  When,  however,  the  stages  of 
the  sperm-cells  within  the  testis  (Fig.  14  C)  are  studied,  it 
appears  that  the  chromatin  of  the  spermatozoon  is  both 
quantitatively  and  qualitatively  equivalent  to  the  chromatin  of 
the  ovum  of  the  same  species.3  When  the  primitive  male 
cells  are  made  into  definitive  spermatozoa,  their  nuclei 
become  more  condensed,  but  their  actual  chromatin  content 
remains  the  same  (Fig.  14  C  and  D).  This  conclusion  is 
further  supported  by  the  fact  that  the  nucleus  of  the  sper- 
matozoon increases  in  size  after  entering  the  egg,  so  that 
before  union  the  male  and  female  pronuclei  are  again  seen 

1  The  only  exceptions  to  this  appear  to  be  the  cases  where  the  chromosome 
formulas  of  the  ovum  and  spermatozoon  differ  because  of  the  presence  of  the 
sex-determining  chromosomes  which  occur  in  certain  species.  See:  page  204 
of  the  present  volume. 


130 


THE  SCIENCE  OF  BIOLOGY 


to  be  quantitatively  and  qualitatively  equivalent.     Fig. 
12  A,  B,  and  C  is  diagrammatic  in  this  particular. 

It  thus  appears  that  the  oosperm,  from  which  the  adult 
organism  arises  by  cell  division  (Fig.  12),  is  composed  of 


FIG.  15.  Male  and  Female  Pronuclei  in  Oosperm 
and  Early  Cleavage.  A,  oSsperm  at  be- 
ginning of  first  cleavage  showing  the  male 
and  female  pronuclei;  B,  metaphase  of 
same;  C,  telophase;  D,  the  two  cell  stage 
with  one  cell  still  showing  a  double  nucleus. 
(Redrawn  from  figures  by  Agar  after 
Amma.) 

equal  amounts  of  chromatin  derived  from  the  two  parents, 
but  of  a  very  disproportionate  amount  of  cytoplasm.  If  the 
latter  were  important  as  the  vehicle  by  which  the  potential- 
ities of  the  adult  are  carried  over,  we  should  expect  an  animal 
to  inherit  a  disproportionate  number  of  its  adult  features 
from  the  female  parent.  This  is  not  the  case.  In  general, 
the  inherited  features  appearing  in  the  adult  are  equally  bal- 
anced. We  therefore  suspect  that  the  chromatin  which  is 
the  material  within  the  germ-cells  that  comes  in  equal 
quantities  from  the  two  sexes  is  the  basis  of  heredity. 
A  further  word  of  explanation  may  be  given  regarding  the 


THE  CELL-DOCTRINE  131 

chromosomes.  These  bodies  appear  at  the  time  of  cell 
division  in  definite  number  and,  with  certain  exceptions,  in 
pairs  (Fig.  13).  The  number  is  as  definite  a  characteristic 
of  a  species  as  five  fingers  or  toes  or  any  other  feature  which 
is  numerically  constant.  The  pairing  is  very  clear  hi  cases 


FIG.  16.  Chromosomes  of  Drosophila.  Diagram- 
matic representation  of  the  male  and  female 
groups.  Note  that  the  chromosomes  are  in 
pairs,  three  of  which  would  be  readily  distin- 
guishable if  the  entire  eight  chromosomes  were 
irregularly  arranged.  The  pairs  marked  XX 
and  XY  are  the  sex  chromosomes.  The  hook 
on  the  Y  is  a  convention.  (Redrawn  from  a 
figure  by  Morgan,  et  a/.). 

where  the  chromosomes  are  of  different  sizes  and  shapes 
(Fig.  16).  Doubling  of  the  number  is  prevented,  at  the  tune 
of  fertilization,  by  the  fact  that  hi  the  final  stages  of  the 
ripening  ovum  and  spermatozoon  the  number  of  chromo- 
somes is  reduced  one-half.  Only  one  member  of  each  pair  of 
chromosomes  goes  to  a  germ-cell.  When  sperm-nucleus 
unites  with  egg-nucleus,  the  full  number  of  chromosomes  is 
restored  and  also  the  pairs.  The  oosperm  is  thus  like  all 
the  later  products  of  its  division.  When  it  passes  into  the 
two,  four,  eight,  and  sixteen  cell  stages,  and  so  to  the  adult, 
the  chromosomes  divide  with  every  cell  division  (Fig.  13). 
Each  cell  of  the  adult  body  possesses  a  nucleus  whose 
chromosomes  have  descended,  through  a  long  series  of  cell 
ions,  from  the  nucleus  of  the  one  cell  stage.  This 
originated  by  a  union  of  equivalent  chromosomes  from  egg 


132  THE  SCIENCE  OF  BIOLOGY 

and  spermatozoon.  The  pairing  of  chromosomes  in  all  the 
cells  of  the  body  (Fig.  16)  is  thus  explained  by  the  bisexual 
origin  of  the  chromosomes. 

When  we  look  at  some  part  of  an  animal's  body  it  some- 
times seems  to  exhibit  a  mosaic  of  characters,  seemingly 
inherited  from  both  parents.  In  the  human  hand,  for  ex- 
ample, the  shape  of  the  fingers,  the  texture  of  skin,  the 
pigmentation  are,  let  us  say,  those  of  the  mother.  The 
nails,  hairiness,  and  double- jointed  thumb  are  those  of  the 
father.  The  biological  conclusion  is  that  such  mosaics  of 
features  constituting  adult  bodies  have  been  inherited  in 
approximately  equal  numbers  from  the  two  parents.  This 
is  the  external  fact  that  we  see  in  human  beings  and  in  the 
animals  within  a  breeding  pen.  There  could  hardly  be  a 
more  precise  basis  for  such  an  equal  inheritance  of  macro- 
scopic features  than  the  microscopic  chromosomes,  within 
every  cell  of  the  body  and  descended  equally  from  the  two 
parents. 

Evidence  for  the  chromosome-theory  is  even  more  de- 
tailed. In  the  fruit  fly  Drosophtta,  which  has  been  the  object 
of  more  extended  studies  in  heredity  than  any  other  animal, 
there  are  four  pairs  of  chromosomes  (Fig.  16).  The  breeding 
results  show  four  groups  of  heritable  qualities,  which  go 
together  in  inheritance  save  for  certain  exceptions  that  do  not 
vitiate  the  chromosome-theory.  These  groupings  or  linkages 
are  shown  in  the  accompanying  table.  It  happens  that  the 
size  of  the  chromosomes  in  the  four  pairs  (Fig.  16)  roughly 
parallels  the  size  of  the  four  groups  of  heritable  characters  as 
thus  far  discovered.  This  may  not  be  significant,  but  one 
suspects  that  the  small  group  of  linked  characters  is  borne  by 
the  small  pair  and  the  large  group  by  one  of  the  large  pairs  of 
chromosomes.  In  view  of  all  the  facts,  the  chromosomes 
appear  to  be  the  most  important  factor  in  heredity.  Through 
them,  rather  than  through  the  cytoplasm,  the  hereditary 
constitution  seems  to  be  transferred  from  one  generation  to 
the  next. 


THE  CELL-DOCTRINE 


133 


GROUPS  OF  CHARACTERS  LINKED  TOGETHER  IN  INHERITANCE 
IN  THE  FRUIT  FLY,  DROSOPHILA  AMPELOPHILA.  Each 
of  the  terms  listed  below  is  a  characterization  of  a  heritable  peculiarity. 
(After  Morgan  et  al.,  "  Mechanism  of  Mendelian  Heredity.") 


GROUP  I 


GROUP  II 


GROUP  III 


Abnormal 

Antlered 

Band 

Bar 

Apterous 

Beaded 

Bifid 

Arc 

Cream  III 

Bow 

Balloon 

Deformed 

Cherry 

Black 

Dwarf 

Chrome 

Blistered 

Ebony 

Cleft 

Comma 

Giant 

Club 

Confluent 

Kidney 

Depressed 

Cream  II 

Low  crossover 

Dotted 

Curved 

Maroon 

Eosin 

Dachs 

Peach 

Facet 

Extra  vein 

Pink 

Forked 
Furrowed 

Fringed 
Jaunty 

Rough 
Safranin 

Fused 

Limited 

Sepia 

Green 

Little  crossover 

Sooty 

Jaunty  I 

Morula 

Spineless 

Lemon 

Olive 

Spread 

Lethal  1 

Plexus 

Truncate  intens. 

Lethal  la 

Purple 

Trident 

Lethal  2 

Speck 

White  head 

Lethal  3 

Strap 

White  ocelli 

Lethal  3a 

Streak 

Lethal  4 

Tip 

Lethal  5 

Trefoil 

Lethal  6 

Truncate 

Lethal  7 

Vestigial 

Lethal  B 

Lethal  Sa 

Lethal  Sb 

Lethal  Sc 

Miniature 

Notch 

Reduplicated 

Ruby 

Rudimentary 

ed 

Short 

Skoo 

Spoon 

Spot 

Tan 

Truncate  iritena. 

Vermilion 

White 

Yrllow 

GROUP  IV 

Bent 
Eyeless 


It   i<  not  impossible  that  certain  features  of  hereditary 
make-up  may  be  carried  in  the  cytoplasm.     The  earliest 


J34  THE  SCIENCE  OF  BIOLOGY 

structures  of  the  embryo  appear  to  be  determined  by  some- 
thing within  this  extra-nuclear  material  of  the  ovum  (Fig. 
12).  But  the  amazing  parallel  between  the  behavior  of  the 
microscopic  chromosomes  and  the  gross  features  inherited 
by  the  adult  is  enough  to  convince  the  majority  of  biologists 
that  the  chromosome-theory  must  be  accepted  as  a  working 
hypothesis  of  the  mechanism  of  heredity. 

The  peculiarities  of  Mendelian  inheritance  are  explicable 
in  terms  of  chromosomes.  Mendel's  law  may  be  illustrated 
by  the  inheritance  of  feather  color  hi  a  cross  between  two 
particular  varieties  of  poultry,  one  of  which  is  black  and  the 
other  a  white  with  black  splashes  (Fig.  17  PI).  This  is  not 
one  of  the  cases  originally  described  by  Mendel,  who  worked 
exclusively  with  plants,  but  it  is  one  of  the  best  for  intro- 
ductory purposes.  When  individuals  of  the  black  or  the 
white  type  are  bred  among  themselves  the  offspring  are 
black  and  white  respectively,  showing  that  black  and  white 
are  pure.  But  when  one  of  these  blacks  is  bred  with  a  white, 
100%  of  the  resulting  offspring  (Fi)  are  blue.  This  seems  like 
blended  inheritance.  We  should  naturally  expect  that  blue 
crossed  with  blue  would  give  blue  in  subsequent  genera- 
tions. But  Mendelian  heredity  is  not  of  this  nature. 

The  result  which  appears  when  the  Fi  blues  are  bred 
together  illustrates  the  distinctive  feature  in  Mendelian 
heredity.  If  the  numbers  are  sufficient,  a  theoretical  ratio 
of  1  Black:  2  Blue:  1  White  is  approximated.  The  blacks 
of  this  F2  generation  give  only  pure  blacks  when  bred  among 
themselves,  the  whites  only  pure  whites.  A  black  bird  of 
this  generation  is  as  pure  black  as  its  black  grandparent, 
and  the  same  is  true  of  the  white.  Segregation  of  the  black 
from  the  white  has  occurred.  The  seeming  blend  of  the  FI 
generation  was  not  permanent,  although  similar  individuals 
comprise  the  50%  of  Blues  hi  the  F2.  These  F2  blues  when 
bred  among  themselves  give  the  same  results  as  the  FI  blues, 
namely,  25%  Black:  50%  Blue:  25%  White.  The  results 
obtained  by  breeding  these  F3  individuals  are  as  previously 


THE  CELL-DOCTRINE 


135 


25  %  Black  50  %  Blue 


White 


The  same  in  subsequent  generations 

PIG.  17.  Mendelian  Heredity  in  Coloration  of  Blue  Andalusian  Fowl.  Aa 
shown  by  the  figure  the  blue  andalusian  cannot  be  established  as  a  breed, 
because  it  is  the  hybrid  produced  by  crossing  a  black  and  a  white  breed 
together  and  because  Mendelian  segregation  is  continually  separating 
out  pure  whites  and  blacks  in  subsequent  generations.  The  breeder 
can,  however,  secure  100  per  cent  of  blue  andalusians  by  crossing  ilic 
white  and  black.  P',  first  parental  generation;  F',  etc.,  first  filial  and 
subsequent  filial  generations. 


136  THE  SCIENCE  OF  BIOLOGY 

found:— Black  X  White  =  Blue;  Blue  X  Blue  =25%  Black: 
0%  Blue  :  25%  White;  Black  X  Black  =Black;  White  X 
vVhite=  White.  Similar  results  appear  in  all  subsequent 
generations. 

It  thus  appears  that  by  following  the  middle  percentage 
of  Blues  one  might  trace  an  exclusively  blue  line  of  descent 
through  many  generations.  If  nothing  were  known  of  the 
collaterals,  it  would  seem  that  the  black  and  white  had 
permanently  blended  into  blue.  In  small  numbers,  only 
blues  might  occur  and  what  is  essentially  a  non-blending 
type  of  inheritance  would  not  be  recognized  as  such.  This 
might  easily  be  the  case  in  records  of  human  families.  The 
essential  feature  in  Mendelian  heredity  is  this  absence  of 
blending,  as  shown  by  the  segregation  of  characters  in  the 
F2  and  in  subsequent  generations.  The  black  and  white 
are  united  in  the  hybrid,  but  the  latter  does  not  give  rise 
to  a  hybrid  race  that  breeds  true.  Hybrids  do  appear,  but 
along  with  them  are  the  two  original  stocks  hi  the  funda- 
mental 1:2:1  ratio.4 

The  adult  individual  may  thus  be  pure  or  hybrid.  In 
a  case  like  the  foregoing,  the  hybrid  is  recognized  by  its 
appearance.  In  some  cases  of  Mendelian  heredity,  a  phe- 
nomenon known  as  dominance  occurs.  One  member  of  a  pair 
of  heritable  qualities  dominates  the  other  to  such  an  extent 
that  the  hybrid  cannot  be  distinguished  from  a  pure  in- 
dividual of  the  dominant  type.  The  cross  between  gray  and 
white  mice  will  illustrate  the  facts.  In  this  instance  the 
gray  is  dominant,  the  white  recessive.5  The  results  are  as 

4  The  blue  fowls  described  above  have  long  been  known  as  Blue  Andalusians. 
This  supposed  breed  was  found  impossible  to  establish  in  any  degree  of  purity, 
because  when  Blue  Andalusians  were  bred  together  an  annoying  percentage  of 
black  and  of  white  birds  appeared.  The  mystery  is  now  explained.  The  blue 
is  a  Mendelian  hybrid  and,  therefore,  can  never  be  established  as  a  pure  breed, 
although  100%  of  blues  can  be  secured  by  the  simple  expedient  of  mating  the 
black  and  white  wasters  which  so  annoyed  the  breeders.  Blacks  and  whites 
are  the  pure  stock. 

6  There  is  no  adequate  explanation  of  why  one  member  of  a  contrasting  pair 
of  characters  should  thus  dominate  the  other.  It  is  simply  observed  to  be  so 


THE  CELL-DOCTRINE  137 

shown  in  Fig.  18.  The  FI  individuals  present  the  same  ap- 
pearance as  the  dominant  parent.  They  are  without  excep- 
tion gray,  as  though  they  were  pure  gray  mice.  The  reces- 
sive feature  is  as  though  absent.  But  these  FI  mice  cannot 
be  exactly  like  the  pure  grays  of  the  PI,  because  they  had 
one  white  parent.  There  must,  therefore,  be  two  kinds  of 
grays,  those  which  have  two  pure  gray  parents  and  those 
which  have  one  pure  gray  and  one  white  parent.  The  ex- 
istence of  two  kinds  of  grays  is  proved  by  the  subsequent 
breeding.  In  the  F2  generation  the  white  reappears.  The 
ratio  is  75%  gray  to  25%  white,  as  shown  by  the  figure. 
Study  of  these  F2  individuals  solves  the  problem.  The 
1:2:1  ratio  is  present,  only  it  is  masked  by  the  dominance 
of  gray  over  white.  The  75%  of  gray  mice  is  shown  by  breed- 
ing tests  to  consist  of  25%  pure  gray  like  the  Pi  grandparent, 
plus  a  50%  of  hybrid  grays  like  the  FI  generation.  The  real 
ratio  is:  25%  Pure  Dominants:  50%  Hybrid  Dominants: 
25%  Recessives.  The  recessives  are  always  distinguish- 
able, since  they  are  what  they  seem  to  be  on  the  outside. 
The  dominants  are  of  two  types — pure  and  hybrid.  Using 
symbols,  the  formula  1  DD  :  2  DR  :  1  RR,  or  1  GG  : 
2  GW  :  1  WW  expresses  the  facts.  It  happened  that 
dominance  appeared  in  the  cases  originally  described  by 
Mendel.  Its  importance  was  consequently  overrated. 
Many  instances  are  now  known  in  which  dominance  is 
incomplete  and  others  in  which  the  terms  dominant  and 

in  particular  cases.  Dominance  may  be  incomplete,  in  which  event  the  hybrid 
can  be  at  once  distinguished  from  the  dominant  parent.  Where  dominance  is 
complete  the  hybrid  and  the  dominant  parent  are  indistinguishable.  In  many 
cases  the  dominant  character  is  observed  to  be  the  presence  of  some  quality 
and  the  recessive  character  the  absence  of  the  same.  Thus  the  gray  mouse  has 
pigment  present  in  its  coat,  the  white  mouse  has  pigment  absent.  The  normal 
human  eye  has  pigment  present,  the  albino  eye  is  devoid  of  this  characteristic, 
so  that  albino  eyes  are  red  being  colored  only  by  the  blood.  These  facts  have 
led  to  the  pre&ence-and-absence  theory,  which  explains  dominance  in  the  manner 
Incomplete  dominance  in  the  Fj  generation  might  be  described  by 
that  often  a  single  dose  of  the  character  is  not  sufficient  to  give  complete 
to  the  dominant  parent. 


138 


THE  SCIENCE  OF  BIOLOGY 


Gray 
(GG) 

White 
(It) 

Gray 
(GW) 

Gray 
(GW) 

as  above 

FIG.  18.  Dominance  of  Gray  over  White  in  Inheritance  of  Coat  Color  in 
Mice.  The  squares  represent  adult  individuals;  the  letters  in  parentheses 
the  hereditary  constitution.  Pi,  P2,  Fi,  etc.,  as  in  Fig.  17. 


THE  CELL-DOCTRINE  139 

recessive  are  hardly  applicable,  since  the  hybrid  differs  from 
each  of  the  parents.  Segregation  not  dominance  is  the  essen- 
tial phenomenon  in  Mendelian  heredity. 

In  the  foregoing  account  the  results  visible  in  the  adult 
animals  have  been  described  without  explanation  of  the 
causes  for  this  peculiar  type  of  inheritance.  Mendel's  claim 
to  distinction  lies  in  the  fact  that  he  explained  the  ratios 
observed  in  segregation  in  a  manner  which  has  stood  the 
test  of  later  investigation.  He  knew  little  of  germ-cells.  In 
his  day  the  finer  details  of  fertilization  were  still  undis- 
covered. He  knew  merely  that  there  were  male  germs  or 
pollen  grains  and  female  germs  or  ovules.  His  explanation 
of  segregation  as  he  would  have  applied  it  to  the  Blue  An- 
dalusian,  had  he  worked  with  that  form,  may  be  stated  as 
follows:  The  original  black  individuals,  PI  in  Fig.  19,  are 
pure  blacks,  since  they  arise  from  a  black  ancestry  and  give 
only  black  descendants  when  bred  among  themselves.  The 
same  holds  for  the  Pi  whites.  The  symbol  B  B  may  be  used 
to  designate  the  black  adults  and  W  W  the  whites.  The 
doubling  of  the  letters  indicates  that  the  individuals  arise 
from  a  double  parentage.  The  blue  or  hybrid  would  then 
be  designated  as  B  W.  In  the  figure  referred  to,  the  squares 
stand  for  adult  individuals,  the  circles  for  germ-cells.  The 
latter  are  represented  with  the  character  B  or  W  taken 
once,  so  that  the  union  of  two  germ-cells  gives  the  B  B, 
B  W,  or  W  W  of  the  adult  formula.  We  are  now  in 
a  position  to  understand  Mendel's  explanation  of  segre- 
gation. 

The  PI  Blacks  (B  B)  arise  from  germ-cells  carrying  black; 
;ind  can  produce  only  germ-cells  carrying  black;  the  PI 
Whites  (W  W)  only  germ-cells  carrying  white.  The  hybrid, 
being  a  union  of  white-carrying  and  black-carrying  germs, 
is  B  W.  The  problem  now  arising  is  what  kind  of  germ- 
<M-11>  will  the  hybrid  (Fi)  produce.  Will  they  carry  both 
B  and  W  or  will  they  carry  B  or  W,  the  one  to  the  exclusion 
of  t  he  other?  The  first  hypothesis  does  not  aid  us  in  expla  i  1 1 


140  THE  SCIENCE  OF  BIOLOGY 

ing  segregation.  The  second  might  seem  improbable,  but 
it  can  be  accepted  if  it  explains  the  facts.  Suppose,  there- 
fore, that  the  F!  germ-cells  do  not  carry  B  and  W,  each 
diluted  one-half,  but  B  or  W,  and  that  the  two  kinds  of 
germ-cells  thus  produced  are  present  in  equal  numbers. 
The  case  would  then  be  as  shown  by  the  figure. 

Suppose  further,  that  each  kind  of  germ-cell  has  equal 
chances  in  fertilization.  Referring  to  the  diagonal  lines 
below  the  FI  germ-cells  (Fig.  19),  the  germ-cell  B  may  unite 
in  fertilization  with  another  cell  B  or  with  a  cell  W;  the  cell 
W  may  unite  with  a  cell  B  or  with  a  cell  W.  This  exhausts 
the  theoretical  possibilities  and  gives  the  ratio  1  B  B  :  2 
B  W  :  1  W  W,  by  the  laws  of  chance.  It  is  the  same  as  in 
matching  heads  and  tails  with  a  coin.  If  you  throw  heads 
your  opponent  may  throw  heads,  if  you  throw  heads  he  may 
throw  tails,  if  you  throw  tails  he  may  throw  heads,  if  you 
throw  tails  he  may  throw  tails;  which  would  be  1  H  H  :  2 
H  T  :  1  T  T  A  simple  algebraic  multiplication  also  illus- 
trates the  case:  (x  +  y)  X  (x  +  y)  =  x2  +  2xy  +  y2.  The 
fundamental  ratio  of  1:2:1  is  thus  explained  as  due  to 
chance  combinations  of  germ-cells  which  are  pure,  in  the 
sense  that  they  carry  that  which  determines  one  member  of 
a  contrasting  pair  of  adult  characters  to  the  exclusion  of  the 
other.  Purity  of  the  germ-cells  with  reference  to  the  paired 
unit-characters  of  the  adult  is  thus  a  primary  assumption  in 
the  explanation  of  Mendelian  ratios. 

The  principles  of  Mendelian  inheritance  as  thus  disclosed 
are:  (1)  that  an  adult  animal  possesses  unit-characters, 
which  (2)  segregate  in  heredity,  and  (3)  that  the  determin- 
ers for  contrasting  unit-characters  are  not  carried  together 
in  the  same  germ-cell.  An  adult  organism  is  a  mosaic  of 
these  unit-characters,  not  a  blend.  Contrasting  unit-char- 
acters may  be  combined  in  the  individuals  of  an  FI  genera- 
tion, but  in  subsequent  generations  they  segregate  in  definite 
ratios.  The  existence  of  the  ratios  is  explained  by  assuming 
that  the  germ-cells  are  thus  pure  with  respect  to  a  pair  of 


THE  CELL-DOCTRINE 


141 


Fio.  19.  Explanation  of  Mendelian  Segregation  in  Terms  of  Germ-Cells.  The 
cases  originally  studied  by  Mendel  \\ere  in  the  edible  pea.  The  present 
figure  shows  how  the  explanation  which  Mendd  offered  applies  to  the 
color  of  the  blue  andalusian  fowl.  Compare  with  Fig.  20,  showing  the 
modern  extension  of  Mendel's  explanation  in  terms  of  chromosomes. 
See  discussion  in  text.  Squares  represent  adult  individuals,  circles  ova 
and  spermatozoa.  Pi,  etc.,  as  in  previous  Figs. 


142  THE  SCIENCE  OF  BIOLOGY 

characters  like  the  black  and  white  and  that  combination 
occurs  by  chance. 

The  application  of  the  cell-theory  in  the  foregoing  explana- 
tion of  the  1:2:1  ratio  is  obvious.  The  germs  to  which 
Mendel  referred  in  general  terms  are  germ-cells.  Fertiliza- 
tion is  a  fusion  of  two  cells,  each  containing  one-half  the 
normal  number  of  chromosomes.  The  modern  chromosome- 
theory  of  heredity,  which  is  a  theory  of  intra-cellular  organ- 
ization, furnishes  an  even  more  precise  explanation  of  the 
phenomena.  The  most  important  discoveries  since  the 
work  of  Mendel  have  been  those  relating  to  the  chromosomes 
in  heredity. 

In  illustration  of  the  relationship  between  chromosome 
behavior  and  Mendelian  heredity,  a  pair  of  characters 
may  be  arbitrarily  represented  by  A  and  a.  The  use  of  the 
large  letter  expresses  the  fact  that  A  is  dominant  while  a  is 
recessive,  The  use  of  two  letters  of  the  same  sort,  rather 
than  two  different  letters,  shows  that  A  and  a  are  a  con- 
trasting pair  of  Mendelian  unit-characters.  The  pure  adults 
would,  therefore,  be  designated  respectively  as  A  A  and  aa; 
the  hybrids  as  A  a.  Suppose  the  number  of  chromosomes  in 
the  body  cells  is  four  pairs,  which  means  four  single  chromo- 
somes to  a  germ-cell,  i.  e.,  one  member  of  each  pair  (cf. 
Fig.  16).  The  case  may  be  represented  as  in  Fig.  20,  again 
using  squares  for  adults  and  circles  for  germ-cells.  The 
addition  of  globular  bodies  indicates  the  chromosomes  as 
they  occur  in  every  cell  of  the  adult  body  and  in  the  germ- 
cells. 

Assume  that  the  A  determiner  is  carried  in  one  of  the 
pairs  of  chromosomes  of  the  dominant  individual  and  the  a 
determiner  in  the  corresponding  chromosomes  of  the  reces- 
sive. This  may  be  indicated  by  writing  the  letters  upon  the 
chromosomes  in  question.  When  reduction  in  the  number  of 
chromosomes  occurs,  during  the  final  ripening  of  ova  and 
spermatozoa,  the  result  is  as  shown  in  the  PI  germ-cells  of 
Fig.  20.  Each  germ-cell  possesses  but  one  of  the  chromo- 


THE  CELL-DOCTRINE 


143 


Fio.  20.  Explanation  of  Mcndclian  Segregation  in  Terms  of  Chromosome*. 
The  number  of  chromosomes  is  taken  as  four  pairs  in  cells  of  adult  body, 
reduced  to  one  member  of  each  pair  in  the  ova  and  spermatozoa.  See 
discussion  in  text.  Squares  and  circles  as  in  previous  figure. 


144  THE  SCIENCE  OF  BIOLOGY 

somes  to  which  the  characters  have  been  assigned,  and  hence 
what  might  be  described  as  a  single  dose  of  the  character  in 
question.  Union  of  the  germ-cells  to  form  the  FI  adult 
produces  an  A  a  combination  in  this  pair  of  chromosomes. 
The  germ-cells  of  the  FI  will  be  as  shown,  because  reduction 
of  the  chromosomes  to  one-half  the  adult  number  occurs 
by  disjunction  of  the  members  of  the  pairs.  Combination 
of  these  FI  germ-cells  will  occur  in  the  1:2:1  ratio,  as  indi- 
cated by  the  F2  adults  of  the  figure,  on  the  assumption  of 
their  union  by  the  laws  of  chance. 

Thus  the  arrangement  and  behavior  of  the  chromosomes 
is  of  such  a  nature  as  to  explain  segregation.  The  hypothe- 
sis that  the  determiners  for  adult  characters  are  carried  by 
the  chromosomes  is  justified  by  the  outcome.  The  chromo- 
somes are  distributed  in  a  manner  that  parallels  the  heredity 
of  the  members  of  a  contrasting  pair  of  unit  characters. 

The  foregoing  explanation  of  Mendelian  heredity  by 
means  of  chromosomes  is  an  explanation  in  terms  of  cells. 
Only,  the  analysis  has  gone  deeper  and  disclosed  the  portion 
of  the  cell  that  is  primarily  concerned.  The  diagnosis  is  more 
complete  than  has  been  indicated  here,  giving  consistent 
results  where  additional  pairs  of  characters  are  involved.6 
But  the  foregoing  explanation  is  sufficient  to  show  that  the 
mechanism  of  Mendelian  heredity  is  a  cellular  one.  Just  as 
the  visible  structure  and  functioning  of  the  body  are  refer- 
able to  microscopic  cells,  so  is  the  inheritance  of  structure 
and  function.  Development  consists  of  cell  division  and 
differentiation  from  a  single-celled  organism,  the  oosperm, 
to  a  many-celled  organism  the  adult  (Fig.  12).  There  is 
cellular  continuity  between  generations.  Herein  lies  the 
physical  basis  of  heredity.  It  seems  inconceiveable  that  a 
single  cell  should  contain  within  its  limits  an  organization 
capable  of  producing  an  adult  if  only  a  suitable  environ- 
ment is  provided.  But  where  adult  characteristics  are 

8  C/.  Table  on  p.  133  of  the  present  volume,  and  the  account  of  the  chro- 
mosome theory  of  sex  determination  on  p.  204. 


THE  CELL-DOCTRINE  145 

shuffled  about  as  in  Mendelian  heredity,  it  is  necessary  to 
suppose  not  only  that  the  adult  is  in  some  manner  contained 
within  the  germ  but  also  that  something  within  the  germ- 
cells  can  be  shuffled  in  a  corresponding  manner.  These 
somethings,  which  are  called  determiners,  genes,  or  factors, 
appear  to  be  located  in  the  chromosomes.  Superficially, 
development  is  a  process  of  building  the  adult  organism  a 
step  at  a  time — epigenesis.  When  examined  more  closely, 
it  is  a  coming  into  being  of  what  is  potentially  existent,  just 
as  the  dealing  of  hands  at  cards  is  the  production  of  an  end 
result  foreshadowed  by  an  arrangement  within  the  pack. 
To  this  extent  the  concept  of  preformation  is  applicable  to 
development.7 

If  the  cell  must  furnish  clues  to  the  resemblances  be- 
tween generations  it  must  also  furnish  clues  to  variation. 
Heredity  and  variation  are  simply  different  aspects  of  the 
reproductive  process.  Like  begets  like,  but.  not  just  like. 
We  often  speak  of  heredity  and  variation  as  conflicting 
forces.  They  are  merely  the  two  sides  of  development. 
Heredity  and  variation  are  the  initial  processes  in  evolution- 
ary change.  Explain  these  two  phenomena  and  you  explain 
the  starting  points  of  evolution.  Cell-theory  and  evolution- 
ary theory  here  meet.  The  discovery  of  a  cellular  mechan- 
ism for  Mendelian  heredity  establishes  a  continuity  between 
fields  of  biological  knowledge  which  are  at  first  glance 
distinct.8  Investigators  continue  to  approach  the  evolution- 

7  A  brief  discussion  of  the  modern  concept  of  the  relation  between  preforma- 
tion and  epigenesis  in  development  appears  on  p.  193  of  the  present  volume. 
Cf.  also:  Parker,  G.  H.,  "Biology  and  Social  Problems,"  Chapt.  Ill, 
Reproduction. 

•Recognition  of  cell  problems  as  related  to  evolutionary  problems  first 
appears  in  the  writings  of  August  Weismann  (1834-1914).  The  nature  of  the 
genetic  continuity  between  parent  and  offspring  having  been  established,  Weis- 
mann realized  that  once  in  each  generation  the  potentialities  of  the  individual, 
and  BO  of  the  race,  are  encompassed  within  the  limits  of  single  cells — the  ovum 
and  the  spermatozoon,  and  the  oiteperm  formed  by  their  union.  Whatever 
restrictions  subsequent  investigation  may  place  upon  his  conclusions,  Weis- 
mann will  remain  a  commanding  figure,  because  he  first  brought  into  correla- 
tion the  two  major  lines  of  biological  interest. 


146  THE  SCIENCE  OF  BIOLOGY 

ary  problem  from  the  side  of  adult  organization  rather  than 
from  the  side  of  individual  development.  But  the  fact  is 
acknowledged  that  evolutionary  origins  must,  in  the  last 
analysis,  be  explained  as  changes  originating  within  cells 
and  perpetuated  by  a  cellular  mechanism. 

RAMIFICATIONS   OF   THE    CELLrTHEORY 

Within  the  field  of  physiological  science,  as  well  as  in 
zoology,  applications  of  the  cell-theory  were  the  great 
achievement  of  the  nineteenth  century.  When  bodily 
activities  were  seen  to  be  nothing  but  cell  activities,  the 
way  was  opened  for  a  comprehensive  explanation  of  all 
general  functions  in  both  animals  and  plants.  Take  the 
production  of  a  secretion  such  as  saliva,  gastric  juice,  or 
perspiration:  The  older  physiologists  had  studied  the 
phenomena  which  were  visible  to  the  unaided  eye.  The 
nature  of  secretions  had  been  investigated,  so  far  as  chemi- 
cal knowledge  allowed.  Many  interesting  phenomena  had 
been  ascertained.9  There  remained  the  problem  of  how 
the  chemical  compounds  dissolved  in  the  water  of  a  partic- 
ular secretion  were  produced  and  secreted.  The  series  of 
chemical  changes  involved  in  the  process  is  still  incompletely 
known.  The  setting  can,  however,  be  described  in  terms 
of  cells. 

One  of  the  glands  hi  the  skin  of  a  frog  will  illustrate  what 
happens  hi  cases  where  the  secretion  is  passed  to  the  outside 
or  to  an  internal  cavity  like  the  stomach.  The  gland  in 
this  instance  is  relatively  simple,  consisting  of  a  flask- 

9  A  classical  example  is  the  work  of  the  American  physician,  William  Beau- 
mont, who  was  fortunate  in  having  under  observation,  for  some  years  following 
1822,  a  soldier  who  had  been  wounded  in  the  stomach  and  whose  wound  had 
healed  in  such  a  manner  that  an  orifice  remained  through  which  the  processes 
of  secretion  and  digestion  could  be  observed.  Many  problems  of  gastric 
digestion  are  still  investigated,  in  a  fashion  comparable  with  that  pursued  by 
Beaumont,  without  reference  to  the  origin  of  the  gastric  juice  within  the  cells, 
but  the  formation  and  liberation  of  any  secretion  is  a  cellular  function. 


THE  CELL-DOCTRINE 


147 


Secretion 


f Ctll 


FIG.  21.  Diagrammatic  Vertical  Section   through  Skin  of   Frog.     Showing 
cellular  structure  and  parta. 

shaped  cavity,  with  the  neck  opening  as  a  pore  on  the  outer 
surface  of  the  skin  (Fig.  21).  Lining  the  gland  is  a  single 
layer  of  cells.  Outside  is  a  network  of  capillaries,  through 
which  passes  a  constant  flow  of  blood.  Each  gland-cell 
produces  within  itself  a  substance,  which,  if  not  the  actual 


148  THE  SCIENCE  OF  BIOLOGY 

secretion,  contains  the  parent  chemical  compounds  out  of 
which  the  secretion  is  formed  as  it  passes  from  the  cell  into 
the  central  cavity.  The  gland-cell  is  like  a  factory,  which 
receives  certain  raw  material  delivered  by  a  common  carrier 
at  the  back  door,  and  transforms  it  into  a  product  that  is 
passed  out  on  the  other  side.  The  blood  is  the  carrier  of 
raw  material,  which  the  gland-cells  receive  and  which  they 
convert  into  the  secretion  exuded  into  the  cavity  of  the  gland 
and  thence  passed  to  the  outside.  A  substance  like  water, 
which  is,  of  course,  present  in  all  secretions,  passes  through 
the  cells  unchanged.  The  substances  distinctive  of  a  partic- 
ular secretion,  and  not  present  in  the  blood,  must,  obviously, 
be  manufactured  within  the  gland-cells  from  material 
received  from  the  blood.  The  gland-cell,  therefore,  re- 
sembles an  industrial  establishment  engaged  in  the  manufac- 
ture of  chemicals.  Some  of  the  physico-chemical  processes 
which  occur  in  cells  of  this  nature  are  well  established. 
Others  remain  to  be  discovered.  No  one  claims  that  having 
thus  localized  the  formation  of  a  secretion  within  the  cell, 
he  has  explained  the  ultimate  vital  phenomena.  The  point 
is  that  in  secretion,  as  in  other  vital  processes,  the  structural 
and  so  the  functional  basis  for  what  goes  on  is  a  cellular 
basis.  The  phenomena  of  muscle  and  nerve  might  be  traced 
in  like  manner  to  their  cellular  foundation.  Structure  and 
function  are  everywhere  explicable  in  terms  of  cells. 

The  science  of  physiology  was  thus  advanced  from  a  study 
of  gross  phenomena,  such  as  the  mass-contraction  of  a 
muscle,  the  conduction  of  a  nerve-impulse,  or  the  simple 
features  of  a  process  like  secretion,  to  an  examination  of 
cellular  activities  underlying  the  more  obvious  phenomena. 
The  publication  of  Verworn's  classical  work  upon  "  General 
Physiology,"  10  hi  which  the  problems  of  physiological 
science  were  attacked  as  cell  problems,  expressed  this  prog- 
ress from  the  study  of  functional  activity  in  the  mass  to  its 
study  within  the  cell.  It  also  indicated  the  advance  toward 

10Verworn,  M.,  "Allgemeine  Physiologic,"  1895. 


THE  CELL-DOCTRINE  149 

a  mechanistic  explanation  of  vital  phenomena.  For  what- 
ever one  may  think  of  the  relative  merits  of  vitalistic  and 
mechanistic  concepts  of  the  life-process,  the  history  of  biolog- 
ical science  shows  that  the  forward  steps  have  usually  con- 
sisted of  further  extensions  of  chemico-physical,  and  hence  of 
mechanistic,  explanations. 

This  development  within  the  science  of  physiology 
exerted  a  profound  influence  upon  the  progress  of  medicine. 
The  theory  of  cells  led  to  medical  advances  which  were  un- 
thought  of  at  an  earlier  period.  We  find  here  the  most 
advanced  phase  hi  that  control  of  nature,  which  may  distin- 
guish biological  science  hi  the  future.  During  recent  years 
the  physiologists  have  laid  the  foundations  for  changes  in 
medicinal  science  as  far-reaching  as  those  necessitated  by 
the  germ-theory  of  disease.  Then-  studies  in  nutrition,  in 
secretion,  in  the  chemistry  of  blood  and  tissue,  and  the  like 
are  restricting  the  art  of  medicine  and  forcing  progress  along 
the  lines  of  science.  These  investigations  could  never  have 
reached  their  present  state  in  the  absence  of  some  com- 
prehensive theory  of  microscopic  organization.11 

The  theory  that  certain  diseases  are  caused  by  minute 
organisms  or  germs,  living  as  parasites  within  the  bodies  of 
animals  and  plants,  has  been  intimately  associated  with  the 
theory  of  cells.  Analogies  between  the  spread  of  disease  and 
the  multiplication  of  living  organisms  were  long  recognized, 
without  being  explained.  For  centuries,  a  variety  of  dis- 
orders were  attributed  to  parasitic  worms,  although  the 
life-cycles  of  forms  like  tapeworms  were  not  ascertained 
until  the  middle  of  the  nineteenth  century.  Minute  para- 
sites had,  however,  been  observed  within  the  bodies  of 
larger  animals  since  the  early  days  of  the  microscope  The 
finding  of  bacteria  in  association  with  particular  diseases 
was,  therefore,  a  suspicious  circumstance.  The  Germ-Theory 
of  disease  was  established,  in  correlation  with  the  cell-theory, 
during  the  third  quarter  of  the  nineteenth  century. 

11  ('/.  IAV,  F.  S.,  "Scientific  Features  of  Modem  Medicine." 


150  THE  SCIENCE  OF  BIOLOGY 

The  confirmation  of  the  germ-theory  as  a  scientific  fact 
begins  with  Pasteur  (1822-1895).  Working  as  a  chemist, 
this  great  Frenchman  undertook  to  investigate  fermenta- 
tion. He  found  that  each  kind  of  fermentation,  had  asso- 
ciated with  it  a  particular  kind  of  organism.  Thus  the  wine- 
yeast  was  always  present  in  fermenting  wine,  the  brewer's 
yeast  in  beer,  the  bread-yeast  in  dough.  The  organisms 
were  necessary  for  the  process.  They  were  also  specific  for 
particular  fermentations.  The  so-called  diseases  of  fer- 
mentation, which  had  caused  such  heavy  losses  to  the  wine- 
makers  and  brewers  of  France,  were  caused  by  the  presence 
of  the  wrong  kind  of  organism  or  by  some  abnormality  of 
functioning  in  the  one  normally  causing  the  fermentation. 
The  grosser  features  of  the  process,  such  as  liberation  of  gas 
and  the  manner  in  which  a  little  leaven  could  leaven  the 
whole,  had  long  been  recognized.  Now,  the  chemical  proc- 
esses involved  and  their  causation  through  the  activities  of 
specific  organisms — yeasts  and  bacteria — were  made  known. 
The  decay  of  organic  matter,  and  its  accompanying  fer- 
mentation, was  explained  as  caused  by  microorganisms. 
The  idea  was  formed  that  diseases  in  man  and  domesticated 
animals,  as  well  as  in  wines  and  beer,  might  likewise  be 
caused  by  microscopic  germs. 

Following  his  work  upon  fermentation,  Pasteur  undertook 
the  study  of  a  disease  of  silk-worms,  which  had  caused  great 
financial  loss  to  the  silk-raisers  of  France.  He  proved  that 
there  were  two  specific  diseases  among  the  worms,  each 
of  them  caused  by  parasitic  bacteria.  The  problem  thus 
became  one  of  preventing  the  worms  from  becoming  in- 
fected, with  the  bacteria,  since  there  was  no  disease  save  as 
it  arose  from  the  parasitic  germs.  Pasteur  next  turned  his 
attention  to  the  disease  known  as  anthrax  and  again  dis- 
covered a  specific  germ,  the  Anthrax  bacillus.  Subsequent 
work  upon  rabies  and  other  diseases  led  to  the  preparation  of 
vaccines  for  particular  maladies.  In  this  manner  Pasteur 
and  his  successors  not  only  established  the  germ-theory  of 


THE  CELL-DOCTRINE  151 

disease  but  also  the  present  practice  of  vaccination  for  a 
variety  of  diseases.12 

The  germ-theory  of  disease  stimulated  renewed  interest 
in  the  problem  of  generation.  If  organisms  originated 
de  novo  or  spontaneously,  their  appearance  was  due  to  con- 
ditions within  the  medium  hi  which  they  appeared.  If  they 
arose  from  preexisting  organisms  by  reproduction,  their 
appearance  was  due  to  conditions  under  which  they  obtained 
entrance.  Pasteur  and  other  workers  during  the  sixties  and 
seventies  of  the  last  century  gave  the  death  blow  to  the 
theory  of  generation  de  novo.  Microscopic  forms  were 
shown  to  have  life-cycles  comparable  with  those  of  larger 
organisms.  Prevention  and  curation  in  a  large  class  of 
diseases  became  the  problem  of  preventing  the  entrance  and 
effecting  the  destruction  of  parasitic  germs.  Contagion  was 
at  length  explained. 

Remarkable  applications  of  the  above  principles  appeared 
in  surgery.  The  surgical  wards  of  the  hospitals  had  formerly 
been  veritable  pesthouses  for  wound-infections.  No  pre- 
cautions availed.13  Lord  Joseph  Lister  (1827-1912)  applied 
to  surgery  the  principles  discovered  by  Pasteur.  The  sup- 
puration of  a  wound  was  the  putrefaction  of  organic  ma- 
terial. Putrefaction  elsewhere  was  caused  by  microscopic 
organisms.  Exclude  or  destroy  the  organisms  and  there 
would  be  no  suppuration.  Lister's  results  were  amazing. 
Surgery  in  which  the  germs  were  destroyed  by  means  of 

11  Before  Pasteur,  certain  general  features  of  the  germ-/oc<  of  disease  and  of 
the  reactions  of  the  body  to  such  invasions  had  been  discerned,  for  example,  the 
discovery  by  Jenner  (1796)  of  vaccination  against  smallpox.  What  Pasteur 
did  was  to  give  the  first  complete  demonstrations  of  diseases  as  caused  by 
parasitic  organisms,  of  infection  as  merely  the  entrance  of  the  parasites,  and  of 
the  control  of  germ-diseases  by  vaccinations.  A  host  of  facts  long  known  to 
K-dical  profession  at  once  became  intelligible. 

11  During  the  American  Civil  War  hospitals  were  even  torn  down  and  new 
ones  constructed  in  vain  attempts  to  stamp  out  gangrene.  But  all  to  no  avail, 
for  the  surgeons  unknowingly  carried  the  infection  attached  to  their  instru- 
ments and  persons.  This  leaven  soon  leavened  the  new  establishment  so  that 
wound-disease  waa  again  rampant, 


152  THE  SCIENCE  OF  BIOLOGY 

antiseptics  was  the  outcome.  Infection  came  to  be  the 
mark  of  a  bungling  surgeon  or  a  rare  accident.  Subse- 
quently, the  methods  of  antisepsis  have  been  hi  part  re- 
placed by  those  of  asepsis  and  by  methods  which  enable  the 
natural  bodily  processes  to  destroy  the  germs  that  may 
find  entrance.14 

The  work  of  Koch  (1843-1910)  is  representative  of  in- 
vestigations which  established  the  principles  of  treatment 
and  diagnosis  now  universal  for  infectious  diseases.  His 
discovery  (1882)  of  the  bacillus  of  tuberculosis  was  epoch- 
making.  Bacteriology  came  into  existence  as  a  distinct 
science  during  the  last  quarter  of  the  nineteenth  century, 
when  a  long  list  of  diseases  were  found  either  to  be  caused 
by  recognizable  germs  or  to  behave  in  such  a  fashion  as  to 
indicate  germinal  causation.  With  the  confirmation  of  the 
mosquito-malaria  theory,  an  important  disease  was  shown 
to  be  caused  by  a  protozoon.  During  the  last  twenty-five 
years,  the  list  of  such  infections  has  been  so  rapidly  extended 
that  protozoa  have  assumed  an  importance  second  only  to 
bacteria  as  disease-producing  organisms.  The  important 
r61e  of  insects,  like  mosquitos  and  house-flies,  in  the  trans- 
mission of  disease  has  been  discovered  within  the  same 
period.  The  immediate  application  of  such  knowledge  in 
medical  practice  renders  these  discoveries  matters  of  com- 
mon information. 

The  germ-theory  thus  brought  revolutionary  develop- 
ments within  the  two  main  branches  of  medical  science. 
Surgery  and  the  treatment  of  disease  became  established  on  a 
new  basis,  because  of  the  comparatively  simple  discovery 
that  many  diseases  and  the  decay  of  organic  matter  are  alike 
caused  by  the  activities  of  microscopic  organisms.  Not  all 
diseases  are  so  caused,  and  the  germs  of  certain  infectious 

14  The  story  is  vividly  presented  by  the  veteran  American  surgeon  W.  W. 
Keen,  "Before  and  after  Lister,"  Science,  June  11,  1915.  See  also: 
"Medical  Research  and  Human  Welfare,"  by  the  same  author;  and  the 
essay  by  O.  W.  Holmes  on  "Puerperal  Fever." 


THE  CELL-DOCTRINE  153 

diseases  have  yet  to  be  recognized  as  such.  Nevertheless, 
what  is  now  the  germ-/oc£  stands  as  the  most  comprehen- 
sive generalization  within  the  field  of  medicine. 

The  bearing  of  the  cell-doctrine  upon  the  germ-theory 
of  infectious  diseases  is  obvious.  The  latter  could  never 
have  become  established  without  detailed  knowledge  con- 
cerning cells.  The  germ-theory  became  established  along 
with  the  fact  of  cellular  continuity  between  generations. 
Just  as  the  physical  basis  of  heredity  was  disclosed  in  terms 
of  cells,  so  the  physical  basis  of  contagion  was  found  to  be 
the  unicellular  germ.  The  one  reacted  upon  the  other, 
although  the  general  theory  of  cells  comprehended  the  par- 
ticular theory  of  germs.  It  is  not  putting  the  case  too 
strongly  to  say  that  the  cell-theory  changed  the  entire  con- 
cept of  the  causation  of  disease,  first,  through  its  support 
of  the  germ-theory  and,  second,  through  its  explanation  of 
all  pathological  functions  as  abnormal  cell  activities.  Not 
only  were  infectious  diseases  explained,  but  a  clue  was 
furnished  for  the  explanation  of  all  bodily  disorders. 

The  history  of  the  cell-theory  illustrates  the  origin,  de- 
velopment, and  ramification  of  a  fundamental  hypothesis. 
A  unifying  explanation  of  innumerable  disjointed  observa- 
tions was  impossible  without  proper  understanding  of  mi- 
croscopic structure.  As  soon  as  the  cell-theory  was  pro- 
mulgated, its  value  was  apparent.  The  organization  of 
animals  and  plants,  both  great  and  small,  was  brought 
within  the  same  category.  The  clue  was  discovered,  both 
as  regards  structure  and  function,  to  the  origin  of  the  in- 
dividual, and  hence  to  the  continuity  between  generations. 
Just  as  the  evolutionary  hypothesis  unified  a  multitude  of 
facts  regarding  visible  structures  and  activities  of  living 
things,  so  the  cell-theory  unified  the  phenomena  that  under- 
lie the  visible  features  of  the  body  as  a  whole.  With  such  a 
theory  established,  biological  science  could  attack  the  prob- 
lems of  the  living  substance  with  some  hope  for  a  successful 
issue. 


154  THE  SCIENCE  OF  BIOLOGY 

Cells  are  the  units  of  structural  organization.  All  normal 
functions  are  cell  functions,  and  likewise  all  abnormal 
activities.  The  value  of  such  a  generalization  is  apparent. 
Its  applications  in  medicine,  in  the  problems  of  development, 
in  heredity,  and  throughout  the  field  of  biological  science, 
can  be  fully  measured  only  by  future  accomplishment.  The 
cell-theory  has  unified  facts  of  the  most  diverse  nature  and 
has  opened  a  way  to  the  discovery  of  ultimate  vital  phenom- 
ena. Outside  the  field  of  evolution,  the  recent  progress  of 
biological  science  has  been  the  progress  of  knowledge  con- 
cerning cells.  Even  heredity  and  variation  are  themselves 
reducible  to  phenomena  of  the  cell. 


CHAPTER  VII 

THE    BIOLOGICAL    SCIENCE    OF    THE    MODERN 

PERIOD:  THE    THEORY   OF   ORGANIC 

EVOLUTION 

THE  Cell-Doctrine  and  the  doctrine  of  Organic  Evolution 
are  the  two  most  fundamental  generalizations  thus  far 
established  in  biological  science.  It  is  difficult  to  say  which 
has  been  the  more  effective  in  unifying  a  wide  range  of 
established  facts.  As  we  have  seen  the  cell-theory  is  a  key 
to  the  structures  and  functions  which  are  everywhere  ob- 
servable in  animals  and  plants.  Its  significance  in  the  his- 
tory of  living  things  is  almost  wholly  by  implication  from 
what  exists  hi  the  present.  The  theory  of  organic  evolu- 
tion is  primarily  significant  as  an  explanation  of  the  past. 
Whether  we  consider  the  one  or  the  other  the  greater  gener- 
alization depends  upon  whether  we  are  interested  in  the 
immediate  vital  phenomena  and  their  control  by  man,  or 
attracted  by  the  philosophical  aspects  of  biology.  Cell 
problems  are  problems  of  the  present  and  of  that  part  of  the 
future  which  will  be  important  to  the  human  race.  The 
problem  of  organic  evolution  is  mainly  a  problem  of  the 
historical  origin  of  the  animal  and  plant  bodies  around  us. 
The  origin  of  the  human  species  in  comparatively  recent 
times  and  the  beginnings  of  life  upon  our  planet  are  two  of  its 
most  interesting  aspects. 

But  organic  evolution  is  only  an  aspect  of  the  Evolution 
of  the  Cosmos.  Evolutionary  development  has  come  to  be 
accepted  as  the  most  reasonable  explanation  for  the  origin 
of  what  now  exists.  This  is  true,  whether  it  be  the  bodies 
of  animals  and  plants,  the  surface  of  the  earth,  or  solar 
systems.  Organic  evolution  is  part  of  the  cosmic  evolution, 
by  which  the  universe  has  reached  its  present  organization. 


156  THE  SCIENCE  OF  BIOLOGY 

The  origin  of  our  solar  system  may  be  removed  from  the 
present  by  billions  of  years  and  the  origin  of  our  earth 
may  seem  too  remote  for  explanation.  But  the  records  of 
the  geological  changes  which  have  given  the  earth  its  present 
surface  are  within  our  comprehension;  and  there  is  no  ade- 
quate reason  for  not  extending  the  same  kind  of  scientific 
explanations  to  beginnings  that  antedate  what  is  ordinarily 
encompassed  by  the  science  of  geology.  The  geologist  takes 
up  the  problem  where  the  astronomer  leaves  it.  The  latter 
may  be  vague  and  uncertain  in  his  conclusions,  but  the  pre- 
sumption favors  his  evolutionary  theories,  because  evolu- 
tion so  clearly  appears  to  have  taken  place  from  the  period 
at  which  the  record  began  to  be  written  upon  the  crust  of 
our  planet.  As  a  part  of  the  geological  record,  the  history 
of  animal  and  plant  life  is  found  imperfectly  recorded  in  the 
rocks. 1 

Organic  evolution  is,  therefore,  not  a  theory  of  the  origin 
of  men  from  monkeys,  but  is  concerned  with  the  origin  and 
development  of  all  the  animal  and  plant  bodies  which  now 
exist ;  and  it  is  part  of  the  larger  theory  of  cosmic  evolution, 
which  postulates  that  the  visible  universe  has  reached  its 
present  state  by  a  process  of  change.  This  change  is  going 
forward  in  the  present,  and  will,  presumably,  continue  hi 
the  future.  Concepts  of  infinite  space  and  infinite  time  are 
involved.  Man's  claim  to  importance,  in  the  dynamic 
system  thus  revealed,  lies  not  in  the  pretense  that  this  planet 
was  prepared  for  his  coming,  but  hi  the  claim  that  he  tran- 
scends the  visible  universe  in  so  far  as  he  comprehends  it. 

1  The  limitations  of  the  palaeontological  evidence  are  well  set  forth  in  a 
famous  chapter  in  Darwin's  "Origin  of  Species,"  entitled  "On  the  Imper- 
fection of  the  Geological  Record."  Despite  the  additions  to  knowledge  which 
have  since  been  made,  the  record  must  always  remain  fragmentary.  Yet  the 
evidence  is  sufficient  to  completely  establish  the  fundamental  fact  of  progres- 
sion. 


THE  THEORY  OF  ORGANIC  EVOLUTION        157 

ANCIENT   AND    MEDIEVAL    IDEAS    REGARDING    THE    UNIVERSE 

The  nature  of  the  Hebrew-Chaldean  tradition  regarding 
the  origin  of  mankind  can  be  appreciated  if  we  examine  the 
stories  concerning  creation  that  are  found  in  the  mythology 
of  other  primitive  peoples.  Such  stories  differ  widely  in 
detail,  but  they  almost  always  ascribe  the  beginnings  of 
the  world  and  of  the  particular  tribe  or  people  to  the  direct 
action  of  some  deity  who  resembles  a  glorified  human  being. 
The  tribe  had  its  origin  either  directly  from  this  being,  as 
child  from  parent,  or  by  his  act  of  creation.  While  there  are 
many  variations  of  the  theme,  the  idea  of  descent  from,  or 
creation  by,  a  god,  who  is  a  glorified  man,  is  the  common 
foundation  upon  which  the  stories  are  elaborated.  Of  course, 
the  fact  that  the  creation  mythology  of  widely  separate 
peoples  has  features  in  common  does  not  prove  a  common 
origin  for  the  many  traditions,  and  it  certainly  proves  noth- 
ing as  to  the  truth  of  these  stories.  The  reasonable  explana- 
tion is  that  primitive  minds  arrived  at  similar  conclusions  in 
the  absence  of  pertinent  data.  When  such  parallelism  exists, 
it  is,  presumably,  because  human  minds  follow  similar  chan- 
nels. As  mythology,  such  stories  are  a  fascinating  study 
for  the  ethnologist.  The  tradition  of  creation  inherited  by 
Christendom  is  interesting  for  comparison  and  because  it  has 
built  itself  into  the  thought  of  western  civilization. 

The  account  of  the  origin  of  man  and  of  the  animals  and 
plants,  which  appears  in  the  first  chapter  of  Genesis  as  part 
of  the  general  account  of  Creation,  was  probably  derived 
by  the  Hebrews  from  their  neighbors  in  Mesopotamia.  It 
is  a  modification  of  a  common  tradition  that,  in  its  essentials, 
was  shared  by  the  early  peoples  around  the  eastern  end  of 
the  Mediterranean.  The  assumed  topography  of  the  uni- 
verse was  quite  definite,  if  we  may  judge  from  many  refer- 
ences in  the  Old  Testament;  and  these  concepts  of  the  He- 
ra were  not  unlike*  those  recorded  by  the  Egyptians. 
According  to  this  belief,  the  earth  was  regarded  as  a  flat 


158  THE  SCIENCE  OF  BIOLOGY 

disk,  covered  by  the  sky  which  was  like  the  ceiling  of  a  dome 
and  rested  upon  the  mountains.  It  was  supposed  that  on  the 
east  and  west  sides  of  this  dome  or  firmament  there  were 
doors,  through  which  the  sun  passed  in  the  morning  and 


FIG.  22.  Schematic  Representation  of  the  Hebrew-Chaldean  Concept  of  the 
Universe.  As  indicated  by  references  in  the  Old  Testament.  These  ideas 
seem  to  have  been  obtained  by  the  Hebrews  from  Mesopotamian  and 
other  earlier  sources. 

departed  at  night.  The  earth  was  surrounded  by  water 
upon  which  it  floated  and  the  water  extended  also  above 
the  firmament  (Fig.  22).  In  the  firmament  were  windows 
and  the  stars  were  fastened  to  its  lower  surface.  Above 
the  firmament  was  Heaven.2  Such  expressions  as,  "the 
foundation  of  the  earth  upon  the  waters,"  "the  foundations 
of  the  great  deep,"  "the  corners  of  the  earth,"  "the  pillars 
of  heaven,"  "the  waters  above  the  firmament,"  "the  sun 

2  Cf.  the  account  of  the  universe  by  Cosmas,  cited  on  p.  51  of  the  present 
volume,  and  that  implied  in  Milton's  "Paradise  Lost." 


