It  may  at  first  appear  anomalous,  and  a  breach  of  the  encyclope-
dical arrangement  of  the  sciences,  that  astronomy  and  biology
should  be  thus  immediately  and  eminently  connected,  while  two
other  sciences  lie  between.  But,  indispensable  as  are  physics  and
chemistry,  astronomy  and  biology  are,  by  their  nature,  the  two
principal  branches  of  philosophy.  They,  the  complements  of  each
other,  include  in  their  rational  harmony  the  general  system  of  our
fundamental  conceptions.  The  ^olar  system  and  man  are  the  ex-
treme terms  within  which  our  ideas  will  for  ever  be  included.  The
system  first,  and  then  Man,  according  to  the  positive  course  of  our
speculative  reason :  and  the '  reverse  in  the  active  process :  the
laws  of  the  system  determining  those  of  Man,  and  remaining  un-
affected by  them.  Between  these  two  poles  of  natural  philosophy
the  laws  of  physics  interpose,  as  a  kind  of  complement  of  the
astronomical  laws ;  and  again,  those  of  chemistry,  as  an  immediate
preliminary  of  the  biological.  Such  being  the  rational  and  indis-
soluble constitution  of  these  sciences,  it  becomes  apparent  why  I
insisted  on,  the  subordination  of  the  study  of  Man  to  that  of  the
system,  as  the  primary  philosophical  characteristic  of  positive
biology.
