120  THE  COGITATA  METAPHYSICA

We  need  not,  therefore,  repeat  them  here.  In  regard
to  this,  however,  and  I  say  it  deliberately,  I  wish  it  to
be  noted  that  Being  is  divided  into  Substance  and
Modes,  not  into  Substance  and  Accidents.  For  Acci-
dent is  nothing  but  a  mode  of  thought  and  exists  only
in  regard  to  this.  For  example,  when  I  say  that  a  tri-
angle is  moved  the  motion  is  not  a  mode  of  the  triangle
but  of  the  body  moved.  Therefore,  in  respect  to  the
triangle  motion  is  only  an  accident  but  in  respect  to
the  body  it  is  real  being  or  mode;  for  motion  cannot
be  conceived  without  a  body  but  it  may  without  a
triangle.
Further,  in  order  that  we  may  the  better  understand
what  has  been  said  and  what  is  to  follow,  we  will
attempt  to  explain  briefly  what  is  meant  by  the  terms
essence,  existence,  idea,  and  power.  We  are  the  more
urged  to  do  this  by  the  ignorance  of  those  who  do  not
recognize  the  distinction  between  essence  and  exist-
ence, or  if  they  do  recognize  it  still  confuse  the  terms
essence  with  the  terms  idea  or  power.  Therefore,  in
order  to  help  them  and  to  make  the  matter  plain  we
attempt  to  explain  this  as  clearly  as  possible.
Chapter  II.
What  should  he  understood  by  the  terms  Essence,
Existence,  Idea  and  Power.