THE  THEORY  OF  ORGANIC  EVOLUTION        159 

as  a  bridegroom  coining  forth  from  his  chamber/'  "the 
windows  of  heaven/'  and  many  others  are  not  mere  figures 
of  speech.  They  are  indications  of  a  picture  of  the  universe 
which  existed  in  the  minds  of  the  writers  of  the  Old  Testa- 
ment. These  phrases  are  thought-fossils  which  tell  us  the 
nature  of  the  Hebrew  concept  of  the  world.3 

The  creation  myths  of  the  early  Greeks  were  mainly  of 
Nordic  origin  and,  therefore,  unlike  those  of  their  eastern 
neighbors.4  But  Greek  mythology  agreed  with  that  of  the 
Hebrew-Chaldeans,  in  its  creation  of  man  by  gods  who  were 
magnified  human  beings.  If  these  Greek  traditions  are  less 
exalted,  they  exhibit  a  human  quality  that  finds  a  sym- 
pathetic response  in  the  western  mind.  The  Greeks  were 
the  first  among  the  European-Mediterranean  peoples  to 
engage  in  critical  speculation  regarding  the  origin  of  the 
cosmos.  Observing  that  all  nature  was  in  a  state  of  flux, 
the  Ionic  philosophers  sought  for  a  permanent  element 
beneath  the  visible  change.  The  claim  that  Greek  thinkers 
formulated  a  theory  of  organic  evolution  can  hardly  be  sub- 
stantiated. Their  evolutionary  hypotheses  were  vague 
theories  of  a  cosmic  character  with  such  elements  as  water, 
air,  earth,  and  fire  as  the  underlying  realities  from  which 
other  visible  forms  came  into  being.  Ideas  of  organic 
development  were  incidentally  expressed  as  a  part  of  this 
philosophical  concept  of  the  evolution  of  the  visible  world. 
The  recognition  of  fossils,  as  the  remains  of  animals  and 
plants  which  had  formerly  lived,  is  an  example  of  the  direct- 
ness of  the  Greek  mind  with  its  sense  for  natural  explana- 
tions. The  fossil  seems  to  have  meant  nothing  which  implied 
a  grasp  of  its  significance  as  evidence  for  a  general  process 
of  organic  evolution.  Xenophanes  (c.  570-480)  recognized 
fossils  as  " proof s  that  the  seas  formerly  covered  the  earth." 

'White,  A.  D.,  "A  History  of  the  Warfare  of  Science  with  Theology  in 
Christendom."  Vol.  I,  p.  90. 

"The  Whit*  Man's  Magic  in   BMMT,"  \VnKhi,  J.,  Scientific  Monthly, 
Dec.,  1919. 


160  THE  SCIENCE  OF  BIOLOGY 

But  his  general  conclusion  was  "that  water  was  the  element 
from  which  the  earth  was  engendered."  Empedocles,  to 
whom  has  been  ascribed  the  formulation  of  a  theory  of  the 
Survival  of  the  Fittest,  "was  an  evolutionist  only  in  so  far 
as  he  taught  the  gradual  substitution  of  the  less  by  the  more 
perfect  forms  of  life."  Perfect  and  imperfect  forms,  he  be- 
lieved, arose  by  spontaneous  generation.5  Persistent  belief 
that  living  beings  were  generated  spontaneously  from  non- 
living matter  was  perhaps  responsible  for  this  failure  of  the 
Greeks  to  pursue  their  speculations  regarding  cosmic  evolu- 
tion to  the  field  of  animal  and  plant  origins. 

Among  the  Romans,  Lucretius  shows  comprehension  of 
the  evolutionary  process  hi  limited  cases.  His  extended 
account  of  the  human  race,  as  originating  from  a  condition 
essentially  like  that  of  the  brute  and  advancing  by  gradual 
stages,  bears  a  remarkable  resemblance  to  the  general  con- 
clusions of  modern  anthropology.  Man  is  pictured  as  first 
a  hardy  animal-like  race  living  in  a  wild  state  without  agri- 
culture and  without  family  life.  His  food  consisted  of  the 
natural  products  of  the  earth  and  of  the  trophies  of  the  chase. 
He  was  without  weapons  save  chance  sticks  and  stones. 
His  earliest  habitations  were  in  the  form  of  caves  and  shel- 
tered places.  The  association  of  mates  gave  rise  to  family 
life.  Weapons  and  implements,  huts,  clothing  of  skins,  and 
fire  were  gradually  acquired.  Language  developed  from 
natural  cries  and  sounds,  such  as  we  now  find  animals  making 
to  one  another.  Music  later  arose.  Metal  succeeded  stone, 
woven  garments  those  of  skins.  Agriculture  came  to  be 
practiced.  Animals  were  domesticated.  Tribal  and  govern- 
mental organization  was  slowly  developed  and  also  belief  in 
the  gods,  until  civilized  existence  had  thus  come  into  being. 
The  whole  account  is  a  remarkable  approach  to  the  modern 
scientific  formulation  of  the  history  of  human  evolution  from 
an  animal  ancestry.  It  rested  upon  knowledge  concerning 
animals  and  savage  races  of  mankind  which  was  then  extant, 

5Osborn,  H.  F.,  "From  the  Greeks  to  Darwin,"  pp.  36-40. 


THE  THEORY  OF  ORGANIC  EVOLUTION   161 

and  is  an  illustration  of  the  fact  that  clues  to  a  rationalistic 
explanation  of  human  origins  were  in  existence  even  at  this 
early  period.6 

Naturally  enough,  these  beginnings  of  evolutionary 
thought  found  no  supporters  during  the  Middle  Ages.  Their 
obliteration  was  an  incident  of  the  decline  of  Greco-Roman 
science  which  has  been  described  in  an  earlier  chapter. 
Christian  theology,  through  its  amplification  of  the  Hebrew 
story  of  Creation,  furnished  an  explanation  of  the  origin 
of  man  and  the  universe  that  was  accepted  as  satisfactory 
until  the  Copernican  system  had  displaced  the  older  astron- 
omy and  the  sphericity  of  the  earth  had  become  a  matter  of 
common  knowledge.  From  the  decline  of  Greek  speculative 
thought  until  the  middle  of  the  eighteenth  century,  there 
was  no  real  grappling  with  the  problem  of  the  historical 
origin  of  organic  beings.  Occasionally  during  the  later 
centuries  of  this  period  there  were  individuals,  like  Leonardo 
da  Vinci,  who  recognized  the  lapse  of  time  involved  in 
geological  change  and  who  understood  the  nature  of  fossils.7 
The  Middle  Ages  stand  for  the  same  stagnation  here,  as  in 
other  lines  of  scientific  thought.  Only,  the  concept  of 
organic  evolution  was  longer  delayed  than  any  other  scien- 
tific generalization  of  equal  importance. 

Organic  evolution  appears  in  its  proper  setting,  if  we 
realize  that  biological  science  has  but  recently  passed 
through  a  period  of  battle  comparable  to  that  through  which 
astronomical  science  passed  in  the  period  after  Copernicus, 
and  geographical  science  following  Columbus.  The  evolu- 

•  Lucretius,  "  De  Rerum  Natura,"  Book  V.  Translation  by  H.  J.  A.  Munro, 
entitled:  "Lucretius  on  the  Nature  of  Things." 

7  Some  of  the  medieval  writings  show  that  fossils  were  well  enough  known 
to  demand  explanation.  For  example,  these  semblances  of  animal  and  plant 
life  were  said  to  be  caused  by  "fatty  matter  set  into  fermentation  by  heat"; 
by  "lapidific  juice";  by  "the  tumultuous  movement  of  terrestrial  particles." 
Or  they  were  regarded  as:  "sports  of  nature";  as  "mineral  concretions";  as 
"creations  of  plastic  force";  as  "models,"  made  by  the  Creator  before  he 
decided  upon  the  fin.il  forms  of  creation .  <»  :is  the  bones  of  animals  which  had 
pgrfahed  in  the  Noachiari  deluge.  White,  A.  D.,  he.  cit. 


162  THE  SCIENCE  OF  BIOLOGY 

tionary  concept  is  as  fundamental  in  biology  as  the  helio- 
centric theory  in  astronomy  or  the  theory  of  the  earth's 
sphericity  in  geography.  This  great  biological  generaliza- 
tion was  not  established  before  the  close  of  the  Renaissance, 
mainly  because  it  was  unthinkable  from  the  standpoint  of 
traditional  cosmogony  and  because  its  demonstration  de- 
pended upon  so  wide  a  range  of  facts.  The  older  idea  of  the 
structure  of  the  heavens  had  passed  away  by  the  end  of  the 
seventeenth  century.  But  there  did  not  seem  to  be  adequate 
reason  for  doubting  the  scriptural  account  of  the  origin  of 
the  universe.  The  Mosaic  account  was  still  accepted  despite 
the  difficulties  which  now  began  to  be  recognized.  The  case 
is  not  dissimilar  from  what  occurred  in  the  nineteenth  cen- 
tury when  attempts  were  made,  to  exclude  man  from  his 
place  in  the  animal  world,  by  the  anti-evolutionists. 

THE  TRANSMUTATIONISTS  OF  THE  EIGHTEENTH  CENTURY 

The  first  scientific  formulation  of  organic  evolution  oc- 
curred toward  the  middle  of  the  eighteenth  century.  The 
biological  contribution  of  the  Renaissance  had  consisted  of 
the  progressive  increase  of  knowledge  in  natural  history. 
During  the  fifteenth,  sixteenth,  and  seventeenth  centuries, 
knowledge  concerning  the  number  and  kinds  of  animals  and 
plants  and  their  distribution  was  acquired.  By  the  opening 
of  the  eighteenth  century  the  question  of  their  origin  had 
begun  to  demand  something  more  than  formal  explanation. 
The  very  number  of  different  kinds  of  animals  made  it 
difficult  to  understand  how  all  could  have  been  named  by 
Adam  or  how  the  progenitors  of  so  many  kinds  could  have 
been  contained  within  the  ark  of  Noah.  Moreover,  the 
problems  of  geographical  distribution  were  being  acknowl- 
edged. The  animals  found  upon  oceanic  islands  presented 
puzzling  questions,  which  were  at  first  explained  on  the 
theory  that  the  ancestors  of  these  animals  had  been  trans- 
ported thither  by  man.  But  men  came  to  doubt  the  possi- 


THE  THEORY  OF  ORGANIC  EVOLUTION        163 

bility  of  the  transportation  of  ferocious  beasts  on  long  and 
arduous  voyages;  while  the  voluntary  transference  of  ani- 
mals, which  were  positive  pests,  seemed  highly  improbable. 
The  Mosaic  account  of  creation  and  the  story  of  the  Noach- 
ian  deluge  became  increasingly  difficult  to  believe  hi  view  of 
the  facts.  But  there  was,  as  yet,  no  alternative  explanation. 

The  classification  of  animals  and  plants,  accomplished  by 
Linnaeus  (1704-1778)  during  the  eighteenth  century,  gave 
additional  emphasis  to  the  facts  which  had  produced  these 
difficulties.  Increasing  knowledge  of  anatomy,  of  embry- 
ology, of  heredity,  and  of  variation  gave  clues  for  the  for- 
mulation of  a  theory  of  organic  evolution  on  a  scientific  founda- 
tion. To  George  Louis  Lecler,  Comte  de  Buff  on  (1707- 
1788),  more  than  to  any  other  individual,  belongs  the  credit 
of  having  formulated  this  first  scientific  theory  of  organic 
evolution.  Buff  on  clearly  expresses  the  idea  that  particular 
types,  like  the  vertebrates,  the  molluscs,  and  so  forth  may 
have  descended  from  a  common  ancestry.  He  even  goes  so 
far  as  to  suggest  that  all  living  things  may  have  arisen  from 
an  identical  source.  Had  he  not  lived  in  an  atmosphere  of 
orthodox  tradition,  Buffon  might  have  gone  much  further 
than  he  did.  His  phraseology  is  guarded  and  often  self- 
contradictory,  but  his  meaning  is  clear.  That  his  fears  of 
persecution  were  not  unfounded  is  seen  by  the  fact  that  he 
was  forced  to  recant  (1751)  by  the  faculty  of  the  Sorbonne 
at  Paris.8 

During  the  latter  half  of  the  eighteenth  century  there 
were  many  other  advocates  of  this  new  doctrine  of  descent 
with  modification.  These  men  were  called  Transmutation- 

•  Buffon's  printed  recantation  is  as  follows:  "I  declare  that  I  had  no  inten- 
tion to  contradict  the  text  of  scripture;  that  I  believe  most  firmly  all  therein 
related  about  the  creation,  both  as  to  order  and  as  to  order  of  time  and  matter 
of  fact,  I  abandon  everything  in  my  book  respecting  the  formation  of  the 
earth,  and  generally  all  which  may  be  contrary  to  the  narrative  of  Moses." 
Quoted  from:  Clodd,  E.,  "Pioneers  of  Evolution,"  p.  96.  Buffon  may  be 
accused  of  indirectness,  but  evidently  his  meaning  did  not  escape  the  vigilance 
of  conrtcrvati.mil. 


164  THE  SCIENCE  OF  BIOLOGY 

ists,  because  they  maintained  the  transmutability  of  species. 
We  have  already  commented  upon  this  first  century  of  the 
modern  scientific  period  as  a  time  when  innovations  were  hi 
the  ah*.  The  theory  of  transmutation,  and  also  certain 
evolutionary  concepts  in  geology,  were  advanced  by  Buffon, 
on  the  basis  of  the  first-hand  knowledge  set  forth  hi  his 
monumental  work  upon  natural  history.  Buffon  was  not 
widely  supported  by  his  scientific  colleagues,  but  another 
Frenchman,  Pierre  de  Maupertuis  (1698-1759),  a  philos- 
opher rather  than  a  scientist,  exhibits  "a  wider  intellectual 
horizon  than  was  common  among  the  men  of  science  of  his 
time."  For  example,  Maupertuis  examined  critically  the 
theory  of  preformation,  which  then  dominated  embryological 
science,  and  found  it  wanting.  He  set  forth  a  remarkable 
theory  of  epigenesis.9  He  apprehended  certain  important 
features  in  the  problem  of  individual  development  at  a 
time  when  this  matter  had  received  scant  consideration. 
Examination  of  the  problems  of  embryology  led  him  to 
consider  those  of  heredity  and  variation.  As  a  result  he 
came  to  regard  the  transmutability  of  species  as  a  far  more 
reasonable  belief  than  their  fixity.  He  conceived  the  gradual 
accumulation  and  the  transmission  of  variations,  carried  on 
for  countless  generations  to  be  sufficient  to  produce  all 
existing  species  from  a  single  original  pair.10  Unlike  Buffon, 
Maupertuis  was  not  primarily  a  contributor  to  scientific 
knowledge.  But  he  possessed  an  insight  into  the  meaning  of 
current  facts  which  was  in  advance  of  the  understanding 
shown  by  the  vast  majority  of  his  scientific  contemporaries. 
A  similar  appreciation  of  meanings  appears  in  the  writings 
of  Denis  Diderot  (1713-1784).  Although  he  was  even  less 

9  The  modern  concept  of  development  as  a  combination  of  preformation  and 
epigenesis  is  explained  on  p.  193  of  the  present  volume.  It  is  worth  noting  that 
Maupertuis  published  his  theory  of  epigenesis  more  than  a  decade  before  the 
modern  scientific  formulation  of  this  doctrine  which  appeared  in  the  "  Theoria 
Generationis,"  by  Kaspar  Wolff  in  1759. 

10Lovejoy,  A.  O.,  "Some  Eighteenth  Century  Evolutionists,"  Popular 
Science  Monthly,  July,  1904. 


THE  THEORY  OF  ORGANIC  EVOLUTION        165 

of  a  scientist  than  Maupertuis,  Diderot  recognized  the 
evolutionary  significance  of  the  details  of  anatomy  that  were 
being  factually  set  forth  by  the  great  Daubenton  (1716- 
1800).  The  latter  appears  to  have  been  oblivious  of  the 
larger  interpretations.  Although  he  was  the  great  pioneer 
in  the  field  of  vertebrate  anatomy,  it  was  not  Daubenton, 
the  scientist,  but  Diderot  the  philosopher,  who  saw  the 
meaning  of  the  facts  in  relation  to  the  mutability  of  species. 
A  vast  array  of  anatomical  data,  which  are  now  regarded  as 
one  of  the  strongest  lines  of  evidence  for  evolution,  was  be- 
coming discernible.  Its  meaning  was  appreciated  by  a  few 
individuals  before  the  middle  of  the  eighteenth  century. 
The  decade  following  1745  witnessed  the  setting  forth,  by 
Diderot  and  Maupertuis,  of  two  of  the  most  important 
lines  of  evidence  for  descent — anatomy  and  inheritance  with 
variation,  and  also  the  publication  of  the  first  volume  of 
Buffon's  "Histoire  Naturelle"  (1749).  "The  appearance  of 
modern  evolutionism,  as  a  theory  definitely  formulated  and 
based  upon  its  proper  embryological  and  anatomical  premises, " 
therefore,  dates  from  the  middle  of  the  eighteenth  century.11 
Throughout  the  latter  half  of  the  eighteenth  century,  the 
theory  of  the  transmutation  of  species  was  a  frequent  topic 

11  In  the  paper  by  Professor  Love  joy,  loc.  cit.,  the  opinions  of  two  other 
eighteenth  century  writers  are  given  at  length — Johann  Gottfried  von  Herder 
(1744-1803),  and  James  Burnett,  Lord  Monboddo  (1714-1799).  The  former 
has  been  greatly  overrated  as  an  early  advocate  of  the  transmutation  hypoth- 
esis. It  is  by  no  means  clear,  according  to  Love  joy,  "that  he  did  not  intend 
explicitly  to  repudiate  it."  Monboddo,  on  the  other  hand,  although  he  cannot 
be  taken  very  seriously  as  a  zoologist,  "was  perhaps  the  first  to  make  widely 
familiar  to  the  British  public  the  doctrine  that  man  is  descended  from  ape-like 
ancestors."  His  associates  were  such  men  as  David  Hume,  Adam  Smith  and 
James  Hutton.  "In  this  society,  so  distinguished  for  its  scientific  attainments 
and  for  original  theories  in  natural  science  and  philosophy,  Monboddo  had  the 
reputation  of  being  one  of  the  most  learned  and  most  original,"  although  it  was 
felt  by  most  of  his  British  contemporaries  "that  he  pushed  originality  in  theo- 
rizing to  the  point  of  fantastic  absurdity  when  he  declared  that  civilized  man 
is  akin  to  the  orang-outang  and  a  descendant  of  progenitors  that  lacked  speech 
and  possibly  had  tails."  "It  is  a  pity,"  said  Dr.  Johnson,  "to  see  Lord  Mon- 
boddo publish  such  notions  as  he  has  done;  a  man  of  sense  and  of  so  much 
flfenot  learning." 


166  THE  SCIENCE  OF  BIOLOGY 

of  conversation  in  intellectual  circles,  particularly  on  the 
continent.  In  England,  the  subject  was  not  widely  con- 
sidered until  it  was  set  forth  at  length  in  the  "Zoonomia"  of 
Erasmus  Darwin  (1794).  In  France,  the  studies,  upon  which 
Lamarck  was  to  base  his  theory  of  the  causes  of  evolutionary 
modification,  were  already  well  advanced  before  the  close  of 
the  century.  As  we  have  seen,  the  closing  decades  of  the 
eighteenth  century  witnessed  a  remarkable  extension  of 
fundamental  concepts  in  many  scientific  lines.  Notable 
among  them  is  this  greatest  of  biological  theories. 

These  early  evolutionists  have  not  received  sufficient 
credit,  because  the  concept  of  organic  evolution  suffered  a 
decline  during  the  early  decades  of  the  nineteenth  century 
and  was  not  generally  accepted  until  after  the  appearance  of 
Darwin's  " Origin  of  Species."  The  fact  that,  as  a  group, 
the  transmutationists  were  not  orthodox  scientists  is  prob- 
ably in  part  responsible  for  their  neglect  and  for  a  certain 
patronizing  attitude  toward  men  like  Maupertuis  and 
Diderot  on  the  part  of  nineteenth  century  commentators  on 
the  history  of  evolutionary  speculation.  There  has  been  too 
much  inclination  to  believe  that  serious  evolutionary  thought 
began  with  Darwin.  As  a  matter  of  fact,  the  state  of  scien- 
tific opinion,  during  the  nineteenth  century  prior  to  1859,  is 
not  creditable  to  the  scientific  workers  in  biological  lines. 
Instead  of  the  open-mindedness,  on  which  scientists  pride 
themselves,  we  see  the  men  of  science  adhering  to  traditional 
interpretations  and  blind  to  the  meaning  of  their  own  facts, 
while  some  of  the  supposedly  inferior  philosophers  were 
alive  to  the  significance  of  the  facts  discovered  by  the  scien- 
tists. The  explanation,  which  suggests  itself,  is  that  the 
mind  which  is  most  capable,  in  the  accumulation  of  details, 
is  frequently  lacking  in  the  appreciation  of  larger  meanings. 
At  certain  times  in  the  history  of  science,  the  systematic 
mind  has  prevailed  and  at  others  the  mind  which  grasps  at 
meanings.  Only  the  exceptional  individual,  such  as  Darwin, 
combines  the  two.  When  lesser  minds  run  to  theorizing,  as 


THE  THEORY  OF  ORGANIC   EVOLUTION        167 

in  the  post- Darwinian  period  of  the  nineteenth  century,  they 
fail  to  produce  results.  When  systematic  minds  of  a  high 
order  reach  new  territory  they  often  miss  the  significance  of 
facts  to  an  amazing  degree,  as  was  the  case  with  Daubenton 
the  anatomist  and  Linnaeus  the  classifier. 

The  weakness  of  the  pseudo-philosopher,  who  dabbles 
in  science,  is  that  his  theories  always  tend  to  outrun  his  facts. 
But  this  is  soon  corrected.  In  the  case  under  discussion  it  is 
ungenerous  for  the  biologist  not  to  acknowledge  the  insight 
of  these  eighteenth  century  savants.  For  despite  their 
dilettantism,  they  perceived  what  the  majority  of  the  techni- 
cal scientific  workers  did  not  recognize  until  a  century  later. 
One  of  the  myths  of  the  history  of  biology  is  the  tradition 
that  the  evolutionary  doctrine  was  not  definitely  formulated, 
for  lack  of  facts,  until  about  the  middle  of  the  nineteenth 
century.  This  is  not  a  fair  historical  statement  and  it  does 
grave  injustice  to  those  thinkers  of  the  preceding  century, 
who  saw  the  meaning  of  biological  facts  at  a  time  when  the 
majority  of  naturalists  were  blind.  It  was  blindness,  rather 
than  scientific  caution  that  caused  the  scientific  formulation 
of  the  evolutionary  theory  to  be  rejected  for  more  than  a 
century. 

THE  LAMARCKIAN  THEORY  OF  THE  CAUSES  OF  EVOLUTION 

Not  only  was  the  earliest  scientific  formulation  of  the 
theory  of  organic  evolution  made  during  the  eighteenth 
century,  but  the  same  century  produced,  in  the  Lamarckian 
Hypothesis,  a  theory  of  the  causes  of  evolution.  Even  if  this 
theory  has  scant  support  at  the  present  day,  its  promulga- 
tion is  indicative  of  the  extent  to  which  evolutionism  had 
developed  by  the  opening  years  of  the  nineteenth  century.12 

K;  date  of  the  first  publication  of  Lamarck's  "  Philosophic  Zottlogique" 
was  1809,  and  other  publications,  containing  references  to  the  problem  of 
organic  evolution  appeared  during  the  first  fifteen  years  of  the  century.  But 
in  view  of  the  fact  that  the  first  decade  of  the  nineteenth  century  was  in- 
tellectually a  continuation  of  the  ci^htoenth  century  jH-riod.  (he  work  of 


168  THE  SCIENCE  OF  BIOLOGY 

The  ideas  of  Jean  Baptiste,  Chevalier  de  Lamarck  (1744- 
1829)  were  a  natural  development  from  the  evolutionary 
concepts  of  Buff  on.  Lamarck  was  primarily  a  man  of 
science  rather  than  a  philosopher.  He  is  usually  regarded  as 
the  founder  of  modern  invertebrate  anatomy.  However 
much  one  may  be  disinclined  to  accept  the  Lamarckian 
doctrine,  its  originator  was  an  active  investigator.  He  is, 
therefore,  not  open  to  the  charge  of  having  been  a  specula- 
tive philosopher  rather  than  a  scientist. 

Historically,  the  importance  of  the  Lamarckian  hypothe- 
sis is  found  in  the  fact  that  it  was  the  first  comprehensive 
formulation  of  the  causes  of  the  evolutionary  process.  Lamarck 
accepted  evolution  as  an  historical  fact.  He  proposed  his 
theory  of  the  inherited  effects  of  use  and  disuse  and  of  the  en- 
vironment, as  an  explanation  of  the  causes  of  evolution.13 

The  gist  of  the  Lamarckian  theory  is  that  the  individual  is 
modified  by  the  use  and  the  disuse  of  its  parts  and  that  these 
modifications  are  transmitted  to  its  descendants.  The  case 
is  similar  with  the  effects  of  the  environment.  An  animal 
which  runs  develops  the  parts  involved.  It  runs  faster  with 
practice  and  it  has  stronger  and  larger  muscles  after  many 
repetitions  of  this  activity,  just  as  does  the  athlete  who  has 
undergone  prolonged  training.  The  adage  "practice  makes 

Lamarck  was  a  product  more  distinctive  of  the  eighteenth  than  of  the  nine- 
teenth century.  Lamarck's  ideas  represent  the  climax  of  the  transmutationist 
doctrines.  Moreover,  the  more  active  working  years  of  his  life  (1744-1829) 
fall  within  the  eighteenth  century. 

13  There  exists  in  non-scientific  circles  at  the  present  day  a  confusion  between 
evolution  as  an  historical  process  and  the  causes  which  have  produced  evolu- 
tion. This  is  frequently  seen  in  the  confusion  between  the  Darwinian  theory 
of  Natural  Selection,  which  is  a  theory  of  the  causes  of  evolution,  and  the  more 
comprehensive  doctrine  of  organic  evolution.  The  historical  fact  of  evolution 
is  as  distinct  from  its  causes  as  the  historical  fact  of  the  colonization  of  the 
western  hemisphere  by  Europeans  is  distinct  from  the  causes  which  have  in- 
duced so  many  people  to  leave  Europe  during  the  past  four  hundred  years. 
The  fact  that  the  Americas  were  thus  settled  is  beyond  reasonable  question. 
The  causes  of  this  migration  westward  of  Frenchmen  and  Englishmen  and 
Spaniards  and  later  Germans,  Irish,  Italians,  and  the  like  are  a  different  matter 
and  one  concerning  which  there  exist  divergences  of  opinion. 


THE  THEORY  OF  ORGANIC  EVOLUTION        169 

perfect"  describes  the  situation  and  no  one  disputes  the 
claim  that  such  changes  do  occur  in  the  individual.  The  con- 
verse, of  the  disuse  of  a  part,  is  no  less  familiar.  The  man 
of  sedentary  life  is  painfully  aware  of  the  reduced  capacity  of 
his  little  used  muscles  after  a  day  of  unusual  exercise.  The 
religious  fanatics  of  certain  countries,  by  the  voluntary  and 
persistent  disuse  of  a  limb,  bring  about  not  only  a  loss  of 
function  in  the  part  but  its  permanent  reduction  in  size.  In 
animals  under  experimentation,  similar  atrophies  can  be 
produced.  Changes  are  also  induced  hi  the  individual  by 
environment.  A  mammal  taken  into  a  cold  climate  is 
stimulated  to  lay  on  fat  or  produce  longer  hair.  An  insect 
may  be  modified  in  color  by  a  change  in  the  water-content 
of  the  atmosphere.  The  lowland  tree,  when  growing  upon  a 
mountain,  is  modified  in  a  manner  peculiar  to  the  new  en- 
vironment. The  human  skin  is  tanned  by  the  sun,  hence 
the  white  man,  after  long  residence  in  the  tropics,  may 
never  recover  his  whiteness  of  face  and  hand,  even  though 
he  returns  to  his  northern  home. 

Many  examples  of  the  effects  of  use  and  disuse  and  of 
environment  will  occur  to  the  reader.  Animals  and  plants 
under  experimentation  give  similar  results.  There  can  be  no 
question  regarding  the  effects  produced  by  these  Lamarckian 
factors  of  use,  disuse,  and  environment  upon  the  individual. 
New  characteristics  are  thus  acquired  by  the  individual ;  and 
the  phrase  acquired  characteristics  has  become  a  technical 
term  in  biology,  having  this  restricted  meaning. 

Thus  far,  we  have  spoken  only  of  the  individual  animal  or 
plant,  which  is  itself  changed  by  the  action  of  these  Lamarck- 
ian factors.  But  the  crux  of  the  theory  is  its  claim  that 
characteristics,  thus  acquired  by  the  individual,  are  inherited 
by  the  next  generation.  It  is  for  this  reason  that  the  La- 
marckian hypothesis  may  be  described  as  the  theory  of 
inheritance  of  acquired  characteristics,  using  the  words  ac- 
quired characteristics  in  the  sense  above  explained.  La- 
marck believed  that  the  changes  so  produced  in  animals  and 


170  THE  SCIENCE  OF  BIOLOGY 

plants  in  a  given  generation  were  inherited  in  the  next;  that 
if  an  animal  used  the  same  parts  in  the  same  way,  generation 
after  generation,  or  if  it  failed  to  use  them,  the  results  were 
cumulative.  Each  generation  added  a  little  and  this  was 
passed  on  to  its  offspring.  Thus  bit  by  bit  the  modification 
was  carried  to  an  extreme  degree.  Lamarck's  own  formula- 
tion of  his  doctrine  was  complicated  by  mystical  ideas  about 
the  animal's  willing  to  do  or  to  be  certain  things.  But  its 
essential  claim  was  that  effects  produced  by  use,  disuse,  and 
environment  were  inherited  by  the  next  generation.14 

The  Lamarckian  theory  of  the  causes  of  evolution  was 
not  widely  accepted  at  the  tune  of  its  promulgation  for  the 
same  reason  that  the  entire  theory  of  transmutation  was 
rejected.  The  opponents  of  the  Lamarckian  doctrine 
criticized  not  only  the  proposed  causes  but  also  the  claim 
that  evolution  had  occurred.  The  Lamarckian  hypothesis 
of  evolutionary  causation  has  survived  to  the  present  day 
and  still  finds  support  from  those  who  are  called  the  Neo- 
Lamarckians.  But  it  has  never  been  widely  accepted.  Of 
late  years  the  failure  to  obtain  conclusive  evidence  for  the 
inheritance  of  characteristics  acquired  by  the  individual  has 
told  heavily  against  the  theory.  It  would  seem  that  if  such 
inheritance  occurs  we  should  by  now  have  secured  experi- 
mental proof.  Convincing  proofs  have  not  been  forth- 
coming. The  majority  of  biologists,  therefore,  regard  the 
Lamarckian  Theory  as  distinctly  not  proved.  Many  go 

14  Some  of  the  specific  cases  which  Lamarck  cites  are  as  follows:  The  webbed 
feet  of  swimming  birds  were  produced  by  the  animals'  efforts  to  spread  their 
toes  in  attempting  to  keep  afloat;  the  legs  of  wading  and  of  perching  birds 
became  long  or  short  by  their  use  in  these  peculiar  fashions;  snakes  lost  their 
limbs  through  disuse.  Snails  acquired  tentacles  by  the  stimulation  of  the 
anterior  end  of  the  body,  as  the  animal  crawled  about  and  came  in  contact  with 
obstacles.  Lamarck's  most  extended  statement  of  his  doctrine  appears  in  his 
"Philosophic  Zo5logique."  Modern  advocacy  of  Lamarckism  will  be  founu 
in:  Packard,  A.  S.,  "Lamarck,  His  Life  and  Work,"  1901;  and  Henslow,  G., 
"The  Origin  of  Plant  Structures,"  1895.  An  excellent,  if  brief,  summary  of 
Lamarckism  appears  in:  Herbert,  S.,  "First  Principles  of  Evolution,"  pp.  111- 
116. 


THE  THEORY  OF  ORGANIC  EVOLUTION        171 

so  far  as  to  believe  there  is  small  chance  of  it  ever  being 
proved.15 

Even  if  the  Lamarckian  hypothesis  should  be  substan- 
tiated by  satisfactory  experimental  proof,  there  still  re- 
main certain  features  of  animal  organization  which  are 
not  readily  explicable  in  terms  of  this  theory.  For  ex- 
ample: The  resemblance  of  many  animals  to  their  surround- 
ings is  so  striking  that  it  is  commonly  regarded  as  a  means 
of  protection  from  enemies  and  hence  of  life  and  death  import- 
ance. The  importance  attached  by  Darwin  to  such  adaptive 
features  of  animal  life  led  to  their  over-emphasis  during  the 
post-Darwinian  period.  It  is  undoubtedly  true  that  many  of 
the  supposed  examples  of  this  form  of  adaptation  are  imagin- 
ary. The  reaction  against  the  assumption  that  almost  every 
structure  and  every  action  of  a  living  thing  was  adaptive 
went  to  the  opposite  extreme,  and  at  the  close  of  the  nine- 
teenth century  some  biologists  seemed  to  regard  the  whole 
phenomenon  of  adaptation  as  a  myth.  When,  however,  due 
allowance  is  made  for  the  over-emphasis  of  adaptation, 
when  it  is  frankly  acknowledged  that  animals  may  have 
many  features  which  are  non-adaptive  if  not  positively 
harmful,  and  when  we  understand  that  it  is  the  all-round 
ability  to  meet  the  necessities  of  existence  rather  than  a  few 
particular  tests,  which  constitutes  survival  value,  the  fact 
remains  that  a  certain  quality  of  fitness  is  one  of  the  most 
widespread  features  among  living  things.  We  cannot  ex- 
plain this  fact  by  denying  its  existence.  Resemblance  to  the 
environment  is  a  fact  in  many  cases.  After  making  every 
allowance,  there  remain  many  instances  which  can  be  ex- 
plained most  reasonably  on  the  assumption  that  resem- 
blance to  the  surroundings  is  an  important  means  of  pro- 
tection. 

u  The  recent  work  of  Guycr  and  Smith,  who  seem  to  have  induced  the 
inheritance  of  eye  defect*  in  rabbits,  in  of  the  greatest  interest;  but  confir- 
mation and  more  extended  eXprtiMi.'M' V  ,  •!!  I-  Iirrdrd  l.rluIV  the  result*  CHD 

be  regarded  as  conclusive-.    Jour.  Exp.  Zool.,  Vol.  31,  No.  2,  1920. 


172  THE  SCIENCE  OF  BIOLOGY 

Granting  the  existence  of  such  adaptative  resemblance,  its 
mode  of  origin  is  something  to  be  explained  by  any  com- 
prehensive theory  of  the  causes  of  evolution.  The  Lamarck- 
ian  theory  does  not  seem  to  give  a  satisfactory  explanation. 
One  cannot  easily  imagine  how  an  animal  by  its  actions  can 
cause  the  color  or  the  shape  of  its  body  to  look  like  its  sur- 
roundings. It  might  remain  quiet  and  arrange  the  parts  of 
its  body  in  certain  positions.  But  to  suppose  that  it  can, 
by  use  or  disuse,  make  its  body  look  like  its  background 
seems  absurd.  Neither  can  one  imagine  how  the  environ- 
ment can  cause  an  animal  to  resemble  the  background,  save 
in  simple  cases  like  that  of  the  caterpillar  which  is  green 
because  the  green  of  the  leaves  devoured  as  food  shows 
through  its  semi-transparent  body.  The  Darwinian  theory 
of  natural  selection,  on  the  other  hand,  offers  a  satisfactory 
theoretical  explanation  of  how  such  fitness  may  have  arisen. 
Against  the  substantiation  of  the  Lamarckian  hypothesis  as 
a  whole,  there  exists,  moreover,  a  body  of  embryological 
evidence,  obtained  during  recent  years,  and  supporting  the 
belief  that  the  mechanism  of  inheritance  is  through  the 
germ-cells  and  not  through  the  body.16 

The  most  notable  supporter  of  Lamarck,  during  the  early 
decades  of  the  nineteenth  century,  was  Etienne  Geoffroy 
Saint-Hilaire  (1772-1844).  St.  Hilaire  emphasized  the  ef- 
fects of  the  environment,  while  Lamarck  had  emphasized  use 
and  disuse.  The  Lamarckian  theory,  as  we  speak  of  it  here, 
includes  all  of  these  factors.  In  1830,  the  year  following  the 
death  of  Lamarck,17  a  notable  scientific  debate  took  place 
between  Cuvier,  who  was  then  regarded  as  the  foremost 
living  zoologist,  and  St.  Hilaire  concerning  the  doctrine  of 
transmutation.  The  superior  acumen  and  the  greater 

18  The  volume  "Heredity  and  Environment,"  by  E.  G.  Conklin,  contains  an 
excellent  statement  of  this  modern  interpretation  of  the  part  played  by  the 
germ-cells  in  heredity. 

17  In  the  later  years  of  his  life,  Lamarck  became  blind  and  lived  as  a  pathetic 
figure,  his  theories  ridiculed  by  most  of  his  contemporaries  and  himself  in 
straightened  circumstances. 


THE  THEORY  OF  ORGANIC  EVOLUTION        173 

knowledge  of  Cuvier  won  the  day.  Transmutation  was 
seemingly  disposed  of  in  the  scientific  world  and  the  Lamarck- 
ian  doctrines  seemed  at  an  end.  But  almost  immediately 
afterward  came  the  publication  of  the  first  edition  of  Charles 
LyelTs  "Principles  of  Geology"  (1830).  In  this  the  theory 
of  geologic  evolution  was  formulated  as  the  only  reasonable 
explanation  of  the  changes  which  have  given  the  surface  of 
the  earth  its  present  form.  The  year  following,  Charles 
Darwin  set  out  on  the  voyage  around  the  world  which  was 
destined  to  become  so  decisive  a  factor  in  his  subsequent 
work  upon  the  origin  of  species.  The  "coming  of  evolution" 
was  at  hand  even  when  its  precursors  seemed  discredited  as 
hi  the  case  of  Lamarck. 


THE   DARWINIAN   THEORY 

There  were  other  reasons  for  the  initial  failure  of  scien- 
tific evolutionism.  But  the  fundamental  reason  was  the 
inertia  of  the  human  mind  when  confronted  with  an  inter- 
pretation of  nature  which  differs  widely  from  established 
tradition.  Belief  in  special  creation  and  an  unscientific 
attitude  toward  the  larger  problems  of  nature  had  dominated 
thought  for  almost  two  thousand  years.  It  was  natural, 
therefore,  that  the  first  scientific  theories  of  evolution  should 
end  hi  failure.  Nevertheless,  this  failure  was  apparent 
rather  than  real. 

During  the  early  decades  of  the  nineteenth  century  the 
great  Cuvier  (1769-1832)  continued  the  work  of  Daubenton 
and  established  the  science  of  Comparative  Anatomy. 
Karl  Ernst  von  Baer  (1792-1876)  followed,  establishing 
Comparative  Embryology  during  the  second  quarter  of  the 
century.  Geological  science  had  received  its  initial  impulse 
during  the  eighteenth  century  through  the  work  of  James 
Hutton  (1726-1797),  whose  "Theory  of  the  Earth"  (1795) 
maintained  that  the  past  history  of  our  planet  was  explicable 
in  term*  of  changes  observable  in  the  present.  In  the  main, 


174  THE  SCIENCE  OF  BIOLOGY 

Button's  ideas  of  volcanic  action,  of  weathering,  erosion, 
deposition,  and  uplift  were  those  which  have  been  elaborated 
by  modern  geology.  His  point  of  view  was  in  every  respect 
scientific.  His  work  constituted  the  foundation  of  British 
geology.  Hutton  was  followed  by  William  Smith  (1769- 
1839)  who  is  called  the  "  Father  of  English  Geology. "  The 
latter  showed,  in  his  "  Strata  as  Identified  by  Organized 
Fossils,"  that  the  layers  of  the  sedimentary  rocks  may  be 


FIG.  23.  William  Smith's  Geological  Section  across  the  South  of  England. 
Exaggeration  of  the  vertical  scale  makes  the  beds  appear  too  steep.  The 
original  drawing  was  in  colors.  (From  Scott,  "Land  Mammals  of  Western 
Hemisphere,"  published  by  the  Macmillan  Co.  Reprinted  by  permission.) 

identified  by  their  fossils.  This  principle,  which  Smith 
applied  hi  his  geological  sections  across  England  (Fig.  23) 
has  since  been  extended  by  geologists,  until  the  correlation  of 
the  sedimentary  rocks  on  different  continents  has  been 
effected  by  extended  applications  of  the  methods  he  laid 
down. 

During  the  early  years  of  the  nineteenth  century,  the 
theory  of  creation,  as  applied  to  the  earth's  surface,  was 
changed  into  what  was  known  as  the  Theory  of  Catastro- 
phism.  According  to  this  theory,  the  earth  was  supposed  to 
have  evolved  through  a  series  of  creations,  between  each  of 
which  life  flourished  until  destroyed  by  a  great  catastrophy 
which  was  the  prelude  to  a  new  creation.  The  catastro- 
phism  hypothesis  was  developed  to  meet  two  facts  that 
were  irreconcilable  with  the  theory  of  a  single  creation:— 
the  discovery  that  animals  of  the  past  were  unlike  those 
of  the  present;  and  the  discovery  that  the  dissimilarity  in- 


THE  THEORY  OF  ORGANIC  EVOLUTION        175 

creased  as  the  record  was  followed  backward  in  time.  Con- 
versely, the  fossils  of  more  recent  time  were  in  many  cases 
almost  identical  with  existing  forms.  Evidences  of  violent 
geological  disturbances  were  taken  to  mean  that  great 
catastrophies  or  cataclysms  had  occurred.  By  supposing 
that  such  cataclysms  had  destroyed  all  life  and  made  neces- 
sary a  new  creation,  it  was  possible  to  save  the  creation 
theory,  since  the  creation  described  in  Genesis  could  then  be 
regarded  as  but  the  last  of  a  series.  The  Day  of  Judgment 
was  the  cataclysm  which  would  bring  the  present  epoch  to  an 
end.  Catastrophism  was  a  step  forward,  in  so  far  as  it 
acknowledged  facts  of  palaeontology,  which  were  then  well 
established,  and  emphasized  the  study  of  natural  forces 
after  the  manner  which  Hutton  had  laid  down. 

Cuvier  was  the  most  forceful  advocate  of  catastrophism. 
His  studies  upon  fossil  animals  forced  him  to  recognize  the 
progressive  sequence  of  the  record,  which  is  now  regarded  as 
one  of  the  strongest  pieces  of  evidence  for  organic  evolution. 
But  he  approached  the  subject  with  preconceived  notions 
that  were  an  inheritance  from  medieval  cosmogony.  He 
was,  therefore,  opposed  to  the  theory  of  descent.  Eventu- 
ally the  facts  of  anatomy  which  he  established  became 
important  evidence  for  evolution. 

While  the  acceptance  of  organic  evolution  was  thus  de- 
layed, the  evolutionary  principle  was  established  in  geolog- 
ical science  by  the  work  of  Charles  Lyell  (1797-1875).  Lyell 
was  not  at  first  a  believer  in  organic  evolution,  but  was  con- 
verted to  this  view  by  Darwin's  "Origin  of  Species."  His 
"Principles  of  Geology"  (1830)  was  widely  read  and  studied. 
It  maintained  its  place  as  an  authoritative  reference  work 
until  the  last  quarter  of  the  nineteenth  century.  The  sig- 
nificance of  this  book  is  found  in  the  fact  that  it  attempted 
to  explain  the  past  in  terms  of  the  present  after  the  manner 
characteristic  of  modern  geology.  Its  sub-title, ' '  An  Attempt 
to  Explain  the  Former  Changes  of  the  Earth's  Surface  by 
Reference  to  Causes  now  in  Operation,"  indicates  the  manner 


176  THE  SCIENCE  OF  BIOLOGY 

of  attack.  It  gave  the  final  blow  to  the  doctrine  of  catas- 
trophism  by  showing  that  there  had  been  no  catastrophies. 
Great  changes  had  occurred,  but  they  had  been  orderly  even 
when  they  were  most  violent.  Unconformity  in  the  layers 
was  as  much  the  result  of  orderly  change  as  was  conformity. 

Lyell's  position  as  a  Uniformitarian  in  Geology  18  inclined 
him  to  disbelieve  the  theory  of  the  transmutation  of  species. 
He  offered  what  was  the  final  convincing  proof  of  geologic 
evolution  as  the  historical  process  by  which  the  crust  of 
the  earth  had  assumed  its  present  form,  and  he  firmly  es- 
tablished the  Huttonian  doctrine  of  interpreting  the  geo- 
logic past  by  means  of  the  present.  We  have  seen  that  the 
feature  of  progression  in  the  fossil  record  had  necessitated 
modification  of  the  idea  of  a  single  creation.  But  with  the 
overthrow  of  catastrophism  by  uniformitarianism,  the 
evidence  for  progression  was  temporarily  ignored.  Belief 
that  geologic  forces  had  been  constant  was  conducive  to 
belief  in  the  constancy  of  species.  Even  Lyell  did  not  ac- 
knowledge facts,  which  were  evident  in  his  time  and  have 
since  become  cardinal  features  in  palaeontology,  until  they 
were  convincingly  stated  by  Charles  Darwin  in  the  "  Origin 
of  Species. " 

The  period  between  1830  and  1859  has  been  commonly 
represented,  by  the  historians  of  organic  evolution,  as  one 
in  which  biological  science  hesitated  to  accept  the  evolution- 
ary hypothesis  because  of  lack  of  evidence.  The  acceptance 
of  evolution,  which  followed  the  appearance  of  the  "  Origin 
of  Species,"  seems  dramatic,  because  the  impression  has  been 

18  The  "Uniformitarians"  opposed  the  "Catastrophists,"  pushing  Button's 
doctrines  to  an  extreme,  by  arguing  that  the  action  of  geological  agencies  in  the 
past  had  been  so  uniform  as  to  preclude  anything  widely  different  from  the 
present.  "They  were  inclined  to  disbelieve  that  the  stratified  formations  of 
the  earth's  crust  furnish  conclusive  evidence  of  a  gradual  progression,  from 
the  simplest  types  of  life  in  the  oldest  strata  to  the  most  highly  developed  in 
the  youngest;  and  saw  no  reason  why  remains  of  the  higher  vertebrates  should 
not  be  met  with  among  the  Palaeozoic  formations."  Geikie,  Archibald,  Enc. 
Brit.,  Article  on  Geology. 


THE  THEORY  OF  ORGANIC  EVOLUTION        177 

fostered  that  scientific  evolutionism  was  a  new  idea  as  late 
as  the  middle  decades  of  the  nineteenth  century.  Among 
English-speaking  naturalists,  however,  "the  theory  was  a 
commonplace  topic  of  discussion  for  two  or  three  dec- 
ades before  1859,  and  especially  after  the  publication  and 
immense  circulation  of  Robert  Chamber's  "Vestiges  of 
Creation,"  of  which  the  first  edition  appeared  in  1844.  Geol- 
ogical textbooks  of  the  period  referred  to  the  theory  of 
transmutation  of  species  as  a  matter  of  course,  though 
usually  only  to  reject  it  as  an  exploded  hypothesis.19  It  is  an 
interesting  fact  in  the  history  of  thought  that  a  more  glar- 
ing obtuseness  is  exhibited  by  the  scientific  mind,  during 
these  decades  before  the  "  Origin/'  than  was  exhibited  by 
the  naturalists  of  the  eighteenth  century  who  saw  nothing 
of  significance  in  the  evidence  for  evolution  set  forth  by 
Buffon  and  his  contemporaries.  It  was  Chambers,  the  lit- 
erary man  and  amateur  naturalist,  who  saw  that  which 
Darwin  had  already  seen,  but  that  to  which  the  majority 
of  technical  workers  were  still  blind. 

It  is  much  to  the  credit  of  Herbert  Spencer  (1820-1903)  that 
he  accepted  unreservedly  the  doctrine  of  organic  evolution, 
as  shown  by  an  early  article  of  his  upon  the  "Development 
Hypothesis."  M  In  this  he  supports  the  despised  Lamarck- 

19  Lovejoy,  A.  O.,  "The  Argument  for  Organic  Evolution  before  the  "Origin 
of  Species,"  Popular  Science  Monthly,  Nov.,  1909. 

10  In  this  article,  which  was  published  in  a  newspaper,  called  the  Leader, 
March  20th,  1852,  Spencer  writes  as  follows:  "Those  who  cavalierly  reject  the 
Theory  of  Evolution,  as  not  adequately  supported  by  facts,  seem  quite  to 
forget  that  their  own  theory  is  supported  by  no  facts  at  all.  Like  the  majority 
of  men  who  are  born  to  a  given  belief,  they  demand  the  most  rigorous  proof  of 
any  adverse  belief,  but  assume  that  their  own  needs  none.  Here  we  find, 
scattered  over  the  globe,  vegetable  and  animal  organisms  numbering,  of  the 
nd  (according  to  Humboldt)  some  320,000  species,  and  of  the  other,  some 
2,000,000  species  (see  Carpenter) ;  and  if  to  these  we  add  the  numbers  of  animal 
and  vegetable  species  that  have  become  extinct,  we  may  safely  estimate  the 
number  of  species  that  huvc  existed,  and  are  existing,  on  the  earth,  at  not  less 
than  ten  millions.  Well,  which  is  tin-  most  rational  theory  about  these  ten 
millions  of  species?  Is  it  most  likely  that  there  have  millions  of 

special  creation^  mo~t  likrlv  that  !>v  rontinual  modifications,  due  to 


178  THE  SCIENCE  OF  BIOLOGY 

ian  theory  as  the  cause  of  evolution,  a  fact  which  probably 
rendered  his  views  on  the  broader  question  of  descent 
less  palatable  to  his  countrymen.  In  his  later  writings, 
Spencer  was  primarily  a  philosopher,  and  this  may  account 
in  part  for  the  scant  acknowledgment  he  has  been  given  by 
scientists  as  compared  with  Darwin.  Nevertheless  he  occu- 
pies an  important  place  in  any  critical  history  of  the  doc- 
trine of  evolution,  because  of  his  early  conviction  that  such  a 
theory  was  the  only  reasonable  interpretation  which  could  be 
placed  upon  the  facts,  as  well  as  on  account  of  his  thoroughly 
scientific  viewpoint. 

The  foregoing  discussion  serves  as  an  introduction  to  the 
work  of  Charles  Darwin  (1809-1882).  Darwin  deserves 
the  place  he  occupies,  because  he  combined  the  grasp  of  the 
philosopher  with  the  accuracy  of  the  scientist.  While  still 
a  young  man,  on  the  Voyage  of  the  Beagle  (1831-1836),  he 
perceived  the  significance  of  biological  and  geological  phe- 
nomena which  he  later  used  as  evidence  for  organic  evolution. 
So  impressed  was  he  by  what  he  had  seen,  in  parts  of  the 
world  where  nature  had  been  little  changed  by  man,  that 
after  his  return  he  began  the  studies  which  culminated 
twenty  years  later  in  his  "Origin  of  Species"  (1859).  The 
simultaneous  announcement  by  Darwin  and  Wallace,  of 
the  theory  of  Natural  Selection  is  a  familiar  story.21  In  the 
summer  of  1858,  Darwin  received  a  letter  from  his  fellow 
naturalist,  Alfred  Russel  Wallace,  who  was  then  in  the  Malay 
archipelago,  asking  Darwin  to  present  on  his  behalf  a  theory 
of  the  origin  of  species  that  Wallace  had  outlined.  The 
conclusions  set  forth  in  this  brief  communication  were 

change  of  circumstances,  ten  millions  of  varieties  have  been  produced,  as 
varieties  are  being  produced  still?" 

21  The  two  brief  papers  were  published  in  the  Journal  of  the  Proceeding  of 
the  Linnean  Society,  1858,  p.  45.  Apparently,  they  made  little  impression,  for 
Darwin  tells  us  in  his  autobiography  that  the  only  published  notice  he  remem- 
bered was  to  the  effect  "  that  all  that  was  new  in  them  was  false  and  what  was 
true  was  old."  Reprints  of  these  papers  will  be  found  in  the  Popular  Science 
Monthly,  Nov.,  1901. 


THE  THEORY  OF  ORGANIC  EVOLUTION        179 

identical  with  those  which  had  been  reached  by  Darwin 
after  years  of  study.  But  so  great  was  Darwin's  generosity 
and  modesty  that  his  first  impulse  was  to  publish  Wallace's 
views  without  any  mention  of  his  own  work.  Fortunately, 
Lyell,  and  Hooker,  the  botanist,  both  of  whom  knew  the 
history  of  Darwin's  work,  persuaded  him  to  announce  the 
results  of  his  own  studies  in  a  similar  formulation.  This  he 
consented  to  do  and  was  also  persuaded  to  prepare  the  more 
extended  statement  which  appeared  a  year  later  as  the 
"  Origin  of  Species."  22 

The  publication  of  this  work  marked  the  beginning  of  a 
new  epoch,  both  in  biological  science  and  human  thought. 
The  origin  of  the  human  species  was  only  suggested,  its 
discussion  being  reserved  for  a  later  volume,  the  "  Descent  of 
Man"  (1871).  The  dramatic  features  attendant  upon  the 
publication  and  promulgation  of  Darwin's  views  are  well 
known.  In  1900,  the  " Origin"  was  rated  as  one  of  the  half 
dozen  books  of  the  century  in  the  number  of  copies  printed. 
What  is  less  well  understood,  even  at  the  present  day,  is 
the  exact  nature  of  Darwin's  scientific  accomplishment  and 
its  significance  in  the  history  of  human  thought. 

Darwin's  work  accomplished  two  things  in  biological 
science: — in  the  first  place,  it  established  organic  evolution 
as  the  only  reasonable  explanation  of  the  past  history  of 
living  things;  and  secondly,  it  offered,  in  natural  selection, 
what  then  appeared  an  adequate  explanation  for  the  origin 
of  species  and  hence  for  the  causes  of  evolution.  Darwin's 
essential  argument  in  the  " Origin  of  Species"  was  that  one 
species  could  give  rise  to  another  "by  means  of  natural 
selection  or  the  preservation  of  favored  races  in  the  struggle 

n  The  cordial  relations  which  existed  between  Darwin  and  Wallace  and  the 
generosity  exhibited  by  both  is  one  of  the  cherished  traditions  of  biological 
science.  The  case  might  have  been  very  different,  since  there  was  abundant 
opportunity  for  professional  jealousy.  Because  of  their  mutual  generosity, 
history  accords  to  Darwin  and  Wallace  a  joint  position  as  discoverers  of 
natural  Helec.tion,  although  it  recognizer  the  priority  whirl)  should  l>e  accorded 
to  Darwin  because  of  his  earlier  and  more  extended  studies. 


180  THE  SCIENCE  OF  BIOLOGY 

for  life."  If  one  species  could  be  shown  to  give  rise  to  an- 
other, the  same  process  could  be  continued.  No  limit  could 
be  set.  And  the  types  thus  produced  could  depart  indefi- 
nitely from  the  parent  form.  Once  the  mutability  of  species 
is  admitted,  the  only  reasonable  conclusion  is  that  evolution 
has  taken  place.  This  argument  was  supported  by  an  im- 
mense collection  of  facts  along  observational  and  experi- 
mental lines.  The  total  result  was  overwhelming,  coming  as 
it  did  more  than  one  hundred  years  after  the  original  pro- 
mulgation of  the  theory  of  transmutation  which  had  been 
repeatedly  rejected  by  the  main  body  of  naturalists.  Evo- 
lution was  accepted  so  quickly  by  scientists  that  the  world 
was  startled.  This  sudden  conversion  gave  rise  to  the  im- 
pression, even  among  scientific  workers,  that  no  serious 
contribution  to  evolutionary  theory  had  been  made  before 
the  period  of  Darwin. 

Moreover,  Darwin's  second  accomplishment,  Natural  Se- 
lection, was  accepted  by  science  as  a  causo-mechanical  ex- 
planation of  evolutionary  change.  The  cogent  statement  and 
the  simplicity  of  the  principle  of  selection  were  of  great  im- 
portance for  its  acceptance  along  with  the  broader  theory  of 
evolution.  For  a  time,  it  seemed  that  selection  offered  a 
complete  explanation  of  evolutionary  causation.  Extended 
exposition  of  the  selection  process  will  not  be  attempted, 
because  we  are  concerned  with  the  general  import  of  the 
theory  in  biological  and  other  lines  of  thought.23  The  tabu- 
lation, known  as  Wallace's  Chart,  which  is  an  admirable 
brief  exposition  of  natural  selection,  may  be  cited  in  this 
connection. 

23  Brief  statements  of  the  theory  of  natural  selection  will  be  found  in  many 
biological  texts.  But  Darwin's  own  exposition,  in  the  first  chapters  of  the 
"Origin  of  Species,"  is  not  so  extended  but  that  one  can  consult  the  original 
source.  G.  J.  Romanes,  " Darwin  and  After  Darwin,"  Vol.  I,  "The  Darwinian 
Theory"  (1896),  represents  a  post-Darwinian  point  of  view.  V.  L.  Kellogg, 
"Darwinism  Today,"  (1907)  is  a  critical  examination  of  the  status  of  the 
Darwinian  theories  at  the  end  of  half  a  century. 


