The
next
step
in
the
pursuit of knowledge, then, is to prove that god
does
indeed
exist. Descartes'
starting
point
for
such
a proof is the principle that the cause of any idea
must have at least as much reality as the content of the idea itself.
But since
my idea of god has an absolutely unlimited content, the cause of this
idea must
itself be infinite, and only the truly existing god is that. In other
words, my
idea of god cannot be either adventitious or factitious (since I could
neither
experience god directly nor discover the concept of perfection in
myself), so
it must be innately provided by god. Therefore, god exists.
