1. Results from Meditation 2
I exist
I am a thinking thing
the mind can be understood independently of the body
The mind is better and more easily understood than anything physical
I can know the content of my mind (my ideas, my conscious states).

2. Ideas
One important result from Meditation 2 is that I can know my ideas.
Ideas are mental states that represent something, they are about something other than themselves (like a picture)
Descartes does not know if the ideas represent things truly, but he knows he has them, and knows what they are about.

3. What is the cause of our ideas?
Three possibilities:
External cause (tree)
Self-caused (unicorn)
Innate (truth)
Descartes does not yet know which of these possibilities is true, but he thinks that ideas need some kind of cause or explanation

4. Can we prove God exists?
It’s important to prove God’s existence, because once we have God, we don’t have to worry about the evil deceiver.
Descartes will use a non-deceiving God to reply to the skeptical arguments of Meditation I
But you can’t use God, until you prove God exists.

5. Principles about causation
Everything must have a cause
The cause must have as much reality as the effect
The cause of an idea must have as much formal reality as is found objectively in the idea.
Descartes needs this last claim to prove God’s existence

6. Formal and objective reality
Formal reality is just reality
But objective reality refers only to ideas.
An ideas objective reality is what the idea is about, what it represents.
If we think of an idea as like a picture, the formal reality of an idea is what is pictured, represented by it.

7. Descartes thinks that if you have an idea, the cause of the idea must be as “real” as whatever the idea represents.
IF this is true, and if I have an idea of God, then I can prove that God must exist.
How?

8. The first proof for God’s existence
I have an idea of God (an infinite, perfect being.
The cause of an idea must have as much formal reality as objectively contained in the idea
Only God has as much formal reality as is contained (represented by) the idea of God
Therefore God exists.

9. Is the argument any good?
Is it true that the only way you can get the idea of God is from God. What other ways might one construct an idea of God?

10. The proof is even worse given Descartes high standards
Remember Descartes says that he will only accept beliefs that are so certain that even an extremely powerful demon cannot deceive him
But if a demon can deceive him about 3+5=7, then that demon can surely also deceive him about “the cause must have as much formal reality as is objectively in the idea”

11. The Cartesian Circle
After proving God exists, Descartes can say God is not a deceiver, God created me, so I can trust my cognitive faculties, at least those idea that I “clearly and distinctly perceive”
But he can’t use this principle to justify the premises of the God argument. He needs God to prove God. But this is a circle.

12. Another argument for God
I exist
I require a cause
Therefore God exists
???????
What is going on here?

13. Causation is not so simple
“For because the entire span of one’s life can be divided into countless parts, each one wholly independent of the rest, it does not follow from the fact that I existed a short time ago that I must exist now, unless some cause, as it were, creates me all over again at this moment, that is to say, which preserves me” (p.78)

14. Time and Causation
Descartes thinks each moment of time is separate from every other moment. Because they are separate, they cannot causally interact.
In order to cause my existence, the cause must be here, with me to cause me to exist. IF its in the past it does not exist, and cannot create me

15. So we need a cause that can be co-present with the effect.
God is outside of time, a divine projectionist creating the world over and over again at each instant.

16. How God helps with skepticism
if God is a perfect being, then God is not a deceiver (deception is an imperfection)
2. If God created me so that I am systematically deceived, God would be a deceiver
3. According to (1) this is impossible. So I can trust my senses, my rational insight.