THE  THEORY  OF  ORGANIC  EVOLUTION        181 
WALLACE'S  CHART  OF  NATURAL  SELECTION 

PROVED   FACTS  CONSEQUENCES 

A    Rapid  Increase  of  Numbers         Struggle  for  Existence 
B    Total  Numbers  Stationary 

C    Struggle  for  Existence  Survival  of  the  Fittest 

D     Variation  and  Heredity  (Natural  Selection) 

E    Survival  of  the  Fittest  Structural  Modifications 

F    Change  of  Environment 

The  importance  of  Darwin's  work  in  the  history  of 
scientific  thought  is  that  it  convinced  science  of  the  truth 
of  organic  evolution  and  proposed  a  plausible  theory  of 
evolutionary  causation.  Since  Darwin's  time,  evolution  has 
received  confirmation  on  every  hand.  It  is  now  regarded  by 
competent  scientists  as  the  only  rational  explanation  of  an 
overwhelming  mass  of  facts.  Its  strength  lies  in  the  extent 
to  which  it  gives  meaning  to  so  many  phenomena  that 
would  be  meaningless  without  such  an  hypothesis. 

But  the  case  of  natural  selection  is  far  different.  Of 
recent  years,  this  theory  of  the  causes  of  evolution  has 
suffered  a  decline.  No  other  hypothesis,  however,  has  com- 
pletely displaced  it,  and  it  remains  the  most  satisfactory  ex- 
planation of  the  origin  of  adaptations,  although  its  all- 
sufficiency  is  no  longer  accepted.  Moreover,  the  initial  step 
in  evolution  is  the  appearance  of  individual  variations  which 
are  perpetuated  by  heredity,  rather  than  the  selection  of 
variations  after  they  have  appeared.  The  interest  of  in- 
vestigators has  now  shifted  to  problems  of  variation  and 
heredity. 

As  a  result  of  this  situation,  there  has  been  much  discus- 
sion among  scientists  regarding  the  adequacy  of  what  is 
often  referred  to  as  the  Darwinian  Theory,  meaning  Natural 
Selection.  In  condemning  selection  as  an  inadequate  ex- 
planation of  the  problem,  biologists  have  often  seemed  to 


182  THE  SCIENCE  OF  BIOLOGY 

condemn  evolution  itself.  It  is  not  strange  that  the  layman, 
for  whom  Darwinism  and  evolution  are  synonymous  terms, 
believes  that  evolution  has  been  rejected  when  he  hears  that 
belief  in  Darwinism  is  on  the  wane.  He  does  not  understand 
that  what  is  thus  meant  by  Darwinism  is  not  evolution,  but 
the  proposed  cause  of  evolution — natural  selection.  This 
point  may  not  seem  vital,  but  those  interested  in  biological 
science  frequently  find  the  situation  used  to  support  claims 
that  the  entire  concept  of  organic  evolution  has  fallen  into 
disrepute.  There  are  many,  even  to-day,  who  rejoice  at 
anything  which  appears  to  weaken  this  major  generalization 
of  biology. 

The  more  important  lines  of  evidence  for  organic  evolution 
may  be  grouped  as  follows: 

1.  Evidence  from  Structure  is  derived  from: 

Comparative  Anatomy 
Comparative  Embryology 
Classification 

2.  Evidence  from  Distribution,  past  and  present,  is  derived  from: 

Palaeontology 
Geographical  Distribution 

3.  Evidence  from  Physiology  is  derived  from: 

Fundamental  Resemblances  in  Vital  Processes 
Specific  Chemical  Resemblance  of  closely  related   forms, 
e.  g.,  Blood  Tests 

4.  Evidence  from  Experimentation  rests  upon : 

Unconscious  Experimentation  upon  Animals  and  Plants  since 
their  Domestication 

Conscious  Experimentation  of  Breeders  and  of  Scientific  In- 
vestigators 

The  first  three  of  the  foregoing  groups  consist  of  evidence 
that  is  wholly  circumstantial.  The  fourth  is  hi  part  experi- 
mental. The  facts  of  comparative  anatomy  and  embryology 
are  what  might  be  expected  if  evolution  has  taken  place. 
Without  evolution  such  facts  are  meaningless.  Classifica- 
tion, since  it  is  based  on  structure,  is  a  part  of  this  anatomical 


THE  THEORY  OF  ORGANIC  EVOLUTION        183 


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Pio.  24.  Evolution  of  the  Elephant.    (From  Scott,  "Land  Mammals  of  Weit- 
Hemiaphere,"  published  by  the  Macmillan  Co.    Reprinted  by  per- 


184  THE  SCIENCE  OF  BIOLOGY 

evidence.  Palaeontology  shows  a  progressive  appearance  of 
higher  and  higher  forms  of  life  in  geologic  tune.  There  are 
also  special  cases,  such  as  the  remains  of  the  horse,  elephant, 
and  the  camel,  which  are  very  convincing  (Figs.  24  and  25). 
The  present  geographical  distribution  of  animal  and  plant 
life  is,  in  many  instances,  explicable  by  reference  to  their 
distribution  at  an  earlier  period.  Innumerable  facts  receive  a 
rational  explanation  hi  terms  of  evolution.  Physiological 
study  shows  that  the  living  substance  of  all  animals  and 
plants  exhibits  fundamental  resemblances  in  waste,  repair 
and  growth,  irritability,  reproduction,  and  the  like.  Hence, 
all  protoplasm  is  perhaps  genetically  akin.  Recent  work  on 
the  chemico-physical  properties  of  blood  is  very  impressive, 
because  it  confirms  conclusions  regarding  relationship  that 
have  been  independently  derived  from  anatomy  and  embry- 
ology. In  all  of  the  foregoing,  the  facts  are  as  they  should  be 
if  evolution  has  occurred.  The  first  three  groupings  are  thus 
circumstantial  evidence.  But  all  evidence  for  the  larger 
evolutionary  changes  must  be  of  this  nature.  The  strength 
of  circumstantial  evidence  lies  in  its  amount  and  variety,  and 
in  these  respects  this  evidence  is  very  strong.24 

Fragmentary  records  of  the  changes  in  animals  and  plants 
under  domestication  together  with  scientific  investigations 
in  breeding,  heredity,  and  variation  constitute  the  evidence 
of  an  experimental  nature.  The  modifications  observed  are 
small,  as  compared  with  those  postulated  by  evolution.  But 
the  time  has  been  short,  and  little  more  than  evidence  for  the 
mutability  of  natural  species  or  of  domestic  breeds  could  be 
expected.  The  significant  fact  is  that  the  experimental 
results  tell  a  similar  story  in  favor  of  evolution.  There 
seems  to  have  been  a  certain  amount  of  evolutionary  change 
hi  our  domesticated  species  during  the  past  ten  or  fifteen 

24  These  conventional  lines  of  evidence  are  presented  at  length  in  many  texts 
which  deal  with  evolution.  G.  J.  Romanes,  "Darwin  and  after  Darwin," 
Vol.  I;  S.  Herbert,  "First  Principles  of  Evolution";  W.  B.  Scott,  "Theory  of 
Evolution,"  all  contain  excellent  statements. 


THE  THEORY  OF  ORGANIC  EVOLUTION        185 


186  THE  SCIENCE  OF  BIOLOGY 

thousand  years.  Modern  experimenters,  like  Darwin, 
Mendel,  and  Morgan,  have  thrown  much  light  upon  the 
workings  of  variation  and  heredity.  The  present  situation 
justifies  the  statement  that  since  the  publication  of  the 
"Origin  of  Species"  organic  evolution  has  been  substantiated 
by  evidence  that  is  now  overwhelming. 

The  effect  upon  biological  science  of  the  acceptance  of 
Darwin's  conclusions  was  startling.  Both  evolution  and 
natural  selection  were  accepted  forthwith.  The  biologist 
sought  to  interpret  old  facts  in  a  new  way  and  to  discover 
new  facts  which  confirmed  the  evolutionary  hypothesis. 
In  zoology,  the  study  of  embryology,  as  a  means  of  deter- 
mining racial  descent,  was  eagerly  pursued,  although  it 
eventually  proved  disappointing  as  an  answer  to  the  broader 
problems  of  relationship.  However,  evolution  was  more 
firmly  established  by  means  of  this  work.  On  the  other  hand 
the  investigations  of  recent  years  have  assigned  less  im- 
portance to  the  theory  of  selection.  When  it  is  understood 
that  Darwinism  may  be  used  to  mean  either  organic  evolu- 
tion or  its  alleged  cause,  natural  selection,  or  both  evolution 
and  selection,  it  becomes  apparent  that  the  dispute  over  the 
efficacy  of  selection  is  not  a  challenging  of  the  comprehensive 
theory  of  organic  evolution. 

The  biological  position  of  the  evolutionary  doctrine  has 
been  established.  Evolution  is  the  clue  to  the  history  of 
living  things.  But  the  doctrine  is  most  important  to  man- 
kind, through  its  influence  upon  human  thinking  outside 
strictly  biological  lines.  Like  the  Copernican  system  of 
astronomy,  it  has  made  the  universe  anew  within  the  minds 
of  men.  The  concept  of  organic  evolution  has  changed 
man's  concept  of  his  position  in  the  order  of  nature.  It  is 
also  changing  our  ideas  regarding  the  organization  of  society. 
Lines  of  thought,  seemingly  remote  from  the  biological  field 
have  been  revolutionized.  The  end  of  this  change  has  not 
come  to  pass. 


CHAPTER  VIII 

CURRENT    PROBLEMS    AND    METHODS   OF 
ZOOLOGICAL  SCIENCE 

IT  is  sometimes  said  that  the  course  of  scientific  progress, 
even  the  existence  of  entire  branches  of  science,  has  been 
determined  by  a  few  men  of  genius,  whose  interest  in  partic- 
ular fields  has  forced  certain  facts  into  prominence.  As  a 
result,  science  develops  in  some  directions  while  it  lags  in 
others.  This  may  possibly  be  true,  but  at  times  we  can 
discern  changes  which  appear  simultaneously  in  the  work  of 
many  individuals,  affect  a  science  as  a  whole,  and  are  thus 
independent  of  any  single  investigator.  The  present  genera- 
tion has  witnessed  a  change  of  this  composite  nature  within 
the  field  of  zoology.  During  the  last  three  decades  a  transi- 
tion lias  been  accomplished  from  a  science  the  methods  of 
which  were  largely  observational  to  one  in  which  the  domi- 
nating methods  are  experimental.  No  commanding  person- 
ality has  been  involved,  but  rather  the  growing  conviction 
of  many  that  progress  cannot  be  continued  without  more 
analytical  methods  of  investigation.  Proceeding  to  specific 
illustrations,  we  may  consider  some  of  the  problems  now 
being  attacked  by  zoologists,  their  methods  of  work,  and  the 
results  attained.  We  may  contrast  their  attitude  with  that 
of  investigators  during  the  greater  part  of  the  nineteenth 
century.  Also,  we  may  consider  what  the  more  analytical 
spirit  means  for  this  branch  of  science.  This  account  of 
present-day  zoology  does  not  summarize  all  current  investi- 
gation. The  method  of  random  sampling  is  applied,  with  a 
view  to  the  selection  of  representative  examples  of  zoological 
research . 

187 


188  THE  SCIENCE  OF  BIOLOGY 

PROBLEMS   OF   DEVELOPMENT 

Embryology: — The  development  of  a  fertilized  egg  into 
an  adult  animal  is  a  marvelous  phenomenon.  During  the 
nineteenth  century  the  general  course  of  this  development 
was  ascertained  for  all  the  major  groups  of  the  animal  king- 
dom. The  cruder  misconceptions,  regarding  the  links  by 
which  an  animal  is  connected  with  its  descendants  and  its 
ascendants,  had  been  corrected  before  the  middle  of  the 
century.  The  cellular  basis  of  development  was  made  clear 
during  the  fifty  years  which  followed.  But  despite  the 
wealth  of  facts  discovered  by  the  embryologists,  the  marvel 
of  the  developmental  process  has  increased  the  more.  Even 
in  the  light  of  recent  experimentation,  it  must  be  confessed 
that  relatively  little  is  known  regarding  causation  in  develop- 
ment, aside  from  a  knowledge  of  the  visible  changes  by 
which  the  egg  becomes  the  adult.  These  changes  we  know 
tolerably  well.  What  we  wish  to  know  is  why  particular 
developmental  changes  occur  as  they  do,  why  this  or  that 
structure  arises  at  a  particular  time,  and  what  is  the  relation- 
ship between  internal  and  external  phenomena.  Now  that 
the  sequence  of  structural  changes  has  been  made  known,  the 
embryological  problem  has  become  the  problem  of  under- 
lying causation.  In  the  solution  of  such  a  problem,  there 
must  be  recourse  to  experimentation. 

Fertilization  illustrates  the  historical  development  of  a 
biological  problem  and  also  the  progress  from  nineteenth  to 
twentieth  century  zoology.  The  fact  that  the  semen  of  the 
male  was  in  some  manner  necessary  for  conception  in  higher 
animals  was  known  to  the  ancients.  Aristotle  wrote  with 
remarkable  acumen  upon  the  reproduction  of  animals. 
The  fact  that  animals  of  certain  sorts  arose  from  eggs  was 
known  wherever  the  eggs  were  sufficiently  large  to  be  recog- 
nizable. The  eggs  of  birds  and  reptiles,  and  later  (Redi, 
1668)  the  eggs  of  smaller  forms  like  insects  were  recognized 
as  the  initial  stages  of  development,  but  this  did  not  explain 


ZOOLOGICAL  SCIENCE  189 

how  the  seminal  fluid  of  the  male  was  related  to  the  genera- 
tive process.  After  the  spermatozoa  and  the  microscopic  ova 
of  many  animals  were  discovered  in  the  latter  part  of  the 
seventeenth  century,  the  role  of  each  was  long  in  dispute— 
the  spermatists  of  the  eighteenth  century  maintaining  that 
the  embryo  arose  from  the  sperm,  the  ovists  that  it  came 
from  the  ovum.  During  this  period  a  considerable  amount 
of  experimentation  was  carried  on  in  the  attempts  to  deter- 
mine, by  filtration  and  similar  methods,  whether  the  sper- 
matozoa or  the  fluid  portion  of  the  semen  constituted  the 
fertilizing  agent  (Spallanzani,  1785). 

During  the  first  half  of  the  nineteenth  century  it  came  to 
be  acknowledged  that  the  spermatozoon  and  not  the  fluid  of 
the  semen,  was  the  activating  agent.  But  the  morphological 
facts  of  fertilization  remained  obscure,  until,  in  1875,  Oscar 
Hertwig  described  correctly  the  cellular  phenomena  of 
fertilization  in  the  egg  of  the  sea-urchin.  It  was  shown  that 
fertilization  consisted  in  the  entrance  of  a  single  spermat- 
ozoon into  the  egg,  and  the  union  of  egg-nucleus  with 
sperm-nucleus  to  form  the  nucleus  of  the  one-cell  stage 
from  which  the  many-celled  organism  originated  by  cell- 
division.  Virchow's  doctrine,  omnis  cellula  e  cellvla  (1856), 
was  fully  confirmed;  and  the  nature  of  the  continuity 
between  generations  was  explained  in  terms  of  the  cell- 
doctrine.  * 

Following  1875  there  ensued  a  period  of  morphological 
study,  during  which  the  exact  nature  of  cell  division  and 
the  structure  of  the  nucleus  of  egg  and  sperm-cells  was  ascer- 
tained. It  became  apparent  that  fertilization  involved  two 
dist  inct  phenomena,  which  should  be  investigated  independ- 
ently, despite  their  intimate  association.  On  the  one  hand 
were  the  phenomena  related  to  the  genetic  problem  of  how 
egg  and  sperm  constituted  the  physical  basis  for  continuity 

tory  of  the  Fcrtili/sition  Problem. "  Science,  Jan.  14, 

1916,  contains  an  authoritative  miramary  of  the  history  and  recent  status  of 
knowledge  concerning  thin  fundamental  process  of  reproduction. 


190  THE  SCIENCE  OF  BIOLOGY 

between  generations,  and  on  the  other  were  those  related 
to  the  physiological  problem  of  how  the  spermatozoon  served 
as  an  activating  agent  which  stimulated  the  egg  and  thus 
caused  its  development.  The  term  fertilization  has  latterly 
been  restricted  to  the  second  set  of  phenomena — the  problem 
of  how  egg  and  spermatozoon  produce  a  cell  capable  of 
division. 

The  analysis  of  fertilization  from  its  morphological  stand- 
point, i.  e.,  the  structural  features  involved  in  the  union  of 
egg  and  sperm,  prepared  the  way  for  the  physiological 
analysis  now  in  progress.2  This  analysis  consists  of  (1) 
work  upon  artificial  parthenogenesis,  and  (2)  biological 
studies  upon  what  may  be  termed  the  fertilization  reaction 
between  egg  and  sperm.  The  present  status  of  the  fertiliza- 
tion question,  as  a  physiological  rather  than  a  morphological 
problem,  illustrates  the  drift  toward  experimentation,  which 
has  followed  upon  the  establishment  of  morphological  facts, 
whether  in  embryo  or  adult. 

But  fertilization  does  not  occur  in  the  development  of  all 
eggs,  although  it  is  necessarily  the  starting  point  in  bi- 
parental  reproduction.  The  phenomenon  of  natural  partheno- 
genesis, by  which  the  ovum  or  unfertilized  egg-cell  develops 
without  the  entrance  of  a  spermatozoon,  occurs  in  a  con- 
siderable number  of  species,  among  the  Insecta,  Crustacea, 
Trematoda,  Rotifera,  Arachnida,  and  perhaps  the  Verte- 
brata.3  Males  are  known  to  exist  hi  most  of  these  cases  and 
fertilization  of  the  eggs  occurs  in  certain  generations,  as  in 
the  plant  lice,  or  certain  eggs  are  fertilized  while  others  are 
not,  as  in  the  case  of  the  honey-bee.  In  some  cases  the  males 
are  unknown,  but  it  is  presumed  that  they  have  not  yet  been 
discovered,  not  that  they  are  absent.  Hence,  in  partheno- 
genetic  species  it  appears  that  certain  eggs  develop  without 
fertilization  by  the  spermatozoa,  while  other  eggs  are  capable 

2Lillie,  F.  R.,  "Problems  of  Fertilization,"  1919. 

'Phillips,  E.  F.,  "A  Review  of  Parthenogenesis,"  Proc.  Am.  Philos.  Soc., 
Vol.  XLII,  No.  174,  1903. 


ZOOLOGICAL  SCIENCE  191 

of  development  only  after  fertilization  like  that  which 
occurs  in  the  great  majority  of  animal  forms. 

The  natural  parthenogenesis  above  described  is  a  com- 
paratively rare  phenomenon.  Its  occurrence  suggests  that 
eggs,  which  develop  in  nature  only  after  fertilization,  may 
be  caused  to  develop  parthenogenetically  if  suitable  stimuli 
are  applied.  This  is  found  to  be  the  case;  and  the  phenom- 
enon is  now  designated  artificial  parthenogenesis,  in  contrast 
to  the  natural  parthenogenesis  which  occurs  in  nature. 
Since  the  first  successful  experiments  in  artificial  partheno- 
genesis some  twenty-five  years  ago,4  it  has  been  found  that 
the  eggs  of  many  animals,  among  which  are  worms,  molluscs, 
echinoderms,  and  vertebrates,  may  be  thus  caused  to 
develop  without  fertilization.  Development,  hardly  to  be 
distinguished  from  that  which  is  normal,  ensues  when  these 
eggs  are  subjected  to  very  dilute  solutions  of  salts,  acids, 
narcotics,  and  other  substances,  to  changes  in  temperature 
and  in  some  cases  even  to  simple  mechanical  stimulation. 
It  is  quite  conceivable  that  there  is  no  egg  of  any  animal 
which  could  not  be  artificially  started  on  its  development  by 
the  application  of  a  suitable  stimulus.5 

Experiments  such  as  these  give  an  understanding  of  fer- 
tilization which  could  never  be  obtained  by  mere  observation 

4  The  first  recorded  attempts  at  artificial  parthenogenesis  are  those  of 

Hpallanzani  (1785),  who  attempted  "to  start  the  development  of  eggs  by 

by  the  action  of  extracts  of  all  the  various  organs,  by  vinegar, 

dilute  alcohol,  lemon  juice  and  other  substances,  all  without  effect."    Lillie, 

I     |{  .      lii    History  of  the  Fertilization  Problem,"  loc.  cit. 

*  As  yet  it  has  been  impossible  to  carry  through  to  an  adult  state  the  embryos 
thus  formed,  save  in  a  few  exceptional  cases.     But  this  could  hardly  be  ex- 
pected at  the  present  stage  of  investigation,  bemuse  the  initiation  of  develop- 
by  these  artificial  means,  is  so  wide  a  departure  from  the  normal  process. 
Moreover,  the  normally  fertilized  eggs  of  these  forms  are  reared  with  difficulty 
laboratory.    But  there  is  a  reasonable  expectation  that  once  the  tech- 
i.s  discovered  many  artifieially  fertili/able  eggs  may  be  carried  through 
their  entire  cycle  to  the  adult     Should  this  l>e  accomplished,  it  would  throw 
linht  u|Km  problems  of  sex  and  of  heredity,  Ixjcause  the  adults  thus  formed 
!*•  without  male  parentage  in  the  ^enerntion  which  immediately  pro- 


192  THE  SCIENCE  OF  BIOLOGY 

of  normal  processes.  The  experimental  initiation  of  develop- 
ment supports  the  hypothesis  that  spermatozoon  brings  to 
ovum  a  minute  quantity  of  an  unknown,  but  no  doubt  dis- 
coverable, substance  which  furnishes  a  necessary  link  in 
the  chain  of  causation  that  initiates  development.  If  a  sub- 
stance, isolated  from  the  spermatozoa,  could  be  brought  in 
contact  with  eggs  and  thus  cause  them  to  develop,6  the 
stimulus  to  development  would  be  recognized  as  a  specific 
substance.  Fertilization  would  then  lose  that  intangible 
quality  which  in  the  past  has  cast  a  spell  of  mystery  over  so 
many  biological  phenomena.  Research  of  this  nature  is  now 
being  carried  forward  by  so  many  investigators  that  we  may 
hope  for  a  comprehensive  understanding  of  this  first  step 
in  development,  although  the  facts  now  established  have 
already  raised  unsuspected  problems.7 

The  work  upon  artificial  parthenogenesis  has  illuminated, 
but  not  explained,  the  process  of  normal  fertilization.  What 
is  called  the  fertilization  reaction  between  egg  and  sperm 
must  be  attacked  by  experimental  work  upon  the  normal 
activation  of  the  ovum  by  the  spermatozoon.  The  story 
of  the  work  now  in  progress  is  too  extensive  to  be  related.  As 
one  investigator  puts  it,  "the  main  physiological  problems 
of  fertilization  are  still  before  us;  all  the  work  has  merely 
prepared  the  way  for  their  solution.  Fertilization  is  the 
knot  in  the  webs  of  successive  generations  which  must  be 
untied  before  we  can  trace  the  strands  from  generation  to 
generation."  For  the  purposes  of  our  present  discussion, 
the  history  of  the  fertilization  problem  shows  the  biological 

•  Cf.  the  work  of  O.  C.  Glaser,  "  Fertilization  and  Egg-secretions,"  Biol. 
Bull.,  Aug.  1921. 

7  Considerable  notoriety  attached  to  the  work  upon  artificial  parthenogenesis 
when  the  results  of  the  first  successful  experiments  by  J.  Loeb  became 
known.  Newspaper  feature  stories  hailed  the  accomplishment  both  as  an  ex- 
planation of  the  immaculate  conception  and  as  a  creation  of  living  protoplasm. 
The  latter  interpretation  was  manifestly  ridiculous,  since  what  had  been  done 
was  to  artificially  stimulate  an  already  living  egg  to  develop  as  it  would  have 
done  under  normal  stimulation  by  the  spermatozoon. 


ZOOLOGICAL  SCIENCE  193 

advance  from  an  observational  study  of  structural  changes 
to  an  experimental  analysis  of  causation. 

To  follow  another  illustration: — one  of  the  most  famous 
disputes  among  the  earlier  embryologists  was  that  of  pre- 
formation  versus  epigenesis.  Is  the  organism  already  formed 
within  the  germ,  like  the  bud  of  a  plant,  and  does  develop- 
ment consist  merely  in  an  unfolding  of  what  is  already  exist- 
ent ;  or  is  development  the  coming  into  being  of  one  feature 
after  another  from  a  beginning  that  is  without  form  and 
void,  in  so  far  as  any  resemblance  to  the  completed  organism 
is  concerned?  The  preformationists  of  the  eighteenth  century 
went  so  far  as  to  develop  an  elaborate  theory  of  encasement, 
by  which  the  germ  was  supposed  to  contain  all  of  the  adult 
structures  in  miniature,  including  the  germs  of  all  future 
generations,  enclosed  one  after  another  in  ever-decreasing 
magnitude,  like  toy  eggs  within  eggs  carried  inward  to 
infinity.  Thus,  the  ovary  of  Eve  could  be  supposed  to  have 
contained  the  encapsuled  representatives  of  all  future  gen- 
erations of  the  human  race. 

Of  course,  no  very  extensive  knowledge  of  embryonic 
stages  was  needed  to  demonstrate  that  the  general  course 
of  development  in  all  animals  is  by  epigenesis  and  not  by 
preformation.  The  fertilized  egg  possesses  at  the  outset 
no  obvious  resemblance  to  the  future  adult.  Adult  organ- 
ization is  attained  through  growth  and  cell  division  and  by 
gradual  differentiation  of  parts  (Fig.  12).  Seemingly,  there 
could  be  nothing  farther  from  an  unfolding  of  what  is  al- 
ready preformed.  But  the  fact  that  two  eggs,  placed  side 
by  side  in  a  dish  of  water,  develop  into  a  frog  and  a  toad, 
or  into  a  starfish  and  a  sea-urchin,  is  evidence  that  some  sort 
of  preformation  does  exist,  unless  one  regards  the  develop- 
ment of  every  individual  as  a  supernatural  process  which 
cannot  be  subjected  to  scientific  analysis.  Hence,  the  ques- 
t  i<  m  of  epigenesis  as  opposed  to  preformation  has  engaged  the 
it  ion  of  experimental  embryologists  during  recent  years. 
I  ho  eggs  of  many  animals,  among  others  the  frog,  sea- 


194  THE  SCIENCE  OF  BIOLOGY 

urchin,  and  starfish,  are  fertilized  and  develop  in  external 
water  without  parental  care.  Here,  experiments  are  pos- 
sible which  could  hardly  be  made  upon  an  egg  developing 
within  a  brood-pouch  or  other  internal  cavity  of  a  parent. 
The  question  of  whether  the  protoplasm  of  the  egg  is  pre- 
formed, to  the  extent  that  certain  of  its  parts  are  destined 
to  give  rise  to  certain  parts  of  the  adult,  has  evoked  con- 
siderable interest.  The  problem  has  been  attacked  experi- 
mentally by  the  removal  of  parts  of  the  egg  in  the  sea- 
urchin  and  other  forms.  Pieces  have  been  cut  from  different 
regions  of  the  fertilized  and  the  unfertilized  egg;  two,  four, 
eight,  and  even  sixteen  cell  stages  have  been  separated  into 
their  component  cells.  These  and  many  other  experiments 
have  been  performed,  with  a  view  of  demonstrating  the 
nature  of  the  organization,  which  must  be  postulated,  since 
it  is  obviously  something  within  the  egg  that  determines  the 
major  features  of  development. 

So  many  and  so  diversified  have  been  these  experiments 
that  we  can  summarize  only  their  general  outcome.  The 
eggs  of  many  animals  exhibit  within  their  cytoplasm  (Fig. 
12)  recognizable  substances,  unlike  the  adult  parts  but 
from  which  the  adult  parts  take  origin.  Such  eggs  are  thus 
visibly  organized  or  preformed  to  the  extent  that  certain 
regions  of  the  egg  become  certain  regions  of  the  adult.  The 
eggs  of  other  animals  exhibit  little  differentiation  which  can 
be,  at  present,  recognized.  In  eggs  of  the  latter  sort,  one 
area  is  more  nearly  of  the  same  value  as  every  other,  and 
recognizable  differentiation  appears  at  a  subsequent  stage 
of  development.  The  truth  seems  to  be  that  the  eggs  of 
different  animals  are  not  alike  with  respect  to  their  visible 
differentiation  at  the  one  cell  stage;  that  the  first  signs  of 
differentiation,  while  visible  in  some  animals  at  the  one  cell 
stage,  are  less  apparent  in  others  until  a  later  stage  of  develop- 
ment; while  in  those  forms  which  have  as  adults  great 
capacity  for  the  regeneration  of  lost  parts,  the  organism 
is  never  so  completely  differentiated  as  to  be  unable  to  re- 


ZOOLOGICAL  SCIENCE  195 

form  an  entire  body  from  a  portion  of  the  whole.8  Whether 
such  an  organization  is  visible  or  not,  something  of  the  sort 
must  be  present  in  every  egg.  Otherwise  there  can  be  no 
explanation  of  the  phenomena  of  heredity,  which  can 
satisfy  the  demands  of  science.  The  embryologist  is  of 
necessity  a  preformationist,  but  not  in  the  older  sense  of  the 
word.9 

In  problems  of  this  nature,  satisfactory  analysis  can  only 
be  based  upon  experiments  which  subject  the  organism  to 
new  and  controlled  conditions.  No  observation  of  normal 
development,  no  matter  how  extensive,  will  go  so  far  toward 
answering  the  question  whether  at  the  two  cell  stage  the  right 
and  left  portions  of  the  animal  are  irrevocably  distributed 
to  right  and  left  cells  as  will  the  simple  experiment  of  sepa- 
rating these  two  cells  and  seeing  what  happens.  In  a  simple 
way,  this  illustrates  the  whole  point  in  the  advancement  of 
zoology  by  means  of  experimentation. 

In  addition  to  this  study  of  embryonic  stages,  there  is 
another  method  of  attacking  the  developmental  problem, 
which  may  be  illustrated  as  follows:  If  one  deals  out  the 
hands  in  a  game  of  cards  and  then  examines  the  cards  in 
each  hand,  he  can,  if  he  knows  the  nature  of  the  dealing, 
infer  the  manner  in  which  the  cards  were  arranged  in  the 
pack  before  the  dealing  began.  One  must  assume  an  ar- 
rangement within  the  pack,  which  bears  a  causal  relation  to 
the  hands  or  he  must  assume  the  miraculous  origin  of  the 
arrangement  which  appears  as  a  result  of  the  dealing.  The 
inference  that  such  an  organization  exists  within  the  pack 
before  the  deal  begins  is  of  the  same  sort  as  that  which  the 
chemist  makes  in  postulating  atoms  and  molecules  which 
have  never  been  seen.  When  one  studies  the  inheritance  of 
qualities  appearing  in  an  adult  animal,  it  is  like  examining 

•  Conklin,  E.  G.,  "  Heredity  and  Environment  in  the  Development  of  Men." 
Wilson,  E.  B.,  "The  Problem  of  Development,"  Science,  Feb.  24,  1905. 

•  The  case  is  analogous  with  that  of  the  physicist  and  chemist  who  postulate 
invisible  molecules  and  atoms,  as  a  basis  for  the  visible  phenomena. 


196  THE  SCIENCE  OF  BIOLOGY 

the  cards  in  the  hands,  while  knowing  something  of  the  dealing, 
but  not  knowing  the  organization  of  the  pack.  If  it  is 
found  that  adult  qualities  appear  in  a  certain  manner,  their 
probable  arrangement  before  the  dealing,  that  is  to  say  the 
development,  can  be  inferred. 

An  amazing  result  of  the  recent  experimental  work  upon 
the  heredity  of  adult  characters  is  that  the  knowledge  thus 
gained  enables  us  to  picture,  without  seeing,  certain  char- 
acteristics in  the  organization  of  the  germ-cells,  much  as  the 
chemist  pictures  the  organization  of  molecules.  There  is, 
however,  one  respect  in  which  the  biologist,  who  seeks  to 
understand  the  germ-cells  has  an  advantage  over  the  chem- 
ist who  postulates  invisible  structures.  There  exists  within 
the  nucleus  of  ovum  and  spermatozoon,  as  in  all  other  cells, 
a  visible  substance,  known  as  chromatin  and  appearing 
at  the  tune  of  cell  division  in  the  form  of  bodies,  the  chro- 
mosomes (Fig.  13),  which  are  constant,  both  in  number  and 
appearance  for  any  given  species.  The  behavior  of  these 
chromosomes,  as  seen  by  the  microscope,  is  so  specifically 
related  to  the  end  results  of  heredity  as  to  virtually  identify 
them  with  the  mechanism  of  transmission  for  certain  adult 
qualities  through  the  germ,  and  hence  to  suggest  the  prob- 
able organization  of  the  germinal  substance.10  It  is  thus 
possible  to  attack  the  problem  of  development  at  its  two 
extremes;  and,  now  that  we  understand  the  situation  to 

10  Morgan,  T.  H.,  "The  Mechanism  of  Mendelian  Heredity,"  1915.  This 
volume  is  a  current  summary  of  conclusions  reached  by  Professor  Morgan  and 
his  students.  The  work,  which  is  still  in  progress,  has  already  yielded  results 
of  such  importance  that  it  is  clearly  the  most  comprehensive  attack  which 
has  been  yet  made  upon  the  problem  of  heredity.  It  is  important  in  relation 
to  the  problem  of  preformation,  because  certain  postulates  can  now  be  made 
regarding  the  organization  within  germ-cells.  If  the  results  are  sustained  and 
extended  in  correlation  with  the  work  of  the  cytologists,  a  supra-molecular 
organization  of  the  germ  may  soon  be  accepted  in  a  manner  comparable  to 
the  way  in  which  the  chemist  accepts  his  working  hypothesis  of  molecular 
organization.  Development  will  then  become  the  problem  of  how  a  germ  with 
a  given  organization  develops  into  a  given  adult  organism — how  the  dealing 
is  accomplished. 


ZOOLOGICAL  SCIENCE  197 

correlate  the  attacks.    Each  supplements  the  other  and  sug- 
gests new  ways  of  advance.11 

Although  the  field  of  embryology  was  among  the  earliest 
to  be  invaded  by  the  experimentalist  in  zoology,  it  is  still 
attractive,  because  there  is  no  phenomenon  of  nature  which 
seems  so  inexplicable  as  the  development  of  an  adult  indi- 
vidual from  a  single  cell.  Unfortunately,  many  of  the 
organisms  most  desired  for  experimentation  do  not  lend 
themselves  to  particular  experiments.  The  structure  of 
the  animal  and  the  nature  of  its  environment  impose  limita- 
tions. But  the  investigator's  ingenuity  frequently  sur- 
mounts difficulties  which  at  first  seem  insurmountable. 
What  impresses  those  who  worked  as  students  during  the 

11  During  the  last  quarter  of  the  nineteenth  century,  August  Weismann 
recognized  the  logical  necessity  of  assuming  germinal  organization,  in  any 
attempt  to  explain  the  physical  basis  of  heredity.  His  book  entitled  "The 
Germ-Plasm"  (1893)  postulated,  theoretically,  a  germinal  organization  by 
which  the  mechanism  of  heredity  and  development  could  be  depicted.  The 
Weismannian  doctrine  fell  into  disrepute  among  biologists,  because  its  author 
set  forth  the  organization  of  the  germ-plasm  upon  a  basis  which  seemed  far  too 
theoretical.  Biology  was  still  under  the  spell  of  the  epigenetic  concept  of 
development,  as  established  by  von  Baer  during  the  first  half  of  the  nineteenth 
century.  The  crude  notions  of  preformation  were  clearly  untenable  and  the 
tendency  was  to  regard  the  germ-plasm  as  undifferentiated  protoplasm.  Noth- 
ing was  known  regarding  Mendelian  heredity  with  its  implications  regarding 
the  germ.  Weismannism  received  wide  discussion  but  scant  acceptance.  But 
the  work  of  the  embryologists  has  since  revealed  a  certain  degree  of  organiza- 
tion within  the  egg.  Simple  undifferentiated  protoplasm  has  been  found  to  be 
non-existent,  since  all  protoplasm  is  differentiated  in  some  degree.  Later,  the 
facts  of  Mendelian  heredity  have  forced  the  postulation  of  a  complex  germinal 
organization.  To  Weismann  belongs  the  credit  for  recognizing  the  necessity  of 
assuming  a  germinal  organization  similar,  in  its  causal  relationship  to  the  adult 
organization,  to  that  which  the  students  of  Mendelian  heredity  have  postulated 
on  the  factual  basis  of  inheritance  of  unit-characters.  The  ridicule  which 
was  for  a  time  heaped  upon  Weismann's  doctrine  resembles  that  which  at- 
tended the  theory  of  organic  evolution  for  many  years  after  it  had  been  recog- 
nized as  a  logical  inference  by  the  scientist-philosophers  of  the  eighteenth 
y.  To-day  experimental  embryologist  and  geneticist  virtually  acknowl- 
edge a  Neo-Weismannism.  The  hypothetical  germinal  unite  of  Weismann's 
theory  have  been  replaced  by  the  hypothetical  determiners  or  genes  of  the 
lian  theory.  It  should  be  remembered  that  Weismann  first  elaborated 
the  theory  of  preformation  in  terms  of  cellular  biology. 


198  THE  SCIENCE  OF  BIOLOGY 

closing  years  of  the  nineteenth  century,  when  descriptive 
embryology  was  still  a  dominant  form  of  investigation,  is  the 
fact  that  the  study  of  embryology  has  become  largely  ex- 
perimental. The  sequence  of  stages  has  been  well  enough 
established  to  make  the  more  subtle  causes  of  development 
the  subject  of  investigation. 

Regeneration : — The  term  regeneration  is  used  to  desig- 
nate the  process  by  which  an  animal  or  plant  repairs  the 
losses  resulting  from  destruction  or  removal  of  parts. 
Capacity  for  regeneration  may  be  small,  as  in  the  higher 
vertebrates  which  possess  only  the  ability  to  heal  wounds,  or 
it  may  be  so  great  that  a  small  piece  cut  from  the  organism 
will  reproduce  the  whole.  The  fresh-water  worms  known  as 
planarians  possess  astonishing  powers  of  regeneration.  If 
the  adult  worm  be  cut  in  two  transversely  (Fig.  26),  each 
piece  becomes  a  complete  animal.  When  divided  length- 
wise, the  pieces  behave  in  a  similar  manner,  failing  to 
regenerate  only  when  too  great  an  area  of  cut-surface  is  ex- 
posed to  bacterial  infection  or  from  other  untoward  circum- 
stances. In  whatever  way  the  piece  may  be  removed,  it 
tends  to  form  a  new  individual  having  the  characteristics  of  the 
original  body,  although  there  are  some  exceptions,  as  when 
heads  or  tails  are  formed  in  the  wrong  position  (Fig.  26  D1)— 
a  phenomenon  which  is  termed  heteromorphosis.  Even  a 
very  small  piece  (one  investigator  has  estimated  that  a 
piece  only  1/250  of  the  bulk  of  the  original  can  form  the 
entire  worm)  is  able  to  heal  its  wounded  surfaces  and  so  to 
change  its  shape  and  proportions  that  growth  alone  is 
necessary  for  the  production  of  a  normal  individual. 

In  the  formation  of  these  new  individuals  by  regeneration, 
we  observe,  hi  addition  to  a  healing  of  the  wound,  a  change 
in  the  relative  proportions  of  the  piece  by  which  the  normal 
shape  is  regained.  This  latter  phenomenon  is  termed 
regulation.  After  it  has  occurred,  the  new  individual  merely 
grows  to  the  original  size.  Another  phenomenon  is  the 
polarity  or  determination  of  the  axes  of  symmetry.  No 


Fio.  26.  Regeneration  in  Planarians.    A,  Planaria  maculata,  normal  adult  propor- 
tion*; B  and  C,  individuals  regenerating  after  cutting  a  worm  in  two  at  e  /  in  A, 
•car  tissue  shown  by  stippled  areas;  B'  and  C/  the  same  assuming  normal  pro- 
•  ions;  D  and  t/,  hetereomorphosis  in  a  piece  cut  from  anterior  end,  a  b  in  A. 
B,  F.  O,  and  //,  regeneration  of  a  short  transverse  segment,  e  d  e  f  in  A,  showing 
regulation  of  proportions  rui  in  B'  and  f";  /.  hrtcromorphosis  in  :in  individn.-il 
lengthwiao  from  posterior  end.    Eyes  and  pharynx  are  shown  by  outline 
within  the  figures;  scar  tissue  by  stippled  areas.    (/  aftor  Morgan.) 


200  THE  SCIENCE  OF  BIOLOGY 

matter  how  the  piece  may  be  cut,  the  axes  of  the  old  body 
somehow  become  those  of  the  new.  It  is  as  though  every 
part  of  the  original  were  laid  down  on  certain  lines  and  these 
lines  persisted  in  the  piece  removed.  Heteromorphosis  is,  of 
course,  an  exception,  though  not  impossible  of  explanation  in 
terms  of  the  normal  polarity. 

The  power  of  regeneration  is  widely  distributed  among  the 
lower  organisms.  Generally  speaking,  those  animals  and 
plants  which  exhibit  in  their  normal  life-cycles  marked 
powers  of  vegetative  reproduction  (budding,  fission,  and  the 
like)  are  found  to  possess  the  greatest  capacity  for  regenera- 
tion. Specialized  forms,  which  reproduce  only  by  means  of 
germ-cells,  can  do  little  more  than  heal  wounds  of  limited 
extent  or  replace  lost  appendages,  as  does  the  crayfish. 
Studies  upon  regeneration  have  shown  the  nature  and  extent 
of  regeneration  in  a  wide  variety  of  forms.  With  these  facts 
known,  it  has  been  possible  to  consider  the  more  subtle 
factors  involved.  The  problems  of  regulation  and  polarity 
have  been  attacked  in  recent  years  with  some  degree  of 
success.  Study  of  the  conditions  under  which  a  piece  of 
an  organism  forms  a  complete  individual  has  thrown  light 
upon  the  nature  of  the  organized  system  that  we  call  an  indi- 
vidual.12 Regeneration,  regulation,  and  polarity  are  part  of 
the  larger  phenomenon  of  growth  and  differentiation  ex- 
hibited by  all  many-celled  organisms.  Results  in  these 
fields  interlock  with  those  obtained  in  the  study  of  embryonic 
development.  The  piece  of  an  organism  which  regenerates 
the  whole  is  obviously  possessed  of  the  same  kind  of  poten- 
tiality that  exists  in  embryonic  tissue.  How  adult  tissues  can 
thus  exhibit  embryonic  capacities  is  an  interesting  problem, 
the  investigation  of  which  may  eventually  throw  light  not 
only  upon  embryonic  development  but  also  upon  certain 
pathological  conditions  which  exist  at  times  in  the  human 
body  and  in  the  bodies  of  higher  animals  and  plants. 

Natural  Death : — The  early  stages  of  development,  which 

"Child,  C.  M.,  "Individuality  in  Organisms,  1915." 


ZOOLOGICAL  SCIENCE  201 

constitute  the  subject-matter  of  embryology,  are  not 
the  only  progressive  modifications,  occurring  within  the  life 
of  the  many-celled  animal.  There  remain  the  minor  changes 
of  adult  life,  and  the  degenerative  changes  immediately  pre- 
ceding the  natural  death  of  the  individual.  Here  again, 
we  find  problems  that  must  be  attacked  experimentally. 
Death  occurs  by  accident  in  the  vast  majority  of  animals. 
In  nature,  only  the  merest  fraction  of  any  generation  lives 
to  grow  up.  The  individuals,  which  live  to  grow  old,  are 
frequently  killed  by  their  enemies  before  natural  death  can 
intervene.  When  accidental  death  does  not  occur,  natural 
death  is,  seemingly,  the  inevitable  fate  of  the  individual 
among  the  multicellular  animals.13  But  this  natural  death 
does  not  come  to  every  cell  encompassed  by  the  body. 
Certain  of  the  germ-cells  continue  to  live,  through  their 
descendants  which  constitute  the  next  generation.  A 
majority  of  the  germ-cells  perish,  while  a  small  minority  of 
them  survives,  if  the  race  continues  to  exist.  Hence,  the 
germ-cells  are  potentially  immortal,  while  the  body-cells 
are  destined  to  perish. 

It  is  perhaps  worth  while  to  inquire  why  one  type  of  cell  is 
thus  able  under  certain  conditions,  namely,  union  in  fertili- 
zation with  another  germ-cell,  to  continue  its  existence  to 
another  generation,  and  so  perhaps  to  all  future  generations. 
The  neighboring  cells  of  the  body  are  destined  for  old  age  and 
death.  Why  this  difference  between  germ  and  body -cell? 
Save  for  cases  of  normal  parthenogenesis,  the  germ-cells 
die,  if  they  do  not  unite  in  fertilization.  Continuation  of 
their  life  hinges  upon  this  one  small  matter  of  union  with 
another  cell.  The  balance  between  death  and  life  is  so 
slight  that,  in  some  of  the  experiments  in  artificial  partheno- 

13  In  animate  which  reproduce  by  budding  or  fission,  it  may  be  that  the 
individual  can  live  on,  as  do  the  germ-cells.  This  has  not  yet  been  proved 
experimentally  for  any  many-celled  animal;  but  plants  like  the  potato  or  the 
begonia  may  be  reproduced  indefinitely  from  cuttings,  and,  theoretically,  an 
animal  like  a  hydra  or  a  planarian  might  continue  budding  or  fission  forever, 
and  thus  continue  living  without  old  age  or  sexual  reproduction. 


202  THE  SCIENCE  OF  BIOLOGY 

genesis,  stimulation  with  a  particular  compound  in  an 
extreme  state  of  dilution  keeps  the  egg  alive,  by  causing  it  to 
develop.14  If  so  small  a  difference  determines  life  or  death 
for  the  germ-cell,  it  may  be  argued  that  the  senile  changes 
of  body-cells  are  the  result  of  conditions  that  may  some 
day  be  comprehended.  Is  it  only  a  dream  to  hope  that 
biological  science  will  eventually  so  analyze  the  conditions 
of  bodily  death  and  germinal  immortality  that  death,  as  a 
natural  process,  may  be  postponed  if  not  eliminated?  15 
Genetics  and  Cytology: — Twentieth  century  study  of 
evolutionary  problems  has  come  to  be  known  as  the  science 
of  Genetics.  Investigation  of  the  origin  of  species  has 
passed  beyond  the  stage  where  it  is  wholly  observational. 
Knowledge  of  heredity  and  variation,  acquired  during  the 
past  thirty  years,  has  brought  the  problem  well  within  the 
scope  of  experimentation.  The  experimental  method  has 
been  established  in  this  branch  of  zoological  study,  although 
its  application  has  not  yet  produced  results  which  have  led 
to  agreement  regarding  the  causal  factors  hi  evolution.  Our 
earlier  contention  that  evolutionary  problems  are,  in  their 

14  The  eggs  of  the  marine  worm,  Thalassema  melita,  may  be  caused  to  develop 
by  artificial  parthenogenesis  after  an  immersion  for  5  minutes  in  a  solution 

containing  17  cc.  of  JQ  HC1  -}-  85  cc.  of  sea-water.    This  is  the  equivalent  of  a 

solution  of  about  .0608%  of  actual  hydrochloric  acid.  Lefevre,  George, 
"Artificial  Parthenogenesis  in  Thalassema  Melita,"  Jour.  Exp.  ZooL,  Vol.  IV, 
No.  1,  1907. 

15  E.  Metchnikoff  has  discussed  at  length  what  science  can  do  to  alleviate 
such  disharmonies  of  the  human  constitution  as  the  evils  of  old  age  and  the 
fear  of  death,  in  his  book,  "The  Nature  of  Man."     (Translation  edited  by 
P.  C.  Mitchell,  1903.)     Metchnikoff's  later  theories,  concerning  the  prolonga- 
tion of  human  life,  through  the  better  adjustment  of  the  physiology  of  nutri- 
tion ("The  Prolongation  of  Life,"  1908),  seem  hardly  tenable  at  the  present 
time.    But  his  formulation  of  this  very  human  problem  illustrates  the  practical 
answers  proposed  by  science  to  a  group  of  questions,  which,  in  the  past,  have 
been  answered  only  by  the  metaphysics  of  religion  and  philosophy. 

More  concrete  aspects  of  the  problem  of  death  are  briefly  summarized  by: 
Jennings,  H.  S.,  "Age,  Death,  and  Conjugation  in  the  Light  of  Work  on  the 
Lower  Organisms,"  Popular  Science  Monthly,  June,  1912;  and  Loeb,  Jacques, 
"Natural  Death  and  the  Duration  of  Life,"  Scientific  Monthly,  Dec.,  1919. 


ZOOLOGICAL  SCIENCE  203 

final  analysis,  cell  problems  is  again  illustrated  by  the 
present  affiliation  of  genetics  with  cytology. 

Cytology,  or  the  science  of  the  cell,  concerns  itself  with 
structure  and  function  hi  cells  of  every  sort.  But  the 
cytologist  has  been  so  occupied  with  the  germ-cells  and  with 
the  early  phases  of  development  that  cytological  investiga- 
tion to  date  is  almost  a  synonym  for  germ-cell  investigation. 
Germ-cells  or  gametes  are  the  links  between  successive 
generations.  Every  many-celled  animal  is  at  one  period  of 
its  life-cycle  encompassed  within  the  limits  of  the  single  cell 
formed  by  the  united  ovum  and  spermatozoon.  The  gametes 
have  naturally  assumed  an  overwhelming  importance  in 
cytology.  They  are  no  less  important  in  genetics,  because 
the  latter  science  must  know  how  adult  characteristics  are 
transmitted  through  the  germ-cells  to  the  next  generation. 
Genetics  and  the  cytology  which  deals  with  germ-cells  are 
but  different  aspects  of  the  same  fundamental  problem. 

We  have  already  described  the  probable  mechanism  of 
Mendelian  heredity  as  it  appears  in  the  chromosomes.  The 
interlocking  of  genetics  and  cytology  was  inevitable,  once 
the  facts  regarding  the  gametes  had  been  established  and 
once  Mendel's  epoch-making  discovery  had  become  gener- 
ally known.  The  chromosomes  of  the  ripening  germ-cells 
were  found  to  behave  in  a  peculiar  manner.  Mendelian 
unit-characters  were  found  to  be  inherited  in  a  fashion 
equally  distinctive.  Suddenly  it  was  realized  that  the 
chromosomes  offered  an  explanation  of  the  segregation 
which  is  the  essential  feature  of  Mendelian  inheritance 
(cf.  Fig.  20). 16  Thus  the  experimental  results  of  genetics 
became  of  interest  to  cytology  and  the  results  of  cytological 
study  assumed  importance  for  genetics.  The  latter  science 
has  arisen  upon  an  experimental  foundation  in  the  breeding 

iUon,  E.  B.,  "Mendel's  Principles  of  Heredity  and  the  Maturation  of 
the  Germ-Cells,"  Science,  Dec.  19,  1902.    This  brief  paper  summarizes  the 

•ne  when  the  cytological  imM-lmriMrn.  whirli  h:i^  simv  fe 
familiar,  was  just  beginning  to  ho  in 


204  THE  SCIENCE  OF  BIOLOGY 

of  animals  and  plants,  first  by  the  practical  man  and  later  by 
the  investigator.  Cytology  has  heretofore  consisted  almost 
wholly  of  observational  studies.  But  under  the  stimulus  of 
genetics  a  measure  of  experimental  work  is  being  undertaken. 
Genetics  and  the  cytology  of  germ-cells  are  now  advancing 
side  by  side.  The  present  theory  of  sex-determination, 
which  is  an  outcome  of  investigations  in  both  cytology  and 
genetics,  illustrates  the  union  of  these  two  fields  of  study  and 
also  the  progress  toward  experimentation. 

The  appearance  of  genetics  as  a  full-fledged  science  is, 
therefore,  a  recent  development.  Mendel's  original  publica- 
tion appeared  more  than  a  half  century,  ago  (1866).  But 
general  knowledge  of  this  great  law  of  heredity  dates  from 
the  closing  decade  of  the  nineteenth  century,  when  it  was 
independently  rediscovered  and  when  the  original  discovery 
became  generally  known.  With  Mendel's  law  as  a  clue,  an 
amazing  advance  has  been  made.  So  much  has  been  learned 
regarding  heredity  and  variation  that  Genetics  has  come  into 
being  as  a  science.  Already  there  are  professorships  and 
research  endowments  within  this  newly  created  field. 
Popular  interest  in  heredity  has  stimulated  the  publication 
of  many  books  and  articles  in  recent  years.  Mendelism  is  a 
familiar  topic,  and  the  science  of  genetics  is  becoming  almost 
as  well  known  to  the  public  as  bacteriology  or  pathology. 

Sex-Determination; — The  factors  which  determine  sex 
in  man  and  the  familiar  animals  have  been  the  subject  of 
innumerable  theories  from  ancient  times  until  the  present 
day,  all  of  which  now  appear  to  be  groundless.  Toward  the 
close  of  the  nineteenth  century  the  hypothesis  most  widely 
accepted  was  that  the  sex  of  the  individual  was  dependent 
upon  the  amount  or  kind  of  food  received  during  the  earlier 
period  of  development.  This  theory  was  believed  to  have 
experimental  evidence  in  its  favor  and  hence  obtained 
recognition  in  biological  circles.  It  was  easily  apprehended 
and  so  gained  wide  acceptance  in  the  popular  mind.  By  the 
terms  of  this  theory,  the  sex  was  at  first  undetermined.  As 


ZOOLOGICAL  SCIENCE  205 

development  proceeded,  the  individual  became  a  male,  if  it 
happened  to  receive  a  scanty  diet;  a  female,  if  it  chanced  to  be 
well  fed.  Experiments  in  overfeeding  and  in  underfeeding  of 
the  young  of  vertebrates  like  the  frog  and  of  invertebrates  like 
the  moth  gave  what  many  regarded  as  conclusive  evidence. 

But  the  experiments  hi  feeding,  which  were  supposed  to 
have  thus  determined  the  sex,  have  been  repeated  in  recent 
years,  with  results  that  do  not  confirm  the  earlier  conclu- 
sions.17 Moreover,  it  has  been  found  that  the  sex  of  many 
animals  is  seemingly  determined  as  early  as  the  stage  when 
the  individual  originates  by  the  union  of  egg  and  spermato- 
zoon. The  individual  becomes  a  male  or  a  female  at  the  very 
beginning.  Nothing  that  happens  in  the  subsequent  devel- 
opment changes  the  sex  as  thus  early  established. 

The  facts  upon  which  the  new  theory  rests  may  be  illus- 
trated by  Fig.  27.  As  we  have  seen  (Fig.  13),  the  nuclei 
of  cells  exhibit  at  the  time  of  division  certain  bodies,  the 
chromosomes,  which  occur  in  pairs  (Fig.  16)  and  in  numbers 
that  are  constant  for  a  given  species.  In  the  present  in- 
stance four  pairs  is  the  number  chosen  for  the  purposes  of 
the  diagram  (Fig.  27).  It  has  been  observed,  in  numerous 
cases  among  insects  and  in  a  smaller  list  of  other  forms,  that 
the  number  of  chromosomes  is  not  the  same  for  the  two 
sexes,  since  males  lack  one  member  of  one  of  the  pairs.18 
The  chromosomes  of  this  particular  pair  are  termed  "X" 
chromosomes,  or  better  sex  chromosomes,  because  their 
distribution  at  the  tune  of  fertilization  appears  to  deter- 
mine the  sex  of  the  individual.  Thus,  the  PI  adults  of 

17  In  the  language  of  one  investigator,  these  later  experiments  "seem  to  show 
that  sex  is  not  determined  by  the  quantity  or  the  quality  of  the  food  that  the 
larvae  receive."  This  conclusion  was  based  upon  experiments  with  tadpoles 
toad.  It  agrees  with  that  reached  by  otluT  investigators  who  have 
rein vesti gated  the  influence  of  food  upon  sex  in  frogs,  moths,  and  other  forms. 
King,  H.  D.,  "Food  as  a  Factor  in  the  Determination  of  Sex  in  Amphil> 
Bid.  Bulletin,  V-.l.  XIII.  \<>  1.  JUDO,  1M7. 

11  In  a  few  cases  the  condition  is  reversed  and  it  is  the  female  that  lacks  one 
chromosome— several  moths  and  butterflies  and  several  birds. 


206 


THE  SCIENCE  OF  BIOLOGY 


FIG.  27.  Chromosome  Theory  of  Sex  Determination  and  Explanation  of  Sex 
Linked  Heredity  in  Terms  of  Chromosomes.  The  number  of  chromosomes 
is  taken  as  6  -f-  1  x  in  the  male  and  6  +  2  x  in  the  female  or  3n  +  1  x  and 
3  n  +  2  x  when  n  =  the  number  of  pairs  of  non-sex  chromosomes.  The 
chromosome,  assumed  to  carry  the  determiner  in  a  case  of  sex  linked 
heredity  like  color  blindness  in  man,  is  partially  shaded.  See  discussion  in 
text.  Squares  represent  adult  individuals,  circles  gametes  (ova  and 
spermatozoa). 


ZOOLOGICAL  SCIENCE  207 

Fig.  27  give  rise  to  germ-cells  having  one  member  of  each 
pair  of  chromosomes.  But  in  the  male  one-half  of  the 
spermatozoa  will  be  without  an  "X"  chromosome,  because 
males  possess  only  one  member  of  this  pair.  In  the  female 
(Fig.  27,  PI),  each  egg  will,  of  course,  have  a  single  sex 
chromosome,  since  both  members  of  this  pair  are  present  in 
the  cells  of  females.  There  are,  therefore,  two  kinds  of 
spermatozoa,  (1)  those  with,  and  (2)  those  without  the 
"X"  chromosome;  but  only  one  kind  of  ovum.  When  such 
sperms  and  ova  meet,  with  equal  chances  of  union,  there 
will  be,  by  the  laws  of  chance,  equal  numbers  of  males  and 
females  produced,  as  shown  by  the  chromosome  combination 
in  the  Fi  generation  of  Fig.  27.  This  agrees  with  the 
observed  fact  that  in  many  animals  the  numbers  are  equal 
in  the  two  sexes  and  explains  how  the  formula  for  the  cells  of 
a  female  comes  to  be  2n  +  2x  and  for  the  male  2n  +  Ix. 
There  has,  therefore,  been  established  for  a  considerable 
number  of  animals,  a  theory  of  sex-determination,  which 
recognizes  not  only  the  germ-cells  as  the  important  item  but 
a  specific  chromosome  within  the  germ-cells.  This  theory  is, 
therefore,  a  part  of  the  general  theory  of  chromosomes  in 
relation  to  heredity. 

