Descartes 3rd meditation, Proving God
1/23/2008 1:48:00 PM
Principle of Adequate Reality- Something has to be at least as real at the
perception of its reality
 As applied to God, Descartes has a great perception of god, that
god is perfect. And under the Principle of Adequate Reality, God’s
reality has to have AT LEAST as much reality as someone’s
perception of god; if that perception is perfection, then only a
perfect being (god) can exist.
 God MUST be an innate idea, Descartes cannot come up with the
perception of perfection (being he himself imperfect), unless there
is actually a god (the reality of at least that much perception)
o Descartes argues that the Innate idea of god came from god
“stamping us with it (the innate idea of god) like a craftsman”
Principle of Sufficient Reason- something “…cannot begin to exist unless
it is produced b something which contains either formally or eminently
everything to be found in the stone.”-Descartes EVERY CAUSE HAS AN
EFFECT
IE fire is made of  combustion/fuel/oxygen
 There must exist these things for fire to exist, there must by
“physical” reason for something existence (there cant be a
randomly appearing cat, because there is an effect with no cause)
Descartes PSR with parents
 My parents caused me, their parents caused them, however that
regression cannot be infinite, there must have been an original
source, and to Descartes, it was god.
Descartes 4th, Truth and Falsity
1/23/2008 1:48:00 PM
Descartes observes that if there is an omnipotent, perfect god, then he, the
creation of that god, must also be unable to error. This logic must be flawed
when Descartes make mistakes. A benevolent god would not intentionally
install a judgment method that would lead Descartes astray.
So…
Adequate Reality god must exist  if perfect god exists, I am
infallible and my judgment and perception should also be infallible If
my ideas are infallible then god exists because I believe it god must
exist…
…this is called the CARTESIAN CIRCLE
Descartes attempts to relieve himself from this circle by arguing that the
proof of god is simply a method by which to trust intuition, and the “proof”
need not to be revisited every time a “clear and distinct” perception
(intuition) presents itself.
Error by humans are caused by the free will that leads us to mistakes.
 Will> Judgment, that allows us to judge things we don’t “clearly and
distinctly understand”
o Why didn’t god fix that loophole and make us perfect

Because perhaps to create perfection in the universe,
we must be capable of mistakes.