Through  the  work  of  the  geneticist,  this  recent  cytological 
theory  of  the  determination  of  sex  is  correlated  with  facts 
known  for  the  inheritance  of  what  are  termed  sex  linked 
characters.  The  peculiar  inheritance  of  color  blindness  in 
man,  which  has  long  been  known  to  be  related  to  the  sex 
of  the  individual,  may  thus  be  explained.  Referring  again  to 
Fig.  27,  let  us  assume  the  existence  of  sex  chromosomes  in 
the  human  body  and  its  germ-cells,  and  assume  further  that 
one  of  these  chromosomes  carries  the  factor  for  color  blind- 
The  presence  of  such  a  factor  may  be  indicated  by 


'•  The  difficulty  in  obtaining  satisfactory  material  makes  the  number  of 
chromosomes  in  man  still  a  matter  of  doubt  Winiwater,  H.  v.  (Arch,  de 
Itiol  ,  Vol.  27,  1912)  has  reported  48  in  (he  female  and  47  in  thr  in-.l.  .  hut 
these  result*  have  been 


208  THE  SCIENCE  OF  BIOLOGY 

shading  a  portion  of  one  of  the  "X"  chromosomes  (Fig.  27). 
Color  blind  men  are  known  to  be  much  more  numerous  than 
color  blind  women.  But  color  blindness  is  transmitted  by  a 
human  male  through  his  daughters  to  approximately  one-half 
of  his  grandsons. 

Explanation  of  this  very  peculiar  inheritance  is  as  follows : 
A  color  blind  man  is  mated  with  a  normal  woman  (Pi, 
Fig.  27).  The  single  sex  chromosome  of  the  man  carries  the 
factor  for  color  blindness,  as  shown  by  the  shading.  One- 
half  of  the  PI  germ-cells  of  the  male  will  be  free  of  the  defect, 
since  they  possess  no  "X"  chromosome.  In  the  FI  genera- 
tion, the  males  are  all  normal  and  free  from  the  defect.  But 
all  the  females  have  an  "X"  chromosome  (partly  shaded) 
which  carries  the  defect.  For  some  reason  such  a  "  single 
dose"  will  not  produce  color  blindness  in  a  woman  although 
it  does  so  in  a  man.  These  FI  females  transmit  the  chromo- 
some bearing  the  defect  in  the  manner  shown  (F2),  so  that, 
where  numbers  are  sufficient  to  indicate  the  ratio,  one-half 
the  grandsons  of  such  matings  are  color  blind  and  the  other 
half  normal;  while  the  granddaughters,  although  all  seem 
normal,  are  one-half  free  of  the  defect  and  one-half  trans- 
mitters of  color  blindness  as  the  figure  shows.  Color  blind 
women  result  from  matings  in  which  two  "X"  chromosomes, 
each  with  the  color  blind  factor,  are  brought  together.  Such 
a  combination  would  be  possible  in  one-half  the  daughters 
arising  from  color  blind  men  mated  with  women  who  were 
transmitters,  i.  e.,  possessed  a  single  dose  of  the  defect.20 

These  results  which  have  been  obtained  from  the  study  of 
sex  linked  characters,  find  their  explanation  in  the  work  of 
cytology.  The  latter  science  has  been  mainly  observational. 
The  cytologist  is  now  stimulated  to  extend  his  analysis  by 
means  of  experimentation.  Hybridization  offers  an  oppor- 
tunity to  produce  new  chromosomal  combinations  by  ex- 
perimental crossing.  The  observational  foundation  is  suf- 
ficient for  the  beginning  of  such  experimentation. 

20  Morgan,  T.  H.,  "Heredity  and  Sex."    Cf.  for  extended  discussion. 


ZOOLOGICAL  SCIENCE  209 

If  sex  is  determined  by  the  kind  of  spermatozoon  which 
happens  to  fertilize  a  particular  egg  (Fig.  27),  the  difficulties 
in  the  way  of  sex  control  seem  insurmountable.  There  ap- 
pears no  immediate  prospect  of  controlling  sex  production 
in  man  and  the  domesticated  animals.  But  something  has 
been  gained  if  it  becomes  clear  that  we  cannot  alter  the  male- 
ness  or  femaleness,  which  is  established  at  the  tune  of  fertili- 
zation, by  changing  the  food  or  environment  of  subsequent 
stages.  The  point  of  attack  is  known,  even  though  control 
seems  well-nigh  impossible  in  the  event  that  sex  is  irrevoc- 
ably determined  at  the  time  of  fertilization.  Investigation 
is  pressing  so  closely  upon  the  solution  of  the  whole  question 
that  the  factors  controlling  the  union  of  the  germ-cells  in 
fertilization,  and  hence  the  sex  of  the  individual,  may  be 
discovered  sooner  than  one  expects.  Control  of  sex  in  man 
and  the  domesticated  animals  is,  therefore,  a  remote,  though 
not  an  unthinkable  possibility.21 

The  changes  from  the  origin  of  an  individual  at  the  tune 
of  fertilization  to  its  disintegration  in  death  are  a  never- 
ending  wonder  to  the  advanced  investigator  as  well  as  to  the 
novice.  So  manifold  has  been  the  work  of  determining  the 
structural  changes,  by  which  the  egg  becomes  the  adult, 
that  embryology  has  but  recently  begun  the  experimental 
analysis  of  causation  in  development  which  is  illustrated  by 
the  work  above  described.  In  this  more  intensive  study, 
experiment  and  observation  must,  of  course,  be  inextric- 
ably interwoven.  Never  the  less  the  major  problem  hence- 
forth must  be  discovery  of  underlying  causation,  rather 
than  description  of  structural  sequence. 

tl  Although  sex-determination  by  means  of  the  sex-chromosome  appears  to 
!><•  \\«  11  established  in  certain  animal  types,  there  may  be  exceptions  to  the 
established  scheme.  Also,  there  may  be  other  factors  which  have  a  deter- 
B  art  ion.  The  studies  of  Riddle  upon  the  pigeon  and  those  of  Whitney 
and  of  A.  F.  Shull  upon  rotifers,  together  with  the  work  of  F.  R.  Lillie  upon 
sex-hormones  in  cattle,  illustrate  the  complexity  of  the  problem  and  slmuM 
make  us  hesitate  to  accept  the  chromosome-theory  as  a  universal  explanation 
of  the  determination  of  sex. 


210  THE  SCIENCE  OF  BIOLOGY 

PROBLEMS   OF  ANIMAL  BEHAVIOR 

The  behavior  of  animals  has  been  recognized  as  a  subject 
for  scientific  investigation  only  within  recent  times.  So 
long  as  the  idea  of  souls  or  similar  activating  agents  persisted, 
there  was  scant  opportunity  for  an  analysis  of  behavior  in 
terms  of  science.  The  earliest  scientific  attack  dates  from 
the  work  of  Descartes  in  the  seventeenth  century,  who  seems 
to  have  originated  the  doctrine  "that  the  bodies  of  animals 
and  men  act  wholly  like  machines  and  move  in  accordance 
with  mechanical  laws."  The  scientific  study  of  behavior 
was  thus  begun  under  the  stimulus  of  the  hypothesis  that 
animals  are  automata,  a  theory  which  is  a  phase  of  the  more 
general  hypothesis  known  as  the  mechanistic  conception  of 


Those  who  originally  maintained  the  Cartesian  doctrine 
soon  outstripped  themselves  and  their  teaching  fell  into  dis- 
repute. No  real  progress  was  made  during  the  eighteenth 
century,  but  in  the  early  part  of  the  nineteenth  century  we 
find  a  tendency  to  interpret  the  behavior  of  animals  as  like 
that  of  humans.  Interest  centered  about  exaggerated  and 
uncritical  accounts  of  the  intelligence  of  the  higher  animals. 
The  study  of  animal  behavior  consisted  largely  hi  the  col- 
lection of  anecdotes,  the  scientific  value  of  which  was  passed 
unchallenged,  outside  of  scientific  circles,  until  a  very  recent 
date.23  Such  work  had  its  value  because  it  fostered  interest 
in  animals  and  in  their  humane  treatment  by  man.  It  was 
possibly  a  reflection  of  the  romantic  period  in  literature  and 
catered  to  imagination  rather  than  to  reason. 

With  the  establishment  of  the  evolutionary  doctrine  soon 

22  Huxley,  T.  H.,  "On  the  Hypothesis  that  Animals  are  Automata,"  Collected 
Essays  Vol.  entitled:  "Method  and  Results." 

23  The  collection  of  stories,  entitled  "The  Animal  Story  Book,"  and  edited  by 
Andrew  Lang,  although  published  at  a  much  later  date  (1896),  is  representa- 
tive of  the  period  in  question.    Its  literary  quality  is  pleasing  and  its  influence 
in  arousing  sympathetic  interest  is  of  the  best,  but  as  scientific  natural  history 
it  is,  of  course,  unreliable. 


ZOOLOGICAL  SCIENCE  211 

after  the  middle  of  the  century,  the  genetic  relationship  be- 
tween animal  and  human  behavior  became  an  absorbing 
problem.  Darwin's  book  upon  "  The  Expression  of  the  Emo- 
tions in  Man  and  Animals "  (1872)  is  representative  of  the 
underlying  assumption  that  human  behavior  is  an  outcome 
of  evolution  from  the  behavior  of  higher  vertebrates.  The 
results  of  the  best  of  this  investigation,  by  such  men  as 
Lubbock,  Romanes,  Preyer,  and  others,  have  been  largely 
confirmed.  It  is  important  to  note  that  their  work  was  ex- 
perimental as  well  as  observational  and  that  it  must  be 
highly  regarded  when  we  consider  that  "  these  investigators 
were  interested  in  the  origin  and  evolution  of  responses  and 
of  psychic  phenomena,  and  not  in  the  mechanics  of  reac- 
tions."  24 

Toward  the  end  of  the  nineteenth  century  interest  again 
swung  in  the  direction  of  the  reduction  of  animal  behavior 
to  mechanical  principles.  This  interpretation  of  behavior 
has  been  widely  advertised  hi  recent  decades  and  experi- 
mental methods  have  been  much  in  evidence.  But  observa- 
tion is  still  of  great  importance.  However  much  we  may 
desire  to  reduce  a  problem  to  one  critical  experiment,  obser- 
vation is  frequently  a  necessary  preliminary  to  the  experi- 
mental attack.  At  the  present  day,  the  sane  verdict  on  the 
question  whether  the  animal  body  is  a  machine,  whose  be- 
havior is  predictable  in  terms  of  a  mechanical  system,  is  that 
the  case  is  not  yet  proven,  although  many  simple  responses 
appear  to  be  mechanistic  in  their  nature.25 

"The  paper  by  S.  O.  Mast  on  the  "Problems,  Methods  and  Results  in 
Behavior,"  Science,  Dec.  13,  1918,  from  which  the  above  quotation  has  been 
drawn,  contains  an  authoritative  resum6  of  the  history  and  present  standing 
of  the  study  of  behavior. 

"The  volumes  by  J.  Loeb,  "The  Mechanistic  Conception  of  Life"  (1912) 
and  J.  S.  Haldane,  the  "Organism  and  Environment"  (1917)  represent,  on 
the  one  hand,  the  point  of  view  of  an  extreme  mechanist,  and  on  the  other, 
that  of  an  investigator  who  is  an  anti-mechanist  rather  than  a  vitalist.  Hans 
Driesch,  in  "The  Science  and  the  Philosophy  of  the  Organism"  (1908),  has 
pushed  the  vitalistic  theories  to  a  greater  extreme  than  any  biologist  of  the 
present  generation,  using  the  facts  observed  in  development  as  the  principal 


212  THE  SCIENCE  OF  BIOLOGY 

Opposed  to  the  doctrine  that  the  animal  body  is  a  ma- 
chine, whose  responses  are  predictable  in  terms  of  a  mechan- 
ism, is  the  doctrine  of  vitalism,  by  which  it  is  maintained  that 
the  actions  of  the  living  body  involve  something  which  is  not 
present  in  any  non-living  machine.  Of  course,  the  mechan- 
ist does  not  maintain  that  all  vital  processes  have  been  re- 
duced to  mechanical  principles.  He  only  maintains,  as  his 
working  hypothesis,  that  they  will  be  so  reduced  when  we 
know  more  about  them.  The  vitalist  maintains,  as  his  hy- 
pothesis, that  mechanistic  explanations  are  insufficient. 
The  whole  question  of  mechanism  versus  vitalism  has  prob- 
ably attracted  much  more  attention  than  it  deserves.  The 
agnostic  position  would  seem  the  only  tenable  one  for  a 
long  time  to  come.  The  vitalist  should  remember  that 
biological  progress  seems  to  be  made  in  the  direction  of 
mechanistic  explanations.  The  mechanist  should  remember 
the  complexity  of  the  phenomena  and  the  scant  progress 
that  has  been  made  toward  their  comprehensive  solution. 
Moreover,  undue  emphasis  of  the  mechanistic  conception 
has  certain  important  human  implications,  which  the  mech- 
anist tends  to  overlook.26  As  a  practical  question,  the 
adoption  of  a  mechanistic  conception  of  human  behavior 

basis  for  his  theories.  The  ideas  of  H.  S.  Jennings,  expressed  in  his  "Behavior 
of  the  Lower  Organisms"  and  numerous  special  papers,  have  always  seemed 
to  the  writer  to  represent  a  discriminating  outlook  upon  the  behavior  problem 
as  a  whole. 

28  These  implications  are  well  stated  by  S.  O.  Mast,  loc.  cit.,  who  writes  as 
follows:  "Mechanism  implies,  as  previously  pointed  out,  that  every  phenom- 
enon is  specifically  associated  with  changes  in  the  special  interrelationship  of 
material  particles,  masses  or  systems,  changes  in  or  states  in  material  con- 
figurations, which  are  absolutely  determined  by  preceding  changes  or  states  in 
material  configuration.  Consequently,  if  mechanism  holds,  every  phenom- 
enon, every  act  of  every  organism  that  ever  existed,  exists  now,  or  ever  will 
exist,  is  absolutely  determined  with  reference  to  character,  time  and  place  and 
has  been  thus  absolutely  determined  from  the  very  beginning.  If  you  can  in 
reality,  at  any  given  instant,  move  your  hand  either  to  the  right  or  to  the  left, 
mechanism  breaks  down,  for  according  to  the  laws  of  mechanics,  if  you  move 
your  hand  to  the  right,  that  movement  is  by  the  material  configuration  within 
and  about  you  absolutely  determined  with  reference  to  place,  extent,  duration 
and  time  and  you  could  not  possibly  have  moved  it  to  the  left  at  that  time." 


ZOOLOGICAL  SCIENCE  213 

seems  inadvisable  in  the  absence  of  overwhelming  evidence. 
And  such  evidence  does  not  exist.  Mechanism  is  a  fatalistic 
doctrine,  and  fatalism  whether  promulgated  under  the  garb 
of  science  or  theology  exercises  a  pernicious  effect  upon 
human  conduct. 

The  question  of  mechanism  in  behavior  is  only  one  phase 
of  the  investigation  of  animal  reactions  at  the  present  day. 
The  nature  of  pleasure  and  pain  and  their  distribution  in  the 
animal  series  is  another  problem  which  is  theoretically  inter- 
esting and  one  which  has  practical  bearings.  Knowledge 
and  not  emotion  should  be  the  basis  for  our  consideration 
of  the  feelings  of  animals.  As  yet  we  have  no  thorough- 
going knowledge  for  the  pleasure-pain  problem,  considering 
the  animal  kingdom  as  a  whole. 

Another  problem  which  many  be  investigated  independ- 
ently of  the  problem  of  mechanism  versus  vitalism  is  the 
origin  and  evolution  of  consciousness.  By  this  is  meant  the 
awareness  or  subjective  experience  which  is  the  basic  feature 
of  each  human  personality  and  which  we  infer  as  existing 
in  other  human  beings  and  in  the  mentality  of  the  animals 
most  like  ourselves.  Two  methods  of  investigating  the  prob- 
lem of  consciousness  present  themselves.  The  older  intro- 
spective method,  which  has  not  yet  become  obsolete,  and 
the  newer  method  of  comparative  behavior.  By  the  former 
method  we  obtain  the  clue  which  leads  to  the  formulation 
of  the  kind  of  consciousness  that  presumably  exists  in  our 
fellow  men  and  in  the  minds  of  animals.  The  comparative 
study  of  animal  behavior  can  yield  a  clue  to  what  goes  on 
inside  the  animal  mind,  only  when  we  interpret  behavior  in 
terms  of  the  results  obtained  by  our  own  introspection. 
Some  modern  investigators  are  content  merely  to  describe 
how  the  animal  behaves  hi  response  to  stimulation  and  to 
put  aside  all  consideration  of  the  subjective  states  which 
may  be  involved.  To  most  of  us  the  question  of  how  the 
awareness  of  the  animal  resembles  our  own  consciousness  is 
too  interesting  a  problem  to  be  thus  thrust  aside. 


214  THE  SCIENCE  OF  BIOLOGY 

Experimentation  is  the  conspicuous  method,  through- 
out this  modern  study  of  behavior.  Observation  is  still 
fundamental  and  is  often  the  only  feasible  means  of  attack- 
ing the  problems.  But  here,  as  in  other  scientific  lines,  the 
experiment  under  controlled  conditions  is  the  goal  of  inves- 
tigation. In  recent  years  the  study  of  behavior  has  been 
extended  to  the  lower  organisms,  in  the  hope  that  simpler 
forms  of  life  would  be  more  understandable  in  this  particular 
and  that  simpler  types  of  behavior  would  be  discovered  and 
synthesized  to  explain  the  reactions  of  higher  animals. 
Much  has  been  accomplished.  The  behavior  of  forms  like 
the  infusoria  is  now  believed  to  be  vastly  simpler  than  when 
likes  and  dislikes,  comparable  to  those  of  men,  were  ascribed 
to  these  lowly  beings.  Yet  the  reactions  of  the  animal  cell 
are  much  the  same,  whether  the  ceil  is  that  of  an  amoeba  or 
one  within  the  human  body.  The  responses,  which  the  living 
protoplasm  makes  to  changes  in  its  environment,  are  more 
complex  in  the  many-celled  body,  hi  so  far  as  this  body  con- 
tains many  different  kinds  of  cells.  But  it  is  not  clear  that 
the  responses  of  individual  cells  of  the  many-celled  body 
are  more  complex  than  the  responses  of  the  individual  cells 
of  the  protozoa.  The  principal  advance  that  has  been  made, 
toward  analysis  and  subsequent  synthesis  of  the  elements 
of  behavior,  is  the  showing  that  behavior  is,  in  its  last  analy- 
sis, a  problem  of  cellular  functions. 

PROBLEMS   OF  NATURAL  HISTORY 

We  have  seen  that  during  the  Scientific  Renaissance 
studies  hi  natural  history  constituted  one  of  the  two  great 
lines  of  biological  advance.  Until  the  middle  of  the  nine- 
teenth century,  perhaps  the  major  part  of  zoological  effort 
was  devoted  to  studies  upon  animals  and  plants  in  the  open 
country.  The  work  to  which  the  naturalist  gave  himself 
within  doors  was  carried  on  primarily  with  a  view  to  the 
classification  of  material  collected  in  the  field.27  The  an- 

27  Such  work   as  that  recorded  in  Darwin's  "Naturalist's  Voyage  round 


ZOOLOGICAL  SCIENCE  215 

atomical,  microscopical,  and  physiological  aspects  of  zoology 
developed  mainly  in  relation  to  medicine.  The  laboratory 
of  the  present  day  has  come  into  existence  in  response  to  the 
demands  of  this  phase  of  zoological  inquiry.  The  great 
museum,  with  its  staff  of  collectors  and  investigators  and  its 
expeditions  for  the  collection  of  material  for  research  or  for 
public  exhibition,  is  the  modern  representative  of  old-time 
natural  history. 

Studies  in  natural  history  were  important  during  the  cen- 
turies of  their  inception,  because  they  enabled  men  to  appre- 
ciate the  wealth  and  diversity  of  organic  nature.  They  were 
also  a  prelude  to  the  doctrine  of  evolution.  At  the  present 
time  their  continuation  by  our  museums  is  particularly 
important  as  a  means  of  preserving  a  record  of  the  larger 
forms  of  life,  which  have  inhabited  the  earth  during  the  Age 
of  Man  but  which  are  fast  approaching  extinction,28  and  as  a 
means  of  cultivating  the  esthetic  and  recreational  values  of 
biological  science.  The  sum  total  of  scientific  work  now  being 
conducted  hi  natural  history  is  probably  greater  than  ever 
before.  The  advent  of  intensive  study  within  the  laboratory 
and  the  spectacular  control,  which  laboratory  workers  have 
now  attained  over  certain  biological  phenomena,  have  caused 
the  work  of  the  naturalist  to  be  regarded  as  one  among 
many  lines  of  study,  and  sometimes  a  dilettanti  line  at  that. 
The  latter  point  of  view  is  unfortunate  in  the  mind  of  the 

the  World,"  published  in  1845,  and  Bates'  "Naturalist  on  the  Amazons" 
(1863)  are  representative  of  the  best  in  the  older  period. 

28  The  progressive  destruction  of  wild  life,  in  all  parts  of  the  world  that  have 
been  gripped  by  western  civilization  is  appalling  from  the  standpoint  of  the 
naturalist.  Even  game  preserves  like  the  national  parks  of  the  United  States 
are  not  safe  from  the  cupidity  of  business  enterprise.  Unless  there  is  a  radical 
change  in  popular  feeling  at  an  early  date,  the  extermination  of  all  the  larger 
mammals  not  capable  of  domestication  and  of  many  of  our  song  birds  is  a 
matter  of  decades  rather  than  centuries.  Perhaps  when  it  is  too  late,  the 
world  of  living  things  will  be  far  less  interesting  because  the  birds  are  mostly 
English  sparrows  and  the  mammals  rats  and  mice.  But  it  is  still  believed  that 
what  we  of  the  West  call  progress  must  continue.  The  volume  by  W.  T. 
Hornaday,  entitled:  "Our  Vanishing  Wild  Life,"  contains  a  statement  of  the 
present  situation  and  an  appeal  for  its  amelioration. 


216  THE  SCIENCE  OF  BIOLOGY 

public  and  reprehensible  on  the  part  of  the  laboratory 
biologist.  Popular  appreciation  of  this  biology  of  the  field 
and  shore  is  attested  by  the  enormous  sales  of  books  upon 
birds,  insects,  shells,  and  the  like.  Interest  hi  natural  his- 
tory is  quite  spontaneous  among  children  and  would,  no 
doubt,  find  more  expression  hi  the  recreation  and  outdoor 
esthetic  enjoyment  of  adult  populations,  if  Nature  Study 
were  effectively  taught  by  the  schools. 

The  scientific  attitude  toward  this  modern  natural  his- 
tory or  field  biology  assumed  a  degree  of  hopelessness  during 
the  closing  years  of  the  nineteenth  century.  The  complexity 
of  inter-relationship  between  living  things,  as  observed  in 
the  field,  was  appalling.  Studies  on  evolutionary  problems 
had  been  largely  field  studies.  The  evolutionary  theory 
seemed,  of  necessity,  to  be  lacking  hi  precise  evidence  for 
evolution  hi  the  present.  Fruitless  discussion  had  char- 
acterized the  later  years  of  the  so-called  Post-Darwinian 
Period.  Insurmountable  obstacles  appeared  to  stand  hi  the 
way  of  progress  beyond  the  analyses  made  by  Wallace  and 
Darwin.  Although  the  zoologist  is  still  appalled  by  the  mag- 
nitude of  the  task,  the  problems  of  natural  history  have  been 
attacked  anew  by  the  modern  science  of  Ecology.  If  they  are 
still  far  from  being  solved,  progress  has  been  made.  The 
ecologist  needs  all  the  powers  of  observation  possessed  by  the 
older  naturalists,  together  with  the  mental  equipment  of  the 
experimentalist.  What  he  does  is  to  take  the  older  observa- 
tions for  what  they  are  worth,  and,  by  carrying  the  intensive 
methods  of  the  laboratory  to  the  field  and  bringing  the  field 
into  the  laboratory,  attempt  an  analysis  of  the  complex 
inter-relationships  which  exist  in  nature.  He  is  not  unduly 
optimistic;  nor  does  he  believe  he  will  shortly  ascertain  the 
many  factors  involved.  But  step  by  step  progress  is  being 
effected.  It  may  be  hoped  that  some  of  the  larger  problems 
will  be  solved,  if  industrial  development  does  not  obliterate 
too  rapidly  the  less  resistant  forms  of  life. 

The  science  of  ecology,  which  has  thus  supplemented 


ZOOLOGICAL  SCIENCE  217 

modern  natural  history,  further  illustrates  the  change  from 
observation  to  experimentation.  The  earlier  studies  were, 
almost  without  exception,  observational  hi  their  nature,  but  a 
point  was  reached  where  progress  became  impossible  by  the 
continuance  of  observation  alone.  No  one  recognizes  more 
clearly  than  does  the  ecologist  the  difficulties  which  attend 
the  introduction  of  experimentation  in  field  zoology. 
Observation  still  constitutes  the  major  method.  In  the 
plant,  which  is  rooted  to  its  environment,  experimental 
investigation  is  less  difficult,  and  hence  the  ecology  of  plants 
has  advanced  beyond  that  of  animals.  Yet  in  spite  of  the 
difficulties,  no  one  doubts  that  here,  as  elsewhere,  observa- 
tion will  be  increasingly  supplemented  by  experimentation. 

RELATION   OF   ZOOLOGY   TO   OTHER   SCIENCES 

The  adoption  of  this  growing  measure  of  experimentation 
has  had  an  important  bearing  upon  zoology  hi  its  relation 
to  allied  sciences.  For  one  thing,  many  biological  inter- 
ests that  were  becoming  divergent  have  become  unified. 
Toward  the  close  of  the  nineteenth  century  it  seemed  that 
such  biological  studies  as  those  found  in  the  works  of  Darwin 
were  becoming  impossible,  because  of  the  appalling  amount 
of  special  knowledge  hi  the  fields  of  zoology  and  botany. 
No  man  could  longer  presume  to  become  a  master  of  both 
sciences.  While  this  is  increasingly  true,  we  find  to-day  that 
the  investigation  of  general  biological  phenomena,  such  as 
growth,  regeneration,  heredity,  and  the  like,  leads  to  the 
study  of  animals  and  plants  by  the  same  investigator.  The 
botanist  and  the  zoologist  find  themselves  on  common 
ground  when  engaged  hi  such  investigations.  A  separation 
which  had  seemed  an  inevitable  but  regrettable  incident  in 
the  advance  of  science  has  been  at  least  postponed. 

Again,  a  closer  union  has  been  effected  between  the 
biological  and  the  physico-chemical  sciences,  through  study 
of  the  physico-chemical  processes  that  occur  in  the  bodies 


218  THE  SCIENCE  OF  BIOLOGY 

of  lower  animals  and  in  plants.  These  have  long  engaged  the 
attention  of  physiologists,  but  until  recently  interest  has 
been  centered  upon  the  higher  vertebrates.  At  the  present 
tune,  zoologists  and  general  physiologists  are  so  engaged 
with  the  bio-chemistry  and  the  bio-physics  of  both  the 
simpler  and  the  more  complex  organisms  that  the  intelligent 
reading  of  many  zoological  papers  demands  as  much  or  more 
knowledge  of  physics  and  chemistry  as  of  natural  history. 
It  may  be  noted,  as  a  sign  of  the  times,  that  candidates  for 
advanced  degrees  in  zoology  are  now  expected  to  be  well- 
grounded  in  chemistry  and  physics,  as  well  as  in  general 
zoology.  These  physical  sciences  are  important  for  the 
zoologist,  not  only  because  they  afford  a  knowledge  of  the 
facts  but  also  because  they  foster  an  appreciation  of  experi- 
mental methods. 

The  ancient  affiliation  between  the  biological  sciences  and 
medical  science  continues.  The  r61e  of  insects  in  disease,  the 
new  sciences  of  Protozoology  and  Parasitology,  the  interest 
of  the  medical  profession  in  heredity,  the  interest  of  the 
zoologist  in  the  physiological  facts  brought  out  by  serum- 
therapeutics,  by  the  study  of  endocrine  secretions,  and  the 
like,  are  examples  that  illustrate  the  many  points  of  contact. 
Zoology  arose  in  close  association  with  medical  science.  The 
more  scientific  medicine  becomes  the  greater  will  be  its  de- 
mands upon  zoological  science.  Extended  medical  experi- 
mentation upon  human  beings  is  impossible,  though  it  often 
happens  that  the  physician  sees  the  end  results  of  such 
experiments,  as  when  a  community  begins  the  use  of  water 
from  a  filtration  plant  after  long  experience  with  water  from 
a  contaminated  source.  The  experimental  work  of  medicine 
must  be  accomplished  mainly  by  use  of  animals.  Since  this 
experimentation  is  necessary  for  the  advancement  of  medical 
knowledge,  medical  investigation  must  deal  with  zoological 
material.  In  the  past  it  has  utilized  the  higher  vertebrates, 
such  as  the  cat,  dog,  rat,  and  guinea-pig.  As  the  human 
mechanism  becomes  subjected  to  a  more  searching  examina- 


ZOOLOGICAL  SCIENCE  219 

tion,  more  fundamental  knowledge  will  be  demanded  and 
medical  science  must  draw  upon  every  part  of  the  animal 
kingdom.  The  lower  invertebrates  and  the  protozoa  are 
already  familiar  objects  in  medical  laboratories. 

As  zoology  becomes  more  exact  hi  its  conclusions,  it  will 
have  greater  value  hi  the  social  sciences.  At  present  the 
influence  of  biological  science  within  these  fields  consists 
largely  in  the  point  of  view  which  it  imparts.  But  the 
significance  of  zoological  and  particularly  medical  knowledge 
is  becoming  evident  to  the  social  worker.  He  is  eager  for  the 
latest  facts  on  heredity,  hygiene,  and  sanitation;  and  this 
eagerness  will  be  lasting.  The  fact  that  the  human  species 
is  a  product  of  evolution  is  acknowledged  by  students  of 
society.  But  we  need  a  wider  understanding  of  the  zoologi- 
cal basis  of  human  behavior  than  now  exists.  Once  estab- 
lished, such  an  understanding  must  exercise  a  profound 
effect  upon  the  social  activities  of  the  human  race.  Now 
that  zoology  is  progressing  toward  the  experimental  analysis, 
and  hence  the  control,  of  vital  phenomena,  its  conclusions 
will  be  held  hi  more  esteem,  because  they  will  rest  in- 
creasingly upon  experimentation.  In  the  future,  the  zo- 
ologist will  be  heard  upon  a  subject  like  heredity,  not  for  his 
much  speaking,  but  because  he  presents  facts  that  cannot 
be  denied  and  that  are  obviously  important  for  the  welfare 
of  mankind. 


PART  III 
THE  PRESENT  IMPORTANCE  OF  SCIENCE 


CHAPTER  IX 

PHILOSOPHICAL  AND  PSYCHOLOGICAL  ASPECTS 
OF  SCIENCE 

SCIENCE  and  philosophy  must  go  hand  in  hand  since  the 
problems  of  organized  thought  have  scientific  bearings. 
Human  thinking  may  be  regarded  as  an  outcome  of  organic 
evolution  and  one  of  the  ultimate  problems  of  science  is  the 
relation  of  mind  and  matter.  How  a  thinking  race  arose  in 
the  course  of  thousands  of  years,  how  thinking  men  come  out 
of  germs  during  the  brief  span  of  individual  development,  and 
how  the  nerve  cells  of  the  brain  are  related  to  consciousness 
are  problems  which  the  scientist  should  investigate,  even 
though  their  investigation  leads  him  within  the  domain  of 
philosophy.  Moreover,  the  natural  sciences  rest  upon  cer- 
tain fundamental  philosophical  assumptions  such  as  the 
theory  that  all  facts  of  experience  may  be  systematically 
related,  through  the  principle  of  adequate  causation.  The 
man  of  science  is  a  philosopher  hi  spite  of  himself  when- 
ever he  attempts  to  determine  the  ultimate  realities  of 
science.  Unless  he  accepts  the  naive  conception  of  nature 
and  assumes  that  the  external  world  is  exactly  what  it  seems 
to  the  unthinking  mind,  he  finds  himself  in  the  grip  of 
philosophy  and  must  acknowledge  his  affiliation. 

THE    FACTS   AND   KNOWLEDGE   OF  SCIENCE 

An  examination  of  the  facts  of  natural  science,  which  are 
commonly  assumed  to  be  realities  external  to  ourselves,  will 
illustrate  the  assumption  by  science  of  philosophical  hy- 
potheses. Before  proceeding  to  this  examination,  let  us 
have  in  mind  the  familiar  distinction  between  the  subject  ivr 

223 


224      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

and  the  objective,  taking  it  in  the  sense  of  what  is  within  and 
what  is  outside  ourselves,  the  7  as  distinct  from  that  which 
is  not  myself.  We  know  the  subjective  element,  because  we 
are  conscious  of  our  own  existence  and  of  our  mental  proc- 
esses. Hence  there  is  one  class  of  facts  which  is  subjective 
in  origin  and  another  which  originates  in  sense-impressions 
which  are  assumed  to  be  induced  by  an  objective  or  external 
reality.  We  know  the  objective  element  solely  through  these 
impressions  of  our  sense-organs.  The  ego  is  like  a  telephone 
operator  shut  in  a  central  office  and  knowing  nothing  of  the 
outside  world  save  by  what  comes  in  through  the  receivers. 
To  the  objective  or  natural  sciences,  sense-impressions  are 
the  ultimate  reality  upon  which  must  be  based  any  theory 
of  an  external  universe  of  matter. 

We  may  pursue  the  case  as  follows:  A  man  has  reason  for 
believing,  because  of  what  he  sees  in  bodies  like  his  own,  that 
his  particular  human  body  presents  anatomical  and  physi- 
ological phenomena  of  the  kind  demonstrable  hi  other 
human  beings  and  hi  the  higher  vertebrates.  The  individual 
knows  his  own  conscious  existence  first  hand,  and  infers 
the  existence  of  everything  else.  Granting  that  7  know  I 
exist,  and  you  know  you  exist,  and  that  we  can  each  infer 
that  the  other  exists,  how  do  we  draw  such  an  inference  and 
what  do  we  mean  when  we  say  that  this  or  any  other  infer- 
ence has  scientific  validity? 

We  know  the  outer  world  only  through  the  medium  of  our 
sense-organs.  You  see  a  book  before  you,  with  its  red  cover, 
gilt  letters,  and  white  leaves;  it  feels  hard;  it  creates  a  noise 
when  dropped;  it  smells  like  a  book  fresh  from  the  bindery. 
If  you  desire  yet  another  form  of  sense-impression,  you 
may  taste  the  cover  or  the  leaves,  as  you  perhaps  remember 
doing  when  a  boy  at  school,  and  so  experience  the  last  type 
of  first-hand  knowledge  which  is  presented  by  the  more 
familiar  senses.  You  know  that  such  an  object  as  the  book 
exists  only  by  these  evidences  derived  from  your  sense- 
organs  and  termed  sense-impressions.  You  have  learned 


PHILOSOPHICAL  AND  PSYCHOLOGICAL  ASPECTS    225 

to  say  that  light  reflected  from  the  book  affects  the  retina 
of  your  eye,  which  in  turn  stimulates  your  optic  nerve,  which, 
in  its  turn,  stimulates  the  centers  of  your  brain.  You  know 
only  the  sensations  which  are  thus  received;  of  the  nature  of 
books  you  know  nothing;  for  you  perceive  nothing  beyond 
the  group  of  sense-impressions  which  you  call  a  book.  If 
the  book  is  a  thing  in  itself  other  than  these  impressions,  you 
do  not  know  it;  for  your  ultimate  objective  reality  consists 
solely  of  sense-impressions. 1 

The  case  is  not  otherwise  with  your  knowledge  of  your 
fellow  men,  and  even  of  your  own  body — sense-organs 
included.  A  friend  before  you  is  a  group  of  sense-impres- 
sions,— like  the  book,  save  that  among  the  many  sense- 
impressions  which  constitute  your  friend  there  are  those 
leading  you  to  infer  the  existence  of  another  personality 
like  your  own.  These  three  cases,  the  book,  your  friend,  and 
your  body,  are  typical  of  the  whole  external  world  of  persons 
and  things;  and  sense-impressions  are  thus  the  ultimate 
external  reality  that  is  perceived  by  the  human  mind.  Upon 
these  impressions  we  build,  within  our  minds,  a  so-called 
external  world.  The  problem  of  what  lies  behind  the  sense- 
impression,  what  is  the  nature  of  the  thing  in  itself,  science 
leaves  to  philosophy,  believing  that  the  nature  of  this  ul- 
timate philosophical  reality  is  not  open  to  investigation  by 
any  of  the  scientific  methods  now  available. 

But  one's  knowledge  of  a  book  could  never  be  so  simple 
a  matter  as  above  described,  unless  indeed  he  were  a  savage 
who  had  never  before  seen  a  book.  No  sooner  do  the  sense- 
impressions  reach  his  consciousness  than  he  remembers  other 
books.  The  title  attracts  his  attention;  he  remembers  books 
with  similar  subject-matter;  and  as  he  reads  the  pages  his 
mind  may  call  up  a  multitude  of  earlier  sense-impressions. 
He  may  remember  how  he  previously  correlated  impressions 
derived  from  books,  and  conceived  of  books  in  general,  or 

1  An  exposition  of  the  facto  of  science,  which  is  similar  to  the  one  hero  :• 
appears  in  Part  I,  Chapter  II  of  the  "Grammar  of  Science,"  by  Karl  Pearson. 


226       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

paper  in  general,  or  lettering  in  general.  The  sense-impres- 
sions received  from  the  printed  pages  are  signs  which  enable 
him  to  conceive  of  possible  sense-impressions  and  to  recall 
so  wide  a  range  of  previous  impressions  and  the  conceptions 
derived  therefrom,  that  the  reading  may  effect  a  profound 
reorganization  of  his  intellectual  life.  Starting  with  sense- 
impressions  past  or  present,  which  seemingly  constitute 
our  only  means  of  knowing  what  goes  on  outside  our  minds, 
which  are  for  us  the  real  outside  world,  our  complex  mental 
states  are  in  some  way  built  up,  until  it  is  impossible  to  say 
whether  anything  like  what  we  term  consciousness  could 
exist  in  a  being  conscious  of  its  own  existence  but  devoid 
of  sense-impressions. 

It  appears,  therefore,  that  what  we  call  external  reality 
is,  for  the  most  part,  created  within  our  minds.  Natural 
science  is  the  discovery  and  systematization  of  facts  whose 
basis  is  sense-impressions.  Generalization  consists  in  the 
interpretations  we  put  upon  our  past  and  present  experience 
with  sense-impressions.  A  science  that  consisted  of  dis- 
jointed sense-impressions  would  be  one  of  unrelated  facts, 
whereas  true  science  consists  in  the  putting  of  simple  facts 
together  and  obtaining  facts  of  a  more  complex  nature  or 
generalizations.  This  point  of  view  does  not  imply  that 
science  is  merely  a  static  organization  of  knowledge,  al- 
though the  accumulated  facts  of  science  may  be  so  regarded. 
Like  an  organism,  science  is  something  happening.  It  is  a 
process  of  rinding  out  the  relationship  and  the  order  of 
phenomena  in  nature.  Predictability,  based  upon  this  ascer- 
tainment of  order  and  relationship,  is  its  most  important 
function. 

While  the  facts  of  natural  science  are  in  the  first  instance 
sense-impressions,  its  field  is  the  content  of  the  human  mind. 
For  out  of  sense-impressions,  at  first  isolated  and  disjointed, 
we  build  up  within  our  minds  a  theory  of  the  whole  which 
constitutes  organized  science.  When  this  view  is  appreciated, 
one  understands  why  scientists  maintain  that  the  facts 


PHILOSOPHICAL  AND  PSYCHOLOGICAL   ASPECTS    227 

compounded  within  our  minds  upon  the  basis  of  sense- 
impressions  are  the  only  trustworthy  facts,  aside  from  the 
subjective  facts  of  the  individual's  existence  and  his  knowl- 
edge of  the  modes  by  which  the  mind  operates.  One  comes, 
therefore,  to  the  belief  that  there  is  only  one  kind  of  knowl- 
edge concerning  external  realities,  and  only  one  way  by 
which  it  is  acquired. 

Scientific  reality,  accordingly,  consists  in  the  fact,  first, 
that  we  get  the  expected  result  hi  consciousness  when  we 
again  experience  a  given  group  of  sense-impressions;  and 
second,  that  the  mental  states  of  other  individuals  appear  to 
follow  a  similar  course.  One  check  upon  the  reality  of  any 
sense-impression  and  upon  the  validity  of  our  conclusions 
therefrom  is  the  commonness  existing  in  our  minds  over  a 
period  of  time  and  the  commonness  which  appears  to  exist 
between  the  impressions  hi  our  minds  and  those  within  the 
minds  of  other  individuals.  A  check  may  also  be  obtained 
by  using  other  senses  than  the  one  temporarily  in  operation, 
as  when  we  verify  sight  by  touch.  Herein  lies  the  difference 
between  reality,  on  the  one  hand,  and  delusion,  illusion,  and 
hallucination  on  the  other.  The  vividness  of  those  latter  ex- 
periences, which  are  peculiar  to  the  individual  is  not  denied, 
what  is  insisted  upon  is  the  difference  between  that  which  is 
the  product  of  a  single  mind  and  cannot  be  produced  by 
other  minds  in  a  normal  state,  and  that  product  which  can 
be  shared  by  many  minds  on  the  basis  of  a  common  under- 
standing of  sense-impressions. 

In  this  connection  the  question  arises  whether  the  human 
mind  has  methods  of  obtaining  knowledge  regarding  external 
realities  other  than  the  one  above  described,  whether  what 
is  vaguely  termed  intuition,  insight,  revelation,  or  the  like 
gives  anything  that  can  be  dignified  by  the  term  knowledge. 
According  to  the  scientific  point  of  view,  these  mystical 
short-cuts  to  knowledge  are  valueless,  because  they  are  so 
<li-imilar  in  different  individuals  that  they  fail  to  give  suf- 
ficient commonness  when  comparisons  are  instituted. 


228       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

It  is  sometimes  insisted  that  scientific  knowledge  is  only 
second-hand  knowledge,  that  conclusions,  even  more  valid 
may  be  reached  by  what  is  popularly  known  as  the  method 
of  intuition.  The  word  intuition  has  a  variety  of  meanings. 
But  in  the  case  under  consideration,  it  is  applied  to  a  faculty 
for  acquiring  reliable  information  quickly  and  without  due 
process  of  reasoning,  to  a  kind  of  royal  road  leading  straight 
to  the  solution  of  any  problem.  Where  intuition  is  used  to 
designate  knowledge  which  is  axiomatic,  the  scientist  can 
have  no  objection  either  to  the  term  or  the  fact.  Thus,  if 
one  says  he  knows  intuitively  that  1  =  1  or  that  2  +  2  =4, 
it  would  seem  that  such  knowledge  is  very  near  to  that  which 
defies  further  analysis  and  which  must  be  taken  intuitively 
at  its  face  value,  because  our  minds  are  so  constructed  that 
we  cannot  think  otherwise. 

We  shall  not  venture  to  discuss  the  concept  of  intuition 
in  its  philosophical  aspects.  The  kind  of  ui tuitions  which  are 
obstacles  to  the  advancement  of  science  are  those  of  every- 
day life.  When  these  are  examined  the  following  proposi- 
tions are  evident:  Intuitions  are  effective  only  within  the 
field  of  complex  phenomena;  they  are  most  emphasized  by 
persons  not  accustomed  to  careful  analysis;  they  were 
formerly  applied  to  many  phenomena  since  brought  within 
the  grasp  of  science.  All  of  which  leads  one  to  suspect  that 
the  matter  is  reducible  to  this :  What  is  simple  we  reason  out; 
what  is  complex  and,  therefore,  not  susceptible  of  exact 
analysis,  we  settle  by  a  mental  process  of  the  same  order  as 
the  hunch  of  the  plain  citizen. 

The  truth  of  these  propositions  is  well  illustrated  by  the 
history  of  knowledge  concerning  disease.  A  century  ago, 
even  a  generation  ago,  an  appalling  amount  of  medical 
diagnosis  rested  upon  an  intuitive  foundation.  To-day,  an 
increasing  amount  of  such  diagnosis  rests  upon  a  scientific 
knowledge  of  organisms  and  of  specific  substances  within 
the  body.  The  history  of  science  is  filled  with  similar  ex- 
amples of  the  unknown,  and  supposedly  unknowable,  of 


PHILOSOPHICAL  AND  PSYCHOLOGICAL  ASPECTS     229 

one  age  becoming  the  known  and  the  predictable  of  the  next. 
This  being  so,  it  is  a  fair  presumption  that  what  we  decide 
to-day  by  intuition  may,  at  a  later  day,  be  brought  within 
the  ken  of  science.  Thus  the  realm  of  the  intuitive  becomes 
a  lessening  one.  Its  name  is  synonymous  with  the  unknown 
or  incompletely  known,  not  with  the  unknowable.  We  have 
intuitions  regarding  what  we  do  not  as  yet  understand, 
and  intuitions  fade  wherever  scientific  analysis  establishes 
a  foothold. 

The  weakness  of  intuition  is  its  individual  bias.  It  is 
the  product  of  a  single  mind,  not  the  collective  agreement 
of  individuals  who  have  examined  the  same  data.  As  such, 
it  is  always  open  to  the  suspicion  of  being  influenced  by 
delusion  or  prejudice.  Intuition  works  differently  with 
different  persons,  reflects  to  a  large  degree  the  personal 
equation,  and  has  the  marks  of  a  process  which  is  not  and 
never  can  become  reliable  hi  the  analysis  of  phenomena. 
The  scientist,  therefore,  believes  the  method  of  intuition 
unsatisfactory  as  a  source  of  knowledge.  When  he  says  he 
knows  subjectively,  he  means  only  that  he  is  conscious  of  his 
mental  states  and  of  their  manner  of  operation;  when  he  says 
he  knows  objectively,  he  means  that  any  normal  individual, 
who  puts  himself  under  similar  conditions,  will  experience 
sense-impressions  from  which  he  may  draw  similar  conclu- 
sions. The  scientist  does  not  claim  to  know  everything. 
He  does  claim  that  such  sources  of  knowledge  as  the  intui- 
tions of  daily  life,  which  are  so  frequently  paraded  as  a 
superior  means  of  knowing,  are  not  knowledge  in  any  sense, 
because  they  seem  to  represent  either  vagaries  of  the  indi- 
vidual mind  or  thought-processes  too  unorganized  to  be  of 
value  in  the  determination  of  either  external  or  internal 
realities. 


230      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

THE   METHOD   OF   SCIENCE 

If  the  field  of  the  natural  sciences  is  the  content  of  the 
human  mind  as  determined  by  the  incoming  sense-impres- 
sions, the  method  of  these  sciences  is  that  by  which  the  mind 
deals  with  the  facts  of  sense-experience.  What  is  called  the 
external  world  is  a  creation  of  the  mind,  which,  it  is  assumed, 
parallels  an  objective  reality.2  The  science  of  logic  attempts 
to  determine  the  methods  by  which  the  mind  acts  in  dealing 
with  the  facts  of  experience.  Science,  therefore,  depends 
upon  logic  to  check  its  conclusions,  but  in  the  history  of 
thought  it  is  significant  that  the  logic  of  scientific  practice 
has  preceded  and  not  followed  the  development  of  logic  as  a 
science.  Thus  the  deductive  logic  of  Aristotle  was  founded 
upon  the  examples  of  mental  procedure  then  in  practice, 
while  the  inductive  logic  advocated  by  Francis  Bacon,  and 
elaborated  by  John  S.  Mill  (1806-1873)  and  others  in  the 
nineteenth  century,  was  a  formulation  of  mental  processes 
which  had  long  been  practiced  and  had  already  created 
modern  science. 

Science  was  described  by  Huxley  as  ''trained  and  organ- 
ized common  sense,"  and  the  methods  of  scientific  analysis 
as  but  extensions  of  those  common  in  everyday  life.3  Hence 
anyone  who  puts  two  and  two  together  and  draws  conclu- 

2Sellars,  R.  W.,  "Critical  Realism,"  Chaps.  I  and  II,  presents  a  statement 
concerning  this  assumption  of  parallelism  which  is  clear  to  the  scientist  at 
least. 

8  Huxley,  T.  H.,  "On  the  Educational  Value  of  the  Natural  History  Sci- 
ences." Collected  Essays,  Volume  entitled:  "Science  and  Education."  This 
much-cited  paragraph  runs  as  follows:  "Science  is,  I  believe,  nothing  but 
trained  and  organised  common  sense,  differing  from  the  latter  only  as  a  veteran 
may  differ  from  a  raw  recruit:  and  its  methods  differ  from  those  of  common 
sense  only  so  far  as  the  guardsman's  cut  and  thrust  differ  from  the  manner  in 
which  a  savage  wields  his  club.  The  primary  power  is  the  same  in  each  case, 
and  perhaps  the  untutored  savage  has  the  more  brawny  arm  of  the  two.  The 
real  advantage  lies  in  the  point  and  polish  of  the  swordsman's  weapon;  in  the 
trained  eye  quick  to  spy  out  the  weakness  of  the  adversary;  in  the  ready  hand 
prompt  to  follow  it  on  the  instant.  But,  after  all,  the  sword  exercise  is  only  the 
hewing  and  poking  of  the  clubman  developed  and  perfected." 


PHILOSOPHICAL  AND  PSYCHOLOGICAL  ASPECTS     231 

sions  that  are  justified  by  the  facts  of  objective  experience 
is  performing  a  scientific  act.  The  man  of  the  street  and 
the  man  of  the  farm  have  much  in  common  with  the  scientist, 
though  the  latter  may  seem  to  them  to  be  both  fool  and 
dreamer, 

As  there  may  be  some  question  regarding  the  meaning 
of  the  term  " common  sense,"  we  may  agree  at  the  outset 
that  a  man  has  common  sense  when  he  deals  rationally  with 
the  facts  of  his  experience.  The  man  of  common  sense  sees 
the  whole  situation  or,  as  the  scientist  would  put  it,  he  con- 
siders all  the  data  and  draws  his  conclusions  therefrom.  We 
think  a  man's  judgment  sound,  if  he  does  what  a  well-bal- 
anced individual  would  be  expected  to  do  when  confronted 
with  all  the  details  of  a  particular  situation.  The  theorist 
fails  if  he  does  not  consider  the  workaday  elements  of  the 
case.  The  practical  man  fails  if  he  judges  solely  by  rule-of- 
thumb  and  without  the  light  of  theoretical  considerations. 
Now  science  has  gone  forward  in  the  past,  not  by  wizardry, 
but  by  the  application  of  this  all-sided  sense  in  the  solution 
of  its  problems.  The  methods  of  thought  which  advance 
science  do  not  differ  in  kind  from  those  of  the  most  hard- 
headed  man  of  affairs  who  creates  a  business  of  international 
proportions. 

The  owner  of  a  quarry  uncovers  a  layer  of  rock  different 
hi  appearance  from  any  before  offered  for  sale  in  his  locality. 
Lacking  expert  advice,  he  begins  to  experiment  and  to  make 
observations,  with  a  view  to  determining  the  utility  of  the 
new  material.  After  subjecting  it  to  a  variety  of  tests,  he 
concludes  that  the  stone  can  be  put  to  certain  uses.  It  is 
good  for  crushing  and  for  rough  masonry,  but  not  for  sills 
and  lintels;  good  for  road  foundations,  but  not  for  surfacing. 
In  reaching  these  conclusions,  he  first  establishes  certain 
facts;  then  compares  these  with  facts  previously  known; 
then  classifies  the  stone  as  good  or  bad  for  a  given  purpose; 
and  thus  arrives  at  the  conclusion  that  a  stone  of  this  na- 
ture may  be  put  to  certain  uses.  He  is  now  in  a  position 


232       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

to  convince  would-be-purchasers  of  the  excellence  of  his 
material.  An  Indian,  selecting  the  proper  flint  for  his  arrow- 
points  in  the  same  locality  centuries  before,  might  have 
gone  through  similar  mental  processes. 

If  we  compare  the  sense  of  science  with  the  foregoing,  the 
case  is  as  follows :  A  geologist  examines  the  same  rock  layer, 
because  of  peculiarities  which  have  attracted  his  attention. 
He  first  makes  a  survey  of  the  entire  bed,  collecting  the  fossils 
and  observing  structural  features,  comparing  as  he  does  so 
the  present  bed  with  others  he  has  seen.  Ripple  marks 
and  mud  cracks  may  tell  of  shallow  water,  fossils  may 
indicate  a  marine  origin,  distorted  bedding  planes  may  give 
evidence  of  lateral  pressure.  At  last,  he  classifies  the  stone, 
as  part  of  a  well  known  geological  horizon,  and  therefore 
belonging  to  a  certain  period  of  the  earth's  history.  In 
such  a  case,  the  geologist  believes  he  has  reached  conclusions 
obvious  to  others,  and  is  prepared  to  take  his  colleagues  over 
the  ground,  exhibiting  facts  and  setting  forth  his  inferences. 

The  quarryman,  did  he  but  know  it,  goes  through  similar 
mental  processes;  though  he  is  likely  to  be  led  astray  because 
his  knowledge  of  rocks  is  after  all  limited,  and  because  hope 
of  gain  is  his  main  incentive.  The  advantage  possessed  by 
the  geologist  lies  in  his  broader  knowledge  and  in  his  desire 
to  establish  the  facts  rather  than  to  make  money.  The  point 
for  us  is  the  parallelism  between  the  mental  processes  of  the 
two  men,  which  are  in  essence  the  inductive  method  of 
science. 

Thus  the  scientific  method,  like  the  scientific  fact,  may  be 
characterized  by  the  adjective  common.  The  facts  and 
methods  of  science  are  those  which  may  be  shared  hi  common 
by  members  of  the  human  species.  They  are  not  the  whim 
of  one  individual,  but  conclusions  reached  by  individuals, 
who  may  be  regarded  as  competent  judges  in  the  particular 
case,  and  who  place  similar  interpretations  upon  groupings 
of  sense-impressions  past  and  present.  This  last  does  not 
mean  that  the  mere  holding  of  a  belief  by  a  large  number  of 


PHILOSOPHICAL  AND  PSYCHOLOGICAL  ASPECTS    233 

persons  is  evidence  of  its  validity.  We  no  longer  suppose 
what  is  "believed  always,  everywhere,  and  by  all"  to  be 
true  merely  because  of  its  wide  acceptance,  as  was  once  the 
case;  for  all  may  labor  under  similar  delusions  and  thus  hold 
the  same  false  belief.  It  means  that  facts,  which  have  been 
established  by  individuals  competent  in  particular  instances, 
remain  constant,  that  is  to  say  common,  for  other  trained 
minds  that  examine  the  phenomena.  The  difference  between 
this  species  of  commonness  and  that  supposed  to  be  obtained 
by  the  esoteric  insight  of  mysticism  is  that  it  rests  upon 
sense-impressions,  and  not  upon  states  which  are  purely 
subjective,  and  therefore  individualistic.  When  these 
sense-impressions  are  sufficiently  checked,  common  con- 
clusions follow.  But  this  does  not  mean  that  later  sense- 
impressions  of  another  sort  may  not  alter  these  conclusions 
in  the  future. 

The  question  as  to  who  are  the  normal  individuals  also 
arises.  To  this  one  can  only  reply  that  the  normal  man  is, 
like  the  average  man  a  creation  of  the  mind.  Every  individ- 
ual has  his  abnormalities  and  his  incompetencies,  the  sub- 
jective feature  termed  the  personal  equation  must  be  ac- 
knowledged. But  as  a  practical  matter,  those  who  are  not 
too  divergent  get  on  well  together.  Obviously  no  two  in- 
dividuals can  have  identical  sense-impressions  of  any  so- 
called  external  object,  but  this  does  not  prevent  a  measure 
of  agreement.  The  more  extensive  is  this  agreement,  in 
both  time  and  place,  the  more  certainty  may  be  attached  to 
an  interpretation. 

Again,  it  may  be  asked,  in  view  of  the  frequent  differences 
of  opinion  among  scientific  men,  whether  any  common  in- 
terpretation of  phenomena  does  actually  exist.  To  which 
it  may  be  answered  that  there  are  common  interpretations 
with  respect  to  certain  phenomena,  and  such  interpretations 
are  increasing  in  number  and  importance  with  the  advancs 
ience.  To  illustrate  specifically:  It  is  a  familiar  fact 
that  all  living  bodies  are  composed  of  units  known  as  cells. 


234      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

The  exceptions  to  this  cellular  organization  of  protoplasm, 
such  as  multinucleated  cells,  plasmodia,  syncytia,  and  so 
forth,  can  all  be  brought  into  alignment  with  the  general 
theory  of  nucleoplasmic  and  cytoplasmic  materials.  There 
was  a  tune  hi  the  history  of  biology  when  nothing  of  the  sort 
was  known,  and  later  a  tune  when  an  hypothesis  of  the  uni- 
versal cellular  organization  of  living  matter  was  proposed  on 
a  basis  of  limited  observation.  This  working  hypothesis 
was  at  first  debatable.  But  the  increasing  number  of  cases 
in  which  cells  were  observed,  soon  led  to  the  acceptance  of 
the  cell-theory  as  an  established  generalization,  which  may 
to-day  be  designated  as  a  fact,  since  it  is  hypothetical  only 
when  we  assume,  as  is  done  in  the  erection  of  the  cell-theory, 
that  all  living  things  are  constructed  after  this  fashion, 
whether  we  have  examined  them  or  not.  Having  studied 
hundreds  of  thousands  of  animals  and  plants  and  found  them 
all  composed  of  cells,  the  theory  is  that  we  shall  continue 
to  find  the  familiar  cellular  organization  as  new  organisms 
are  examined.  The  term  cell-theory  is,  like  the  term  theory 
of  gravitation,  theoretical  only  when  it  is  assumed  that  it 
will  hold  good  elsewhere,  or  when  analysis  is  pushed  further 
and  we  theorize  about  underlying  causes.  No  one  disputes 
the  existence  of  cells,  or  the  assumption  that  they  will  be 
found  as  long  as  microscopes  are  used  any  more  than  he 
disputes  the  universality  of  gravitation  because  of  which  it 
is  believed  that  stones  fall  when  dropped  from  a  height 
whether  it  be  in  California  or  Japan  or  on  the  planet  Mars. 
There  is,  therefore,  much  common  agreement  regarding  the 
existence  of  cells,  and  the  agreement  extends  to  many  details 
of  their  structure  and  activity,  as  for  example  that  all  cells 
contain  chromatin  and  that  all  cells  have  arisen  from  pre- 
existing cells. 

When  it  is  said  that  the  cell-theory  meets  with  common 
acceptance,  we  mean  that  a  host  of  trained  observers  have 
examined  the  microscopic  structure  of  innumerable  plant 
and  animal  bodies  and  found  them  composed  of  cells.  Hence, 


PHILOSOPHICAL  AND  PSYCHOLOGICAL  ASPECTS    235 

there  exists  among  competent  scientists,  a  consensus  of 
opinion  which  is  formally  known  as  the  cell-theory;  in  other 
words  a  common  sense  in  which  this  phrase  is  accepted.  The 
only  way  this  sense  differs  from  the  sense  of  persons  without 
biological  experience  is  that  it  rests  upon  wider  and  more 
critical  observation  and  is,  therefore,  the  more  reliable.  It 
happens  that  these  conclusions  regarding  cells  may  be  drawn 
only  by  persons  trained  to  the  use  of  microscopes ;  and  only 
after  special  preparation  of  the  materials  examined,  which 
is  an  illustration  of  what  Huxley  meant  by  trained  and  or- 
ganized sense.  It  is  not  that  the  observations  and  conclu- 
sions involved  are  fundamentally  different  from  those  of 
everyday  life.  They  are  refinements  of  these,  made  pos- 
sible by  the  training  of  the  scientist  and  the  organization 
of  his  material.  There  is  no  necromancy  in  science.  Its 
methods  are  the  logical  methods  of  thought  which  normal 
individuals  regularly  use.  Science  has  often  made  initial 
strides,  through  the  work  of  investigators  who  perceived 
the  unifying  features  in  large  groups  of  previously  unrelated 
phenomena,  and  whose  daring  hypotheses  at  first  resembled 
the  flight  of  poetic  imagination  or  the  vision  of  some  genius 
of  the  commercial  world.  But  what  has  finally  counted  has 
been  the  confirmation  of  hypotheses  step  by  step,  until  they 
have  become  commonplace  knowledge  verifiable  by  any- 
one who  reviews  the  phenomena. 

Another  example  may  be  given.  Certain  of  the  early 
embryologists  defended  the  dictum,  omne  vivum  ex  ovo,  as 
expressing  the  manner  of  generation;  and  later  embryolo- 
gists have  extended  this  generalization,  until  we  accept  the 
statement  that  "every  cell  comes  from  a  preexisting  cell." 
We  mean  by  the  modern  statement  of  the  older  doctrine, 
that  the  facts  have  been  recorded  by  earlier  investigators 
and  confirmed  by  later  ones;  that  we  have  seen  for  ourselves 
the  process  of  fertilization  and  development;  and  that  our 
fellow  workers  are  familiar  with  the  phenomena,  for  they 
talk  with  u-  of  what  they  have  seen.  Moreover,  it  is  assumed 


236       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

that  we  shall  see  these  processes  again  and  again  as  observa- 
tion is  extended.  Because  the  work  is  done  by  men  who  have 
spent  years  in  study,  the  methods  are  by  no  means  those  of 
supermen,  but  only  refinements  of  everyday  work  and 
thought.  Here  as  elsewhere,  there  is  plenty  of  common 
agreement  and  opportunity  for  verification  of  the  simpler 
facts. 

Refinement  in  the  technique  of  analyzing  phenomena 
thus  constitutes  the  sole  difference  between  the  scientific 
and  the  popular  method  of  drawing  conclusions.  In  ad- 
justing any  mechanical  device,  one  may  be  exercising  a  very 
common  kind  of  sense.  But  it  is  a  sense  which  differs  from 
that  exhibited  by  the  scientific  investigator,  only  in  so  far 
as  the  facts  examined  by  the  investigator  are  the  more  com- 
plicated and  can  be  approached  only  after  extended  prepara- 
tion. The  man  who  builds  a  concrete  sidewalk  in  his  yard 
learns  by  experience  and  experiment,  and  by  thinking  things 
out  as  he  goes.  The  investigator  who  is  trying  to  advance 
our  knowledge  regarding  the  chemistry  of  cement,  does 
essentially  the  same  thing.  Only  he  begins  far  ahead  of  the 
untrained  man;  and  having  a  broader  knowledge,  he  recog- 
nizes possibilities  of  error  that  the  other  does  not  compre- 
hend. 

The  conclusion  that  we  reach  is,  therefore,  that  there  is 
nothing  really  unique  in  science  or  hi  the  method  of  science. 
Scientists  are  not  wizards,  but  men  who  apply  to  natural 
phenomena  the  methods  of  analysis  used  by  logical  minds  in 
the  affairs  of  daily  life.  The  simpler  facts  of  science  can  be 
shared  by  all  who  possess  the  training  necessary  for  their 
apprehension.  If  the  more  complex  facts  are  less  commonly 
apprehended  it  is  because  they  are  complex  and  hence  dif- 
ficult of  verification  or  subject  to  erroneous  interpretation. 
Moreover,  any  normal  person,  who  trains  himself  to  ex- 
amine the  phenomena  of  nature,  may  be  expected  to  sub- 
scribe to  the  common  agreements  as  formulated  by  well 
established  generalizations.  If  there  is  debatable  ground 


PHILOSOPHICAL  AND  PSYCHOLOGICAL  ASPECTS     237 

and  difference  of  opinion,  it  is  because  science  no  sooner 
gets  a  fact  tolerably  well  established  than  it  proceeds  to 
other  facts.  While  we  agree  upon  the  interpretation  of  cer- 
tain data,  conflicting  data  may  be  adduced  at  any  time;  or 
we  may  undertake  entirely  new  lines  of  investigation,  which 
for  a  time  yield  uncertain  results.  Having  satisfied  ourselves 
as  to  the  general  course  of  development  in  the  individual, 
and  having  a  common  agreement  regarding  the  same,  we 
press  on  to  something  new,  like  the  problems  of  fertiliza- 
tion and  of  differentiation.  Here,  we  find  ourselves  upon 
ground  where  the  facts  are  so  sparsely  established  that  we 
are  unable,  for  the  present,  to  discover  a  common-sense 
basis  on  which  to  formulate  a  theory.  Divergent  views  exist 
hi  science  only  because  the  life  of  science  is  progress,  and 
because  science  concerns  itself  with  what  is  to  be  done  rather 
than  with  what  has  been  accomplished.  Divergent  opinions 
frequently  eventuate  in  agreement  as  soon  as  the  facts  are 
known  and  established. 

The  function  of  the  subjective  process  in  the  advance- 
ment of  science  now  becomes  clear.  The  fundamental  clas- 
sification of  human  thought  is  along  the  lines  of  subjective 
and  objective  reality.  A  so-called  normative  science  like 
logic  deals  with  the  operations  of  the  subjective  element  in 
its  manipulation  of  facts  and  cannot  of  itself  alone  lead  to 
now  truth  regarding  a  supposedly  external  reality,  although 
it  may  discover  more  effective  methods  of  handling  the  facts 
of  sense-impression.  The  popular  suspicion  that  the  logician 
is  merely  juggling  with  words,  even  when  his  methods  are 
sound,  seems  to  rest  upon  conviction  that  the  technique 
of  reasoning  is  no  more  than  a  tool  and  therefore  subordinate 
to  the  material  upon  which  it  works.  Belief  that  the  human 
mind  can  obtain  knowledge  of  any  so-called  external  or 
objective  reality,  by  means  that  are  wholly  subjective,  is 
repugnant  to  the  thought  of  natural  science  as  well  as  to  the 
ft  'inmon  sense  of  mankind. 


238       THE  PRESENT  IMPORTANCE  OF  SCIENCE 
SCIENTIFIC   LAWS  AND   SCIENTIFIC   TRUTH 

Scientific  laws  might  better  be  termed  generalizations, 
because  they  are  merely  formulations  of  experience.  The 
use  of  the  term  law  is  misleading,  if  it  results  in  belief  that 
scientific  laws  must  be  regarded  as  established  by  some 
agency.  In  primitive  times,  the  laws  of  social  custom  were 
believed  to  have  had  divine  origin;  and  later,  civil  laws 
were  known  to  be  established  by  men.  Hence,  the  popular 
connotation  of  law  is  that  of  a  rule,  established  by  some 
power,  and  which  must  be  obeyed.  By  analogy,  the  laws  of 
nature  are  regarded  as  principles  established  for  the  guidance 
of  the  universe.  Nature  thus  appears  to  act  under  a  sort  of 
legal  necessity,  whereas  the  fact  is  that  we  merely  have  so 
constantly  or  so  definitely  observed  certain  sequences  and 
complexes  of  inter-relationship  that  we  feel  certain  they  will 
reappear  under  similar  circumstances.  It  is  extremely 
difficult  to  escape  the  idea  of  necessity  in  the  case  of  the 
relationship  which  is  designated  cause  and  effect.  But  even 
here  scientific  analysis  reveals  no  necessity,  beyond  the 
relationship  between  phenomena  which  has  been  observed 
in  so  definite  a  fashion  that  the  cause  may  be  presumed 
always  to  be  followed  by  its  effect.  A  law  in  natural  science 
is  a  short-hand  method  of  describing  the  probable  order  of 
phenomena.  In  general,  such  laws  are  regarded  by  scien- 
tists as  discovered  relationships,  not  as  agencies  which  force 
nature  to  move  in  particular  directions. 

It  is  true  that  science  holds  the  hypothesis  of  adequate 
causation  as  the  most  fundamental  tenet  of  its  faith.  The 
reply  of  science  to  the  claim  that  "the  day  of  miracles  has 
passed"  is  that  there  never  was  a  day  of  miracles,  since 
every  phenomenon  has  its  adequate  cause.  Nevertheless, 
the  exact  basis  of  the  certainties  called  scientific  laws  should 
be  held  in  mind.  It  might  be  stated  in  this  wise:  Suppose 
the  present  represents  the  middle  of  time.  There  is  no  other 
way  of  regarding  the  present,  because  time  must  be  thought 


PHILOSOPHICAL  AND  PSYCHOLOGICAL  ASPECTS     239 

of  as  extending  indefinitely  into  both  past  and  future. 
Suppose  that  a  human  mind  could  know  all  that  had  ever 
happened  in  the  past.  One  would  then  know  only  one-half 
of  the  possibilities,  because  there  would  be  as  much  time, 
and  therefore  experience,  yet  to  come.  At  most,  one's 
assumption  that  what  had  always  happened  would  continue 
to  happen  could  rest  only  upon  what  might  be  termed  a 
fifty  per  cent  experience  of  the  possibilities.  Granted  that 
far  less  certainty  than  this  is  good  enough  for  practical  pur- 
poses, the  theoretical  situation  is  worth  bearing  in  mind. 

To  pursue  the  matter  further,  the  difference  between  a 
coincidence  and  a  law  of  nature  is  perhaps  not  so  funda- 
mental as  is  supposed.  In  the  case  of  a  coincidence,  there  is 
an  association  of  phenomena  sufficiently  unusual  to  attract 
attention.  In  the  case  of  a  scientific  law,  we  have  seen  cer- 
tain phenomena  associated  so  frequently  or  hi  such  a  defi- 
nite relationship  that  we  have  been  led  to  assume  their  in- 
variable association  hi  the  future.  There  is  no  necessity  for 
the  continuance  of  a  given  association  beyond  the  fact  that 
it  has  been  always  so  observed  or  that  the  definiteness  of  the 
relationship  makes  even  a  single  case  appear  conclusive. 
Thus,  if  you  saw  a  red  headed  man  on  a  white  horse  you 
would  think  nothing  of  the  circumstance.  If  you  saw 
another  such  combination  a  block  further  on,  you  might 
notice  the  coincidence.  If  you  saw  one  at  every  corner,  you 
would  begin  to  suspect  that  it  was  not  a  mere  coincidence 
but  a  constant  relationship.  And  if  you  had  never  seen 
white  horses  without  red  haired  men  on  their  backs  and 
always  at  street  intersections,  you  would  elevate  this  group- 
ing of  related  phenomena  to  the  level  of  a  fact,  established  by 
scientific  observation  and  to  be  expected  in  the  future,  just 
as  one  expects  present-day  birds  to  have  feathers  and  beaks. 
When  so  formulated  as  to  state  its  assumed  occurrence  for 
the  past,  present,  and  future,  such  a  fact  or  group  of  facts 
would  become  a  law  of  science. 

Tlu»    forpfcoing   illustration    is   drawn    from   the   field   of 


240       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

relationship  that  is  called  classification.  The  case  is  not 
otherwise  when  the  law  involves  the  relationship  of  sequence, 
as  determined  by  experiment.  Thus,  experiments  may 
determine  that  certain  phenomena  are  to  be  recorded  by 
the  series  2-4-6-8-10  and  so  forth.4  Here  again,  one  ob- 
serves a  certain  grouping  of  the  phenomena.  The  serial 
feature  introduces  a  more  definite  time  or  space  element  and 
a  greater  complexity  of  inter-relationship,  but  it  is  not  clear 
that  it  alters  the  underlying  situation.  Scientific  laws  are 
not  a  kind  of  primaeval  legislative  enactment  to  which 
nature  must  conform,  they  are  merely  formulations  of 
observed  relationships.  If  we  would  cease  to  speak  of  them 
as  laws,  and  call  them  generalizations,  certain  unwarranted 
implications  would  cease  to  encumber  the  philosophy  of 
science. 

Again,  the  scientist  has  come  to  realize  that,  in  the  case  of 
complex  phenomena,  what  he  regards,  as  truth  at  any  partic- 
ular time  may  not  be  final.  Like  every  one  else,  he  tends  to 
believe  truth  as  permanently  established,  when  the  tests  of 
science  have  been  exhaustively  applied  to  a  particular 
interpretation  of  a  group  of  phenomena.  If  the  case  be  one 
of  comparative  simplicity,  there  is  strong  presumption  in 
favor  of  the  finality  of  such  an  interpretation.  But  all  that 
is  meant  when  we  say  anything  is  true,  is  that,  with  our 
present  knowledge,  a  certain  timely  statement  can  be  made. 
Such  a  conditional  statement  is  the  truth  at  any  given 
moment.  If,  at  a  subsequent  time,  new  facts  necessitate 
reformulations,  we  then  say  the  truth  is  quite  different  from 
what  we  once  thought  it  to  be;  and  this  new  statement  may 
in  its  turn  be  changed  or  replaced. 

Thus,  what  is  held  to  be  true  by  one  generation  may  not 

4  The  discovery  of  a  multitude  of  serial  relationships  in  which  one  term  of  the 
series  is  &  function  of  what  follows  seems  to  be  the  most  distinct  advance  made 
by  modern  science  over  the  scientific  method  of  ancient  times.  In  Greek 
science  the  classificatory  relationship  A  <c  was  comprehended,  but  the  func- 
tional relationship  was  obscure.  It  is  this  functional  relationship  which  so 
reinforces  the  idea  of  necessity  in  causation. 


PHILOSOPHICAL   AND  PSYCHOLOGICAL  ASPECTS    241 

be  held  true  by  the  next;  because  we  designate  as  true  that 
which  holds  with  the  data  available  at  a  given  time.  By 
this  test,  the  Ptolemaic  system  in  astronomy  was  truth  for 
the  time  being.  Although  later  replaced  by  another  concept, 
Aristotle's  explanation  of  respiration,  as  a  means  of  cooling 
the  blood,  was  a  good  one  for  the  knowledge  of  the  period  and 
hence  could  be  regarded  as  true  in  its  day.  Absolute  truth 
may  be  attainable,  may,  indeed,  have  been  attained  in  some 
instances.  But  when  men  believe  that  they  have  arrived  at 
finality  hi  truth  they  get  into  trouble  and  when  the  scientist 
thinks  any  truth  is  established  for  all  time,  science  is  in 
danger  of  ossification.  Scientists  need  to  tell  themselves 
that  their  truths  are  working  hypotheses  and  that  truths 
which  seem  firmly  established  may  some  day  be  overturned. 
It  is  a  fact  that  the  simpler  truths  established  by  science 
regarding  natural  phenomena  are  more  certain  than  any- 
thing else  within  the  objective  field.  Nevertheless,  the  truth 
in  science  must  always  be  held  open  to  extension  or  modifica- 
tion, if  not  to  complete  replacement. 


CHAPTER  X 

THE  NATURE  AND  MEANING  OF 
SCIENTIFIC  RESEARCH  l 

THERE  is  an  exhortation,  supposedly  epitomizing  the  wis- 
dom of  practical  life:  " Don't  waste  your  time  speculating 
on  why  black  hens  lay  white  eggs.  Get  the  egg. "  This  is, 
perhaps,  good  advice  in  business  affairs,  and  appeals  to 
many  as  a  sensible  doctrine.  Yet  the  most  cursory  survey 
of  the  progress  of  civilization  will  show  that  the  men,  who 
have  done  most  for  the  world  in  a  practical  way,  have  often 
been  those  who  have  speculated  on  just  such  problems — and 
who  have  solved  them.  To-day,  the  man  who  gets  the  most 
eggs  is  he  who  in  breeding  and  rearing  his  poultry  follows 
the  methods  established  by  the  scientific  study  of  heredity, 
of  selection,  and  of  general  physiology.  And  it  is  worth 
remembering  that  the  workers  who  established  the  more 
important  of  these  facts,  were  not  lured  to  their  work  by  the 
prospect  of  financial  gain,  but  grappled  with  scientific 
problems  because  of  a  conviction  that  knowledge  of  such 
matters  was  worth  while,  and  in  the  long  run  indispensable 
to  human  welfare. 

If  we  analyze  the  getting  of  eggs,  as  it  goes  on  in  the 
varied  activities  of  our  modern  world,  we  find  that  industry 
is  everywhere  rooted  hi  the  facts  of  science.  Not  uncom- 
monly, whole  fields  of  commercial  enterprise  go  back  to 
some  simple  but  fundamental  scientific  generalization. 
Thus,  the  canning  industry  is  founded  upon  what  the  biolo- 
gist terms  biogenesis  or  the  fact  that  no  life  arises  save  from 
preexisting  life.  Since  putrefaction  is  an  incident  of  the 

1  The  material  which  appears  in  this  chapter  is  substantially  the  same  as  that 
used  in  a  lecture  at  Oberlin  College  in  January,  1913,  and  later  published  in  the 
American  Museum  Journal,  Vol.  XVIII,  No.  7,  1918. 

242 


SCIENTIFIC  RESEARCH  243 

growth  of  microscopic  life  in  organic  materials,  there  can  be 
no  putrefaction  where  all  living  germs  have  been  destroyed, 
by  heat  or  other  means,  and  where  new  germs  cannot  obtain 
access.  The  chemical  processes  which  underlie  so  many 
industries  have  all  been  built  upon  the  fundamental  theory 
of  chemical  combination,  which  was  elaborated  during  the 
latter  half  of  the  eighteenth  and  the  first  half  of  the  nine- 
teenth century.  The  generalizations  of  physical  science 
regarding  the  indestructibility  of  matter  and  energy  are 
similarly  important. 

We  all  recognize  with  Leonardo,  that  "  science  gives 
certainty  and  science  gives  power. "  We  also  recognize  that 
only  by  painstaking  effort  can  scientific  knowledge  be 
obtained.  We  commonly  fail  to  recognize  the  nature  of  the 
scientific  studies  which  have  preceded  the  discovery  of  many 
facts  applicable  to  our  daily  lives.  The  scientific  discov- 
eries of  the  past  constitute  the  foundations  of  life  in  civilized 
communities  as  well  as  of  modern  industry;  and  the  scien- 
tific discoveries  of  the  present  will,  if  we  do  our  share,  be  as 
vital  in  the  lives  of  future  generations.  We  should  eliminate 
from  our  minds  the  terms  pure  and  applied  science.  This 
distinction  is  a  false  one,  because  no  line  of  separation  exists. 
On  every  hand,  discoveries  of  a  theoretical  and  general 
nature  are  of  practical  value;  and,  conversely,  practical 
achievements  are  a  continual  stimulus  to  further  investiga- 
tions along  theoretical  lines.  These  in  turn  influence  prac- 
tice in  new  and  wholly  unexpected  ways. 

Any  research  that  promises  substantial  additions  to 
knowledge  is  worth  doing  in  the  present,  because  in  the  past 
such  work  has  often  yielded  results  undreamed  of  at  its 
inception.  The  history  of  science  urges  us  to  the  continua- 
tion of  theoretical  and  non-utilitarian  investigation  hi  the 
present,  however  much  we  may  be  tempted  to  press  the 
more  obviously  utilitarian  lines  of  study.  Research  along 
lines  immediately  useful  will  take  care  of  itself,  for  we  are  all 
convinced  that  it  is  worth  while.  But  where  the  immediate 


244       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

return  is  not  in  evidence,  it  requires  a  certain  faith  in  the 
final  outcome,  which  can  only  be  held  by  those  who  know 
what  has  happened  again  and  again  in  the  past. 

It  is,  therefore,  important  that  scientists  emphasize  what 
is  called  pure  research.  Scientific  men  have  not  made  the 
importance  of  this  item  of  their  creed  sufficiently  clear  to  those 
who  are  not  scientists.  They  should  preach  to  the  public 
as  well  as  to  their  fellows  the  need  for  investigation  un- 
hampered by  utilitarian  demands.  The  oneness  of  scien- 
tific study  should  be  emphasized,  to  the  end  that  all  may 
understand  how  science  advances  and  all  may  live  in  the 
faith  that  knowledge  of  natural  phenomena  is  worth  more 
than  it  costs  to  discover. 

There  is  small  danger  that  we  shall  fail  to  appreciate 
practical  research — how  to  grow  thirty  bushels  of  wheat 
where  ten  grew  before  or  how  to  produce  a  new  antitoxin. 
But  there  is  danger  that  we  may  fail  to  see  the  other  side,  that 
the  men  capable  of  doing  creative  work  as  investigators  may 
be  unable  to  find  a  livelihood;  and  that  in  the  present,  as  in 
the  past,  the  advance  of  science  may  depend  too  largely 
upon  the  chance  meeting  of  brains  and  means.  To  show  that 
this  danger  is  real,  not  imaginary,  it  may  be  said  that  hi 
zoological  science  there  are,  in  the  United  States  to-day, 
relatively  few  positions  in  which  a  young  man  of  promise 
may  earn  a  living  in  pure  science.  He  may  teach,  with  some 
chance  for  investigation,  or  he  may  find  limited  opportuni- 
ties in  the  applied  zoology  of  government  or  state  service  or 
of  commercial  enterprise.  But  for  the  man  who  gives 
promise  of  being  competent  to  do  the  pioneering  demanded 
by  pure  science,  there  is  almost  no  opportunity  for  a  living. 
A  like  condition  obtains  in  many  other  scientific  lines  and 
this  failure  to  provide  opportunity  for  the  worker  of  promise 
is  a  reflection  upon  our  civilization;  for  we  are  drying  up  the 
springs  which  feed  the  fountain,  and  the  extent  of  the  loss  is 
incalculable.2 

2  Since  these  paragraphs  were  written  the  National  Research  Council  has 


SCIENTIFIC  RESEARCH  245 

Conspicuous  ability  as  an  investigator  is  comparatively 
rare  and  every  effort  should  be  made  to  discover  the  men 
who  give  promise  of  such  attainment.  When  found,  they 
should  have  their  chance,  should  be  given  clearance  papers 
for  a  voyage  into  the  unknown.  Men  who  have  this  ability, 
who,  standing  upon  the  ground  already  mapped,  can  see  the 
distant  mountains,  and  whose  imagination  pictures  the  path 
across  the  intervening  valleys  and  deserts,  are  like  the 
explorers  of  a  virgin  continent;  they  " yearn  beyond  the  sky- 
line where  the  strange  roads  go  down."  The  human  race 
has  emerged  from  barbarism  because  the  desire  for  knowledge 
has  impelled  men  of  this  adventurous  spirit,  in  spite  of  dis- 
couragement and  misunderstanding,  persecution  and  death, 
to  search  after  the  facts  of  science  in  what  is  for  man  the  last 
"dark  continent" — the  realm  of  nature: 

"We  were  dreamers,  dreaming  greatly, 

in  the  man-stifled  town; 
We  yearned  beyond  the  sky-line  where 

the  strange  roads  go  down. 
Came  the  Whisper,  came  the  Vision,  came 

the  Power  with  the  Need, 
Till  the  Soul  that  is  not  man's  soul  was 

lent  us  to  lead." 

This  stanza  of  Kipling  will  serve  to  enforce  the  analogy 
between  the  "nature-searcher"  and  the  explorer  which  we 
shall  here  develop.  It  shows  also  that  modern  science  has 
not  destroyed  the  opportunity  for  imagination.  For, 
though  "the  old  order  changeth,"  there  remains  in  our 
thinking  that  which  brings  the  emotional  appeal  of  lofty 
imaginings;  for  here  indeed,  man  does  contend  with  gods 
and  strives  to  wrest  from  them  the  knowledge  that  shall 
make  his  future  more  secure. 

The  history  of  almost  any  line  of  scientific  investigation 

come  into  being.    One  of  the  encouraging  possibilities  of  this  organization  i- 
its  emphasis  of  research  as  a  profession  demanding  adequate  recognition. 


246       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

will,  if  traced  back,  afford  illustrations  of  the  value  of  pure 
research.  For  the  purpose  of  illustrating  what  has  happened 
again  and  again,  several  representative  cases  may  now  be 
elaborated. 


DEVELOPMENT  OF  KNOWLEDGE  REGARDING  MICROORGANISMS 

By  means  of  this  illustration,  we  propose  to  show:  that 
facts  now  recognized  as  of  life-and-death  importance  for  the 
whole  civilized  world,  had  their  beginnings  in  investigations 
which  were  of  questionable  value  when  judged  by  the 
utilitarian  standards  of  the  past;  and  further,  that  society 
might  profit  by  this  bit  of  history  and  assume  a  more 
farsighted  policy  hi  dealing  with  scientific  investigation  in 
the  present. 

That  many  diseases  are  caused  by  minute  organisms, 
living  as  parasites  within  the  bodies  of  animals  and  plants, 
and  so  producing  the  derangements  called  disease,  is  a  fact 
made  familiar  during  recent  years.  It  is  also  well  known 
that  progress  in  the  discovery  of  germs  hitherto  unrecognized, 
of  antitoxins,  of  vaccines,  and  the  like  is  saving  the  lives  of 
millions.  At  the  present  day,  diphtheria  is  no  longer  the 
dangerous  and  often  fatal  disease  it  was  even  twenty  years 
ago.  If  we  take  the  precautions  already  well  tested,  there  is 
no  danger  that  yellow  fever  will  again  scourge  our  gulf 
cities,  or  bubonic  plague  devastate  Europe  and  America  as  it 
still  devastates  the  Orient.  We  have  conquered  typhoid 
fever,  at  least  in  cases  of  local  epidemics  or  where  large 
bodies  of  men  are  sent  into  dangerous  territory,  and  no  man 
can  foresee  where  such  control  of  disease  will  end. 

These  are  familiar  facts.  The  steps  by  which  the  mastery 
has  been  attained  are  less  well  known.  We  take  this  mastery 
as  a  matter  of  course,  without  understanding  the  historical 
development  of  the  knowledge  which  now  means  life  or 
death.  It  is  true  one  may  be  familiar  with  the  most  recent 
chapters,  as  heralded  in  the  newspapers  and  current  mag- 


SCIENTIFIC  RESEARCH  347 

azines,  when  an  antitoxin  for  diphtheria  or  a  method  of 
preventing  typhoid  fever  has  been  announced.  But  these 
are  only  the  recent  pages  of  a  book  long  in  the  making,  to 
find  the  title  page  of  which  we  must  turn  back  through 
many  years  and  to  matters  having  little  apparent  connection 
with  what  is  now  before  us. 

To  illustrate  this  last  statement,  let  us  trace  the  course  of 
man's  discoveries  regarding  the  microorganisms,  taking  as  a 
convenient  starting  point  the  year  (1676)  when  the  Hol- 
lander, Anthony  van  Leeuwenhoek,  discovered  with  the 
microscope,  but  lately  come  into  use  as  a  toy  and  source  of 
amusement,  what  he  described  as  "  little  animals  observed 
in  rain,  well,  sea,  and  snow  water  as  also  in  water  wherein 
pepper  had  lain  infused."  3  Leeuwenhoek's  discoveries  were 
no  doubt  regarded  as  useless  by  his  contemporaries,  save  a 
few  by  whom  his  work  was  highly  esteemed.  The  possession 
of  a  modest  income  enabled  him  to  devote  a  generous  portion 
of  his  time  to  study;  and  at  the  end  of  a  long  life  he  had 
examined  with  his  microscope  all  he  could  lay  hands  upon  in 
both  animate  and  inanimate  nature.  Among  other  things, 
he  discovered  some  of  the  larger  bacteria,  many  protozoa, 
the  passage  of  blood  from  arteries  to  veins  through  the 
capillaries  (the  one  link  needed  to  complete  Harvey's  evi- 
dence for  circulation) ;  and  he  was  the  first  to  describe,  if  not 
the  discoverer  of,  the  human  spermatozoon.4 
He  became  the  first  great  microscopist.  Thus  at  first: 

"We  were  dreamers,  dreaming  greatly, 

in  the  man-stifled  town; 
We  yearned  beyond  the  sky-line  where 
the  strange  roads  go  down." 

'See:  Kent,  W.  Sayviile,  "Manual  of  the  Infusoria,"  for  quotations  from, 
and  an  account  of,  the  work  of  Leeuwenhoek. 

4  Interesting  facts  regarding  the  life  and  work  of  Leeuwenhoek  will  be  found 
in  the  article  by  D.  F.  Harris,  "Anthony  van  Leeuwenhoek  the  First  Bac- 
teriologist," Scientific  Monthly,  Feb.,  1921.  Cf.  also:  Locy,  "  Biology  and  its 
Makers." 


248      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

Despite  crude  and  imperfect  microscopes,  knowledge  of 
these  animalcules  grew  apace,  and  during  the  eighteenth 
century  the  more  important  types  were  recognized.  Their 
discovery  reopened  the  discussion  of  spontaneous  generation, 
which,  a  few  years  before  Leeuwenhoek's  first  observations, 
had  been  discredited  in  the  case  of  insects  and  the  larger 
organisms.  The  conflict  was  renewed  between  the  opposing 
forces.  During  this  struggle  facts  were  established  which 
not  only  aided  in  the  final  triumph  of  the  modern  theory  of 
biogenesis,  but  also  resulted  in  extensions  of  knowledge 
useful  in  other  directions. 

With  the  advent  of  the  cell-theory  in  1839  and  with  marked 
improvements  in  the  microscope,  the  distinction  between 
multicellular  and  unicellular  organisms  was  established. 
Finally,  the  age-long  controversy  was  closed  by :  Pasteur,  in 
his  studies  upon  disease  and  fermentation;  Tyndall  in  his 
examination  of  the  floating  matter  of  the  air;  Dallinger  and 
Drysdale,  who  first  observed  the  complete  life-cycle  of  a 
protozoon;  and  a  host  of  others.  And  here,  these  "  nature 
searchers,"  who  since  the  days  of  Leeuwenhoek  had  been 
pressing  their  forces  into  the  seemingly  useless  fields  that 
teemed  with  microscopic  life,  joined  with  the  men  long  baffled 
in  their  fight  for  human  lives,  and  gave  to  medicine  the 
support  needed  in  reaching  the  vantage  ground  from  which 
to  discover  a  new  horizon-line  in  the  germ-theory  of  disease. 

For  a  long  time,  physicians  had  known  that  diseases  were 
catching.  "The  pestilence  that  walketh  in  darkness,"  was 
no  idle  figure  of  speech.  An  analogy  between  the  spread  of 
disease  and  the  spread  of  living  organisms  had  been  pointed 
out  for  centuries.  But  only  in  the  nineteenth  century,  in  the 
generations  of  our  fathers  and  grandfathers,  did  the  medical 
men,  aided  by  the  investigators  who  had  ventured  into  the 
wider  domain  of  abstract  science,  show  that  the  germ  is  so 
truly  the  cause  of  infectious  disease  that  without  the  micro- 
croscopic  germ  the  disease  does  not  exist.5  Since  the  firm 

6  First-hand  contact  with  the  medical  discussion  of  this  period  may  be  ob- 


SCIENTIFIC  RESEARCH  249 

establishment  of  this  germ-theory,  now  the  germ-fact  of 
disease,  investigations  in  this  direction  have  received  in- 
creasing support;  until  in  recent  years  we  have  seen  the 
establishment  of  several  institutions  for  general  medical  in- 
vestigation, such  as  the  Rockefeller  Institute  in  New  York 
City  and  the  State  Cancer  Laboratory  in  Buffalo.  So  im- 
mediate have  been  the  results,  we  may  well  believe  that 
laboratories  of  this  character  are  destined  in  the  near  future 
to  be  generously  supported  by  public  and  private  funds. 
The  fact  of  most  importance,  however,  is  that  these  recent 
triumphs  in  an  applied  science  had  their  beginnings  in  the 
days  of  Leeuwenhoek.  He  was  the  first  of  a  host  of  investiga- 
tors in  this  field,  who  did  not  consider  the  immediate  utilita- 
rian values  of  what  they  sought.  These  men  persevered  in 
the  belief  that  all  facts  of  nature  are  worth  while  and  lived 
and  died  hi  the  faith  that  somehow,  sometime,  the  facts 
they  established  would  find  a  place  in  man's  scheme  of  the 
universe. 

"Then  the  wood  failed — then  the  food  failed — 

then  the  last  water  dried — 
In  the  faith  of  little  children 
we  lay  down  and  died." 

Did  our  space  allow,  we  could  follow  this  history  in  more 
detail;  we  could  show  that  the  more  important  of  the  earlier 
workers  were  students  in  pure  science,  attempting  to  make 
what  were  termed  in  the  earlier  days  "  Contributions  to 
Knowledge";  that  the  long  fight  over  the  question  of  sponta- 
neous generation  was  for  centuries  only  an  abstract  and 
academic  matter,  of  no  seeming  value  in  everyday  affairs; 
that  the  burden  of  this  pioneer  work  was  borne  by  men  who 
were  given  scant  public  assistance  and  little  recognition,  who 
followed  no  path  of  least  resistance. 


in  Oliver  Wendell  Holmes'  essay  upon  "Puerperal  Fever,"  written  in 
1843.  This  is  a  medical  classic  and  has  the  advantage  of  being  found  in  almost 
every  library. 


250      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

"On  the  sand-drift — on  the  veldt-eide — 

in  the  fern-scrub  we  lay, 
That  our  sons  might  follow  after 
by  the  bones  on  the  way." 

The  lesson  is  plain.  Are  we  in  this  day  of  enlightenment 
doing  much  better  by  the  workers  in  pure  science?  We  hail 
extravagantly  the  successful  investigator  in  applied  science 
and  he  is  well  rewarded;  though  what  he  receives  is  in- 
significant compared  with  that  allowed  to  swashbuckling 
captains  of  industry.  But  we  do  not  provide  for  the  man  of 
promise  in  abstract  science  a  chance  to  keep  at  his  work,  in 
the  hope  that  he  may  make  real  contributions  to  knowledge. 
We  are  greedy  over  the  finished  commercial  product,  while 
we  turn  out,  to  starve  or  teach,  the  young  men  among  whom 
the  Leeuwenhoeks  of  some  future  science  must  be  found. 
The  conclusion  is  that  our  civilization  though  made  possible 
by  the  control  of  nature  which  science  has  brought,  is  not 
offering  adequate  opportunity  for  further  investigation.  We 
are  neglecting  that  which  might  lead  to  things  as  undreamed 
of  as  was  the  germ-theory  of  disease,  when  Anthony  van 
Leeuwenhoek  discovered  in  1676  "  certain  little  animals  in 
rain,  well,  sea,  and  snow  water  and  also  in  water  wherein 
pepper  had  lain  infused." 


LIFE-CYCLE    OF   THE    FRESH-WATER  MUSSEL 

The  life-cycle  of  the  fresh-water  mussel  further  illustrates 
the  nature  and  importance  of  research  in  science.  First, 
because  the  details  of  this  unique  life-history  were  dis- 
covered after  years  of  study  by  those  adventurers  of  science 
who  struck  into  the  hinterland  of  nature,  where  lay  no  beaten 
trails;  and  second,  because  the  facts,  established  in  this 
earlier  period  and  with  no  utilitarian  aim,  have  during  the 
past  twenty  years  been  turned  to  account  in  commercial 
enterprise.  We  find  here  an  illustration  of  the  discovery  of 


SCIENTIFIC  RESEARCH 


251 


C.TKI.HE 

FIG.  28.  Fresh-water  Mussel,  Lampsilis  subrostrata,  and  Developmental 
Stages.  Above,  the  gravid  female  showing  fan-shaped  brood-pouches  (a 
portion  of  outer  gill).  Middle,  side  and  end  views  of  the  glochidium  larva 
greatly  magnified.  Many  thousands  of  these  larva  would  be  found  in 
each  brood-pouch.  The  groups  of  hair-like  projections  on  the  figure  to 
right  are  sensory  organs.  The  fibres  of  the  muscle  by  which  the  valves  of 
the  glochidial  shell  are  clamped  upon  the  gill  filament  of  a  fish  appear  at 
the  bottom.  Below,  four  views  of  a  young  Lampsilis  which  has  recently 
begun  life  upon  the  bottom  after  its  parasitism  on  the  fish.  The  outline 
of  the  jrl.tchidial  stage  is  still  seen  upon  the  shell  which  is  growing  rapidly. 
The  animal  moves  actively  by  means  of  the  "foot"  which  is  thrust  from 
between  the  valves  of  the  shell.  (After  Lefevre  and  Curtis.) 


252      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

economic  values  in  a  field  originally  explored  without  this 
incentive. 

Briefly,  the  life-cycle  of  the  mussel,  as  illustrated  by 
Figs.  28,  29,  and  30,  may  be  summarized  as  follows:  The 
sexes  are  separate,  the  spermatozoa  are  discharged  freely 
into  the  water,  entering  the  body  of  the  female  with  the 


FIG.  29.  Glochidia  of  Lampsilis  on  Gill  Filaments  of  a  Fish.  Above,  small 
portion  of  a  filament  with  single  glochidium  partially  overgrown  thirty 
minutes  after  original  attachment.  Below,  small  portion  of  a  gill  show- 
ing several  filaments  heavily  infected  with  glochidia,  which  are  now 
completely  overgrown  by  the  gill  tissue.  At  moderate  temperatures  such 
glochidia  complete  their  parasitism  in  from  three  to  four  weeks.  (After 
Lefevre  and  Curtis.) 

respiratory  water  currents  and  there  fertilizing  the  eggs 
contained  in  brood-pouches  which  are  formed  by  a  modifica- 
tion of  the  gills.  Development  now  begins  and  continues 
until  a  larval  stage,  known  as  the  Glochidium,  is  reached. 
In  this  state  the  young  are  discharged  from  the  female.  The 
glochidium,  which  in  size  is  near  the  limit  of  visibility  for  the 
unaided  eye,  now  rests  upon  the  bottom  and  must  perish 


SCIENTIFIC  RESEARCH 


253 


before  many  days  unless  it  is  accidentally  brought  into  con- 
tact with  a  fish.  In  this  event,  it  fastens  itself  upon  a  fin  or 
gill  of  the  fish,  causes  a  growth  of  the  fish's  epithelium  and, 
in  the  course  of  a  few  hours,  is  completely  enclosed  within 
the  tissues  of  its  host.  Thus  securely  placed,  it  undergoes 
development  to  a  stage  in  which  it  is  able  to  assume  the  life 


FIG.  30.  Rock-bass  (Ambloplites  rupestris)  about  five  inches  in  length,  infected 
with  glochidia  of  Lampsilis  ligamentina.  About  2,500  were  successfully 
carried  through  the  metamorphosis  by  each  fish  in  this  infection.  Note 
the  large  number  on  the  gills  and  the  small  number  on  fins.  (After 
Lefevre  and  Curtis.) 

of  the  parent  mussel.  It  then  drops  from  the  fish  and  takes 
up  an  existence  upon  the  bottom  which  it  continues  through- 
out life.  Two  points  are  of  importance  in  this  cycle.  First, 
the  glochidium  is  a  stage  at  which  development  ceases  and 
death  ensues,  unless  the  larva  becomes  attached  as  a  parasite 
upon  a  fish.  Secondly,  the  gaining  of  this  favorable  environ- 
ment within  the  fish's  tissues  is  wholly  accidental;  and  so 
many  glochidia  perish  without  so  doing,  they  must  be  pro- 
duced in  enormous  numbers  in  order  that  the  chances  of 
destruction  be  overcome  and  the  continuance  of  the  species 
assured. 

When  we  examine  the  paths  followed  in  the  establishment 
of  the  facts  above  outlined,  it  so  happens   that  the  trail 


254      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

again  begins  with  Leeuwenhoek.  Before  his  day  it  was  not 
even  known  whether  there  existed  in  lowly  organisms  like 
these  mollusca  anything  comparable  to  the  maleness  and 
femaleness  recognized  in  higher  forms.  Their  whole  mode  of 
generation,  whether  spontaneous  or  by  means  of  eggs,  was  a 
matter  of  theoretical  dispute.  In  his  efforts  to  solve  these 
fundamental,  but  at  the  time  wholly  academic,  questions, 
Leeuwenhoek  turned  his  microscope  upon  the  fresh-water 
mussels  and  discovered  the  innumerable  eggs  and  larvae 
which  crowd  the  brood-pouches  of  the  females.  These  he 
correctly  interpreted  as  the  young  of  the  mussel  in  which 
they  were  found;  and  it  is  clear  from  his  descriptions  that  he 
saw  enough  of  their  development  to  justify  his  conclusion 
that  mussels,  like  the  more  familiar  forms  of  animal  life, 
arose  from  eggs. 

In  the  subsequent  advance  of  our  knowledge  two  periods 
are  conspicuous,  one  marked  by  a  mistaken  hypothesis,  the 
other  by  the  discovery  of  the  parasitism.  The  first  period 
(1797  to  about  1830)  was  ushered  hi  when  the  failure  to 
secure  stages  beyond  the  glochidium  led  to  the  so-called 
Glochidium-Theory,  which  maintained  that  the  larvae  were 
not  the  young  of  the  mussel  from  which  they  were  obtained 
but  a  wholly  different  species  of  bivalve  living  within  the 
mussel  as  a  parasite.  This  theory  had  the  negative  advan- 
tage of  an  incorrect  hypothesis,  it  aroused  opposition  and 
called  forth  investigations  which  showed  once  for  all  that  the 
glochidium  was  the  young  of  the  mussel  in  whose  brood- 
pouch  it  occurred.6 

The  collapse  of  the  glochidium-theory  left  the  subsequent 
stages,  by  which  the  larvae  reach  the  condition  of  miniature 
adults,  an  unmapped  territory  where  all  trails  went  blind. 
Not  until  1866,  when  a  young  German  investigator,  Leydig, 

8  In  passing,  it  is  of  interest  that  the  word  Glochidium,  by  which  we  still 
designate  these  larvae,  had  its  origin  at  the  period  when  the  supposed  parasites 
were  described  as  a  species  parasitic  upon  the  mussel  and  named  Glochidium 
parasiticum. 


SCIENTIFIC  RESEARCH  255 

made  the  somewhat  accidental  observation  of  glochidia 
living  as  parasites  upon  fishes,  was  the  clew  discovered  and 
the  work  of  following  the  later  stages  made  possible.7  During 
this  final  period,  the  post-glochidial  development  became 
well  known  and  the  earliest  stages  of  egg  and  embryo  were 
reexamined  in  the  interests  of  fundamental  research  upon 
development.  Most  significant  of  all  in  illustration  of  the 
importance  of  abstract  research,  is  the  fact  that  from 
Leeuwenhoek's  beginning,  all  this  work  was  part  of  an  attempt 
to  understand  the  nature  of  individual  development.  It  was  in 
no  sense  directed  toward  utilitarian  ends.  Originally,  it  was 
a  question  of  the  mode  of  generation,  whether  spontaneous  or 
by  eggs  and  sperms.  Later,  it  became  a  question  of  compar- 
ative embryology  and  the  tracing  of  each  organ  in  the  body 
back  to  the  cell  or  group  of  cells  from  which  it  originated. 
Through  it  all,  the  direct  pressure  of  utilitarian  considera- 
tions is  nowhere  to  be  found;  but  rather  a  belief  by  the  in- 
vestigators that  the  facts  were  worth  knowing,  because  they 
gave  a  broader  horizon  to  the  landscape  of  nature. 

In  1891  the  first  pearl  button  was  cut  from  a  fresh-water 
mussel  shell.  The  business  soon  became  a  substantial 
industry  and  within  ten  years  the  destruction  of  the  mussel 
beds  in  the  Mississippi  River  seemed  imminent.  At  the 
request  of  the  manufacturers,  the  United  States  Bureau  of 
<Ties  undertook  a  brief  survey  and  offered  some  whole- 
some advice,  all  of  which  was  disregarded  with  the  opening 
of  now  sources  of  supply  in  Arkansas,  Indiana,  and  along  the 
Ohio.  Seven  years  later,  under  the  stress  of  a  still  diminish- 
ing supply,  the  manufacturers  again  approached  the  Bureau 
of  Fisheries,  with  the  result  that  the  Bureau  made  an  ex- 
tensive study  of  the  mussel,  having  in  view  its  artificial 
propagation.  The  results  of  this  investigation  have  been 
brought  together;8  and,  since  there  are  still  many  funda- 


'LeydiR,   F.,   "MitthciluiiK   iilx'r  don   Panmitismus  junger  Unioniden  an 
Ftochon  in  N..1I        Tiilmim-n.  I  Frmkfort  :i    M  .  1866. 

•Lefevre,  G.,  and  Curtis,  W.  C.,  "Studies  on  the  Reproduction  and  Artifi- 


256       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

mental  questions  involved,  the  federal  government  has  con- 
structed, at  Fairport,  Iowa,  a  station  for  the  investigation  of 
these  and  all  other  problems  of  fresh-water  biology,  and  as  a 
part  of  this  station,  a  hatchery  for  the  rearing  of  mussels  by 
artificial  means.9 

Although  much  remains  to  be  done  before  the  rearing  of 
the  button  mussels  is  established  upon  a  commercial  basis, 
the  results  are  encouraging  and  it  may  be  hoped  that  before 
many  years  the  supply  of  raw  material  will  be  drawn  from 
beds  artificially  produced  and  maintained.  As  this  work  in 
applied  science  advances,  it  is  conceivable  that  the  men  who 
have  dealt  with  these  practical  problems  may  win  popular 
recognition  greater  than  that  given  to  any  of  their  pred- 
ecessors during  the  two  hundred  and  fifty  years  since 
Leeuwenhoek.  Be  this  as  it  may,  it  is  to  the  earlier  workers 
that  the  larger  measure  of  credit  belongs;  for  theirs  was  the 
more  unique  attainment.  Between  the  two  is  the  difference 
between  the  men  who  broaden  a  beaten  trail  and  those  who 
penetrate  territory  wholly  new. 

THE   PROGRESS   OF   KNOWLEDGE   CONCERNING   HEREDITY 

The  problem  of  heredity  is  our  final  illustration  of  the 
relation  between  theoretical  and  practical  knowledge  in  the 
history  of  science.  In  this  field  we  have  known  so  little, 
have  so  failed  in  the  discovery  of  land-marks  until  very  recent 
years,  that  biological  science  is  only  beginning  to  get  its 
bearings  and  to  hew  its  way  into  the  wild.  We  to-day  stand 

cial  Propagation  of  Fresh-water  Mussels."  Bulletin  Bureau  of  Fisheries, 
Vol.  XXX,  1910.  See  also:  the  miscellaneous  papers  by  other  investigators, 
published  in  Bull.  Bur.  Fisheries  since  1910;  and  particularly,  Coker,  R.  E. 
etal.  "Natural  History  and  Propagation  of  Fresh-water  Mussels,"  Bull. 
Bur.  Fisheries,  Vol.  XXXVII,  1919-20. 

9  This  station,  which  is  probably  the  most  extensive  establishment  of  its 
kind  in  the  world,  is  described  briefly  by  R.  S.  Coker,  "The  Fisheries  Biological 
Station  at  Fairport,  Iowa."  App.  I,  Rept.  U.  S.  Commissioner  of  Fisheries, 
1920. 


SCIENTIFIC  RESEARCH  257 

like  those  who  have  just  effected  a  landing  upon  a  new  con- 
tinent, whose  supply  camps  are  established,  whose  ax-men 
are  out,  and  who  are  beginning  the  march.  This  is  a  field 
of  investigation  where  discoveries  are  so  new  that  men  have 
not  yet  grasped  their  importance  nor  set  the  facts  to  work 
in  ways  to  suit  their  needs.  This  is  a  problem  of  the  future, 
and  as  such  appeals  more  strongly  to  imagination. 

The  fact  of  hereditary  resemblance  must  have  been  recog- 
nized since  man  first  gave  attention  to  the  breeding  of  domes- 
ticated animals,  or  first  saw  that  his  offspring  were  like  him- 
self. But  heredity  remained  rather  the  plaything  of  the 
philosopher  than  the  problem  of  the  scientist,  until  the  man- 
ner of  individual  generation  had  become  established  and  the 
germ-cells  recognized  as  its  physical  basis.  All  the  earlier 
work  upon  reproduction  and  development,  all  the  investi- 
gations which  centered  around  the  discussion  of  spontaneous 
generation,  all  the  studies  which  led  to  the  cell-theory  were 
necessary  to  establish  our  present  position,  and  to  give  the 
modern  investigation  of  heredity  its  point  of  departure. 
With  these  things  behind  it,  heredity  has  become  a  subject 
of  prune  interest  in  present-day  biology,  and  only  hi  the  last 
quarter  century  has  our  attack  begun. 

Two  men  stand  out  as  pioneers  of  the  recent  advance— 
Gregor  Mendel,  whose  work  was  the  earlier  done  but  the  later 
known;  and  Francis  Galton,  who  should  be  credited  with 
collecting  valuable  data  and  with  arousing  public  interest 
by  his  eugenic  propaganda,  although  his  laws  of  heredity 
now  seems  of  small  value. 

Without  attempting  an  explanation  of  either  the  Galto- 
nian  or  the  Mendelian  theory  of  heredity,  a  word  may  be  said 
in  illustration  of  an  essential  difference  between  the  two.10 
Most  of  us  are  familiar  with  the  tables,  published  by  insur- 
ance companies  and  stating  the  expectation  of  life  for  a  man 
at  a  given  age.  You  are,  say  thirty  years  old.  The  table 

10  The  cellular  aspects  of  Mendelian  heredity  have  boon  briefly  discussed  in 

Chapter  VII.  pp.  i:«M4. 


258       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

says  you  may  expect  to  live  until  you  are  sixty-four.  This 
is  well  so  far  as  it  goes.  It  is  comforting  to  feel  one  has  that 
much  lease  on  life,  even  though  his  life  is  almost  half  spent. 
And  this  knowledge  does  very  well  for  life  insurance  com- 
panies, since  it  can  be  applied  to  thousands  of  policy  holders 
with  a  degree  of  certainty  that  places  the  whole  superstruc- 
ture of  the  insurance  business  upon  a  stable  foundation. 
In  your  particular  case,  however,  this  kind  of  certainty  is 
not  satisfying,  since  it  can  tell  you  nothing  of  your  own  or 
any  other  individual's  duration  of  life.  Though  you  die 
to-morrow  or  live  to  be  a  hundred,  your  life  merely  counts 
as  one  item  in  the  statistics  upon  which  such  tables  are 
based. 

The  insurance  tables,  therefore,  allow  us  to  make  proph- 
ecies for  populations,  but  not  for  individuals,  and  this  is  essen- 
tially the  nature  of  Galton's  law  of  heredity.  It  attempts  to 
say  what  will  be  the  inheritance  on  the  average,  but  leaves  us 
in  the  dark  as  to  what  will  happen  in  the  individual  case. 
If,  on  the  other  hand,  the  life  insurance  company  were  able, 
after  looking  you  over,  to  say  that,  barring  death  by  acci- 
dent, you  would  become  an  octogenarian,  or  to  say  that  in- 
ability to  resist  disease  would  cut  you  off  at  forty,  then  we 
should  have  the  kind  of  prophecy  it  is  possible  to  make  in 
cases  of  Mendelian  inheritance  which  have  been  thoroughly 
investigated.  For  here,  we  can,  by  proper  testing  of  the 
individual,  foretell  the  characters  he  will  transmit  to  his 
descendants.  Galton's  law  is  then  of  value  as  a  statistical 
statement,  but  as  a  guide  in  the  fundamental  analysis  of 
heredity  it  can  scarce  be  compared  with  the  law  of  Mendel. 

The  discovery  of  the  Mendelian  phenomena,  like  most  im- 
portant advances  in  the  science  of  biology,  was  not  the  re- 
sult of  any  feverish  search  for  utilitarian  values.  Mendel's 
interests  were  along  theoretical  lines.  The  account  of  his 
experiments  remained  buried  hi  an  obscure  publication, 
until  after  the  same  phenomena  had  been  rediscovered  by 
later  workers  about  1900.  And  now,  less  than  a  quarter  of 


SCIENTIFIC  RESEARCH  259 

a  century  later,  Mendelism  is  becoming  a  household  word. 
So  many  facts  have  already  been  accumulated  and  so  re- 
volutionary are  some  of  its  conceptions,  that  we  begin  to 
doubt  whether  our  other  theories  of  heredity  have  had  any 
value  whatsoever.  And  we  look  forward  with  hope,  because 
we  are  at  last  upon  firm  ground  and  have  found  a  way  of 
advance. 

The  results  which  must  inevitably  flow  from  the  obscure 
beginning  made  by  Mendel  are  not  easily  appreciated,  so 
great  is  the  importance  to  mankind  of  accurate  knowledge, 
and  hence  control,  of  heredity.  Already  the  breeding  of 
domestic  animals  is  feeling  the  impetus,  and  the  super- 
stitions that  have  clouded  the  efforts  of  practical  breeders 
are  becoming  things  of  the  past.  The  breeder  of  animals  who 
would  have  large  success  from  now  on,  must  be  not  only 
biologically  trained;  he  must  know  every  twist  and  turn  of 
the  latest  Mendelian  formulae.  For  the  same  laws  hold 
good  in  many  different  animals  and  plants,  in  the  wool  of 
sheep  and  in  the  colors  of  flowers.  Breeding  will  soon  be- 
come an  exact  science,  demanding  extensive  biological  train- 
ing and  a  thorough  knowledge  of  the  short-hand  terminology 
which  the  Mendelian  worker  has  devised  for  the  visualizing 
of  his  complex  phenomena. 

For  the  human  race,  we  may  eventually  breed  better  men. 
Though,  of  course,  the  time  is  far  distant  when  any  selective 
mating  will  be  possible,  save  as  we  develop  a  social  tradition 
that  makes  us  feel  disgraced  if  we  marry  where  the  stock  is 
clearly  defective,  and  save  as  we  enforce  a  rigorous  prohibi- 
tion of  the  right  which  conspicuously  defective  individuals 
now  have  to  inflict  their  full  quota  of  descendants  upon 
society.  These  things  will  come  slowly,  for  the  social 
organization  is  discouragingly  stable,  and  we  cannot  be  over- 
sanguine  when  we  contemplate  the  attainment  of  perfection 
at  some  future  period.  As  Huxley  puts  it,  "If  the  tem- 
perature of  space  presented  no  obstacle,  I  should  be  glad  to 
entertain  this  idea  of  ultimate  human  perfection;  but  judg- 


260      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

ing  from  the  past  progress  of  our  species,  I  am  afraid  that 
the  globe  will  have  cooled  down  so  far,  before  the  advent  of 
this  natural  millennium,  that  we  shall  be,  at  best,  perfected 
Esquimaux." 

For  practical  purposes,  however,  it  is  encouraging  that  man 
may  improve  his  condition  in  the  course  of  a  century  or  so, 
a  thing  we  obviously  do  accomplish  in  some  degree.  And 
we  may  expect  material  advance  in  the  near  future,  if  we 
do  no  more  than  prohibit  what  is  clearly  bad,  while  giving 
social  approbation  to  the  kind  of  matings  which  make  for 
better  men.  But  shall  we  stop  here  once  we  recognize  the 
facts?  We  have  given  up,  among  individuals  if  not  among 
nations,  the  cherished  right  to  knock  the  other  fellow  on  the 
head  if  he  disagrees  with  us;  and  the  type  of  mind  which 
desires  progress  rather  than  precedent  believes  that  the 
future  will  see  the  surrender  or  restriction  of  other  rights  now 
regarded  as  fundamental.  It  may  even  come  to  this  matter 
of  marriage  and  giving  in  marriage.  Already  we  are  making 
the  attempt  to  prevent  hereditarily  defective  individuals 
from  reproducing  their  kind,  something  we  can  accomplish 
only  when  the  facts  of  heredity  are  fully  known  for  these 
particular  cases.  Moreover,  eugenic  propaganda  lead  the 
thoughtful  and  conscientious  members  of  society  to  consider 
their  obligations  in  the  light  of  heredity. 

When  we  really  get  beyond  the  present  sky-line  we  shall 
do  more  than  this;  for  the  future  will  demand  better  brain 
and  more  of  it  than  the  past,  and  a  sound  body  to  go  with 
the  better  brain.  It  has  been  said  that  "the  rulers  of  the 
world  have  been  big  eaters";  which  is  probably  true,  in  so 
far  as  those  who  hold  their  fellow-men  effectively  in  hand 
are,  commonly,  men  and  women  of  some  brute-force.  One 
might  say,  as  the  converse  of  this,  that  the  thinkers  of  the 
world  are  below  the  average  in  physical  attainment.  For, 
while  it  cannot  be  stated  accurately,  it  seems  clear  that  na- 
ture exacts  heavy  penalties  for  too  much  intellectual  effort, 
and  that  for  most  of  the  race  physical  toil,  even  though 


SCIENTIFIC  RESEARCH  261 

arduous,  is  still  the  most  wholesome  of  all  activities.  How 
to  realize  the  old  Greek  ideal  of  the  sane  mind  in  the  healthy 
body  is  still  afar  off.  Present  results  indicate  that  heredity, 
and  not  environment  or  education,  leads  to  permanent 
progress.  If  this  is  so,  the  application  of  the  facts  of  heredity 
to  our  species  will  be  one  of  the  great  problems  of  the  future. 
We  see  now  that  we  are  on  the  right  track,  and  that  an  ade- 
quate knowledge,  and  hence  control,  of  heredity  may  be 
possible  sooner  than  we  had  thought. 

Returning  to  the  main  contention,  what  we  have  seen  in 
the  history  of  man's  study  of  the  microorganisms,  in  a  more 
restricted  case  like  the  fresh- water  mussel,  and  in  the  broad 
field  of  heredity,  will  be  found  in  other  lines.  Facts  appar- 
ently remote  from  present  needs  come  to  be  the  very  life 
blood  of  subsequent  generations.  There  are,  doubtless, 
barren  fields,  but  almost  any  facts  of  nature  are  worth 
studying,  since  only  by  continuous  searching  do  we  find  that 
for  which  we  seek.  If  a  child  is  lost  on  a  mountain  and  there 
are  searching  parties  out  beating  the  bushes,  now  here,  now 
there,  or  systematically  covering  the  ground,  the  one  who 
actually  finds  the  child  may  be  rewarded;  when  in  reality 
it  is  largely  an  accident  that  he  rather  than  another  suc- 
ceeded in  the  quest.  It  is  more  than  likely  the  credit  belongs 
to  another  who  so  organized  the  hunt  that  nothing  could 
be  overlooked.  In  our  quest  for  facts,  we  must  so  advance 
that  no  spot  is  left  wholly  unexplored;  for  we  cannot  tell 
what  importance  any  part  of  the  field  may  assume.  We 
cannot  afford  to  concern  ourselves  to-day  merely  with  what 
seems  useful,  since  the  more  important  advances  of  the  past 
have  commonly  been  made  through  fields  which  at  first 
gave  small  promise  of  value. 

To  some  extent  the  needs  of  practical  life  have  induced 
men  to  explore  the  unknown  territory  of  nature.  But  to  a 
greater  extent  investigators  have  been  led  into  this  terri- 
tory by  their  attempts  to  learn  more  of  nature,  irrespective 
of  utilitarian  values.  We  should,  therefore,  spare  no  effort 


262       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

to  make  such  investigations  possible.  The  recent  history 
of  science  indicates  that  a  larger  amount  of  research  is  now 
in  progress,  " where  the  strange  roads  go  down,"  than  at 
any  time  in  the  past,  and  that  the  more  important  part  of 
this  work  is  being  pursued  without  the  incentive  of  financial 
gain.  In  the  face  of  the  very  general  failure  to  appreciate 
this  situation,  the  scientist  should  consider  the  means  to  a 
better  understanding.  The  case  should  be  presented  in  a 
way  to  make  men  understand  that  pure  science  is  not  "just 
a  lot  of  this  bug  business,"  as  is  sometimes  said  of  zoology, 
but  a  " man's  job,"  which  appeals  to  imagination  and  which 
taxes  to  their  limit  the  intellectual  resources  of  mankind— 
a  task  we  must  take  up  where  our  forebears  lay  it  down. 
That  to  conclude  our  analogy: 

"Follow  after — we  are  waiting, 

by  the  trails  that  we  lost 
For  the  sound  of  many  footsteps, 

for  the  tread  of  a  host. 
Follow  after — follow  after — 

for  the  harvest  is  sown: 
By  the  bones  about  the  wayside 

ye  shall  come  to  your  own!" 


CHAPTER  XI 

THE  ROLE  OF  SCIENCE   IN    THE  SOLUTION  OF 
SOCIAL  PROBLEMS 

ACCEPTING  the  broad  definition  of  science,  as  the  product  of 
human  rationality  applied  to  the  phenomena  of  nature,  it  is 
possible  to  claim  for  science  a  larger  place  in  the  affairs  of 
men  than  could  otherwise  be  maintained.  What  men  call 
civilized  society  with  its  material  surroundings,  its  indus- 
trial, political,  and  social  institutions,  its  state  of  mind  that 
makes  civilization  a  possibility,  has  arisen  as  the  collective 
product  of  human  ideas  acting  upon  the  human  and  the 
material  environment.  This  vast  complex  is  ultimately  a 
product  of  individual  human  minds  reacting  to  their  world 
of  persons  and  things.  The  first  steps  were,  of  course, 
wholly  unconscious.  As  civilization  became  established, 
occasional  thinkers  began  to  understand  the  significance  of 
rationality  in  the  control  of  environment.  In  later  times,  an 
increasing  number  have  apprehended  human  social  organ- 
ization as  a  process  in  space  and  time,  have  sought  to  ascer- 
tain the  end  toward  which  it  has  progressed,  and  have 
considered  the  extent  to  which  man  can  assume  direction  of 
its  progress  in  the  future.  As  a  result  of  the  analyses  made 
uch  philosopher-historians  as  Guizot,  Buckle,  Comte, 
Carlyle,  Spencer,  Hegel,  and  others,  it  seems  fair  to  say  that 
the  end  toward  which  civilization  has  blindly  directed  its 
main  effort  is  the  elevation  and  expansion  of  the  individual. 
In  the  advancement  of  civilization  through  the  action  of 
the  human  mind  upon  its  environment,  no  one  factor,  such 
as  religion  or  science  or  hero-worship,  can  be  regarded  as  all- 
important.  But  in  so  far  as  it  is  definable  as  the  rational 
attack  upon  phenomena,  science  holds  a  unique  position. 

253 


264      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

In  view  of  the  definition  of  science  above  given,  we  under- 
stand why  the  scientist  does  not  accept  the  naive  formulas, 
by  which  the  progress  of  society  is  frequently  explained,  for 
example,  belief  that  the  advances  of  western  nations,  during 
the  past  nineteen  hundred  years  has  been  mainly  a  function 
of  the  dominant  religion.  The  spirit  of  the  greatest  of 
ethical  masters  is  in  no  small  measure  responsible,  but  the 
progress  of  western  culture  is  a  more  complex  affair. 

Acceptance  of  the  traditional  explanations  of  progress 
would  be  unimportant,  if  such  an  attitude  did  not  lead  to 
blindness  in  situations  which  involve  the  future  of  mankind. 
We  must  have  in  mind  the  entire  situation — must  consider 
all  the  data.  When  this  is  done,  the  rational  processes  of 
the  mind,  which  constitute  the  motive  power  of  science, 
appear  as  a  dynamic  factor  in  human  progress.  Behind  the 
life  of  the  civilized  community,  with  its  elevation  and  ex- 
pansion of  the  individual,  is  the  driving  force  of  ration- 
ality. 

THE  MATERIAL  FOUNDATIONS  OF  SOCIAL  WELL-BEING 

Whether  or  not  it  be  agreed  that  the  development  of  the 
individual  to  the  limits  of  his  capacity  constitutes  the  goal 
of  human  effort,  it  is  fairly  obvious  that  human  progress 
from  the  Renaissance  onward  has  proceeded  in  this  direction. 
The  modern  Utopia  seems  to  be  a  world  in  which  men  will 
not  be  debarred  from  a  realization  of  the  best  that  is  hi  them, 
save  by  the  obligation  to  give  to  others  an  equal  opportunity. 
We  are  far  from  the  goal,  but  enough  has  been  effected  that 
we  may  dream  of  a  day  when  no  human  individual  will  lack 
the  opportunity  to  achieve,  both  physically  and  mentally, 
the  best  that  lies  within  him.  Equality  of  capacity  would 
seem  a  biological  impossibility,  but  equality  of  opportunity  is 
not  unattainable  within  reasonable  limits.  It  is  this  upward 
surge  of  individuality  that  has  produced  the  democratic 
movements  of  the  recent  centuries;  and  the  best  guarantee 


SCIENCE  AND  SOCIAL  PROBLEMS  265 

for  the  ultimate  success  of  democracy  is  this  persistent  de- 
mand for  individual  opportunity  which  can  scarce  be  secured 
under  aristocratic  forms  of  government,  whether  such  forms 
be  landed  or  capitalistic. 

The  betterment  of  his  material  environment  is  important 
not  alone  for  man's  physical  gratification.  Such  betterment 
enables  men  to  devote  their  attention  to  that  which  is  not 
bread.  The  " misery  of  boots,"  as  one  writer  aptly  de- 
scribes it,  must  be  overcome  before  the  individual  can 
realize  his  spiritual  desires.1  The  proposal  to  fill  men's 
stomachs  as  a  stimulus  to  their  morals  is  worthy  of  attention, 
even  though  experience  shows  that  great  material  prosperity 
is  not  conducive  to  the  spiritual  advancement  of  individuals 
or  of  nations.  A  degree  of  prosperity  is  indispensable,  though 
an  excess  may  prove  disastrous.  Luxury,  if  we  mean  by  this 
the  comforts  over  and  above  the  necessities  of  life,  may  be 
taken  as  one  of  the  measures  of  civilization. 

Hence,  the  most  obvious  application  of  science  to  the 
problems  of  society  lies  in  this  direction.  Science  has  estab- 
lished a  control  of  nature,  through  which  the  material  wel- 
fare of  mankind  can  be  permanently  secured.  In  civilized 
lands,  men  can,  if  they  will,  produce  enough  for  the  entire 
population  to  eat  and  to  wear.  The  problem  is  no  longer 
how  to  produce  the  necessities  of  life,  it  is  how  to  distribute 
them.  In  production,  we  are  far  ahead  of  our  power  to 
effect  a  just  distribution.  The  socialist  is  largely  correct  in 
his  contention,  that  if  we  would  deal  fairly  in  distribution  no 
man  would  be  obliged  to  work  long  hours  in  shop  or  mine,  but 
could  devote  a  fair  measure  of  time  to  his  spiritual  interests, 
and  that  under  such  a  system  many  social  problems  would 
disappear.  The  first  claim  for  science,  as  having  important 
applications  in  the  problems  of  society,  is,  therefore,  its 
stabilization  and  extension  of  material  factors  which  are 
indispensable.  This  value  should  not  be  minimized,  since 
it  lies  at  the  basis  of  civilized  life,  although  it  is  easy  to  cite 
>  Wells,  H.  G.f  "This  Misery  of  Boote." 


266       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

other  applications  not  so  immediately  allied  to  things 
material. 

The  claim  that  material  environment  and  social  conditions 
arising  therefrom  largely  determine  aspiration  and  accom- 
plishment will  be  challenged  in  certain  quarters.  There  are, 
in  general,  two  methods  of  procedure,  which  are  held  to  be 
efficacious  as  means  to  progress.  The  one  is  by  exhortation 
and  example,  the  other  by  making  it  possible  for  the  good  in 
men  to  find  an  outlet.  The  former  is  important,  but  the 
latter  is  prerequisite  to  the  social,  and  hence  to  the  spiritual, 
advancement  of  large  bodies  of  men.  Without  belying  the 
thesis  that  the  more  important  values  of  science  are  spiritual, 
we  may  regard  material  conditions  as  of  the  utmost  impor- 
tance, hi  so  far  as  they  place  spiritual  attainmant  within 
reach.  It  can  be  shown  that  material  factors  are  a  most 
effective  stimulus  to  social  progress;  and  scientific  knowledge 
is  the  means  by  which  new  material  factors  are  brought  into 
being. 

Although  the  individual  and  not  his  environment  is  the 
primary  factor,  the  ideals,  the  opinions,  and  the  mental 
habits  of  men  are  so  closely  related  to  their  conditions  of  life 
that  improvement  of  material  and  social  environment  is 
regarded  by  many  able  thinkers  as  the  most  practical  and 
effective  means  to  progress.  It  is  even  maintained  that  the 
moral  relations  of  men  in  any  age  are  largely  a  product  of  the 
cultural  level  of  the  population.  Great  moral  leaders  arise 
and  exhortation  has  its  uses,  but  there  can  be  no  real  progress 
save  as  the  level  of  material,  and  therefore  of  social,  condi- 
tions is  gradually  advanced.  If  this  be  acknowledged,  at- 
tention should  be  directed  to  the  amelioration  of  the  condi- 
tions which  "stop  down"  aspirations  that  might  spring  into 
being.  The  cultural  level  is  the  vulnerable  point  of  attack, 
if  we  really  want  progress.  The  reason  why  exhortation  is  so 
popular  is  that  it  hurts  no  one,  does  not  produce  disturbing 
consequences,  and  is  inexpensive  for  those  who  foot  the  bills.2 

2  This  point  of  view  is  ably  maintained  by  J.  Beattie  Crozier  in  the  volume 


SCIENCE  AND  SOCIAL  PROBLEMS  267 

The  obvious  fact,  which  most  of  us  will  admit,  is  that  "all 
exhortations  to  duty  and  morality,  and  to  elevation  and 
expansion  of  mind,  in  the  face  of  material  and  social  condi- 
tions adverse  to  the  growth  of  these  virtues,  are  a  waste  of 
time  and  human  energy;  and  are  as  absurd  as  to  expect  a 
rich  and  vigorous  fruitage  from  trees  or  plants  in  spite  of 
adverse  conditions  of  soil."3  Unfavorable  material  and 
social  conditions  are  a  check  upon  cultural  progress  and 
hence  upon  the  aspirations  of  men.  Individual  conscience 
and  perseverance  are  not  a  myth.  But  in  a  world  where 
things  make  so  many  of  their  relationships,  that  is,  their 
ethical  values,  through  their  influence  upon  the  minds  of 
men,  it  is  idle  to  suppose  that  high  idealism  will  long  flourish 
in  the  face  of  a  sordid  environment.  The  talk  about  men 
being  men  in  spite  of  adverse  social  and  material  circum- 
stances is  well  enough,  but  it  is  a  terribly  effective  means  for 
the  perpetuation  of  iniquitous  conditions.  If  men's  ideals 
are  not  literally  bred  of  their  surroundings,  it  is  true  that 
their  ideals  are  thus  conditioned.  The  material  and  social 
environment,  in  other  words  the  general  cultural  level,  is  a 
limiting  factor  in  the  advance  of  society  along  the  lines  of  the 
elevation  and  expansion  of  the  individual. 

Scientific  knowledge  of  fact  has  importance  in  the  above 
connection,  because  through  science  alone  can  men  control 
their  material  and  social  surroundings.  Invoking  a  super- 
natural control  of  these  surroundings  may  be  still  practiced, 
in  the  case  of  little-understood  phenomena  like  disease  and 
the  weather.  But  confidence  in  the  effectiveness  of  such 
invocations  is  rapidly  disappearing,  because  mankind  is 
learning  that  the  new  way  and  the  sure  way  lies  through  the 

4  ( 'ivilization  and  Progress,"  in  which  he  strenuously  opposes  the  doctrine  that 

civilization  is  to  be  forwarded,  rather  by  exhortations  to  duty  and  morality, 

>y   the  gradual    amelioration   of  the   material   and  social  conditions 

.kind      (Yo/.icr  is   thus  opposed   to  Carlyle,  whose   emphasis    upon 

spirit  ml    values    led    him    (<>    pour   contempt  upon    the    whole    of    material 

1  Croiier,  J.  B.,  Inc.  ri/.,  p. 


268       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

knowledge  called  science.  When  it  is  once  discovered  that 
any  set  of  phenomena  is  predictable,  and  to  that  extent 
controllable  after  the  manner  of  science,  men  cease  to  believe 
in  the  control  of  these  phenomena  by  supernatural  agencies. 
Thus  it  happens  that  the  realm,  in  which  supernatural 
controls  are  believed  to  be  effective,  is  being  progressively 
diminished.  The  scientific  method  is  likewise  important,  be- 
cause through  this  method  alone  can  men  induce  the  frame 
of  mind  necessary  for  progress  and  for  the  control  of  social 
institutions. 

Concrete  examples  of  the  relation  between  scientific 
knowledge  and  the  material  and  social  conditions  in  civil- 
ized life  need  hardly  be  cited.  This  practical  aspect  of 
science  is  familiar  to  all.  The  man  in  the  street  knows  that 
science  gets  him  what  he  wants  hi  his  industrial  enterprises, 
in  agriculture,  in  household  convenience,  and  in  all  the 
varied  materialities  of  life.  This  aspect  of  science  consti- 
tutes its  justification  in  the  eyes  of  the  world.  Moreover, 
the  familiar  facts  in  the  recent  history  of  the  western  nations 
make  it  a  matter  of  common  knowledge  that  a  host  of 
popular  material  comforts,  which  were  only  for  the  rich  and 
powerful  at  an  earlier  day,  are  the  outcome  of  a  practical 
knowledge  of  the  natural  world,  which  is  the  more  exact 
knowledge  of  applied  science. 

Social  progress  depends  largely  upon,  first,  the  extent  to 
which  society  has  developed  the  material  conditions  upon 
which  any  advance  of  the  cultural  level  must  depend,  and 
second,  upon  the  extent  to  which  these  conditions  have  been 
diffused  and  equalized.  The  material  basis  for  the  finer 
aspirations  must  be  the  birthright  of  a  large  majority, 
before  any  change  can  be  expected.  Within  the  recent 
centuries,  science  has  accomplished  this  extension  and 
democratization  of  the  material  environment  in  western 
society,  by  increasing  both  the  volume  and  the  nature  of  the 
physical  comforts  which  the  majority  can  enjoy.  Science 
has  created  the  material  foundations  of  western  culture. 


SCIENCE  AND  SOCIAL  PROBLEMS  269 

Upon  these  foundations  it  has  been  possible  to  raise  a 
growing  edifice  of  aspiration. 

It  therefore  appears:  that  scientific  knowledge  is  the 
means  to  control  of  the  physical  environment;  that  proper 
physical  environment  is  prerequisite  to  a  proper  social  en- 
vironment among  men;  and  that  the  level  of  any  society  is  an 
immediate  function  of  the  material,  and  hence  the  social, 
conditions  that  exist.  In  a  savage  society,  living  without 
safe  and  permanent  means  of  subsistence,  the  higher  forms 
of  relationship  between  individuals  are  non-existent.  Aspi- 
ration cannot  exceed  the  cultural  level.  In  a  modern  com- 
munity, where  decent  material  conditions  are  denied  to  any 
large  class  of  the  population,  and  where,  as  a  result,  social 
conditions  are  at  their  worst,  it  is  idle  to  expect  a  flowering 
of  the  nobler  aspirations.  If  these  aspirations  are  thus 
related  to  material  conditions,  which  are  dependent  upon 
scientific  knowledge,  the  basic  importance  of  science  in  the 
solution  of  social  problems  must  be  acknowledged. 

FUNCTION   OF  SCIENCE   IN   SOCIAL  PROGRESS 

But  important  as  its  material  applications  may  appear,  a 
deeper  social  significance  lies  in  the  influence  of  science  upon 
the  outlook  of  the  individual  mind.  The  manifold  inter- 
actions between  the  members  of  a  modern  community  are 
dependent  upon  science  for  their  successful  outcome,  al- 
though here  the  relationship  is  less  direct  and  the  com- 
plexity of  phenomena,  which  involve  men  as  well  as  things, 
is  such  that  the  applications  of  science  are  less  easily  recog- 
nizable. The  influence  of  science  in  this  connection  lies  hi 
the  fact  that  scientific  thinking  produces  a  state  of  mind 
which  makes  for  that  expansion  and  extension  of  the  individual 
which  appears  to  be  the  goal  of  civilized  society. 

Society  suffers,  because  its  members  are  so  largely  in- 
fluenced by  their  emotions.  Mankind  will  doubtless  con- 
tinue to  be  guided  by  the  heart  rather  than  the  head,  but  it  is 


270       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

to  be  hoped  the  former  may  listen  more  to  the  latter.  That 
is  to  say,  it  is  important  that  we  consider  probable  conse- 
quences before  adopting  new  lines  of  procedure.  At  the 
beginning  of  clear  thinking,  in  all  politico-social  questions  are 
facts  that  have  been  more  or  less  scientifically  ascertained. 
The  scientific  method  is  needed  at  every  turn,  if  complex 
social  situations  are  to  be  dealt  with  in  any  other  fashion 
than  by  the  blundering  methods  of  the  past.  The  plea  is  not 
that  the  scientist  is  always  a  good  citizen,  but  that  the 
scientific  method  is  useful  for  the  citizen;  that,  as  social 
life  becomes  more  complex,  it  is  necessary  to  apply  the 
method  of  science,  as  a  tool  wherewith  to  shape  the  conclu- 
sions which  shall  guide  our  social  conduct.  The  need  for 
scientific  knowledge  and  insight  is  particularly  great  now 
that  society  has  become  so  highly  organized.  At  an  earlier 
day,  the  problems  were  simpler  and  the  ignorance  of  the 
population  was  the  element  that  made  the  situation  seem 
hopeless.  To-day,  ignorance  is  still  the  greatest  bar  to 
progress,  but  it  is  an  ignorance  that  shows  signs  of  enlight- 
enment and  that  is  frequently  maintained  on  an  artificial 
basis  by  tradition  and  propaganda. 

The  difficulty  in  taking  over  the  scientific  frame  of  mind, 
to  fields  where  personal  considerations  hold  sway,  is  acknowl- 
edged. The  scientist,  who  exhibits  dispassionate  judgment 
in  a  restricted  field  of  investigation,  is  not  infrequently  as 
narrow-minded  in  his  social  judgments  as  the  individuals  hi 
other  callings  whom  the  scientist  sometimes  holds  up  to 
scorn.  It  is  difficult  to  be  open-minded  and  dispassionate 
where  self-interest  is  involved.  But  the  frame  of  mind 
which  is  avowedly  and  conscientiously  disinterested  and 
progressively  inclined  is  more  likely  to  produce  good  citizen- 
ship than  the  one  which  habitually  works  on  closed  circuits. 

There  is  one  very  practical  point  of  difference,  in  the 
application  of  scientific  principles  within  the  field  of  the 
social  as  compared  with  the  natural  sciences,  which  has  a 
bearing  upon  the  taking  over  of  the  scientific  habit  of  mind. 


SCIENCE  AND  SOCIAL  PROBLEMS  271 

It  is  comparatively  easy  to  make  experiments  in  the  natural 
sciences.  Two  chemical  compounds  may  be  brought  to- 
gether, a  group  of  physical  conditions  may  be  arranged,  an 
animal  or  a  plant  may  be  subjected  to  new  conditions;  even 
in  medical  science,  it  is  not  difficult  to  find  an  individual 
whose  hopelessness  over  his  own  case  or  whose  altruism  will 
lead  him  to  try  the  new  cure  or  to  allow  himself  to  be  in- 
fected with  the  virus.  It  only  takes  one  experimenter  and 
one  trial  to  begin  with.  If  that  is  a  success  the  experiment 
may  be  repeated  again  and  again;  and,  in  the  case  of  ex- 
periments upon  individual  human  beings,  satisfactory 
results  quickly  lead  to  the  willingness  of  a  larger  number  of 
individuals  to  become  subjects  for  experimentation.  The 
result  of  this  in  such  cases  as  the  use  of  anaesthetics  and  of 
anti-typhoid  vaccination,  is  the  very  rapid  extension  of  any 
procedure  that  gives  satisfactory  results. 

But  within  the  field  of  social  phenomena,  the  trained 
observer  may  feel  sure  that  a  social  experiment,  such  as  a 
reform  of  the  currency,  is  justifiable.  Yet  to  perform  the 
experiment,  it  is  necessary  not  merely  to  convince  one 
human  being,  then  another,  and  another,  but  to  persuade  the 
dominating  element  of  a  population  to  submit  to  untried 
conditions.  Moreover,  the  complexity  of  the  situation  and 
the  time  required  are  such  that  the  outcome  may  always  be 
called  in  question.  It  is  as  though  a  civil  engineer  could 
never  experiment  with  the  stresses  and  strains  on  his  bridge 
until  just  such  a  bridge  had  been  built  full  size;  and  could 
not  build  it  until  he  persuaded  a  majority  of  the  population 
to  embark  upon  a  venture  which  might  prove  disastrous, 
ociety  from  the  beginning  of  civilization  has  been  con- 
tinually embarking  upon  such  ventures,  unconsciously 
blundering  through  with  them  at  whatever  cost  in  human 
life  and  treasure. 

Conscious  attempts  to  solve  the  problems  of  society 
have  had  no  very  obvious  influence  in  the  past  nor  do  they 
in  the  present.  !><•<  'i.'il  decisions  are  made  not  l>\ 


272      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

competent  thinking  but  by  blind  reactions.  The  effort 
of  innumerable  individuals,  each  pushing  his  own  way  and 
led  by  what  appeals  to  his  own  imagination,  constitute  the 
medium  in  which  progress  develops.  Nevertheless,  if  ra- 
tionality amounts  to  anything  hi  the  world  of  social  re- 
lationship, we  must  act  on  the  assumption  that  intelligent 
analysis  counts  in  the  long  run.  Now  that  so  many  are  able 
to  read,  even  if  they  read  only  newspapers,  it  is  possible  for 
human  thought  to  carry  farther  than  ever  before. 

The  thinker  is  always  at  a  disadvantage  as  compared 
with  the  demagogue,  because  the  latter  so  readily  captures 
the  popular  imagination.  The  discriminating  insight  into 
the  problems  of  human  life,  which  may  characterize  the 
finer  intelligence,  is  often  directly  felt  by  only  a  small  circle  of 
readers  and  acquaintances.  But  hi  the  end  the  progress  of 
society  seems  to  be  dominated  by  the  ideas  of  a  few  minds; 
and  usually  these  ideas  are  relatively  simple  because  they 
are  fundamental.  Descartes  and  Darwin  are  examples  of 
individuals  whose  thought  has  influenced  the  structure 
of  society.  The  triumphs  of  the  ancient  science  were  seem- 
ingly obliterated  by  the  unscientific  attitude  of  the  Roman 
mind  and  by  the  social  disasters  that  overtook  the  Roman 
Empire.  Yet  the  concepts  of  Hellenic  genius,  through  their 
re-creation  and  extension  hi  the  Renaissance,  made  the 
modern  world. 

Open-minded  consideration  of  ideas  involving  social  re- 
adjustments is  clearly  related  to  the  conscious  direction  of 
social  progress.  Society  regards  change  with  such  suspicion 
there  is  no  danger  that  change  will  ever  occur  with  undue 
rapidity,  despite  the  recurrence  of  revolution.  Conservatism 
is  seldom  out  of  the  saddle  for  long  at  a  time,  and  is,  in  gen- 
eral, supported  by  all  forms  of  human  activity,  with  the 
possible  exception  of  science.  Religion,  art,  government, 
and  even  education  represent  the  conservation  of  what  has 
been  already  won.  Science  is  the  one  field  of  human  endeavor, 
which,  from  its  very  nature,  looks  forward  rather  than  back- 


SCIENCE  AND  SOCIAL  PROBLEMS  273 

ward.  Religion  harks  back  to  revelation;  government,  as 
expressed  by  law,  is  founded  upon  precedent,  the  emotional 
factor  hi  art  arouses  primitive  psychic  states.  Science  is  not 
only  the  latest  born,  it  is  also  the  only  form  of  human 
activity  which  is  continually  projecting  itself  into  the  future. 

Under  these  circumstances,  the  scientific  frame  of  mind, 
with  its  disregard  for  precedent,  is  of  evident  value  in  solving 
social  problems.  Open-mindedness  and  fair  judgment  in 
such  questions  are  essential  to  progress.  Honesty  is  needed, 
and  so  is  sense.  The  method  of  science  is  the  method  of  fair 
judgment  and  of  the  open  mind — the  state  of  mind  which 
makes  progress  a  possibility.  Moreover,  the  method  of 
scientific  thinking  is  the  competent  method  in  the  analysis 
of  complex  situations,  despite  the  claims  for  intuition.  One 
might  characterize  the  land  of  thinking  that  is  done  by  the 
vast  majority  of  human  beings  as  in  one  dimension.  A 
small  number  think  in  two  dimensions,  and  a  very  few  in 
three.  This  last  form  of  thought  is  about  as  comprehensible 
to  the  individual  of  the  one  dimensional  mind  as  is  the  fourth 
dimension  of  the  mathematician  to  the  ordinary  layman. 
Blind  acceptance  of  what  is,  because  it  has  been,  is  an  ex- 
ample of  one  dimensional  thought.  Habit  and  tradition  in- 
cline us  to  take  things  pretty  much  as  we  find  them.  When 
an  individual  arises  who  seriously  questions  tradition,  he  is 
regarded  as  dangerous. 

Now  it  is  against  the  flooding  current  of  traditional  beliefs 
that  science  has  struggled  in  the  past  and  must  struggle  in 
the  future.  The  unscientific  frame  of  mind  does  not  seem  to 
be  born  into  men  so  much  as  it  is  trained  into  them  by  educa- 
tion. The  cases  of  individuals  who  begin  in  the  old  grooves, 
but  by  some  lucky  chance  of  education  or  opportunity 
find  themselves  and  grow  into  the  broader  state  of  mind,  are 
sufficiently  numerous  that  one  need  not  feel  discouraged  for 
the  race.  But  it  is  a  serious  indictment  of  our  educational 
system  that  the  schools  are  much  concerned  with  what  has 
happened  and  little  with  what  might  happen  if  men  would 


274      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

use  more  of  their  wits.  The  true  ideal  of  education  is  a 
leading  out,  as  the  derivation  of  the  term  implies,  and 
this  is  in  line  with  the  ideal  of  science,  which  is  the  discovery 
of  new  truth. 

Science  causes  social  progress  by  its  incessant  erosion  of 
the  traditional  ideas  that  tend  to  keep  society  within  the 
established  bounds.  Science  is  thus  a  dynamic  factor.  This 
does  not  mean  that  great  civilizations  are  impossible,  without 
organized  science  in  the  modern  sense,  but  that  society 
advances  only  in  so  far  as  it  is  influenced  by  the  spirit 
characteristic  of  science.  Ancient  Egypt  possessed  a  high 
civilization,  founded,  as  we  have  seen,  upon  scientific 
knowledge  in  the  arts.  But  the  Egyptian  and  also  the 
Mesopotamian  civilizations  possessed  little  beyond  the  pomp 
and  panoply  of  social  organization,  because  their  culture  was 
not  an  expression  of  the  progressive  spirit  expressed  in  terms 
of  collective  organization.  Greece,  alone  among  the  ancient 
nations,  kindled  the  undying  fire.  The  scientific  factor  in 
western  society  first  arose  in  Hellas.  Some  of  the  far-eastern 
civilizations  of  modern  times  seem  to  represent  a  frame  of 
mind,  essentially  like  that  of  earlier  cultures.  They  are  not 
likely  to  be  shaken  from  their  lethargy  so  long  as  the  spirit 
of  conservatism  prevails.  India,  for  example,  is  not  likely  to 
be  profoundly  changed  by  the  preaching  of  any  new  religious 
philosophy,  for  India  is  surfeited  with  religious  philosophies, 
but  by  the  development  of  a  willingness  to  break  with  tra- 
dition. The  history  of  Japan  within  the  last  half  century 
shows  what  can  happen  when  the  spirit  of  change  strikes 
home.4 

The  claim  that  the  progressive  attitude  of  science  furnishes 
a  dynamic  factor  hi  social  progress  thus  rests  upon  the  fact 
that  the  scientific  state  of  mind  is  the  one  that  readily  breaks 
with  tradition.  Science  is  a  persistently  radical  factor  in 

4  We  do  not  imply  that  the. immediate  outcome  in  Japan  or  elsewhere  is 
other  than  deplorable.  But  the  results  that  can  be  attained  where  there 
exists  the  will  to  break  with  tradition  must  be  acknowledged. 


SCIENCE  AND  SOCIAL  PROBLEMS  275 

society.  It  works  from  the  bottom,  by  changing  material 
conditions  in  such  a  way  that  new  horizons  are  opened.  It 
works  from  the  top,  by  challenging  old  ideas  and  traditional 
schemes  of  social  organization.  The  conservative  function 
has  its  value,  but  the  radical  function  gives  us  new  worlds 
for  old. 


THE   SCIENTIFIC   VERSUS   THE    LEGALISTIC   MIND 

.As  intimated  in  the  preceding  section,  two  contrasting 
points  of  view  appear  within  the  social  field.  It  is  not  that 
human  minds  are  sharply  divided  in  two  different  sorts,  but 
that  two  states  of  mind,  which  all  men  possess  in  some 
degree,  contend  for  the  mastery.  On  the  one  hand  is  what 
may  be  described  as  the  legalistic  frame  of  mind,  and  on  the 
other  the  scientific.  The  use  of  the  term  legalistic  does  not 
imply  that  the  former  attitude  is  the  exclusive  possession  of 
one  profession,  although  it  is  well  exemplified  by  the  mental 
outlook  of  many  lawyers.  This  word  is  used,  because  it  is 
more  expressive  than  such  a  term  as  conservative.  The 
radical  and  forward-looking  nature  of  the  scientific  mind  has 
been  sufficiently  explained.  The  obstacles  to  its  expansion 
can  be  illustrated  by  a  comparison  with  the  antithetical 
spirit  of  legalism. 

What  is  here  designated  as  legalistic  is  the  spirit  which  is 
tied  to  the  past,  and  which  looks  for  guidance  to  what  has 
been  done,  rather  than  to  what  might  be  done  in  any  social 
situation.  This  mental  state  appears:  in  the  lawyer,  who 
believes  that  constitutions  should  be  the  molds  for  society 
rather  than  being  molded  by  society;  in  the  churchman, 
who  believes  that  men  exist  to  glorify  the  Church  and  not 
the  Church  to  express  the  idealism  of  men;  in  the  political 
Bourbon,  who  harps  upon  the  democratic  ideals  of  the  past 
without  making  their  obvious  applications  in  the  present; 
in  the  military  man,  enmeshed  in  red-tape  and  unable  to 
find  his  way  out;  and  in  the  industrial  magnate,  who,  having 


276      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

accumulated  wealth  in  ignorance  of  the  world  of  ideas  and  of 
the  essential  facts  in  human  progress,  poses  as  an  expert  in 
the  problems  of  society  and  opposes  any  suggestion  of 
change  in  the  social  situation.  On  its  emotional  side,  this 
type  of  mind  is  often  strongly  religious  in  a"  formal  way.  It 
possesses  moral  convictions  which  are  incapable  of  progres- 
sive development;  while  a  general  inclination  toward  mysti- 
cism and  conventionality,  together  with  a  willingness  to 
accept  irrational  explanations,  indicate  that  it  is  a  survival 
and  might  properly  be  described  as  archaic,  when  com- 
pared with  the  outlook  of  the  modern  world.  The  intimate 
relation  existing  between  the  sacerdotal  and  the  militaristic 
spirit  is  but  one  example  of  a  linkage  that  connects  to- 
gether a  whole  series  of  mental  states  which  are  deep-seated, 
and  which  are,  in  general,  opposed  to  the  rationalism  of 
scientific  thought. 

The  behavior  of  the  legalistic  mind  within  the  legal  pro- 
fession presents  striking  illustrations.  Research  in  anthro- 
pology and  archaeology  has  shown  the  probable  course  by 
which  law  and  justice  originated  from  their  foundation  upon 
the  minimum  of  mutual  confidence,  which  was  necessary, 
before  any  associations  beyond  the  family  could  be  formed; 
and  upon  the  attempts  to  punish  digression  from  the  un- 
written laws  of  the  group.  Some  measure  of  loyalty,  self- 
restraint,  and  honesty  had  to  be  enforced  from  the  first. 
Law  and  the  administration  of  justice  arose  from  this  natural 
source  and  not  from  supernatural  revelations.  The  later 
evolution  of  the  law  and  its  ideals  hi  the  European  world  are 
familiar  to  the  student  of  history.  The  law  has  exercised  its 
larger  functions,  only  hi  so  far  as  it  has  adjusted  itself  to  the 
new  demands  of  a  changing  social  order.  It  is  necessary  to 
have  regard  for  precedent  in  order  to  conserve  those  prac- 
tices of  the  past  which  are  applicable  to  the  present.  But 
the  real  problem  for  the  law  is  what  is  here  and  now,  not  what 
was  at  an  earlier  period.  The  lawyer  tends,  unconsciously, 
to  feel  that  his  law  came  down  from  heaven,  and  that  what  has 


SCIENCE  AND  SOCIAL  PROBLEMS  277 

been  is  more  sacred  than  what  might  be.  This  is  not  unnatural, 
because  it  is  an  important  function  of  the  law  to  administer 
the  kind  of  justice,  which  has  been  arrived  at  through  the 
experience  of  the  past;  and  because  the  results  of  experimen- 
tation are  uncertain.  To  the  conservative  mind,  there  is  a 
majesty  to  tradition  and  precedent,  because  they  represent 
what  so  many  individuals  have  accepted  hi  the  past,  it 
matters  not  how  blindly. 

The  stickling  for  the  phraseology  of  an  indictment,  while 
the  essential  facts  of  the  case  are  disregarded,  is  a  familiar 
illustration  in  the  legal  procedure  of  our  own  land.  The  Eng- 
lish law,  from  which  ours  took  origin,  has  largely  eliminated 
this  insistence  on  the  letter,  which  arose  at  a  time  when 
merciful  judges  attempted  by  this  subterfuge  to  save  unfor- 
tunate individuals  from  the  action  of  harsh  laws.  Insistence 
upon  the  letter  has  survived  in  America,  because  we  are  a 
conservative  nation,  and  because  the  members  of  an  over 
crowded  profession  must  earn  livings.  The  lawyer  is  wonder- 
fully able  to  keep  in  mind  the  essential  point,  in  true  scien- 
tific fashion,  when  he  is  after  the  facts  of  evidence.  As  a 
judge  upon  the  bench,  he  shows  that  he  can  sift  out  facts 
according  to  the  method  of  science.  His  point  of  view  is 
wholly  different  when  it  comes  to  the  law  as  a  function  of 
society.  To  the  mind  of  the  scientist,  the  law  should  drive 
through  with  an  eye  to  the  main  issue,  which  is  the  adminis- 
tration of  justice  in  a  changing  world.  Neither  justice  nor 
morality  have  absolute  values  which  men  have  as  yet  dis- 
covered. The  belief  that  they  have  such  values  is  a  survival 
from  the  concept  of  a  static  world. 

The  violent  resistance  of  the  legal  mind  to  innovations, 
which  threaten  social  readjustment,  is  a  result  of  the  self- 
interest  involved  where  law  and  business  hunt  together, 
and  of  the  precedent-following  mind.  For  example,  the 
suggestion  that  in  cases  where  an  employer  surrounds  his 
employees  with  riot-producing  conditions,  he  is  to  be  classed 
as  one  of  the  responsible  parties  is  a  new  idea  and  as  such 


278      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

it  falls  upon  stony  ground  when  cast  into  the  legal  mind. 
But  forget  the  law  and  regard  the  case  with  an  open  mind! 
What  is  it  we  are  after  any  way?  Is  it  the  profit  of  the  in- 
dividual employer  or  is  it  the  expansion  of  the  individual,  in 
so  far  as  his  expansion  does  not  stifle  the  opportunities  of 
other  individuals  like  himself?  Proposed  restriction  of  the 
employment  of  industrial  spies  is  a  further  example  of  a  legal 
innovation  that  will  no  doubt  be  opposed  by  the  mental 
attitude  of  legalism  as  well  as  by  the  paid  activities  of  the 
legal  henchmen  of  the  industrial  world.5 

Take  the  broad  problem  of  vested  rights:  The  scientist 
holds  no  brief  for  confiscation.  But  what  appalls  him  is  to  see 
conservatism,  so  blind  as  not  to  realize  that  confiscation  is 
sure  to  come  when  a  social  situation  becomes  intolerable, 
as  during  the  French  Revolution  and  more  recently  in  Russia. 
There  is  a  type  of  mind  which  never  realizes  that  the  reason 
why  men  protect  property  is  that  protection  of  property  is 
necessary  for  the  safety  of  the  individual.  The  individual 
and  his  life  is  the  real  issue.  In  the  long  run,  vested 
property  rights  can  survive  only  as  they  square  with  the 
right  of  the  individual  to  life  and  opportunity.  There  are 
lawyers  who  have  the  broader  view  of  law.  But  there  are 
too  many  of  them  who  think  society  is  static,  and  that  ideas 
can  be  restrained  by  machine  guns  and  policemen's  clubs, 
backed  up  by  legal  precedents. 

The  influence  of  industrialism  in  civilization  presents  a 
curious  contradiction,  in  this  conflict  between  the  legalistic 
and  the  scientific  mind.  Modern  industry  has  been  re- 
sponsible, more  than  any  material  factor,  for  the  spread  of 
the  matter-of-fact  and  rationalistic  point  of  view.  The  idea 
of  scientific  causation  has  established  itself  in  the  popular 
imagination,  largely  through  the  fact  that  men  have  every- 

5  The  development  of  the  spy-system  in  industry  has  been  investigated 
under  the  auspices  of  the  Cabot  Fund  for  Industrial  Research.  See  pamphlet 
entitled:  "The  Labor  Spy,"  which  is  a  reprint  of  articles  published  in  The  New 
Republic  by  Sidney  Howard. 


SCIENCE  AND  SOCIAL  PROBLEMS  279 

where  become  familiar  with  the  laws  under  which  machines 
are  set  in  operation.  The  idea  of  man  as  a  controller  and 
director  of  natural  forces  and  not  as  a  worker  of  miracles, 
and  of  nature  as  something  which  acts  according  to  discover- 
able laws  has  been  the  work  of  the  thinkers.  Its  wide 
acceptance  has  been  an  incident  of  modern  industrial  de- 
velopment. This  situation  was  mentioned  in  our  account 
of  the  practical  applications  of  science  during  the  closing 
decades  of  the  eighteenth  century.  Moreover,  on  its  com- 
mercial side,  the  industrial  character  is  distinctly  matter- 
of-fact  and  scientific,  caring  mainly  for  results.  The  growth 
of  such  a  frame  of  mind  exercises  an  important  influence 
upon  the  intellectual  horizon. 

But  with  the  rise  of  great  industrial  organizations  during 
recent  years,  the  inertia,  with  which  science  has  always  to 
contend,  appears  in  a  new  guise.  The  stronger  forces  of 
conservatism  to-day  appear,  intrenched  within  the  indus- 
trial domain.  The  more  extensively  the  older  dominance 
of  Church  and  Government  is  replaced  by  the  all-powerful 
domination  of  bourgeois  Industry,  the  more  Industry  be- 
comes an  obstacle  to  the  freedom  of  science.  In  the  past, 
the  scientific  spirit  has  contended  with  ancient  dogma  in 
the  form  of  theology.  To-day,  it  is  being  confronted  with 
the  Great  God  Business,  which,  although  it  fosters  the  mate- 
rial extensions  of  science,  is,  on  the  other  hand  opposing  the 
extension  of  the  scientific  frame  of  mind  in  the  solution  of 
social  problems.  Just  as  industrialism  tends  to  eliminate 
war,  by  establishing  a  pax  commercii,  while  the  rivalries 
which  it  engenders  constitute  the  underlying  cause  for 
modern  wars,  so  industrialism,  while  fostering  the  spread 
of  a  scientific  state  of  mind  among  the  toilers,  shifts  the  au- 
thority in  society  from  those  who  dominate  Church  and 
State  to  those  who  dominate  Industry.  It  thus  enthrones 
Industry  as  the  strongest  defender  of  the  status  quo  against 
which  the  scientific  spirit  now  contends.  The  hopeful 
aspects  of  the  situation  are  the  growth  of  the  scientific 


280      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

state  of  mind  among  the  masses  and  the  growing  demand 
from  the  engineer  and  expert  technician  for  a  position  of 
equal  importance  with  that  accorded  to  the  capitalist.  The 
matter-of-fact  demands  of  science  are  having  their  influence 
in  the  central  organization  as  well  as  in  the  lower  levels  of 
industry. 

Psychology  may  some  day  know  enough  regarding  the 
reactions  which  indicate  a  permanent  closure  of  mental  cir- 
cuits so  that  many  an  elderly  gentleman,  who  would  now 
occupy  a  place  of  authority  in  matters  of  social  welfare,  will 
be  relegated  to  a  subordinate  position,  in  favor  of  the  man 
of  open  mind,  who  has  enough  elasticity  remaining  in  his 
arteries  and  elsewhere  to  make  him  fit  to  assume  authority 
in  matters  that  affect  the  lives  and  happiness  of  large  num- 
bers of  men.  In  war,  if  war  lasts  that  long,  it  may  also  be 
possible  to  select,  at  the  outset,  generals  whose  wits  have  not 
undergone  ossification;  and  in  industry  to  curtail  the  in- 
fluence of  those  who  are  hopelessly  unable  to  meet  new  social 
situations. 

The  fact  that  men  easily  establish  a  reputation  for  sanity 
and  sound  judgment  when  they  never  depart  from  established 
points  of  view,  and  the  fact  that  men  tend  always  to  regard 
as  sane  those  who  agree  with  them  are  the  two  strong  but- 
tresses which  support  the  wall  of  conservatism  against  the 
pressure  of  new  ideas.  It  is  considered  safe  to  follow  the  prec- 
edent. But  is  the  folio  whig  of  precedent  the  mark  of  insight 
so  much  as  of  the  lack  of  this  quality?  The  sheep-like  tend- 
ency to  go  with  the  herd  is  a  very  human  trait,  but  is  it 
what  we  should  honor?  Will  it  get  us  anywhere  in  the 
future? 

Like  industry,  modern  journalism  acts  as  an  encourage- 
ment and  also  as  an  impediment  to  the  scientific  attitude 
of  mind.  A  situation  has  developed,  which  we  are  just  begin- 
ning to  recognize,  and  which  marks  the  appearance  of  prop- 
aganda as  a  distinct  factor  in  social  progress.  What  has 
been  essentially  propaganda  has  always  been  used  in  society, 


SCIENCE  AND  SOCIAL  PROBLEMS  281 

when  certain  individuals  or  groups  have  sought  to  mold  the 
ideas  of  a  population  by  indirect  methods.  The  modern  and 
secular  form  of  propaganda  has  developed  hi  intimate  rela- 
tion to  the  advertising  of  modern  business.  The  character- 
ization of  advertising,  "  as  persuading  people  to  buy  things 
they  do  not  need  and  would  not  want  if  they  were  not  over- 
persuaded/'  may  be  resented,  but  it  possesses  a  measure  of 
truth.  What  we  designate  as  propaganda  is  the  attempt  to 
influence  public  opinion  by  subtle  and  indirect  means. 
Where  the  attempt  is  made  by  direct  appeal  and  frank  ac- 
knowledgment of  purpose,  the  term  advertising  is  to  be  pre- 
ferred. Propaganda  and  advertising  are,  however,  so  in- 
extricably connected  that  distinctions  are  arbitrary.  The 
case  of  corporations  that  spend  large  sums  in  advertising, 
which,  although  descriptive  of  the  articles  for  sale,  is  pri- 
marily designed  to  build  up  a  favorable  opinion  and  thus 
enable  the  corporation  to  combat  governmental  action, 
illustrates  the  relationship.  The  abuse  of  news  colums  for 
this  purpose  is  familiar  to  all. 

With  the  extension  of  literacy,  the  printed  rather  than 
the  spoken  word  became  the  medium  of  mental  exchange; 
and  the  newspaper  has  now  become  the  most  effective  con- 
troller and  director  of  ideas,  which  civilization  has  ever 
known.  Not  even  the  Church  at  an  earlier  day  possessed  so 
effective  a  means  of  molding  the  thoughts  of  men.  The 
newspapers  are,  in  general,  organs  of  conservatism,  because 
they  are  so  closely  allied  to  great  commercial  interests.  The 
dangers  hi  such  a  situation  are  evident.  Now  that  popular 
opinion  has  become  so  important  a  factor  in  social  progress, 
this  opinion  should  be  correctly  informed.  The  ideas  which 
the  press  constantly  reiterates  become  dominant.  The  social 
dangers,  inherent  in  the  use  of  propaganda  to  perpetuate 
the  archaic  frame  of  mind,  can  only  be  dealt  with  by  the 
methods  of  scientific  analysis,  backed  by  determination  to 
get  at  the  bottom  of  particular  cases  despite  the  mass  of 
selfish  motive  that  obscures  the  issue.  The  general  prob- 


282       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

lem  of  how  to  secure  a  measure  of  social  honesty  in  a  world 
of  knaves  is  here  illustrated.  There  can  be  no  progress  to- 
ward its  solution  without  recourse  to  the  facts  and  the  method 
of  science  and  without  subordination  of  the  legalistic  to  the 
scientific  frame  of  mind. 

Further  examples  of  the  conflict  between  this  formal, 
conservative,  sacerdotal,  legalistic,  and,  in  general,  archaic 
attitude  and  the  scientific  spirit  might  be  cited.  The  illus- 
trations given  are  sufficient  to  show  the  nature  of  the  strug- 
gle and  the  fields  in  which  it  is  waged.  We  do  not  claim  that 
scientists  as  a  group  have  a  monopoly  of  the  scientific  frame 
of  mind,  but  that  the  nature  of  science  is  such  that  the  for- 
ward-looking attitude  tends  to  be  emphasized  more  than 
any  other.  Science  must  be  willing  to  stand  the  gaff,  when- 
ever it  can  be  convicted  of  a  lack  of  open-mindedness  and 
a  backward-looking  spirit.  Men  naturally  prefer  that  to 
which  their  individual  experience  has  made  them  accustomed, 
both  in  ideas  and  in  material  surroundings.  Conservatism 
has  this  great  law  of  human  thinking  always  at  its  back. 
But  the  frame  of  mind  that  challenges  tradition  is  not 
impotent.  Had  it  been  so,  a  certain  type  among  the  higher 
apes  would  never  have  broken  with  the  traditions  of  animal 
mentality,  as  happened  at  a  remote  period  of  human  ancestry. 

INFLUENCE   OF   SCIENCE    UPON   GOVERNMENT 

The  influence  of  science  upon  governmental  organization 
may  now  be  considered.  There  are,  in  the  last  analysis, 
but  two  forms  of  government — aristocracy  and  democracy. 
Aside  from  maintaining  order  and  administering  justice, 
government  exists  to  promote  the  general  good.  To  this 
all  will  agree.  But  what  constitutes  the  general  good  and 
how  it  may  best  be  promoted  are  questions  regarding  which 
there  is  no  such  agreement.  Self-interest  and  prejudice, 
together  with  divergent  points  of  view  make  unanimity  of 
opinion  seem  hopeless.  Aristocracy  and  democracy  are 


SCIENCE  AND  SOCIAL  PROBLEMS  283 

both  so  strongly  defended  upon  the  ground  that  each  pro- 
duces the  greatest  good,  one  wonders  whether  the  problem 
is  not  so  complicated  that  the  bearing  of  science  upon  the 
form  of  government  cannot  be  ascertained.  Nevertheless, 
certain  clues  are  apparent.  The  fact  that  the  western  ideal 
of  democracy  has  developed  side  by  side  with  the  scientific 
frame  of  mind,  and  that  aristocracy  is  commonly  associated 
with  the  older  forms  of  thought  is  not  without  meaning. 

Science,  with  its  emphasis  upon  matter-of-fact  judgments 
and  its  disregard  for  precedent,  has  been  a  factor  at  every 
step  in  the  advance  from  the  despotic  aristocracies  of  the 
ancient  world  to  the  modern  democratic  states.  In  ancient 
times,  government  was  intimately  associated  with  religious 
leadership,  the  ruler  being  either  a  priest  or  an  individual 
regarded  as  consecrated  by  divine  authority.  Belief  in  the 
divine  right  of  kings  was  the  last  disturbing  survival  of  this 
ancient  union  of  Church  and  State.  Secularization  of  gov- 
ernment has  gradually  broken  down  the  connection  between 
ruler  and  priest.  Rationality  has  applied  itself  in  political 
life;  and  since  political  life  accomplishes  for  the  many  what 
philosophy  does  for  the  few,  the  spread  of  the  rationalistic 
attitude  has  been  encouraged  by  the  political  activities  of 
larger  numbers  of  men.  The  judicial  spirit,  which  is  an  out- 
come of  the  secularization  of  government,  is  the  rational, 
scientific  spirit  appearing  within  the  political  field.  The 
give-ADd-take  of  political  activity  fosters  a  spirit  of  inde- 
pendence and  the  spirit  of  independence  leads  to  new  forms 
of  thought  along  other  lines. 

We  regard  democracy  as  a  sound  concept  of  government, 
because  of  its  effects  upon  the  individual.  One  must  believe 
that  the  influence  of  a  dominant  and  privileged  group,  par- 
ticularly one  that  rules  by  hereditary  right,  is  not  conducive 
to  the  extension  and  elevation  of  the  individual  mind  for 
which  mankind  seems  to  be  striving.  The  fact  that  the 
forms  of  democratic  government,  through  which  the  eleva- 
tion of  the  individual  has  been  attempted,  have  often 


284      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

unsuccessful  does  not  mean  that  the  ideal  of  democracy  is 
unsound. 

In  taking  this  position  with  reference  to  democracy,  we 
are  not  insensible  to  the  claims  of  aristocracy.  The  inequal- 
ity of  men  is  a  biological  fact,  but  it  is  also  a  fact  that  men 
resemble  one  another  hi  their  more  essential  particulars  of 
mind  as  well  as  body,  hence  the  genus  Homo.  It  appears 
from  biological  studies  that  intellectual  ability  is  widely 
distributed,  and  chance  Mendelian  combinations  may  at 
any  time  give  rise  to  genius  in  peasant  hut  or  city  slum.  The 
indictment  of  aristocracy  is  that  it  degrades  the  masses; 
while  among  the  few  that  are  elevated,  a  large  proportion 
are  maintained  hi  their  position  by  hereditary  advantage 
and  not  by  personal  worth.  The  relation  of  servant  to  master 
is  beautiful  in  a  way,  if  the  master  be  a  just  one  and  the 
servant  faithful.  But  the  finer  human  qualities  are  not 
developed  by  those  who  are  submissively  obedient,  nor  by 
those  who  assume  the  obedience  of  others  to  be  their  right. 
It  is  when  men  contend  with  men  in  a  fair  field  with  no  fa- 
vors that  the  virile  qualities  of  the  human  spirit  make  their 
appearance.  Those  who  cry  that  men  should  think  on 
duties  not  on  rights  forget  that  duty  means  submission,  and 
that  while  submission  may  be  necessary  at  tunes  it  should 
be  regarded  as  a  means  to  an  end  not  an  end  hi  itself. 

An  established  aristocracy  must  always  be  founded  upon 
certain  unfair  advantages.  These  advantages  may  be  the 
visible  splendor  of  vast  estates  and  palaces  or  they  may  be 
the  prestige  which  makes  great  splendor  unnecessary  to 
command  the  respect  of  inferiors.  The  industrial  aristocracy 
of  the  modern  community  is  a  case  where  the  visible  founda- 
tion is  hi  evidence,  while  the  German  Junker,  whose  income 
from  his  land  was  far  from  lucrative,  was  a  case  where  pres- 
tige was  substituted  for  more  impressive  possessions.  From 
now  on,  it  would  seem  impossible  for  any  form  of  society 
to  endure  which  does  not  tend  toward  equal  opportunity 
among  the  people  as  a  whole.  True,  the  attempts  at  de- 


SCIENCE  AND  SOCIAL  PROBLEMS  285 

mocracy  among  the  western  nations  have  had  a  pitiful  out- 
come to  date.  It  appears  that  we  have  but  replaced  an 
aristocracy  of  birth,  originating  hi  military  prowess,  by  one 
of  wealth,  originating  hi  commercial  greed.  The  new  masters 
have  no  tradition  of  a  God-given  obligation,  and  they  possess 
no  creed  but  that  of  power.  The  outcome  can  only  be  an 
entrenched  aristocracy,  worse  if  anything  than  the  older 
forms,  unless  we  can  check  the  concentration  of  wealth  and 
its  transfer,  through  inheritance,  to  those  who  have  not  done 
the  concentrating,  to  say  nothing  of  the  producing. 

This  new  aristocracy  casts  its  shadow  directly  athwart 
the  progress  of  society  as  a  whole,  since  material  and  social 
conditions  must  be  in  a  measure  equalized,  before  there 
can  be  an  approach  to  the  equality  of  opportunity  which 
alone  can  satisfy  the  demands  of  an  advancing  civilization. 
Science  made  modern  industrialism  a  possibility.  Indus- 
trialism has  been  the  most  important  factor  in  completing 
the  overthrow  of  feudal  aristocracy.  And  now  industrialism 
creates  new  aristocratic  traditions.  The  solution  of  the  situa- 
tion again  lies  with  science,  this  tune  with  science  applied 
directly  to  the  problems  of  society.  It  has  been  said  that  the 
cure  for  the  evils  of  democracy  is  mare  democracy.  This  does 
not  appear  to  be  true,  if  by  more  democracy  we  mean  more 
voting  on  more  detailed  issues,  as  in  the  practice  of  the 
initiative  and  referendum.  But  if  we  mean  by  more  de- 
mocracy a  nearer  approach  to  the  ideal  which  proclaims 
equal  opportunity  to  all  and  special  privilege  to  none,  the 
cure  is  to  be  recommended.  Equality  of  opportunity  has 
become  imaginable,  because  science  presents  the  means  to 
this  end,  however  difficult  the  road.  Society  seems  to  have 
reached  an  impasse,  unless  a  greater  measure  of  this  equality 
can  be  realized  through  more  effective  social  organization. 
Science  points  the  way  to  such  organization. 

A  better  balance  of  power  between  the  different  groups 
in  society  would  seem  one  of  the  means  of  securing  greater 
equality  of  opportunity.  An  equality  of  mights  tends  to- 


286       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

ward  an  equality  of  rights.  Hence,  democratization  of  indus- 
trial enterprise  appears  to  be  one  of  the  most  important 
single  steps  now  before  us.  Such  democratization  can  be 
accomplished  only  by  the  application  of  scientific  knowledge 
to  particular  problems  of  social  organization,  and  by  the 
further  extension  of  the  scientific  frame  of  mind  as  it  affects 
our  concept  of  the  rights  of  the  individual.  The  idea  of  a 
common  humanity  and  of  the  dignity  of  individual  human 
life  was  promulgated  on  its  ethical  side  by  the  Founder  of 
Christianity.  On  the  intellectual  side,  this  recognition  of 
the  dignity  of  man  seems  first  to  have  become  a  fact,  rather 
than  a  notion,  during  the  Renaissance  in  Italy.  At  that 
time,  distinctions  of  birth  lost  their  former  importance, 
because  "men  were  here  first  thoroughly  and  profoundly 
understood.  This  one  single  result  of  the  Renaissance  is 
enough  to  fill  us  with  everlasting  thankfulness.  The  logical 
notion  of  humanity  was  old  enough — but  here  the  notion 
became  a  fact."  6  The  earlier  ideas  of  merit  or  demerit,  as 
inherent  in  particular  social  groups,  first  began  to  disappear, 
under  the  influence  of  the  rationalistic  doctrine  of  personal 
merit  and  demerit.  This  point  of  view  has  since  had  an  im- 
portant influence  upon  the  spread  of  the  democratic  prin- 
ciple of  equal  opportunity. 

It  is  also  possible  that  some  relatively  simple  material 
discovery  may  have  far-reaching  effects  as  an  equalizer  of 
opportunity.  Historians  commonly  believe  that  the  intro- 
duction of  gunpowder  into  Europe  worked  in  this  manner, 
by  making  the  footman  the  equal  of  the  knight  on  horse- 
back, and  by  rendering  the  feudal  castle  no  longer  secure 
against  attack.  Latterly,  the  development  of  elaborate 
engines  of  warfare  have  again  given  stability  to  entrenched 
power,  battleships  and  artillery  to  powerful  states,  machine 
and  poisonous  gas  to  the  hands  that  can  use  them 
rebellious  subjects.  But  it  is  conceivable  that,  with 
some %ew"' '"twist, jrf  material  discovery,  all  these  may  pass 

Ito'BurcKmrdt,  J.,  "The  Civilization  of  the  Renaissance  in  Italy,"  p.  354. 


SCIENCE  AND  SOCIAL  PROBLEMS  287 

away.  Nations  and  social  groups  within  nations  which  now 
find  themselves  physically  impotent  may  come  into  new 
powers. 

Individual  organisms,  contending  for  the  opportunity 
to  live,  is  the  scheme  of  things  throughout  the  world  of 
living  nature.  Individuality,  with  the  minimum  of  restraint, 
appears  to  be  the  working  basis  of  the  animal  and  plant 
world.  The  democratic  ideal  is  in  line  with  the  individua- 
tion  that  pervades  organic  nature  and  that  finds  its  highest 
expression  in  the  extension  and  expansion  of  the  individual 
which  appears  to  be  the  goal  of  civilization.  Individualism 
is  restrained  among  animals  and  plants  by  the  presence  of 
many  individuals  together.  Where  new  territory  is  being 
occupied,  by  men  or  animals,  individualism  may  go  mad, 
as  it  has  done  in  America  during  the  era  of  exploitation  now 
drawing  to  a  close.  The  outcome  of  such  an  orgy  must  be 
either  a  new-formed  aristocracy  or  the  bringing  to  heel 
of  individualism  hi  order  that  the  many  may  again  have 
opportunity. 

In  view  of  the  historical  movement  toward  democracy 
and  the  present  status  of  democratic  government,  we  be- 
lieve that  the  ideals  of  science  are  parallel  with  the  ideals  of 
democracy;  that  the  growth  of  science  has  fostered  the 
growth  of  democracy;  and  that  democracy  offers  the  type 
of  governmental  organization  which  is,  of  necessity,  com- 
mitted to  the  development  of  science  in  the  future.  In  the 
recent  past  the  influence  of  science  and  of  the  scientist  in 
government  has  been  indirect.  Law  and  the  legal  profes- 
sion have  been  dominant,  because  government  has  con- 
sisted largely  of  the  administration  of  established  procedures. 
The  dominance  of  the  lawyer  in  government  is  natural  and 
almost  inevitable.  But  when,  as  in  our  own  country,  the 
situation  becomes,  what  has  been  jocosely  termed,  "a  gov- 
ernment of  the  lawyers,  by  the  lawyers,  and  for  the  lawyers," 
such  government  is  not  conducive  to  an  intelligent  handling 
of  many  important  < \ \ i» -i  i<  >n-.  The  precedent-following  ni in< I 


288      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

may  be  looked  to  for  guidance  so  far  as  government  is  the 
administration  of  what  has  been  established.  But  in  so  far 
as  government  consists  of  problem-solving,  it  might  better 
be  conducted  by  those  whose  business  is  the  solution  of 
problems.  The  successful  conduct  of  government  in  the 
modern  world,  although  it  consists  largely  of  the  perform- 
ance of  established  operations,  also  demands  the  ability  to 
grapple  with  new  situations  and  to  solve  problems  which 
already  exist.  The  failure  to  perform  this  second  function 
is  due  to  the  dominance  in  government  of  a  mental  attitude 
which  is  interested  in  operating  the  machinery  as  it  has  been 
operated,  and  not  in  the  invention  of  new  machinery  or  of 
new  methods  of  operating  the  old. 

Democracy  can  justify  itself  only  by  more  effective  ac- 
complishment than  hi  the  past.  Science  appears  to  have 
fostered  the  democratic  ideal  in  the  past.  At  the  present 
day,  science,  rather  than  legalism,  offers  the  means  of  triumph 
to  democracy  in  the  future.  A  time  must  come  when  the 
scientist,  and  by  scientist  we  mean  the  engineer,  the  chemist, 
the  sociologist,  the  economist,  and  the  like,  will  be  accorded 
his  rightful  place  in  the  affairs  of  state. 

In  the  foregoing  discussion  of  science  in  relation  to  the 
problems  of  society,  the  general  applications  of  the  scientific 
point  of  view  have  been  emphasized,  rather  than  specific 
applications  in  concrete  problems.  As  in  the  ensuing  dis- 
cussion of  values,  it  is  assumed  that  the  practical  impor- 
tance of  science  is  familiar  to  all.  We  have  emphasized  the 
influence  of  science  upon  the  human  mind.  Its  concrete 
applications  in  social  questions,  like  public  health,  eugenics, 
industrial  problems,  divorce,  the  problems  of  sex,  of  popula- 
tion, of  public  taste,  and  the  like  might  have  been  considered 
at  length.  But  we  have  chosen  what  we  regard  as  the  under- 
lying significance  of  science  within  the  field  of  human 
relationships. 

The  idea  at  the  bottom  of  western  society  seems  to  be  that 
man  does  not  need  to  sit  passively  content  with  his  lot,  but 


SCIENCE  AND  SOCIAL  PROBLEMS  289 

that  he  can,  within  limits,  control  his  environment.  Control 
is  secured  through  science.  The  immediate  outcome  of  this 
underlying  concept  is  frequently  disastrous  to  much  in  the 
older  cultures  that  might  well  be  preserved.  It  appears  that 
no  other  type  of  organization  can  stand  against  the  matter- 
of-fact.  Whether  this  practice  can  succeed  remains  to  be 
seen;  but  for  the  present  it  goes  steadily  forward.  Science 
acts  as  a  dynamic  factor  in  progress,  on  the  one  hand  by 
ameliorating  the  material  conditions  of  human  life,  and  on 
the  other,  by  continually  destroying  dogmas  that  restrain 
the  human  spirit.  Scientific  knowledge  induces  not  only 
new  worlds  of  a  material  sort,  it  also  constructs  new  worlds 
of  social  relationship  as  outgrowths  of  its  material  creations. 
In  addition,  it  opposes  the  formal  and  legalistic  point  of 
view,  and  aligns  itself  with  democracy. 


CHAPTER  XII 
THE  HIGHER  VALUES  OF  SCIENCE  ' 

THE  material  values  of  science  are  widely  acclaimed.  Its 
higher  values  are  commonly  ignored.  For  the  man  of  the 
street,  science  represents  only  control  of  his  physical  en- 
vironment. As  a  matter  of  fact,  the  changes  induced  by 
science  within  this  environment  are  insignificant,  when  com- 
pared with  those  wrought  within  the  human  mind.  To 
designate  these  higher  values  of  science,  the  term  spiritual 
may  be  used,  over  against  the  term  material,  without  further 
implications  and  without  attempt  at  exact  definition.  If 
we  speak  of  man's  spiritual  yearnings  in  contrast  to  his 
material  needs,  we  may  not  have  a  clear  concept  of  what  the 
former  term  signifies;  but  we  acknowledge,  by  the  frequent 
drawing  of  such  a  contrast,  the  existence  of  that  which  is  the 
opposite  of  material.  That  which  constitutes  the  spirit  of 
the  man,  while  too  elusive  for  definition  is  no  less  a  reality.2 
Science  emancipates  the  spirit  of  man  by  freeing  it  from 
ignorance  and  superstition.  The  freedom  thus  acquired 
enables  him  to  make  proper  use  of  his  material  surroundings. 
It  is  time  for  more  emphasis  to  be  laid  on  this  value  of 
science.  On  the  material  side,  science  has  won  and  its 
victory  has  been  acknowledged  and  acclaimed.  On  the 

1  A  considerable  portion  of  the  matter  contained  in  this  chapter  appeared  in 
Science,  June  14,  1918,  as  part  of  the  Symposium  conducted  by  the  American 
Society  of  Zoologists,  Minneapolis,  Dec.  29, 1917. 

2  The  term  spiritual  possesses  an  unfortunate  connotation  for  the  scientific 
mind.    But  there  is  no  reason  why  a  word  for  which  a  satisfactory  synonym 
can  hardly  be  found  should  be  monopolized  by  a  particular  field  of  thought.    If 
scientific  men  speak  of  their  scientific  spirit,  they  may  with  equal  propriety 
refer  to  the  spirit  of  man  and  to  the  spiritual  values  of  scientific  knowledge, 
without  implying  either  belief  in  ghosts  or  tacit  acceptance  of  certain  concepts 
of  orthodoxy. 

290 


THE  HIGHER  VALUES  OF  SCIENCE  291 

spiritual  side,  the  fight  is  on;  but  its  importance  is  not  yet 
comprehended.  Lest  science  fail  in  its  larger  mission,  the 
significance  of  the  higher  advance  should  be  made  known. 
Science  is  obliged  to  exploit  its  material  triumphs  in  order  to 
gain  support  in  its  combat  with  the  idols  of  the  past.  The  prac- 
tical man  cares  little  for  the  thoughts  of  scientist  or  philos- 
opher unless  they  can  be  turned  to  economic  account.  He 
nevertheless  acquires  the  scientific  point  of  view  by  insensi- 
ble stages,  because  he  habitually  employs  both  the  method 
and  the  knowledge  of  science  in  his  everyday  life.  Science  is 
the  great  transformer  of  opinion  at  the  present  time.  And 
this  transformation  is  accomplished  primarily  through  the 
material  efficiency  of  scientific  knowledge.  Just  as  religion 
was  more  effective  spiritually,  when  it  was  believed  that 
supplication  brought  desired  material  blessings,  so  science 
is  effective  at  the  present  day.  But  the  material  benefits 
which  science  has  conferred  upon  mankind  do  not  constitute 
the  highest  scientific  values. 

SCIENCE    AND    IMAGINATION 

It  is  often  said  that  nothing  remains  for  imagination,  now 
that  science  has  destroyed  the  mystery  of  the  universe. 
This  statement  has  no  basis  in  fact,  and  arises  from  a  mis- 
understanding of  what  science  has  accomplished.  Instead  of 
restricting  imagination,  science  has  so  enlarged  the  mental 
horizon  that  imagination  may  take  a  bolder  flight.  To 
primitive  man  and  to  the  savage  who  survived  in  this  state 
until  recent  times,  nature  appeared  a  thing  of  caprice  rather 
than  of  ordered  sequence.  The  world  was  one  of  spirits, 
good  and  evil,  who  had  always  to  be  considered  and  with 
whom  man  must  make  his  peace.  The  day  as  well  as  the 
night  was  peopled  with  beings  who  ruled  in  the  absence  of 
any  definite  sequence  of  events,  and  safety  could  be  found 
only  by  submission  or  propitiation.  Under  these  conditions 
imagination  had  full  play.  But  who  in  the  present  genera- 


292      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

tion  would  choose  this  kind  of  imagination?  Possibly  a  few 
modern  mystics  and  people  of  irrational  and  superstitious 
type  of  mind. 

When  men  first  observed  the  changeless  motion  of  the 
stars  " without  haste,  without  rest,"  and  gained  an  inkling 
that  the  same  orderly  sequence  might  apply  to  all  natural 
phenomena,  the  opportunity  for  imagination  was  not  lost. 
It  was  placed  on  a  higher  plane.  The  inhabitants  of  Europe, 
whose  forefathers  once  imagined  the  Islands  of  the  Blest  to 
lie  beyond  the  Atlantic  and  the  Inferno  of  lost  souls  to  be 
within  the  bowels  of  the  earth,  have  undoubtedly  relin- 
quished many  fields  hi  which  the  imagination  of  medieval 
man  found  exercise.  But  what  a  vista  has  been  opened! 
Consider  the  sweep  through  time  and  space  of  the  concept  of 
evolution :  The  measureless  past  even  of  our  own  planet,  the 
cooling  of  the  gaseous  and  later  molten  mass,  the  differentia- 
tion of  the  land,  the  seas,  and  the  atmosphere,  the  appear- 
ance of  the  earliest  life,  and  its  progress  through  time,  the 
age  of  invertebrates,  the  ages  of  fishes,  amphibia,  reptiles, 
and  mammals,  the  emergence  at  length  of  the  ape  who  walked 
like  a  man,  and  the  struggling  ascent  of  his  descendants 
during  the  glacial  epoch.  The  account  of  creation  in  the 
book  of  Genesis,  when  compared  with  the  tale  outlined  by 
modern  science,  is  like  some  nursery  story,  cherished  as  part 
of  a  departed  childhood  and  wonderful  hi  its  proper  setting, 
but  not  to  be  classed  with  the  great  symphony  made  known 
by  science,  although  having  its  place  in  legendary  literature.3 

The  clouds  are  no  less  wonderful  because  we  know  some- 
thing of  their  relation  to  the  weather.  One  can  watch  the 
sunset,  entranced  by  its  colors  and  imagining  islands  in  a 
flaming  sea  or  castles  hi  the  air.  The  ocean  still  "goes 
nakedly  between  the  weed-hung  shelves."4  Or  let  us  think 

8  A  vivid  portrayal  of  these  steps  in  evolution  is  given  at  some  length  in  the 
opening  chapters  of  the  "Outline  of  History,"  by  H.  G.  Wells.  This  author 
has  made  an  eloquent  plea  for  a  new  "Bible  of  Civilization,"  in  his  volume 
"The  Salvaging  of  Civilization." 

4  Leslie  Stephen  has  well  answered  the  yearning  sometimes  expressed  for  a 


THE  HIGHER  VALUES  OF  SCIENCE  293 

of  man  as  the  victor  over  nature,  notwithstanding  those 
laws  which  are  inexorable  for  other  living  things.  No 
other  species  is  known  to  have  spread  itself  so  widely  over 
the  earth  and  to  have  so  changed  its  environment  to  suit  its 
needs.  Herein  lies  the  difference  between  man  and  the  rest 
of  the  animal  world.  Wherever  else  an  animal  has  been 
subjected  to  a  new  environment,  the  result  has  been  death  or 
the  evolution  of  a  new  type  suited  to  meet  the  changed 
conditions.  But  man  has  taken  himself  and  his  domesticated 
plants  and  animals  into  surroundings  to  which  neither  he 
nor  they  are  naturally  adapted;  and,  instead  of  paying  the 
penalty  inevitable  in  a  state  of  nature,  they  have  survived, 
and  flourished.  Where  nature  would  say  "Die!"  man  has 
said,  "I  will  live!"  And  he  has  succeeded,  because  he  has 

return  to  the  imaginings  of  an  earlier  day  in  the  following  passage:  "Words- 
worth expresses  the  familiar  sentiment  when  he  wishes  that  he  could  be  'a 
pagan  suckled  in  some  creed  outworn.'  The  sight  of  Proteus  and  Triton  might 
restore  to  the  world  the  long-vanished  charm.  Now,  as  far  as  science  is  con- 
cerned, we  are  tempted  to  say  that  Wordsworth  is  simply  wrong.  The  Greek 
mythology  gave  an  inaccurate  representation  of  the  facts.  The  more  accu- 
rately we  know  them  the  better  for  us.  A  slight  acquaintance  with  the  law  of 
storms  is  far  more  useful  to  the  sailor  than  any  guess  about  a  mysterious  being, 
capriciously  raising  the  waves,  and  capable,  perhaps,  of  being  propitiated  by 
charms.  From  the  purely  utilitarian  point  of  view,  we  are  the  better  off  the 
closer  the  correspondence  between  our  beliefs  and  the  external  realities.  But, 
further,  we  are  tempted  to  say  the  same  even  in  a  poetical  sense.  Why  should 
Wordsworth  regret  Proteus  and  Triton?  Because  the  Greek  inferred  from  the 
sea  the  existence  of  beings  the  contemplation  of  whose  power  and  beauty  was 
a  source  of  delight  to  him?  But,  in  the  first  place,  the  facts  are  to  Wordsworth 
what  they  were  to  the  Greek.  If  the  Greek  thought  the  sea  lovely  in  colour  or 
form,  the  colour  and  the  form  remain.  The  imaginary  being  in  whom  the 
phenomena  were  embodied  could  only  be  known  through  the  phenomena. 
The  beauty  is  beautiful  still,  though  we  no  longer  infer  an  imaginary  cause. 
Nothing  is  lost  but  a  dream,  and  a  dream,  which,  by  its  nature,  could  only 
reflect  the  reality.  Why  not  love  the  sea  instead  of  loving  Proteus,  who  is 
but  the  sea  personified?  And,  secondly,  we  must  add  that  the  dream  reflects 
the  painful  as  well  as  the  pleasurable  emotions.  When  the  superstition  was  a 
living  reality,  instead  of  a  poetical  plaything,  we  may  be  sure  that  it  expressed 
horror  as  well  as  delight.  The  sailor,  imagining  a  treacherous  deity  lurking 
beneath  the  waves,  saw  new  cause  for  dread,  and  would  often  have  been  glad 
enough  to  learn  that  Proteus  was  a  figment."  "English  Thought  in  the 
Eighteenth  Century,"  p.  14,  2nd  Edn. 


294       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

forced  from  his  environment  the  readjustments  necessary 
for  his  well-being.  Not  always  is  this  possible.  The  path 
is  not  one  of  ease,  but  it  is  being  steadily  pursued.  In  the 
essay  entitled  "Nature's  Insurgent  Son,"  a  noted  British 
scientist 5  compares  man  to  an  insurgent  gone  so  far  in  his 
rebellion  that  there  is  no  return,  for  whom  capitulation  can 
mean  only  death.  The  rebel  against  natural  forces  must 
continue  on  his  course  until  the  end  is  won,  if  he  would  find 
safety.  Man  cannot  now  return  to  the  dominion  of  nature, 
he  must  see  the  battle  through,  and  succeed  by  mastering 
his  environment  and  so  controlling  his  destiny.  Hence 
knowledge  of  how  to  secure  this  mastery  is  more  vital  to 
him  than  aught  else. 

Again,  take  the  poetry  of  modern  invention.  For  it  is 
there  in  plenty  when  you  know  how  to  find  it,  as  Kipling  has 
done  time  and  again,  but  nowhere  better  than  in  his  verses 
on  "The  Deep-sea  Cables. " 

The  wrecks  dissolve  above  us;  their  dust  drops  down  from  afar- 
Down  to  the  dark,  to  the  utter  dark,  where  the  blind  white  sea- 
snakes  are. 

There  is  no  sound,  no  echo  of  sound,  in  the  deserts  of  the  deep, 
Or  the  great  gray  level  plains  of  ooze  where  the  shell-burred  cables 
creep. 

Here  in  the  womb  of  the  world — here  on  the  tie-ribs  of  earth 
Words,  and  the  words  of  men,  flicker  and  flutter  and  beat- 
Warning,  sorrow  and  gain,  salutation  and  mirth — 

For  a  Power  troubles  the  Still  that  has  neither  voice  nor  feet. 

They  have  wakened  the  timeless  Things;  they  have  killed  their 

father  Time; 

Joining  hands  in  the  gloom,  a  league  from  the  last  of  the  sun. 
Hush!  Men  talk  to-day  o'er  the  waste  of  the  ultimate  slime, 
And  a  new  Word  runs  between:  whispering,  "Let  us  be  one!" 

There  is  a  great  fund  for  imagination  in  the  wireless 

6Lankester,  E.  Ray,  "The  Kingdom  of  Man." 


THE  HIGHER  VALUES  OF  SCIENCE  295 

message.  "Warning,  sorrow  and  gain,  salutation  and 
mirth"  pass  over  our  heads  on  the  wings  of  the  air,  and  the 
telling  of  their  passage  illustrates  the  presence  of  natural 
phenomena  concerning  which  man  knoweth  naught,  but 
which  are  not  unknowable.  Have  we  not  gained  far  more 
than  we  have  lost  by  such  advances  of  science?  Imagination 
need  not  go  unfed,  when  out  of  the  fog,  the  night  and  the 
distance,  as  though  from  another  world,  comes  that  which 
signals  Save  our  Ship,  to  listening  ears  a  thousand  miles 
away  on  sea  and  shore. 

THE   ESTHETIC   QUALITY   IN   SCIENTIFIC   THINKING 

Esthetic  appreciation  may  seem  at  first  thought  to  have 
no  place  in  the  field  of  science.  Yet  if  we  analyze  the  case, 
our  esthetic  responses  become,  when  stripped  of  what  is 
non-essential,  intellectual  rather  than  sensuous  pleasures. 
The  "good,  the  beautiful,  and  the  true, "  as  we  see  them,  are 
largely  that  to  which  we  are  accustomed,  whether  it  be  a 
social  institution,  a  style  in  dress,  or  a  scientific  theory. 
Moreover,  their  cost,  as  one  critic  shows,6  is  a  factor  whose 
importance  is  commonly  underrated.  But  may  we  not  hold 
to  the  faith  that  the  beautiful  and  the  ugly  represent  realities 
over  and  above  that  to  which  one  is  accustomed  and  based 
upon  some  measure  of  thoughtful  analysis?  The  difficulty 
is  in  regard  to  the  standard  or  plane  of  judgment.  Within 
the  purely  intellectual  realm,  however,  we  are  on  safer 
ground.  For  example,  the  satisfaction  one  experiences  hi  the 
demonstrated  theorem  or  in  the  chain  of  evidence  when  the 
last  link  is  forged,  has  its  clearly  esthetic  quality.  There  is 
the  same  feeling  of  completeness  as  hi  beholding  the  creation 
of  artist  or  sculptor  from  which  nothing  could  be  taken  away 
or  nothing  added  without  marring  its  perfection.  Let  it  be  ad- 
mitted that  we  appreciate  such  things  merely  because  our 
minds  run  in  certain  channels.  The  fact  remains  that  our 

•  Vcblen,  T.,  "The  Theory  of  the  Leisure  Clan." 


296       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

minds  so  function,  and  that  as  long  as  human  minds  continue 
to  be  what  they  are  we  may  expect  them  to  follow  similar 
courses.  Stories  are  told  of  great  minds  completing  their 
scientific  discoveries  in  a  state  bordering  on  religious  exalta- 
tion. The  tale  of  Isaac  Newton's  emotional  excitement, 
when  he  saw  himself  approaching  the  verification  of  his 
great  hypothesis,  is  a  classic  example.  The  story  is  that 
being  overcome  by  his  emotions  he  asked  a  friend  to  com- 
plete his  calculations.  The  result  was  that,  "in  a  state  of 
excitement  which  is  said  to  have  been  so  great  that  he  could 
hardly  see  his  figures,  he  proved  that  the  fall  of  a  stone  to 
the  earth  and  the  majestic  sweep  of  the  moon  in  her  orbit 
may  be  ascribed  to  one  and  the  same  cause. "  7 

But  ordinary  men  may  feel  the  thrill  of  discovery  even 
when  the  work  is  not  their  own.  In  intellectual  manhood 
one  recalls  how  certain  theories  in  science  or  ideas  in  litera- 
ture gripped  the  mind  when  they  were  first  apprehended. 
It  mattered  not  that  they  had  been  produced  by  others. 
They  opened  new  horizons.  Nascent  generalizations,  such 
as  the  Mosquito-Malaria  theory  as  first  proposed  or  the 
explanation  of  Mendelian  heredity  and  of  sex-determination 
in  terms  of  chromosomes,  give  the  joy  of  discovery  even  to 
those  who  have  no  part  in  their  investigation.  In  spite  of 
uncertainties  and  the  necessity  for  further  study,  one  often 
feels  that  he  is  gazing  at  a  picture,  near  completion  and  so 
wonderfully  ordered  as  to  call  forth  esthetic  fervor.  To 
many  of  us,  therefore,  scientific  thinking  and  the  contem- 
plation of  the  theories  of  science,  present  an  esthetic  appeal 
of  the  first  order. 

Moreover,  it  is  a  fact  that  some  of  the  highest  forms  of 
esthetic  appreciation  are  of  comparatively  recent  origin, 
having  been  developed  within  the  period  dominated  by 
modern  science.  Of  all  the  ancient  peoples,  the  Greeks 
attained  the  greatest  development  of  the  esthetic  sense;  and 
all  things  considered,  no  modern  race  has  ever  equalled  their 

7  Whetham,  W.  C.  D.,  and  C.  D.,  "  Science  and  the  Human  Mind,"  p.  129. 


THE  HIGHER  VALUES  OF  SCIENCE  297 

attainment.  But  in  some  respects  esthetic  appreciation 
was  undeveloped  even  among  the  Greeks.  The  beauties  of 
the  landscape  seem  to  have  been  largely  ignored,  at  least 
such  beauty  is  not  commonly  referred  to  in  the  Greek  liter- 
ature that  has  been  preserved.  The  influence  of  Christian 
theology  partly  obliterated  what  remained  of  the  classical 
artistic  sense  after  the  fall  of  the  Roman  Empire.  Despite 
the  Gothic  cathedrals,  which  typify  medieval  exaltation 
and  aspiration,  the  modern  esthetic  spirit  has  been  a  new 
birth  coincident  with  the  rise  of  the  rationalistic  spirit. 
Dante's  appreciation  of  nature  was  a  new  note  and  is  dis- 
tinctly modern.  Petrarch's  descriptions  of  natural  scenes, 
his  mountain  climbing,  and  the  beginning  of  modern  land- 
scape painting  in  the  work  of  the  Italian  and  Flemish  artists 
of  the  fifteenth  and  sixteenth  centuries,  are  examples  of  the 
lifting  of  the  veil  thrown  over  nature  during  the  Middle 
Ages.  These  esthetic  developments  have  occurred  in  a 
period  dominated  by  science.8 

It  is,  therefore,  hard  to  believe  that  there  exists  in  science 
anything  hostile  to  the  esthetic  frame  of  mind,  when  we 
realize  that  this  re-creation  of  the  esthetic  sense  and  its 
subsequent  development  have  been  accomplished  in  part  by 
individuals,  who,  from  Petrarch  onward,  have  been  imbued 
with  the  spirit  of  the  modern  scientific  mind.  The  Greek 
use  of  art  to  inculcate  right  thinking  meets  the  unqualified 
approval  of  the  modern  scientific  student  of  the  methods  of 
education.  And  it  is  recognized  by  every  broad-minded 
follower  of  science  that  outside  the  sphere  of  scientific  in- 
vestigation there  exists  another  approach  by  which  men  may 
draw  near  to  nature,  namely,  through  the  appreciation  of 
nature's  beauty.  The  scientist,  therefore,  finds  esthetic 
delight  in  his  intellectual  endeavor,  and  he  does  not  find  his 
senses  dulled  to  the  beauties  of  nature,  save  as  the  intensive 
study  of  particular  phenomena  inevitably  leads  to  a  certain 

•Burckhardt,  J.,  "The  Civilization  of  the  Renaissance  in  Italy,"  Pt.  IV, 
Chap.  Ill,  'The  Discovery  of  Natural  Beauty." 


298      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

disregard  of  what  is  seen  by  the  artist.  The  artistry  of  the 
microscopic  organism  or  of  the  spiral  nebula  is  not  unper- 
ceived  by  the  man  of  science,  but  he  is  interested  also  in  other 
aspects  of  these  natural  objects.  Not  being  an  artist,  the 
scientist  does  not  perhaps  fully  recognize  all  the  form  and 
color  that  is  evident  to  the  artistic  eye.  But  neither  does 
the  artist  recognize  all  the  special  details  which  are  appreci- 
able to  the  scientist. 


SCIENCE   AND    FAIR  JUDGMENT 

A  further  aspect  of  science,  having  spiritual  value,  is  the 
ideal  of  fair-mindedness  inherent  in  the  scientific  method  of 
reasoning.  If  the  essential  element  of  scientific  thinking  is 
reasoning  hi  a  way  to  reduce  the  personal  equation  to  a  min- 
imum, science  may  perform  an  important  service  by  helping 
us  to  impersonal  judgments  in  other  lines.  The  scientific 
attitude  of  mind  aids  in  dispassionate  consideration  of 
subject-matter  that  is  frequently  dominated  by  prejudice. 

The  concept  of  evolution,  both  organic  and  inorganic, 
may  be  cited  in  illustration.  If  this  be  presented  as  an  inter- 
pretation of  the  facts  of  nature,  to  be  accepted  or  rejected 
on  the  same  basis  as  one  would  the  earth's  sphericity  or  the 
Copernican  theory  of  the  solar  system,  it  is  easy  to  show  that 
the  cases  are  parallel,  when  viewed  impersonally  and  as 
scientific  problems.  Once  involved  in  the  subject,  one 
passes  insensibly  to  the  problems  of  society,  which  are  at 
bottom  evolutionary  problems.  Poverty  and  crime,  eu- 
genics and  euthenics,  the  organization  of  the  state,  and  the 
rights  of  the  individual  are  debatable  hi  no  such  simple 
terms  as  comparative  anatomy  and  embryology,  palaeon- 
tology or  ecology;  and  because  of  this  they  are  subjects  for 
prejudiced  controversy  rather  than  open-minded  discus- 
sion. Let  us  take  the  case  of  poverty  as  an  example.  One 
possessed  of  the  scientific  temperament  cannot  possibly 
regard  this  as  a  question  to  be  decided  wholly  in  terms  of 


THE  HIGHER  VALUES  OF  SCIENCE  299 

the  convenience  and  profit  of  the  landlord  or  the  employer 
of  labor.  It  is  a  question  involving  the  welfare  of  the  in- 
dividual and  of  society,  and  all  the  facts  that  seem  to  have 
a  bearing  need  to  be  carefully  considered,  before  an  effective 
policy  can  be  discovered  leading  to  the  elimination  of  this 
festering  sore  from  our  social  life.  The  biologist  may  be 
influenced  by  his  preconceptions  of  heredity  and  environ- 
ment, the  humanitarian  by  his  quickened  sympathies;  but 
in  so  far  as  either  shuts  his  eyes  to  the  evidence  and  fails 
to  consider  all  the  factors  involved,  he  is  false  to  the  scien- 
tific spirit,  which  must  be  the  final  arbiter  in  the  just  de- 
cisions of  conscience.  We  contend,  therefore,  that  the  scien- 
tific method  furnishes  the  only  talisman  that  can  be  used 
effectively  in  solving  the  complex  problems  of  social  life; 
since  it  enables  us  to  grapple  with  these  problems  in  dispas- 
sionate fashion,  and  since  it  makes  for  fair  judgment  and 
the  elimination  of  prejudice. 

This  elimination  of  what  influences  the  you  and  the  me, 
in  favor  of  what  can  be  agreed  upon  as  a  fair  interpretation 
by  us  all,  is  no  easy  matter.  Scientific  men  do  not  always 
live  up  to  their  ideal  of  dispassionate  thinking  within  their 
own  domain,  nor  do  they  always  carry  over  this  ideal  to 
daily  life.  But  the  impersonal  manner  of  thought  is  a  price- 
less possession  of  the  human  race.  If  men  strive  to  apply 
it  in  the  problems  of  human  relationships,  the  effort  is  worth 
while,  however  short  it  falls  of  the  ideal.  We  need  more 
facts  of  science  for  our  material  progress;  but  more  than  this 
we  need  the  unprejudiced  judgments  of  science  for  the  pene- 
tration of  sham  and  for  the  elimination  of  personal  interest 
in  dealing  with  our  fellow  men. 

THE   SCIENTIFIC   SPIRIT  AND    THE    OPEN   MIND 

The  ideal  of  fair  judgment  necessitates  living  in  a  state  of 
suspended  judgment  with  reference  to  many  questions. 
Those  who  acquire  the  scientific  frame  of  mind  find  that  it 


300      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

enables  one  to  live,  on  the  edge  of  difference,  instead  of  in 
the  emotional  attitude  of  onesidedness.  For  one  who  assumes 
the  latter  position,  the  important  questions  of  life  are  settled, 
it  matters  not  in  how  dogmatic  a  fashion.  It  is,  of  course, 
sometimes  better  to  settle  a  question,  even  wrongly,  than 
to  endure  the  paralyzing  effects  of  an  uncertainty  that 
inhibits  action,  where  action  of  some  sort  should  be  taken 
without  delay.  But  it  is  a  very  human  failing  to  form  judg- 
ments upon,  and  to  settle  out  of  hand,  matters  which  call 
for  investigation  before  any  intelligent  action  can  be  taken. 
The  ability  to  suspend  judgment  is  a  necessary  corollary 
of  the  fair  judgment,  which  all  men  profess,  but  which  so  few 
attain  that  one  wonders  how  it  can  ever  be  attained  by  men 
of  action.  Men  so  yearn  for  the  settlement  of  important 
problems  that  settlement  is  commonly  made,  irrespective 
of  the  facts  which  might  be  ascertained.  The  mind  tends  to 
emotional  rather  than  intellectual  decisions,  and  to  a  closing 
of  the  circuit  once  a  decision  has  been  reached.  Established 
convictions  prejudice  the  thought  of  every  individual  in 
ways  of  which  he  is  quite  unconscious.  An  open  mind  is 
the  ideal  to  which  most  men  aspire,  but  which  they  never 
fully  attain. 

The  open-mindedness  that  comes  with  the  ability  to 
suspend  judgment,  where  judgment  cannot  be  based  upon 
adequate  data,  is  an  ideal  of  science.  The  very  nature  of 
scientific  truth  makes  it  clear  that  the  open  mind  must  be 
maintained,  even  in  matters  which  the  scientist  believes  to 
have  been  firmly  established.  Science  has  value,  because 
its  methods  of  thought  dignify  both  the  suspension  of  judg- 
ment and  the  willingness  to  revise  judgment  that  condi- 
tion the  open  mind. 

The  intellectual  advancement  of  individuals  and  thus  of 
nations  is  obviously  dependent  upon  the  acceptance  of  new 
ideas.  The  opposition  to  any  significant  change  hi  social 
customs,  in  legal  enactments,  or  in  religious  beliefs  is  but 
an  illustration  of  the  fact  that  the  individual  resents  any 


THE  HIGHER  VALUES  OF  SCIENCE  301 

alteration  in  that  to  which  he  is  accustomed.  The  reason 
why  youth  accepts  innovations,  which  shock  old  age,  is  that 
the  mind  of  youth  has  not  become  so  wedded  to  established 
practices.  If  the  innovation  survives,  and  becomes  a  part 
of  the  social  order,  the  generation  which  has  accepted  it 
may  later  resist  a  further  change.  One  of  the  tragedies  of 
life  is  the  fact  that  so  many  minds  close  at  the  threshold  of 
what  might  have  become  a  great  adventure.  We  hear  a 
great  deal  about  the  individuals  who  choose  the  wrong  moral 
direction,  and  the  facts  are  serious  enough;  but  we  hear 
little  about  those  who  choose  the  closed  in  place  of  the  open 
frame  of  mind,  whose  intellectual  development  ceases  before 
they  are  grown  to  man's  estate  and  who  go  through  life  with 
a  mental  attitude  that  is  immune  to  new  ideas.  Whatever 
the  shortcomings  of  the  individual  scientist,  the  ideal  of 
science  is  one  of  intellectual  development,  of  a  state  of  mind 
that  is  always  open  to  conviction  when  presented  with  new 
evidence.  This  mental  habit  is  not  easily  maintained  be- 
cause of  the  human  tendencies  aforementioned.  It  is,  how- 
ever, indispensable  to  intellectual  and  also  to  moral  progress. 
In  professional  life,  men  not  infrequently  fail  because 
they  lose  the  capacity  to  grow  intellectually.  The  individual 
begins  perhaps  with  an  education  that  puts  him  ahead  of 
the  majority  of  his  competitors.  As  the  years  go  on,  he 
gradually  fails,  while  other  men  go  steadily  forward  to 
greater  accomplishment.  It  is  not  the  sclerosis  of  old  age 
stopping  down  the  blood  supply  to  the  brain,  but  a  sclerosis 
whifh  overtakes  the  mind  perhaps  at  the  beginning  of  man- 
hood. Material  success  may  be  attained,  but  intellectually 
life  is  at  an  end  when  the  circle  is  closed  and  when  there  is  no 
chance  to  enlarge  its  circumference.  The  intellectual  life 
is  the  life  of  mental  expansion,  so  that  one  cannot  limit  its 
boundaries  and  continue  to  live.  The  physician,  who  is 
too  busy  practicing  to  study  either  his  patients  or  his  jour- 
th<»  clergyman,  whose  theology  does  not  change  with 
jx  ning  years,  the  college  professor,  who  settles  coin- 


302      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

fortably  into  the  same  intellectual  routine,  all  go  the  way 
of  the  closing  mind  which  is  so  easy  and  so  natural  for  man- 
kind. When  a  man's  opinions  on  complex  problems  do 
not  change  for  a  term  of  years,  it  is  well  for  him  to  beware, 
if  he  has  any  ambition  to  be  more  than  he  has  been.  And  the 
same  might  be  said  of  nations. 

How  this  intellectual  slothfulness,  which  is  the  mark  of 
the  closed  mind,  affects  society  through  the  Church  and 
through  Government  could  be  easily  illustrated  from  the 
history  of  any  modern  country  did  space  permit.  The 
point  of  this  discussion  is,  however,  that  science  counts  on 
the  side  of  the  open  mind,  and  that  the  new  ideas,  by  means 
of  which  advancement  is  effected,  will  fall  on  fertile  ground 
only  to  the  extent  that  open-mindedness  prevails. 

THE   VALUE   OF   SCIENTIFIC   SKEPTICISM 

Usage  has  given  the  word  skeptic  a  reproachful  meaning. 
A  term,  which  originally  signified  thoughtful  or  inquiring,  has 
been  so  long  used  as  a  controversial  epithet  that  it  expresses 
an  odious  distinction.  Frequently,  the  skeptic  is  mentioned 
as  though  he  were  an  undesirable  citizen.  Now  skepticism 
and  its  correlated  attitudes  of  agnosticism  and  open-minded- 
ness  are  intrinsic  features  of  the  scientific  frame  of  mind. 
Skepticism,  concerning  that  which  cannot  be  accepted, 
without  disregarding  the  facts  of  the  case,  is  a  commendable 
position.  It  is  an  attitude  of  mind  which  is  unusual  in  a 
world  where  decisions  must  be  made  and  action  taken,  and 
where  lack  of  conviction  exercises  a  paralyzing  influence  upon 
the  conduct  of  an  enterprise.  We  can  be  sure  that  the  world 
will  be  full  of  the  credulous  rather  than  the  skeptical,  that 
those  who  doubt  will  continue  to  be  a  minority.  But  as  we 
have  seen,  human  progress  has  not  been  the  product  of 
credulity  and  the  ignorant  acceptance  of  unwarranted  con- 
clusions. 

The  popular  usage  of  the  term  skepticism  assigns  it  to  the 
vocabulary  of  theology.  We  shall  here  use  the  term,  in  its 


THE  HIGHER  VALUES  OF  SCIENCE  303 

more  general  sense,  as  meaning  thoughtful  doubting  of  that 
which  cannot  be  proved,  and  shall  consider  the  significance 
of  such  a  state  of  mind.  What  we  shall  try  to  show  is  that 
some  measure  of  skepticism  regarding  present  practice  is  the 
foundation  for  a  spirit  of  toleration.  The  history  of  religious 
toleration,  for  example,  shows  that  skepticism,  regarding 
the  authority  for  theological  dogmas,  was  the  force  that 
finally  curbed  persecution.  Conviction  that  he  is  right  is 
part  of  the  psychology  of  the  persecutor.  To  doubt  the 
grounds  for  one's  convictions  means  eventually  the  collapse 
of  intolerance. 

Religious  toleration  is  fairly  well  established  in  western 
society,  but  so-called  heathen  communities  often  exhibit  a 
spirit  which  puts  us  to  shame.9  If  there  is  less  of  toleration 
within  the  politico-economic  field,  a  reasonable  degree  is 
practiced,  save  hi  times  of  excitement  when  it  appears  that 
intolerance  is  very  near  the  surface.  This  is  perhaps  because 
political  and  economic  convictions  matter  so  greatly  in  our 
practical  world,  while  theological  convictions  have  come  to 
be  regarded  as  unimportant.  For  example,  if  one  is  skeptical 
as  to  the  perfections  of  the  existing  social  order,  and  chal- 
lenges the  conviction  that  the  founders  of  the  nation  possessed 
an  omiscience  enabling  them  to  create  a  form  of  govern- 
ment which  must  remain  unchanged,  his  mental  attitude  is 
far  from  unimportant  in  the  eyes  of  the  authorities.  It 
not  only  irritates,  by  going  counter  to  what  has  been  assumed 
as  a  matter  of  course,  it  also  suggests  disagreeable  possibil- 
ities, such  as  changes  in  material  and  economic  conditions. 
Denunciation  of  skepticism  is  sound  procedure  for  those  who 
would  maintain  the  status  quo  in  any  field,  because  skepti- 
cism eventually  means  toleration  and  hence  possible  modifi- 
cation of  the  established  order. 

The  value  of  skepticism  to  the  human  mind  lies  in  the  fact 
that  it  creates  the  frame  of  mind,  which  is  willing  to  break 

•  A  forceful  statement  of  tin-  r.  ]iKious  toleration  existing  in  a  certain  East 
Indian  state  is  pven  by  Price  Collier  MI  Th.  \\ ,  t  in  th.  East,"  p.  274. 


304      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

with  established  convictions,  and  which,  therefore,  makes 
progress  possible.  Skepticism  is  part  and  parcel  of  the 
general  scientific  attitude  of  wanting  to  know  and  of  wanting 
to  know  the  grounds  for  knowing.  The  function  of  skepticism 
in  relation  to  intellectual  and  other  progress  is  that  it 
challenges  convictions  which  produce  intolerance  and  end 
in  persecution.  The  value,  which  inheres  in  a  wholesome 
questioning  of  all  authority  as  such,  is  so  great  that  we  can 
ill  afford  to  decry  the  doubter.  The  skeptical  individual,  is 
the  exceptional  individual,  because  men  tend  to  go  with  the 
herd.  There  is  no  danger  that  the  skepticism  which  even- 
tuates in  group  activities  will  undermine  traditions  that  do 
not  deserve  destruction. 

In  a  world  of  action,  skepticism  cannot  go  far  without  a 
rebound,  since  skepticism  defeats  its  purpose  when  it  results 
in  doing  nothing  in  an  emergency.  It  is  a  thoroughly  scien- 
tific procedure  to  recognize  the  importance  of  the  skeptical 
frame  of  mind,  and  at  the  same  time  to  recognize  the  paral- 
ysis that  comes  when  skepticism  degenerates  into  a  pessi- 
mism that  sees  no  solution  and  possesses  no  convictions.  The 
cure  for  the  impotent  frame  of  mind,  which  is  thus  pro- 
duced, lies  in  action.  The  doer  must  be  in  some  measure 
a  doubter  of  tradition,  if  his  work  advances  to  higher  levels. 
When  doubting  ties  the  hands  that  will  not  long  be  tied, 
doubts  are  flung  aside  by  the  demand  for  doing.  Every  one 
knows  that  he  must  know  he  can  do  it  to  go  on  to  victory,  and 
there  is  this  same  attitude  in  the  collective  behavior  of  the 
group. 

Historical  examples,  showing  how  skepticism  has  grad- 
ually replaced  the  intolerance  of  an  earlier  tune  by  the 
toleration  we  now  enjoy,  will  occur  to  the  reader.  The 
spirit  of  toleration  exhibited  by  ancient  Rome  may  be  cited 
as  a  genuinely  scientific  quality  of  the  Roman  mind.  The 
success  of  the  Roman  conquests  was  in  no  small  measure  due 
to  the  respect  accorded  to  the  beliefs  of  the  conquered.  The 
Roman  outdid  the  Greek  in  this  particular.  The  beliefs  of 


THE  HIGHER  VALUES  OF  SCIENCE  305 

Rome  suffered  in  consequence.  The  spirit  of  toleration, 
which  thus  existed  hi  ancient  tunes,  was  followed  by  the 
intolerance  and  persecutions  of  the  Middle  Ages,  which 
were  only  brought  to  a  close  by  the  changes  hi  intellectual 
outlook  resulting  from  scientific  knowledge.  As  the  spirit  of 
truth-seeking  became  more  prevalent,  doubt  arose.  With 
the  advent  of  doubt,  persecution  began  to  wane. 

The  persecutions  sanctioned  by  the  Medieval  Church  were 
an  outcome  of  the  doc tr hie  of  exclusive  salvation.™  Since 
there  was  but  one  manner  of  salvation,  the  Church  was  jus- 
tified in  maintaining  that  it  should  "  compel  them  to  enter 
in."  The  justification  of  coercion  being  admitted,  persecu- 
tion followed.  Pagan  worship  succumbed,  the  Jews  in  Europe 
were  horribly  maltreated,  the  attempts  of  Frederick  II  to 
found  a  humane  culture  in  southern  Italy  were  stamped  out, 
the  Protestant  defection  brought  on  the  Religious  wars. 
Protestantism  proved  little  better.  Calvin  burnt  Servetus 
because  of  his  views  regarding  the  Trinity.  The  Puritans  hi 
England  and  America  persecuted  those  who  did  not  accept 
their  dogmas,  and  were  in  turn  subjected  to  persecution  fol- 
lowing the  Restoration.  The  first  real  step  toward  toleration 
in  England  was  the  growth  of  skepticism  regarding  the  doc- 
trine of  exclusive  salvation  which  had  been  at  the  root  of  per- 
secution. The  date  of  the  Toleration  Act  (1689)  is  signifi- 
cant, although  its  passage  was  largely  the  result  of  political 
changes.  Throughout  this  span  of  fifteen  centuries,  from  the 
decline  of  the  old  to  the  appearance  of  the  new  spirit  of 
toleration,  it  is  evident  that  not  one  sect  or  group  was  at 
fault,  but  rather  a  frame  of  mind  that  gave  unquestioning 
allegiance  to  traditional  beliefs  and  that  regarded  as  impious 
the  doubts  which  eventually  put  an  end  to  an  insufferable 
situation.  The  history  of  the  decline  of  belief  in  magic  and 
witchcraft  might  be  used  in  further  illustration  of  the  func- 
tions of  skepticism.  But  the  foregoing  outline  of  the  passing 
of  religious  intolerance  will  Midi 

"LecLy,  W.  K    II       History  of  Rationalism  in  Europe." 


306      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

Historical  analogies  are  valuable,  because  they  are  so 
generally  accepted.  But  it  may  be  doubted  whether  we 
actually  learn  anything  from  history,  except  as  we  find  that 
history  reinforces  what  is  observed  to  be  true  in  the  present. 
Events,  which  are  now  transpiring  in  the  world,  are  a 
better  illustration  of  the  contention  that  the  foundation 
of  toleration  is  doubt,  and  that  without  a  degree  of  doubt 
neither  religious  nor  any  other  form  of  toleration  can 
exist. 

The  general  politico-social  situation  which  has  been  a 
product  of  the  Great  War  exhibits  points  of  interest.  There 
is  a  parallel  between  what  occurred  centuries  ago,  as  the 
outcome  of  an  accepted  theological  dogma,  and  what  is 
occurring  at  the  present  day  as  a  result  of  the  social  dogma 
that  political  salvation  can  be  secured  only  through  the 
traditional  forms  of  government.  War  is  a  period  of  intoler- 
ance in  all  lines.  Having  entered  a  struggle  of  life-and- 
death  importance  the  nation  feels  that  those  "not  with  us 
are  against  us,"  and  at  such  a  tune  it  is  idle  to  expect  the 
same  toleration  of  divergent  opinion  upon  the  matter  in 
hand,  as  in  less  strenuous  times.  The  most  to  be  hoped  is 
that  the  nation  will  not  allow  either  its  individual  citizens  or 
its  constituted  authorities  to  indulge  in  practices  that  will 
be  cause  for  shame  as  soon  as  the  excitement  has  subsided. 
War  is,  moreover,  conservative,  if  not  reactionary,  in  its  in- 
fluences, since  it  tends  to  make  men  feel  that  they  should  hold 
to  what  has  been  gained,  and  must,  for  the  time  being,  put 
aside  any  thought  of  organic  changes  in  government.  Thus 
in  Germany,  while  the  war  was  on  and  likely  to  succeed, 
there  was  little  chance  for  the  social  developments  that 
were  in  the  air  before  it  began.  The  same  was  true  in  Great 
Britain  and  in  the  United  States.  A  man  fighting  for  his 
life  has  no  time  to  examine  the  steps  toward  the  expansion 
and  elevation  of  individual  existence.  Political  reaction  is 
to  be  expected  during  war,  and  perhaps  following  war  in  the 
case  of  nations  that  are  victorious.  The  problem  is  to  bring 


THE  HIGHER  VALUES  OF  SCIENCE  307 

about  the  return  to  conditions  in  which  progress  and  not 
reaction  is  the  watchword. 

In  times  of  reaction,  the  existing  forms  of  government 
appear  as  the  exclusive  means  of  political  salvation.  Legal- 
istic minds  support  tradition,  and  the  general  prejudice  in 
favor  of  the  existing  has  full  sway.  What  is  is  right.  Those 
who  condemn  it  are  in  the  wrong  and  should  be  dealt  with. 
Persecutions,  of  the  kind  tolerated  at  the  present  day,  are 
likely  to  follow.  When  to  the  uncritical  deductions  of  the 
honest  citizen  there  is  added  the  support  of  those  who  profit 
financially  by  the  situation  as  it  exists,  the  outcome  fre- 
quently gives  no  cause  for  congratulation.  The  aftermath 
of  war  has  brought  us  to  such  a  state  in  America,  and  there 
is  no  assurance  that  insidious  survivals  of  this  condition  will 
not  impede  social  progress  for  a  generation  to  come.  After 
the  political  offenders  are  released  and  the  mobs  cease  to 
function,  reaction  may  still  dominate  the  nation. 

Specific  examples  will  occur  to  anyone  who  follows  the 
history  of  current  events.  The  thing  to.be  criticised  is,  not 
so  much  the  capitalists  or  the  socialists  or  the  bolshevists  or 
union  labor  or  the  lawlessness  of  the  mobs,  as  it  is  the  frame 
of  mind  which  accepts  that  which  has  been  as  the  standard  of 
what  ought  to  be,  and  having  done  this,  proceeds  to  condemn 
all  who  do  not  hold  to  this  exclusive  manner  of  salvation. 
Persecution  naturally  follows.  As  in  the  past,  the  decline  of 
this  state  of  mind,  which  is  at  the  root  of  persecution,  can 
come  only  when  doubt  is  cast  upon  the  underlying  assump- 
tion that  the  traditional  forms  of  organization  and  activity 
constitute  the  highest  good. 

Skepticism,  therefore,  appears  to  have  its  value.  Beliefs 
possessing  scant  foundation  cannot  be  made  the  basis  for 
dogmatic  assertion  and  its  implied  intolerance,  when  chal- 
lenged at  their  source.  Skepticism  has  been  the  most 
effective  support  of  toleration  in  the  past  and  it  occupies  a 
similar  position  in  the  present.  The  skepticism  of  scion <v 
is  not  the  trifling  doubt  of  dilettantism.  Science  is  thoughtful 


308      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

inquiry  into  the  order  of  nature,  human  nature  included. 
Thoughtful  inquiry  demands  skepticism,  wherever  the 
grounds  for  a  conclusion  appear  inadequate.  Within  its  own 
field,  science  escapes  the  paralyzing  effects  of  skepticism, 
because  science  is  continually  encouraged  by  its  material 
accomplishments.  It  is,  therefore,  able  to  function  un- 
disturbed by  the  pessimism  bred  of  abstract  thought. 
Within  the  field  of  human  relationships,  skepticism  becomes 
effective  only  where  the  facts  make  then*  meaning  clear. 
The  doubting  mind,  like  the  open  mind,  is  the  one  through 
which  comes  progress  and  displacement  of  the  idols  of  tradi- 
tion. 

SCIENCE   AND    EMANCIPATION 

But  even  more  important  that  its  values  as  a  material 
foundation,  as  a  broader  field  for  imagination  and  esthetic 
emotion,  as  an  example  of  fair  judgment  and  the  open  mind, 
and  as  the  foe  of  persecution,  is  the  value  of  science  in  the 
intellectual  emancipation  of  mankind.  The  faith  of  science 
that  truth  makes  men  free  has  been  more  than  justified. 
Many  lesser  cases  might  be  cited,  but  a  single  comprehensive 
example  of  the  emancipation,  which  has  followed  the  spread 
of  an  important  scientific  doctrine,  will  suffice.  The  theory 
of  organic  evolution  is  the  best  illustration  afforded  by 
biological  science,  and  perhaps  by  science  in  general. 

As  we  have  noted,  the  evolutionary  theories  current 
among  the  Greeks  were  tinctured  with  philosophy.  Lacking 
concreteness,  these  philosophical  concepts  made  little  head- 
way. The  beginnings  of  modern  evolutionism  appear  in  the 
accumulations  of  facts  regarding  animals  and  plants,  which 
marked  the  closing  centuries  of  the  Scientific  Renaissance. 
To  Buffon  and  to  other  less  known  writers  of  the  eighteenth 
century  belongs  the  credit  for  having  first  promulgated  the 
evolutionary  theory  in  a  form  that  was  scientific  rather 
than  philosophical,  and  that  carried  a  measure  of  convic- 
tion, despite  its  crudities  and  the  hamperings  of  theological 


THE  HIGHER  VALUES  OF  SCIENCE  309 

criticism.  One  cannot  turn  the  pages  of  Buffon's  encyclo- 
paedic work  without  a  growing  respect  for  his  knowledge  of 
animal  life.  Obviously,  the  foundation  for  much  of  our 
comparative  anatomy  of  vertebrates  was  even  then  estab- 
lished. In  a  preceding  chapter  it  has  been  shown  how 
Lamarck  was  the  first  to  offer  a  theory  of  the  causes  of 
evolution  and  how  he  failed  to  make  his  case  as  against  the 
authority  of  Cuvier;  also  how  the  latter,  although  opposing 
the  theory  of  evolution,  accumulated  some  of  its  strongest 
evidence,  through  his  studies  in  comparative  anatomy;  and 
how  von  Baer  supplemented  this  by  his  work  in  embryology. 
We  saw,  finally,  that  in  Darwin's  day,  there  were  ample  data 
for  the  establishment  of  the  historical  fact  of  evolution,  if  not 
for  the  determination  of  its  causation.  The  almost  immedi- 
ate acceptance,  in  biological  science,  of  Darwin's  views  and 
the  spread  of  the  evolutionary  concept  to  other  fields,  during 
the  remaining  years  of  the  nineteenth  century,  are  well 
known.  We  are  here  concerned  with  the  effect  of  the  evolu- 
tionary doctrine  upon  human  thought  in  the  present  and  the 
possible  extension  of  its  influence  in  the  future. 

The  triumph  of  the  evolutionary  concept  completed  the 
overthrow  of  those  older  ideas  of  the  universe  which  cul- 
minated in  medieval  theology.  Evolution  was  the  final 
extension  of  that  enlarging  mental  horizon  disclosed  by  the 
fact  of  the  earth's  sphericity  and  the  Copernican  explanation 
of  the  solar  system,  conceptions  which  are  indissolubly 
united  and  each  of  which  represents  a  stride  forward  in 
the  face  of  resistance.  Copernicus  would  have  suffered,  as 
Galileo  did  later,  had  the  full  implications  of  his  theory  been 
recognized  before  his  death.  Buffon  was  not  in  physical 
danger,  though  forced  to  recant.  Darwin,  though  heaped 
with  abuse,  suffered  no  real  inconvenience  at  the  hands  of 
his  critics,  for  he  lived  in  a  more  tolerant  and  enlightened 
age. 

During  the  three  centuries  involved,  man's  picture  of 
himself  changed  from  that  of  a  being,  recently  created  and 


310       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

awaiting  a  day  of  judgment  in  the  not  distant  future,  to  that 
of  a  being  originating  as  part  of  organic  nature  and  set  in  a 
universe  without  beginning  and  without  end.  The  by- 
product of  this  intellectual  revolution  was  an  emancipation 
of  the  human  spirit  from  the  bonds  of  authority.  Authority 
indeed  remains,  but  it  is  no  longer  the  authority  of  book 
or  priest,  however  potent  such  authority  may  still  appear  to 
be.  In  its  place  stands  the  authority  of  nature;  and  so  great 
has  been  the  emancipation  we  have,  as  yet,  recognized  but 
an  insignificant  measure  of  the  changes  in  human  thinking 
which  must  follow. 

While  we  can  best  visualize  the  effects  of  the  evolutionary 
doctrine  by  reviewing  its  historical  development,  it  is 
equally  important  that  one  recognize  what  is  happening 
to-day;  hi  what  way  this  doctrine  has  affected  theological 
beliefs  since  the  publication  of  Darwin's  "  Origin  of  Species  " 
(1859) ;  what  has  happened  in  philosophy;  and  what  changes 
have  occurred  in  our  outlook  upon  the  problems  of  society. 

In  theology,  the  evolutionary  doctrine  is  carrying  us 
from  the  concept  of  a  single  religion,  revealed  to  man  by 
agents  duly  inspired,  to  the  concept  of  a  multitude  of 
religions  of  varying  worthiness,  but  all  the  outgrowth  of 
yearnings  which  originated  with  human  intelligence.  In 
other  words,  religion  of  whatever  sort  is  a  product  of  organic 
evolution,  just  as  human  intelligence  is  a  product  of  evolu- 
tion. When  religion  is  so  regarded,  we  need  not  condone  the 
shortcomings  of  the  fathers  nor  strive  for  metaphysical 
explanations  of  sin  and  death,  of  sorrow  and  pain;  since 
these  are  but  the  present  outcome  of  our  origin  from  the 
brute.  We  know  in  part  whence  we  came,  if  not  whither  we 
are  going,  and  it  is  enough  if  we  may,  by  our  own  efforts, 
somewhat  improve  the  material  and  spiritual  state  of  our- 
selves and  our  children.  This  point  of  view  has  been  reached, 
not  by  a  sudden  break  with  the  past,  but  by  a  gradual  shift 
of  mental  attitude  which  makes  the  older  doctrines  impos- 
sible of  acceptance.  The  evolutionary  concept  has  been 


THE  HIGHER  VALUES  OF  SCIENCE  311 

applied  to  religion,  as  to  every  other  expression  of  organic 
nature;  and  the  result  has  been  a  revolution,  accomplished 
before  its  beginnings  were  recognized.  Thus  science  has 
brought  emancipation  from  theological  bondage,  and  set 
free  the  spirit  of  man  for  higher  flights  in  the  future. 

In  philosophy,  the  evolutionary  theory  has  necessitated  a 
change  from  the  concept  of  a  static  to  that  of  a  dynamic 
universe,  as  witness  the  contrast  between  the  philosophical 
systems  of  the  early  nineteenth  century  and  the  views  of 
Bergson.11  This  change  has  not  yet  completed  its  remodel- 
ling of  philosophical  theories.  But  only  a  philosopher  can 
explain  its  workings  in  detail. 

In  the  field  of  social  phenomena,  the  influence  of  the 
evolutionary  theory  appears  in  the  recurrent  question- 
ing of  the  necessity  for  existing  conditions.  If  the  revolu- 
tions of  the  later  eighteenth  and  earlier  nineteenth  centu- 
ries attacked  the  foundations  of  civic  power  and  sought  to 
install  the  authority  of  peoples  over  that  of  kings,  the  un- 
seen revolution  induced  by  the  evolutionary  theory  has 
shaken  the  whole  edifice  of  social  tradition.  Whatever  is 
may  be  the  natural  outcome  of  the  evolution  of  society  to 
date,  but  it  is  not  thereby  right  nor  is  it  necessarily  perma- 
nent. The  evolutionist  may  recognize  the  stability  of  social 
customs  that  have  arisen  by  evolution;  but  he  also  recog- 
nizes these  customs  as  subject  to  change.  Moreover,  the 
human  race  must  consider  the  intelligent  direction  of  its 
future  evolution  as  a  possibility,  however  remote.  Evolu- 
tion has  not  always  taken  the  most  desirable  course,  as 
witness  the  degeneration  incident  to  parasitism;  and  while 
man  will  probably  have  little  to  do  with  its  outcome  in  the 
human  species,  what  he  may  do  is  worth  considering. 

The  influence  of  the  evolutionary  concept  may  be  seen 

11  It  docs  not  seem  to  the  writer  that  the  ideas  of  Bergson  are  particularly 
enlightening  to  the  biological  scientist.  They  exhibit  too  much  of  mysticism. 
But  they  illustrate  the  advent  of  a  philosophy  which  takes  more  cognizance  of 

organic  evolution 


312      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

again  in  the  attitude  toward  a  variety  of  social  problems. 
Disease  and  crime  are  not  inevitable  conditions  to  be  treated 
by  curative  measures  only.  They  are  to  be  attacked  with 
all  the  knowledge  at  our  command,  and  finally  eliminated  by 
the  evolution  of  a  type  of  man  and  a  form  of  society  in  which 
such  evils  will  be  non-existent.  Man  is  no  longer  piously 
content  with  his  lot,  merely  because  he  sees  no  prospect  of 
immediately  changing  it.  Conditions  have  changed  in  the 
past  and  mankind  wants  to  change  them  in  the  future. 
Man  is  not  content  to  let  evolution  take  its  course  with  him, 
he  strives  to  make  it  go  his  way.  Thus  the  insight  into 
social  problems  which  evolution  has  brought  gives  a  habit  of 
mind  that  will  brook  no  limitation  of  the  human  spirit.  As 
within  the  field  of  philosophy,  so  within  the  field  of  social 
phenomena,  this  changing  point  of  view  is  an  outcome  of 
the  recognition  of  a  dynamic  as  opposed  to  a  static  world. 

There  is  thus  taking  place,  under  the  influence  of  the 
evolutionary  doctrine,  a  subtle  change  of  ideas  and  of 
beliefs,  comparable  to  the  changes  of  intellectual  outlook  in 
the  past,  by  which  superstitions,  like  infant  damnation, 
witchcraft,  demoniacal  possession,  and  the  belief  in  ghosts 
were  rendered  impotent.  Such  changes  occur  in  what  may 
be  designated  the  frame  of  mind.  They  are,  seemingly, 
effected  not  so  much  by  argument  as  by  the  imperceptible 
growth  of  a  conviction  that  the  traditional  belief  is  un- 
reasonable. Old  beliefs  often  persist,  apparently  in  full 
vigor,  until  the  collapse  is  at  hand;  but  when  beliefs  begin  to 
excite  ridicule,  their  course  is  nearly  run.  The  history  of 
scientific  progress  has  been  marked  by  spiritual  emancipa- 
tions. To-day  the  process  still  goes  on,  for  supernaturalism 
is  not  yet  fully  vanquished,  but  lingers  on  as  a  miasma  of 
society. 

In  this  manner,  science  feeds  the  spiritual  as  well  as  the 
material  man.  Science  deals  with  that  we  can  measure  and 
weigh,  is  wholly  impersonal,  is  a  thing  of  intellect  rather  than 
of  emotion.  But  intellect  and  emotion  are  not  separate 


THE  HIGHER  VALUES  OF  SCIENCE  313 

entities  of  the  mind,  rather  the  mind  is  a  unit  which  has  its 
intellectual  and  its  emotional  sides.  The  raw  material  of 
scientific  fact  is  susceptible  of  unlimited  organization  within 
the  mind,  and  this  process  of  organization  gives  play  alike  to 
the  intellectual  and  the  emotional  aspects  of  man's  nature. 
If  we  have  made  our  point,  it  has  been  shown  that  the 
progress  of  science  has  given  the  mind  of  man  infinitely 
more  than  it  has  taken  away. 


CHAPTER  XIII 

MANKIND  AND  THE  FURTHER  PROGRESS 
OF   SCIENCE 

AN  attempt  has  now  been  made  to  delineate  the  place  of 
science  in  human  affairs.  The  materialities  of  civilized  life 
rest  upon  scientific  knowledge.  The  spirit  of  the  modern 
world  is  the  rationalistic  spirit  of  science.  Mankind  is 
becoming  increasingly  dependent  upon  the  creations  of 
hand  and  mind  which  science  has  brought  forth.  If  vast 
populations  must  be  artificially  fed  and  clothed,  science  be- 
comes a  necessity  in  the  lives  of  men.  The  extent  to  which 
mere  physical  demands  should  be  satisfied  may  be  questioned, 
but  once  established  they  become  insistent.  On  the  material 
side,  the  science  of  the  future  must  concern  itself  with  facts 
of  serious  import  regarding  exhaustion  of  natural  resources 
and  increases  of  population.  The  mad  expenditure  of  human 
effort  in  pursuit  of  the  material  luxuries  of  civilized  life 
cannot  continue  indefinitely,  unless  new  sources  of  energy 
are  discoverable.  But  even  in  that  event,  men  may  become 
convinced  that  such  effort  is  not  worth  while;  since  satisfac- 
tion of  physical  needs  is  not  the  highest  human  aspiration. 
Science  has  this  more  lasting  significance — well-balanced 
lives  can  be  lived  only  in  the  scientific  spirit.  The  great 
problem  of  the  scientific  future  is  spiritual  adjustment,  not 
physical  gratification.  Although  nothing  seems  able  to 
stand  against  material  matter-of-fact,  this  aspect  of  science 
must  eventually  occupy  a  subordinate  position.  A  brief 
consideration  of  certain  possibilities  concludes  the  dis- 
cussion. 

It  is  sometimes  declared  that  science  has  reached  the 
point  of  diminishing  returns,  that  future  advances  cannot 

314 


MANKIND  AND  THE  PROGRESS  OF  SCIENCE    315 

equal  those  already  made.  The  easier  work  has  all  been 
accomplished,  and  hence  substantial  progress  will  shortly 
come  to  an  end.  Never  again  can  there  be  such  a  period  as 
the  recent  centuries.  Without  venturing  a  prophecy,  these 
statements  may  be  challenged,  in  so  far  as  they  express  con- 
viction that  the  greatest  triumphs  of  science  lie  behind  us. 
Such  pessimism  is  foreign  to  biological  science  and  we  doubt 
its  existence  in  other  lines  of  scientific  effort. 

The  ultimate  goal  of  scientific  endeavor  is  conquest  of 
the  universe,  in  so  far  as  this  is  demanded  by  human  wel- 
fare and  aspiration.  Despite  seeming  pretension,  science  is 
not  vainglorious.  New  and  more  difficult  problems  arise 
from  each  problem  solved.  There  seems  no  immediate  near- 
ing  of  the  goal.  The  Cosmos  we  know  to-day  is  unbeliev- 
ably complex  and  more  is  being  disclosed.  Things  un- 
dreamed of  in  our  philosophy  continually  appear.  Consider, 
for  example,  the  concept  of  a  super-universe,  which  has 
arisen  as  an  outcome  of  recent  astronomical  investigations; 
and  the  Theory  of  Relativity. 

Nature  still  presents  unlimited  problems,  and  the  desire 
for  intellectual  dominion  is  a  guarantee  for  the  continuation 
of  scientific  effort  hi  the  future.  The  biological  discovery  of 
man's  place  in  nature  did  more  than  change  traditional 
beliefs;  it  gave  a  point  of  departure  into  a  future,  unknown 
but  fraught  with  possibilities.  Mankind  has  grasped  the 
idea  of  controlling  nature  through  understanding  of  natural 
law.  And  once  this  lays  firmer  hold  upon  imagination,  there 
will  be  no  satisfying  of  desire  save  by  the  advancement  of 
scientific  knowledge.  The  permanent  future  of  science 
seems  assured,  in  so  far  as  human  inclination  is  concerned. 
Neither  lack  of  incentive  nor  exhaustibility  of  unexplained 
phenomena  will  check  its  progress,  but  rather  the  limitations 
of  human  understanding. 

There  is  no  positive  evidence  for  a  progressive  evolution 
of  human  intelligence  during  the  recent  centuries.  The  race 
is  apparently  at  a  stands! ill  in  thi<  particular,  unless,  indeed, 


316      THE  PRESENT  IMPORTANCE  OF  SCIENCE 

regression  may  not  be  in  progress,  as  a  result  of  recent  ma- 
terial changes  in  civilized  life.  The  absence  of  precise  data 
precludes  extended  discussion,  but  a  permanent  equilib- 
rium would  have  such  momentous  consequences  that  mere 
indications  should  not  be  disregarded.  If  we  can  obtain 
even  suggestive  evidence,  by  comparison  of  the  mental 
product  of  the  present  day  with  that  of  the  past,  or  in  any 
other  manner,  the  facts  are  worthy  of  consideration. 

Comparison  indicates  that  human  mentality  of  to-day 
does  not  differ  appreciably  from  that  which  existed  in  the 
dawn  of  written  history.  Discounting  present  capacity  in 
terms  of  cultural  heritage,  the  wise  and  foolish  seem  to 
have  been  distributed  in  much  the  same  proportions  during 
many  centuries.  If  defectives  were  less  gently  handled  in 
primitive  times,  it  tended  to  raise  the  average.  But  since 
the  progressives  were  as  commonly  repressed,  little  change 
was  effected.  Neither  do  the  physical  features  of  mankind 
offer  conclusive  evidence  of  evolution  during  the  centuries 
in  question.  Resistance  to  certain  diseases  is  probably  an 
instance  of  progressive  modification.  But  this  is  being  nul- 
lified by  the  curative  and  preventive  measures  which  medical 
science  has  recently  placed  at  the  disposal  of  society.1 

The  individuals  who  exhibit  high  mentality  at  the  present 
day  seem,  therefore,  to  possess  no  greater  capacity  than  did 
those  of  earlier  times.  A  modern  boy  may  easily  know  more 
fundamental  facts  of  natural  science  than  did  any  of  the 
Greek  philosophers,  but  there  is  not  one  chance  in  a  million 
that  he  will  become  their  equal.  Modern  men  of  ability 
do  not  seem  superior  to  those  of  antiquity,  hi  view  of  ac- 
complishment under  different  conditions.  As  for  the  aver- 
age intelligence  of  to-day,  the  biologist  challenges  all  claims 
that  inherent  ability  has  changed  perceptibly  during  thou- 
sands of  years. 

The  superiority  of  the  ancient  Greeks  did  not  consist 

1  Reid,  Archdall,  "The  Principles  of  Heredity,"  1896;  Holmes,  S.  J.,  "The 
Trend  of  the  Race,"  1920. 


MANKIND  AND  THE  PROGRESS  OF  SCIENCE    317 

in  the  possession  of  minds  greater  than  any  which  have  ap- 
peared elsewhere,  but  in  the  presence,  within  a  small  popu- 
lation, of  a  greater  proportion  of  able  individuals.  One  com- 
petent critic  declares  that  the  average  ability  among  the 
Athenians  in  the  period  of  their  glory  was  as  far  above  that 
of  Englishmen  at  the  present  time  as  the  average  ability  of 
the  English  is  above  that  of  African  negroes.2  Accurate 
comparison  is,  of  course,  impossible,  but  judged  by  intel- 
lectual accomplishment  the  statement  seems  no  exaggera- 
tion. So  far  as  the  evidence  goes,  the  European  races  have 
not  advanced,  either  in  average  or  in  exceptional  intellec- 
tual capacity,  since  the  days  of  the  Greeks,  perhaps  not  since 
the  decline  of  the  Cro-Magnards.3 

The  biological  significance  of  such  a  conclusion  is  obvious. 
It  creates  a  justification  for  eugenic  propaganda.  For  the 
present  purpose,  we  merely  point  to  the  limitations  that 
may  be  placed  upon  scientific  progress  by  the  absence  of 
minds,  which  exceed  the  capacity  of  any  that  have  preceded 
them,  and  by  a  lowered  average  of  mentality  in  whole  popula- 
tions. There  is  danger  here  for  science  as  well  as  for  society. 
The  advancement  of  science  is  more  likely  to  be  checked  by 
such  limitations  of  the  human  mind  than  by  exhaustion 
of  unsolved  problems. 

Hope  for  an  unlimited  advancement  of  natural  knowledge 

:i  the  biological  possibility  that  the  human  species  has 

not   reached   an  equilibrium  with  respect  to  intellectual 

ability,  even  though  it  may  seem  to  have  been  at  a  standstill 

2  "It  follows  from  all  this  that  the  average  ability  of  the  Athenian  race,  is, 
on  the  lowest  possible  estimate,  very  nearly  two  grades  higher  than  our  own — 
that  is,  about  as  much  as  our  race  is  above  that  of  the  African  Negro."  Galton, 
F.,  "Hereditary  Genius,"  1892  Edn.,  p.  330. 

a  The  Cro-Magnards  were  the  highest  of  the  cave  races  of  Europe.  They 
finally  disappeared  sometime  within  the  past  twenty-five  thousand  years.  In 
skull  capacity  (1800  c.cm.)  some  of  th<»  individuals  discovered  seem  slightly 
to  exceed  the  best  races  of  modern  times.  Although  they  could  not  have 
been  other  than  savages,  when  judged  by  present  standards,  their  physical 
features  and  perhaps  their  inherent  mentality  were  remarkable.  Osborn, 
H  I  ,  "Men  of  UM  <  >M  Stone  Age,"  p.  299. 


318       THE  PRESENT  IMPORTANCE  OF  SCIENCE 

for  some  thousands  of  years.  The  idea  of  a  superman  is 
more  than  a  subject  for  jest  to  those  who  look  into  the  future 
and  who  recall  the  races  of  the  Eurasian  continent  before 
the  appearance  of  Homo  sapiens.  The  advance  of  science 
may,  indeed,  be  checked  by  the  present  level  of  intelligence. 
But  further  evolution  may  remove  this  limitation. 

As  for  the  immediate  possibilities  in  biological  lines,  it  is 
necessary  only  to  trace  the  growth  of  scientific  knowledge 
and  become  familiar  with  current  investigations  to  appreciate 
the  promise  of  the  morrow.  The  nineteenth  century  brought 
revolutionary  advancement  in  the  physico-chemical  field. 
The  twentieth  century  bids  fair  to  witness  similar  progress 
within  the  domain  of  biology.  Not  only  the  medical  aspects 
of  biological  science,  but  its  social  aspects  as  well,  offer  start- 
ling possibilities.  The  results  that  may  eventually  flow 
from  the  eugenic  and  euthenic  principles  already  established 
are  difficult  to  picture.  Biology  seems  to  be  entering  upon  a 
period  in  which  many  of  its  current  problems  may  be  solved. 
Whatever  their  solution  the  results  will  benefit  mankind. 

As  we  have  seen,  control  over  nature  is  merely  acqui- 
escence in  nature's  laws  and  the  ordering  of  human  affairs 
in  such  fashion  that  nature  serves  the  needs  of  man.  The 
winds  and  waves  obey  us,  in  so  far  as  we  effect  adjustments 
whereby  they  accomplish  our  purpose.  In  the  past,  control 
has  been  extended  mainly  within  the  domain  of  inanimate 
nature.  Relatively  little  has  been  accomplished  with  re- 
spect to  vital  phenomena;  but  men  have  caught  the 
vision.  Because  they  have  dreamed  of  a  glorious  near- 
future,  many  of  the  present  generation  wish  they  might  live 
out  the  present  century  and  play  a  part  hi  the  eradication 
of  disease,  the  prolongation  of  human  life,  and  all  the  attain- 
ment which  seems  within  reach.  Just  as  the  existing  mastery 
of  non-living  nature  has  become  possible  through  scientific 
knowledge,  so  must  the  control  of  living  nature  be  accom- 
plished. In  the  long  run,  such  a  result  is  capable  of  bringing 
greater  happiness  than  mankind  has  ever  known. 


MANKIND  AND  THE  PROGRESS  OF  SCIENCE    319 

What  science  intends,  both  for  the  immediate  and  the 
remote  future,  is  to  keep  going.  The  scientist  believes  that 
his  rationalistic  method  offers  a  means  of  moving  forward, 
which  sets  no  limit  and  sees  no  end.  He  is  content  to  main- 
tain the  advance  without  undue  speculation  regarding  im- 
mediate or  ultimate  goals.  There  are  plenty  of  problems 
within  vision,  and  many  opportunities  for  applications  of  the 
facts  now  established.  Most  to  be  feared  is  a  frame  of  mind 
that  discourages  investigation,  for  example,  any  widespread 
conviction  that  certain  classes  of  problems  cannot  be  solved. 
Whether  he  advances  knowledge  or  not,  the  individual 
scientist  is  determined  to  keep  trying;  for  it  is  his  creed  that 
to  try  persistently  will  in  time  produce  worth  while  results. 

The  future  of  mankind  seems  likely  to  be  a  scientific  fu- 
ture. Modern  culture  has  come  into  being  through  science 
and  through  the  control  of  natural  phenomena,  which  is 
bred  of  scientific  knowledge.  The  rationalistic  scientific 
spirit  is  the  spirit  of  the  modern  world.  Any  thinking  man 
can  comprehend  the  relation  of  science  to  human  affairs, 
although  comprehension  may  demand  reversal  in  mental 
orientation.  Science  is  the  product  of  human  reason  applied 
to  the  phenomena  of  nature,  human  nature  included.  Its 
course  has  not  been  run.  The  future  is  bright  with  a  prom- 
ise that  stands  at  the  threshold  of  realization.  Ignoring  of 
science  by  one  generation  bars  the  door  of  progress  and 
the  next  generation  suffers  accordingly.  Understanding  of 
science  is  the  greatest  legacy  we  can  bequeath  to  posterity. 


INDEX 


Abelard,  54 

Academies  of  Science,  89 

Acquired  characteristics,  169,  170 

Adams,  G.  B.,  50,  67,  82 

Adaptation,  171-172 

"Admirable  Doctor,"  the,  62 

Adriatic  sea,  78 

Advertising,  281 

jEgeans,  19,  26,  27 

Agar,  128,  130 

Age  of  Reason,  115 

Agnosticism,  302 

Agobard,  53 

Agricultural  Revolution,  106 

Albertus  Magnus,  60 

Alchemy,  36,  83 

Alexandrian  Library,  35,  56 

Alexandrian  Museum,  see  Museum 

Alfonso,  King,  of  Naples,  82 

Algebra,  57,  58 

Al-Mamun,  56,  57 

American  Museum  of  Natural  His- 
tory, 185 

Amma,  130 

Anatomy,  comparative,  165, 173,  182, 
184 

Andalusian  fowl,  135,  136 

Animalcules,  see  Microorganisms 

Anthrax,  150 

Antipodes,  51-52,  61 

Antisepsis,  152 

Apes,  99 

Applied  science,  107-108 

Arab  Conquest,  55,  56 

Arab  culture,  characterization  of,  58 

Arab  science,  36,  53,  54,  56,  59,  67,  90 

Archimedes,  32,  35 

Aristarchus,  32 

Aristocracy  and  science,  283-289 

Aristotle,  33,  34,  62,  63,  64,  68,  84, 
230,241 

Arithmetic,  23,  24,  27 

Arkwright's  \v;itcr  frame,  105 

Asepsis,  152 

logy,  24,  76,  81 

Astronomy,  24,  57,  62,  64,  72,  83, 
94,96 

Athenians.  28,  317 

<  Theory,  33,  97,  98 


Authority,  4-8, 310;  see  also  Tradition 
Automobile,  62 
Averroes,  58,  64,  76 
Avicenna,  58 
Awareness,  213 

Babylonian  science,  3,  .23 

Bacillus  of  tuberculosis,  152 

Bacon,  Francis,  62,  74,  91,  106,  111, 

112,  230 
Bacon,  Roger,  58,  62-63,  65,  67,  68, 

90,  91,  106,  112 
Bacteria,  85,  247 
Bacteriology,  120 
von  Baer,  K.  E.,  173,  197,  309 
Bagdad,  56 
Baikie,  J.,  26 
Baptism,  51 
Barbarians,  60 
Basil,  47 
Bates,  215 
Bayle,  113,  114 
Behavior  of  Animals,  210-214 
Berbers,  59 

Bestiaries,  see  Physiologi 
Bible,  see  Scriptures 
Biblical  traditions;  see  Scriptures 
Binomial  nomenclature,  98 
Biogenesis,  242,  248 
Biological      science      and      modern 

thought,  10,  73,  84,  95,  119-120, 

149,  217,  318 

Biological  Station,  Fairport,  256 
Biology  and  medicine,  218 
Blanckenhorn,  M.,  13 
Blood  tests  182,  184 
Boccaccio,  77 

Botanical  gardens,  36,  84,  85 
Botany,  84,  217 
Boyle,  72,  83,  97 
Brahe,  Tycho,  72 
Breasted,  J.  H.,  13,  21 
Breeding  of  animals,  87,  257,  259 
Brooks,  W.  K.,  88 
Browne,  C.  A.,  32,  36,  48 
Bruno,  Giordano,  74 
Buckle,  263 
Button,  99,  16&-164,  168,   177,  308, 

309 


322 


INDEX 


Burckhardt,  J.,  53,  54,  87,  297 
Bureau  of  Fisheries,  U.  S.,  255 
Burials,  early  Egyptian,  17 
Burnett,  James,  see  Monboddo 
von  Buttel-Reepen,  H.,  11 

Cairo,  medical  college  of,  57 

Calendar,  18,  23,  62 

Cancer  Laboratory,  Buffalo,  249 

Cards,  dealing  of,  compared  with 
development,  195 

Carlyle,  Thos.,  263 

Carpenter,  W.  B.,  177 

Cartesian  doubt,  112 

Cartwright's  power  loom,  105 

Cams,  J.  V.,  50 

Castelli,  89 

Catastrophism,  174-175 

Catastrophists,  176 

Cattle,  hornless  Egyptian,  19 

Causation,  6,  31,  33,  223,  238 

Cell,  120-122,  233 

Cell-doctrine,  see  Cell-theory 

Cell-lineage,  125 

Cell-theory,  84,  94,  98,  100,  120,  121, 
123,  142-146,  153,  155,  189,  234, 
248 

Celsus,  47 

Cereals,  early  Egyptian,  17 

Chaldean  records,  23 

Chambers,  Robt,,  177 

Charlemagne.  60,  68,  90 

Charlemagne  s  Reformation,  53 

Chemical  combination,  theory  of, 
94,  97 

Chemical  science,  35,  57,  72,  83,  97 

Child,  C.  M.,  200 

China,  11 

Christianity,  42,  44,  45-46,  49,  56 

Chromatin,  122,  127,  196 

Chromosomes,  127,  128,  131,  191, 
203;  and  color  blindness,  207-208; 
and  heredity,  127-134,  142-144, 
207;  and  sex,  205-208;  in  man, 
207 

Church  of  Rome,  60,  110 

Circulation  of  blood,  84,  247 

Circumference  of  earth,  58 

City  beautiful,  80 

Civilization,  analysis  of,  263;  as 
dependent  on  science,  10;  as  af- 
fected by  science,  263;  beginnings 
in  Egypt,  16-22;  continuity  be- 
tween Greek  and  earlier  cultures, 
28 

Classical  language  requirements,  6-7 

Classification,  87,  98,  120,  163,  177, 
182,  240 


Clement  IV.  63 

Climate  and  culture,  21 

Clodd.  E.,  163 

Closed  mind,  the,  301 

Cnossus,  Hill  of,  25 

Coincidences  and  laws  of  science,  239 

Coker,  R.  E.,  256 

Collier,  Price,  303 

Color  blindness,  207-208 

Columbus,  71,  161 

Combustion,  98 

Commerce  and  science,  11,  67,  102- 

104 

Common  sense  and  science,  230-237 
Commonness  in  sense-experience,  227 
Compass,  58 

"Compel  them  to  enter  in,"  114 
Compounds,  chemical,  83,  97 
Compton's  muslin  wheel,  105 
Comte,  263 

Conklin,  E.  G.,  125,  172,  195 
Consciousness,  213 
Conservation  of  Energy.  94,  97 
Conservatism  vs.  spirit  of  science,  272 
Constantinople,  69 
Contagion,  151,  248 
Control  of  nature,    through    science, 

4,  9,  45,  62,  74,  91,  106-109,  111, 

149,  219,  261,  267,  315,  318,  319 
Copernican  Theory,  7,  39,  82,   161, 

186,  298,  309 
Copernicus,  35,  72,  75,  82,  83,  96, 

161,309 
Corot,  79 

Cosmas,  51-53,   158 
Cosmogony,  3,  75,  155-162 
Cosmos,  31-32,  40,  75,  158,  315 
Coster,  Laurens,  74 
Cotton,  23 

Counter  Reformation,  110 
Crete,  25-26 
Cretans,  see  JSgeans 
Critical  spirit,  74,  76-77,  90 
Cro-Magnards,  317 
Crozier,  J.  Beattie,  266,  267 
Crusades,  59,  67,  68 
Ctesibius,  35 
Cultural    level,     as     influenced    by 

science,  268-269 
Cuvier,  172,  173,  175,  309 
Cytology,    202-204;    see    also    Cell, 

and  Cell-theory 
Cytoplasm,  122,  134 

Dallinger,  248 
Dalton,  98 

Dante,  34,  75-76,  297 
Dark  Ages,  42-55 


INDEX 


323 


Darwin,  Chas.,  98,  156,  166,  173,  175- 

181,  186,  217,  211,  214,  272,  309, 

310 

Darwin,  Erasmus,  166 
Darwinian  theory,  168,  173-186 
Darwinism  to-day,  180 
Daubenton,  165,  173 
Day  of  Judgment,  175 
Death  and  old  age,  201-202 
Debate  of  1830,  173 
Deists,  110 
Deluge,  79,  162-163 
Demagogue   vs.   thinker,   272 
Democracy,  30,  283-289 
Democritus.  32,  40,  97 
"De  Naturis  Rerum,"  85,  86 
"De  Rerum  Natura,"  40,   161;  see 

also  Lucretius 
Descartes,  74,  75,  83,  110,  112,  113, 

210,  272 
"Descent   of   Man,"    Darwin,    179; 

see  also  Man's  place  in  Nature 
Determiners,  140,  142,  144,  145 
Determinism,  212 
Development,    123,     125-126,    188- 

202,  192,  195-196 
"  Development  Hypothesis,"  Spencer, 

177 

Devil,  62 

Dias,  Bartholomew,  71 
Dickinson,  G.  Lowes,  30 
Diderot,  Denis,  164-165,  166 
Differentiation  see  Development 
Diminishing  returns,  point  of,  314 
Disease,  20,  100,  149^-153 
Domestication  of  animals  and  plants, 

17,  20,  182,  184 
Dominance,  136-137 
Donation  of  Constantine,  82 
Draper,  J.  W.,  23,  36,  57,  89 
Driesch,  Hans,  211 
Drosophila,  131,  132,  133 
Drysdale,  248 
Duns  Sootus,  64 
r,  Albrecht,  72 


Renaissance,  53 
Ecology^  120,  216 
Economic  development,  74 
Education,  6,  274 
Egypt,   physical   conditions  of,   21; 

see  also  Nile  Valley 
Egyptian  culture  and  science,  3,  11- 

274 

Egyptian  race,  18,  21 
Eight  wnth-cf-ntury  ncinicc.   101 
Moment*,  chemical,  «)7,  B8 
Elephant,  evolution  <>f.  183,  184 


Elixir  of  life,  36,  59 

Emancipation  and  science,  308-313 

Embryology,  comparative,  173,  182, 
184,  186,  188;  see  also  Develop- 
ment 

Empedocles,  32,  33,  160 

Encyclopaedists,  96 

Energy,  97 

English,  intellectual  ability  of,  317 

Environment,  4,  169 

Eoliths,  16 

Epicurean  philosophy,  40 


Epigenesis,  145,  164,  193-197 

Esthetic   appreciation,    295-298 

Ether,  98 

Eugenics,  25^261,  317 

Europeanization  of  world,  103 

Eusebius.  47 

Evans,  Sir  Arthur,  26 

Evolution,  75,  94,  98,  99,  120,  145, 
155-156,  292,  298;  and  philosophy 
311;  and  religion,  310-311;  and 
social  phenomena,  311-312;  and 
theology,  310-311;  causes  of,  167- 
168;  coming  of,  176-179;  con- 
fusion between  fact  and  causes  of, 
168;  cosmic,  96,  155,  156;  evidence 
for,  182;  geologic,  156,  164,  173; 
Greek  speculation  on,  31-33,  159; 
human,  160;  influence  of  the  con- 
cept, 308-319;  influence  upon 
studies  in  animal  behavior,  211; 
of  elephant,  183,  184;  of  horse, 
184,  185;  organic,  94,  98,  99,  120, 
155-156,  161,  163;  present  status, 
186;  theory  and  cell-theory  com- 
pared, 153,  155 

Exclusive  salvation,   305 

Experimentation,  in  Arab  science, 
57;  in  medical  science,  218;  in 
social  sciences,  271;  in  zoology, 
187,  195,  197,  208,  214 

External  world,  225 

Ewing,  J.  A.,  105 

Factors,  see  Determiners 

Factory  system,  104 

Facts  of  science,  5,  7,  223-229 

Fair  judgment  and  science,  298-299 

Families,  98 

Faraell,  L.  R.;  30 

Ferrero,  Guglielmo,  45 

F(>rtili/.:iti<>n,  122,  127,  129,  188-193 

Fire  engine,  35 

Flint  \vorki-i>.  11,  16 

Flood,  see  Deluge 

Floivnc.r,   S7 

I  IMMH  machine,  62,  79 


324 


INDEX 


Flying  shuttle,  105 

Fossils,  78,  79,  159,  161,  174,  175,  176 

Frederick  II,  305 

Freedom,  as  established  by  Renais- 
sance, 92 

French  Revolution,  278 

Fresh-water  mussel,  252-253 

Frog,  development,  124-126;  skin 
gland,  147 

Galen,  5,  39,  84 

Galileo,  35,  72,  82,  83,  96,  101,  309 

Galton.  Francis,  257,  317 

Galton's  analysis  of  heredity  con- 
trasted with  Mendel's,  257-258 

da  Gama,  Vasco,  71 

Gametes,  see  Germ-cells 

Geikie,  Archibald,  176 

Genera,  98 

Genes,  see  Determiners 

Genesis,  157,  292 

Genetics.  202-204 

Genius,  individuals  of,  74,  75,  81,  317 

Genus,  33 

Geo-centric  theory,  82 

Geographical  discoveries,  67;  distri- 
bution, 162-163,  182,  184;  science, 
35,  71.  83,  96 

Geography  and  racial  traits,  61 

Geological  science,  35,  78,  79,  156, 
173,  175^176,  177 

Geologist,  illustration  of,  232 

Gerbert  of  Rheims,  54,  58,  62 

Germ-cells,  126,  140,  203 

Germ  diseases,  246,  248-249 

Germ-theory  of  disease,  101,  149-153 

German  science  and  industry,    108 

von  Gesner.  Conrad,  73,  87 

Gilbert  of  Colchester,  71 

Giovanni  Pico  della  Mirandola,  74. 
81 

Glacial  Period,  11,  12,  13,  16 

Glaser,  O.  C.,  192 

Glochidium,  252;  theory,  254 

Gnosticism,  49 

God,  5.  30,  47,  50,  75,  157 

Goose  barnacles,  61 

Gonzaga,  Francesco,  Duke  of  Man- 
tua, 87 

Government  as  influenced  by  science, 
282-289 

"Grand  Age,"  of  Crete,  26 

Gravitation,  83  96 

Great  God  Business,  279 

Great  War,  306 

Greco-Roman  culture,  continuity 
with  Egyptian  and  Mesopotamian, 
18,22 


Greece,  antecedents  of,  25;  intel- 
lectual failure  of,  31-32 

Greek,  ideal  of  life,  9,  30;  mind  and 
modern  science;  31;  mythology 
as  basis  for  imagination,  293; 
science,  3,  29,  274 

Greeks,  intellectual  superiority  of, 
316-317;  origin,  27;  racial  stock 
of  Athenians,  28 

Grenada,  89 

Grew,  121 

Guizot,  F.,  263 

Gunpowder,  58 

Gutenberg,  74 

Guyer,  M.  F.,  171 

Haldane,  J.  S.,  211 

Hargreave's  spinning  jenny,  105 

Harmony,  spiritual,  of  Greece,  37 

Harris,  D.  F.,  247 

Harvey,  73,  84,  247 

Hawes  C.  H.,  and  H.  B.,  26 

Heated  air  engine,  35,  105 

Hebrew-Chaldean  traditions,  157- 
159,  161 

Hegel,  263 

Hellenes,  see  Greeks 

Hellenistic  Age,  37,  58 

Henslow,  G.,  170 

Herbert,  S.,  170,  184 

Heredity,  181,  195,  219,  256^261; 
and  variation,  as  cell-problems, 
145;  cellular  basis  of  126-145; 
chromosome  theory  of,  127-134, 
142-144;  sex-linked,  208 

Hero  of  Alexandria,  35,  105 

Hertwig,  Oscar,  189 

Heteromorphosis,  198 

Higher  Criticism,  7 

Hindu  science,  56 

Hindus,  57,  58 

Hippocrates.  32,  36,  39 

"Historic  Naturelle,"  Buffon,  165 

Histology,  85,  120 

"Historia   Animalium,"    Gesner,    87 

Hobbes,  74 

Hohenheim,  Philippus  von;  see  "Par- 
acelsus" 

Holmes,  O.  W.,  152,  249 

Homeric  Tales,  27 

Hooke,  121 

Hooker,  the  botanist,  179 

Hornaday,  W.  T.,  215 

Horse,  domestic,  23;  evolution  of, 
184,  185 

Howard,  Sidney,  278 

Human  intelligence,  evolution  of, 
315-317 


INDEX 


325 


Human    progress,    means    to,    266; 

influence  of  the  cultural  level,  266; 

ineffectiveness  of  exhortation,  266 
Humanism,  9,  76,  89,  92 
Humanistic  philosophy,  6,  9,  40 
Humanists,  73,  76-77,  82 
Humbolt,  177 
Hume,  112,  113,  165 
Button,  79,  165,  173,  174,  176 
Huxley.  T.  H.,  112,  210,  230 
Hypatia,  48 

Ice-age;  see  Glacial  Period 

Image  Worship,  46 

Imagination  and  science,  291-295 

Impersonal  thinking,  299 

Implications  of  science,  114^115 

India,  11,  274 

Individual,  expansion  and  elevation 
of,  263 

Individualism  in  society,  287 

Inductive  sciences,  91 

Industrial  Revolution,  95,  104,  107, 
109 

Industrialism   and   science,   278-279 

Industry  in  relation  to  science,  95, 
102-109 

Infidels,  67 

Innovation,  301 

Insects  and  disease,  152 

Intolerance,  109,  302-309 

Introspection,  213 

Intuitions,  227-229,  237 

Invention  and  the  Industrial  Revo- 
lution, 105 

Inventor  vs.  the  scientist,  107-108 

Iron,  23 

Islam,  59 

Italy,  67 

Japan,  274 
Jastrow,  J.,  25 

.  100.  151 

.K-nnings.  H.  S.,  202,  212 
Jesus,  ethical  teachings  of,  45-46 
Jews.  57,  59 
Joachim  of  Flora,  54 
Johnson,  Dr.  Samuel,  165 
Jones,  W.  H.  S.,  45 
Journalism,  280-281 

Kant,  112,  113 

Kay's  flying  Hhuttle,  105 

152 

KflOogg.  V.  L.,  180 
Kent,  W.  Sayville,  247 

2,  75.  83 
Km*,  H    6.,ifc 


Kipling,  R.,  245,  294 

Knowledge,  objective,  229;  of  science, 

223-229,  237;  subjective,  229 
Koch,  152 
Koran,  56 
Kramer,  Gerhard,  "Mercator,"  71 

Lamarck,  166,  167,  168,  172,  173,  309 
Lamarckian  hypothesis,  99,  167-172, 

Lang,  A.,  210 

Lankester,  E.  Ray,  112,  294 

Laplace,  96 

Lavoisier,  98 

Law;  see  Legalistic 

Lawyer  in  government,  287 

Laws,  of  science,  238-240 

Lecky,  W.  E.  H.,  46,  51,  76,  113,  305 

Lecler,  see  Buffon 

Lee,  F.  S.,  149 

Leenwenhoek,  73,  85,  247,  248,  249, 

250,  255 

Lefevre,  George,  202 
Lefevre  and  Curtis,  251,  252,  253,  255 
Legalistic  frame  of  mine,  275-282 
Leibnitz,  74 
Leonardo,  da  Vinci,  74,  77-83,  101, 

112,  161,  243 

Leone  Battista  Alberti,  74,  82 
Leydig,  F.,  255 
Libby,  Walter,  32 
Life,  origin  of,  33,  99 
Lillie,  F.  R..  189.  190,  191,  209 
Linkage  in  heredity,  132-133 
Linnaeus,  98,  163,  167 
Lions,  86 

Lister,  Lord  Joseph,  151 
Locke,  74,  112,  113  ' 
Locy,  W.  A.,  85,  86 
Loeb,  J.,  192,  202,  211 
Logic,  31,  230,  237 
Lombardy,  78 

Lovejoy,  A.  O..  96,  99,  164,  165,  177 
Lubbock,  Sir  John,  211 
Lucretius,  40,  97,  160,  161 
da  Luzzi,  84 
Lyell,  Chas.,  173,  175,  179 

Machine,  earliest  known,  20 

Magellan,  71 

Mahaffy,  J.  P.,  29,  36 

Malaria,  45,  152,  296 

Malpighi,  85,  73,  121 

Mankind,     in    relation    to    science, 

319;  see  also  Control  of  Nature 
Man,   paleolithic.   11;  pliocene,   16; 

pre-ohellean,  16 
Man's  place  in  nature,  10,  99,  156, 


326 


INDEX 


160,  165,  179,  186,  202,  293-294, 

309,  315 

Man's  relation  to  nature,  111 
Mariolatry,  46 
Mast,  S.  6.,  211,  212 
Matarazzo,  87 
Material  foundations  of  society   in 

relation  to  science,  264-269 
Material    progress    in    relation    to 

science,    107-109 
Material  vs.   spiritual   influences  of 

science,  4,  9,  114-115,  290 
Mathematical  science,  58,  72,  83,  84 
Mathematics  and  philosophy,  74 
Matter,  32,  97,  98 
Maupertuis,  164,  165,  166 
McCurdy,  E.,  79 
Mechanistic  conception  of  life,  210- 

213;  conception  of  nature,  112 
Medical  science,  76,  94,  100,  228 
Medicine,  and  biology,  218;  chemical, 

83 
Medieval,    craftsman,    5;   frame  of 

mind,  52,  54,  63-64,  65,  68,  90, 

92?  305;  science,  4,  53-55,  85 
Mediterranean  race,  27,  38 
von  Megenberg,  Conrad,  85,  86 
Mendel.  Gregor,  257,  258,  259 
Mendelian   heredity,    134,    139-145, 

197,  203,  296 

Mendel's  analysis  of  heredity,  con- 
trasted with  Galton's,  257-258 
Mendel's  Law,  203,  204;  rediscovery 

of,  258 

Menageries,  see  Zoological  Gardens 
Mercator,  71 
Meriam,  J.  C.,  11 

Mesopotamia,  physical  conditions,  22 
Mesopotamian,  civilizations,  18,  22, 

274;  peoples,  22 
Metal  implements,  17 
Metcalfe,  M.  M.,  61 
Metchnikoff,  E.,  202 
Method  of  science,  230-238 
Mice,  dominance  of  gray  over  white, 

136 
Microorganisms,  95,  100,   150,  240- 

250,  247 

Microscope,  62,  84,  95,  247 
Microscopy,  84,  88,  247 
Middle  Ages,  42,  49-50,  53,  60,  65, 

67-69,  297;  see  also  Medieval 
Mill,  J.  S.,  230 
Mina,  23 

Minoan  civilization,  25 
Miracles,  110 
Mitchell,  P.  C.,  202 
Mitosis  or  Mitotic  cell  division,  128 


Modern  Scientific  Period,  60,  94 

Mohammedan,  see  Arab,  67 

Molecules  and  atoms,  98 

Monasteries,  55 

Monboddo,  Lord,  James  Burnett,  165 

Monotheism,  30 

Montaigne,  Michel,  74,  113 

Moors,  59,  89 

Moorish  Kingdom,  56 

Morgan,  T.  H.,  133,   186,   196,   199, 

208 

Mosquito-malaria  theory,    152,   296 
Munro,  H.  J.  A.,  40, 161 
Murray,  Robert,  61 
Museum  at  Alexandria,  35-36,  39,  58 
Muslin  wheel,  Compton's,  105 
Mussel,  fresh-water,  250-256 
Mycenae,  26 

National  Research  Council,  244 

Natural  history,  84,  88,  214-217 

Natural  law  vs  super-natural,  110; 
see  also  Superstition 

Natural  resources,  314 

Natural  Selection,  40,  168,  172,  178, 
179,  180,  181,  186 

Naturalism,  91,  110 

Nature,  control  of  by  man;  see  Con- 
trol of  Nature 

"Nature's  Insurgent  Son,"  Lank- 
ester,  294 

Nature-eearcher  and  the  explorer,  245 

Nature  Study,  216 

Near  East,  11,  25,  103 

Nebular  hypothesis,  96 

Negroes,  intellectual  ability  of,  317 

Neo-Weismannism,  197 

Nestorians,  57 

Newcommen's  steam  engine,  105 

Newton,  Isaac,  72,  75,  83.  96.  97,  296 

Nile  Valley,  13-15;  see  also  Egypt 

Nordic  race,  27,  38 

Normative  sciences,  237 

Notation,  see  Numerals 

Nucleus,  122;  vs.  cytoplasm  in 
heredity,  134 

Numerals,  23,  24,  37,  57 

Objective  reality,  224   237 

Observation,  in  Arab  science,  57; 
in  zoology,  187;  see  also  Experi- 
mentation 

Old  age  and  death,  201-202 

Omar,  Khalif,  56 

"Omne  vivum  ex  ovo."  235 

"Omnis  cellula  e  cellula,"   189 

Oosperm,  130 

Open  mind,  the,  299 


INDEX 


327 


Open-mindedness,  270,  302 

Organization  of  germ,  195-197 

Organized  science,  3 

Origen,  48 

"Origin  of  Species,"   98,    166,    173, 

175-180,  186,  310 
Osborn,  H.  F.,  11,  34,  160,  317 
Ovists,  189 
Ovum,  122,  127 

Pacioli,  72 

Packard,  A.  S.,  170 

Paganism  and  Christianity,  45-46 

Paracelsus,  73 

Parasites,  149 

Parasitology,  218 

Parker,  G.  H.,  145 

Parthenogenesis,  190-191,  201,  202 

Pascal,  74,  83 

Pasteur,  150,  151 

Pathology,  120 

Pearl  button  industry.  255 

Pearson,  Karl,  225 

Pergamum,  39 

Persecution,  54,  109,  113,  114,  303, 
305,307 

Perugia,  87 

Peter  of  Apono,  76,  82 

Petrarch,  76r  82,  89,  297 

Philistines,  27 

Phillips,  E.  F.;  190 

Philosopher,  influence  of  the,  113; 
in  relation  to  science,  111 

Philosophers,  159,  166,  167 

Philosopher's  stone,  59 

"  Philosophic :  Zoologique,"  167,  170 

Philosophy  in  relation  to  everyday 
life,  113;  evolution,  311;  religion 
in  Greece,  30-31;  science,  111,  113, 
223;  theology,  74 

Philosophy,  of  scholasticism,  68; 
origin  of  modern,  112;  The  Aris- 
totelian vs.  Platonic,  34 

Phlogiston-theory,  83,  97 

Phonieians,    19,    102 

al  degeneration  of  Romans,  44 
al  science,  72,  83,  84,  91.  •»:. 

<  <>-chemical  .-nuly  <>f  biological 

phenomena.  218 
Physiologi,  50,  76,  85,  87 
Physiological  processes,  cellular  baais 

of,  140-11!) 

Physiology,  84,  182,  183 
Platonic  philosophy,  34 
v,  the  elder,  89,  78 
Plow,  20 
l*o  rivor,  78 


Polarity,  198,  200 

Post-Darwinian  Period,  167,  171 

Postal  system,  23 

Potter's  wheel,  20 

Pottery,  17 

Pound,  23 

Poverty,  298 

Power-driven  machinery,  105 

Power  loom,  Cartwright's,  105 

Practical  inventions,  104 

Practical  needs  in  relation  to  theo- 
retical knowledge;  see  Theory  and 
Practice 

Practical  vs.  theoretical  knowledge, 
104,  106;  see  also  Theory  and 
Practice 

Preformation,  145,  164,  193-197 

Presence-and-absence  theory,   137 

Preyer,  211 

Primitive  ideas  of  Cosmos,  75;  see 
also  Cosmogony 

Prince  Henry,  the  "Navigator,"  71 

Printing,  74 

Probability,  theory  of,  74 

Professional  growth,  301 

Progression,  in  geological  record,  176 

Propaganda,  280-281 

Protective  resemblance,  172 

Protoplasm,  121,  123 

Protozoa.  85,  152,  247,  248 

Protozoology,  218 

Providence,  visitations  of,  100 

Psychology,  280 

Ptolemaic  system,  241 

Ptolemy  of  Alexandria,  35,  39,  82 

"PuchderNatur,"85,  86 

Pure  science,  107-108,  250 

Puritans,  305 

Pyramid  Age,  20 

Quarryman,  illustration  of,  231 

Race  suicide  of  Romans,  44 

Radium.  97 

Rationalism,  65,  74,  75-91,  94,  95, 
110,  111,  114 

Ray.  John,  73,  88 

Reality,  internal  and  external, 
227 

Reality,  scientific,  227 

Recessive.  139 

Red  headed  man  on  horee,  illustra- 
tion of,  239 

Redi,  73,  85,  100,  188 

Reformation,  82,  91,  110 

Rrnrncratinn,  l'.»S-'JOO 

Regulation.  I'.N,  200 


328 


INDEX 


Relativity,  theory  of,  315 

Religion,  and  ev9lution,  310-311; 
and  Philosophy  in  Greece,  30-31 ; 
and  science,  7-8,  24-25,  30,  43- 
49,  310;  natural,  of  Deists,  110; 
past  and  future,  7-8 

Renaissance,  5,  55,  59,  66,  264r- 
308;  and  establishment  of  modern 
science,  66,  82;  cultural  antece- 
dents, 67-69,  70-75;  earlier  and 
later  periods  of?  70,  77;  extent  as 
a  scientific  period,  66;  science  of 
in  contrast  to  modern,  70;  scien- 
tific discoveries  of,  112;  signifi- 
cance for  science,  66,  69,  95; 
summary  of  its  accomplishments, 
90-93 

Research  laboratories,  249 

Revelation,  7,  310 

Revival  of  Learning,  see  Renaissance 

Revolution,  French,  91;  Industrial, 
95;  spiritual  induced  by  science, 
4;  see  also  Science  and  Scientific 
Revolutions,  religious  and  political, 
92 

Rheims,    54 

Riddle.  Oscar,  209 

Rockefeller  Institute,  249 

Roman  culture,  38-39;  notation, 
58;  science,  40,  43-44 

Romanes,  G.  J.,  180,  184,  211 

Romans.  37-38 

Rome,  decline  of,  43-45 

Royal  Society  of  London,  89 

Russian  Revolution,  278 

Sahara,  12 

Salerno,  medical  college  of,  57 

Saltness  of  sea,  79 

Satan,  54,  62,  63 

Savery's  steam  engine,  105 

Schleiden,  121 

Scholastic  vs.  scientific  system,  112, 
113 

Scholasticism,  64-65,  68,  77,  88,  90 

Schoolmen;  see  Scholasticism 

Schools,  among  Arabs,  56;  of  Charle- 
magne, 90 

Schultze,  123 

Schwann,  121,  123 

Science,  as  advanced  by  the  phi- 
losopher, 111;  beginnings  of  mod- 
ern, 32,  82;  broader  influences 
of,  114;  characterizations  of,  3, 
78,  114,  230,  263;  during  Modern 
Period,  4,  9,  101,  109,  115;  impli- 
cations and  extensions  of,  114-115, 
166;  influence  upon  government, 


282-289;  intentions  of,  319;  its 
influence  upon  frame  of  mind, 
312-313;  position  of  modern,  114- 
115;  practical  values  of,  314;  pure 
and  applied,  243-244,  see  also 
Theory  and  Practice;  vs.  scho- 
lasticism, 112,  113;  spirit  of,  vs. 
conservatism,  272;  in  education, 
273-274;  vs.  supernaturalism,  267- 
268;  the  ideal  of,  with  reference 
to  state  of  mind,  301 

Science  in  relation  to,  aristocracy, 
283-289;  advancement  of  civili- 
zation, 263-264;  commerce,  102- 
104;  common  sense,  230-237;  cos- 
mogony, 3.  75,  155-162;  democ- 
racy, 283-289;  emancipation, 
308-313;  esthetic  appreciation, 
295-298;  fair  judgment,  298-299; 
future  of  mankind,  319;  good  citi- 
zenship, 270;  human  reason,  3, 
319;  imagination,  291-295;  in- 
dustrialism, 278-279;  industry, 
102-109;  material  foundations  of 
society,  264;  modern  philosophy 
of  life,  9;  modern  thought,  4; 
persecution,  109;  philosophy,  97, 
111,  113,  223;  religion,  see  Re- 
ligion; social  problems,  298-299; 
social  progress,  269;  superstition, 
74;  toleration,  109 

Scientific,  awakening,  summarized, 
90-91;  certainty,  nature  of,  238- 
239;  facts,  223-229;  frame  of  mind, 
268,  270,  273,  282  ;vs.  the  legalistic, 
275-282;  generalizations,  238-240; 
hypotheses,  illustrated  by  cell- 
theory,  153;  knowledge.  223-229; 
laws,  3,  238-240;  method,  82,  230- 
238,  268;  spirit,  3,  42,  299,  314; 
truth,  240-241 

Scientist,  in  government,  280;  vs. 
the  inventor,  107-108 

Scientists,  their  appreciation  of 
meanings,  166-167 

Scott,  W.  B.,  174,  183,  184 

Scriptures,  5,  8,  7,  47,  51-53,  63,  68, 
309-311 

Secretion,  146-148 

Secularization,  67 

Sedgwick,  W.  T.,  23,  31,  32 

Segregation  in  Mendelian  heredity, 
134-136,  139,  140-144 

Sellars,  R.  W.,  230 

Sense-impressions,  in  relation  to 
reality,  224-227 

Sequence,  in  relation  to  causation, 
240 


INDEX 


329 


Sex,  chromosome,  205;  control,  209; 
determination,  204-210;  in  lower 
organisms,  254 

Sex-linked  heredity,  208 

Ships,  20 

Shull,  A.  F.,  209 

Signatures,  Doctrine  of,  50 

Skepticism,  74,  113,  302-308;  and 
indecision,  302,  304;  and  tolera- 
tion, 303,  304;  and  persecution, 
303;  during  Renaissance,  76-77; 
growth  of,  90;  in  politico-economic 
field,  303 

Skin  gland  of  frog,  147 

Slavery,  45 

Slocum,  S.  E.,  23 

Smallpox,  101,  151 

Smith,  Adam,  165 

Smith,  Elliott,  18 

Smith,  E.  A.,  171 

Smith,  Wm.,  174 

Social,  phenomena  in  light  of  evolu- 
tion, 311-312;  progress  as  in- 
fluenced by  science,  269;  reorgani- 
zation incident  to  Industrial  Revo- 
lution, 106;  sciences,  94,  96 

Soil  exhaustion,  45 

Solutions,  97 

Sorbonne,  163 

Spallanzani,  100,  123,  189,  191 

Sparta,  28 

Species,  88,  98 

Spectacles,  62 

Spencer,  Herbert,  177,  178,  263 

Spermatists,    189 

Spermatozoon,  122,  127,  129,  247 

Spinoza,  74 

Spinning  jenny,  Hargreave's,   105 

Spiritual  values  of  science,  4,  9,  114- 
11"),  290;  see  also  Science  and 
Scientific 

Split-wheat,  22 

Spontaneous  generation,  33,  85,  100, 
123-124,  151,  160,  248,  249 

St.  Ambrose,  46 
!:iirp,  172 

Stahl,  72,  97 

St.  Augustine,  53 

Stahl  72,  97 

Standard  measures,  23 

Steam  engine,  35,  62.  105 

Steam  locomotive,  105 

Steamboat,  105 

Steamship,  62 

Stephen,  Leslie,  111,292 

Stevinus  of  Bruges,  72 

o  development,  192 

!M 


Subjective  reality,  224,  237 

Sumerians,  22 

Superman,  206,  317 

Supernaturalism,  and  naturalism  91, 
110,  267,  312 

Superstition,  40,  75;  see  also  Tradi- 
tion 

Surgery,   151,   152 

Surveying  instruments,  57 

Survival  of  Fittest,  33,  160,  181 

Suspension  bridge,  62 

Swammerdam,  73,  85 

Sylvester  Giraldus,  61 

Symonds,  J.  A.,  53,  77,  92 

Synesius,  48 

Taxonomy,  see  Classification 
Taylor,  H.  O.,  21,  24,  38,  43,  52,  63, 

Telescope,  62 

Temptation  of  Eve,  25 

Theology,     and     religion,     present 

status,   8;   in   light  of  evolution, 

310-311;  in  relation  to  philosophy, 

74;  see  also  Religion 
"Theoria  Generationis,"  164 
Theory  and  practice,  231,  236,  242- 

243,  248-250,  256,  258,  261-262 
Thing-in-itself,  225 
Thinker  vs.  demagogue,  272 
Thomas  Aquinas,  64,  76,  110 
Thomas  of  Cantimpre",  85,  86 
"Thought-fossils,"   159 
Tickner,  F.  W.,  105 
Tiryns,  26 
Toleration,    56,    74,    94,    103,    114, 

303-305,  307 
Toleration  Act,  305 
Torricelli,  89 
Toscanelli,  71 
Towns,  26 
Tradition,    74,    270-275,    280,    282. 

299^302;  see  also  Authority  and 

Scriptures 
Transmutationj  99 
Transmutationists,  162-167 
Trinity,  46 
Truth,     in    science,    240-241;    and 

human  freedom,  308 
Turks,  59 

Tyler,  H.  W.,  23,  31,  32 
Tyndall,  248 

Uhlhorn,  G.,  43,  44,  47 
Unconformity,  176 
rnifonnitarians,  176 

•  haraetere,  140,  197 
I'tmvr-r.  MB  <  'osmoa 


330 


INDEX 


Universities,  35,  55,  68,  88,  89 
Urban  life?  45 
Use  and  disuse,  169 
Utopia,  264 

Vaccination,  101,  151 

Vaccines,  150 

Valla,  82 

Variation,  181;  and  heredity,  as  cell 

problems,  145;  inheritance  of,  164 
Veblen,  T.,  295 
Verwora,  M.,  148 
Vesalius,  73,  84 
Vespucci,  71 
Vested  rights,  278 
"Vestiges  of  Creation,"  177 
da  Vinci,  see  Leonardo 
Virchow,  189 
Vitalism,  211-213 
Voltaire,  113,  114 
Voyages  of  discovery,  39 
"Voyage   of   the   Beagle,"    Darwin, 

173,  178 

Wallace.  A.  R.,  178,  179 
Wallace's  chart,  180-181 
Water  frame,   Arkwright's,    105 
Watson,  J.  A.  S.,  185 
Watt's  steam  engine,  105 
Weaving  industry,  105 
Weismann,  A.,  145,  197 


Wells,  H.  G.,  265,  292 

Western  culture,  controlling  idea  of, 
288 

Whetham,  W.  C.  D.,  and  C.  D.,  23, 
29,  64,  79,  296 

White,  A.  D.,  48,  61,  63,  161 

Whitney,  D.  D.,  209 

William  of  Occam,  64 

Wilson,  E.  B.,  120,  195,  203 

von  Wmiwater,  H.,  207 

Wireless  message,  295 

Wolff,  K.,  164 

"Wonderful  Century,"  20 

Wordsworth,  293. 

Worker,  modern  industrial,  his  out- 
look, 5 

Wright,  J.,  159 

"X  "-chromosome,   see    Sex-chromo- 
some 
Xenophanes,  159 

Zoological,      gardens,      36,      85-87; 

science,    recent   developments    of, 

187 
Zoology,  and  experimentation,   187, 

UK,  197,  208,  214;  and  the  social 

sciences,  219;  in  relation  to  other 

sciences.  217 
"Zoonomia,"  166