Descartes's Meditations III and IV

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Meditation III
Summary of the Argument for the existence of God

1. For any effect, there must be as much reality (positive properties) in the cause as there are in that effect
2. Ideas may fail to correspond to something outside of me, but their cause must contain as much reality as the thing they are ideas of
3. I have an idea of God as the most real thing
4. The source of this idea of God must be at least as real as God
5. The thing at least as real as the most real thing is the most real thing
6. God is the cause of my idea of God
7. God exists

Meditation IV

• Descartes feels he has shown
  • I am a thinking thing, which is without extension, and this is more clear and distinct than my body ("In fact the idea I clearly have of the human mind -- insofar as it is a thinking hting, not extended in length, breadth or depth, and having nothing else from the body -- is far more distinct than the idea of any corporeal thing.")
  • God exists
• Why is there error?
• Error is judgment that is incorrect
• God would not deceive, so the world does not appear falsely
• God would not make something imperfect, so why is my judgment imperfect?
• Two caveats
  1. I may not understand what God is up to
  2. The whole may be perfect but parts may appear imperfect
• Error is in judgments, and judgments are the product of intellect and of will
• Through the intellect I perceive ideas
• Through the will I (among other things) assert that a perceived idea corresponds with something in the world
• God gave me a limited intellect: I can conceptualize God's perfect intellect, and see my is far inferior. (But: God is not imperfect for having given me a limited intellect.)
• My will is as great as God's, because the will is just the faculty of choosing to do or not do something. Will cannot be divided, it is a simple, so God made no mistake in giving me a will like God's own
• There is no error in my capability of intellect, and no error in my capability of will, but when I apply will to the intellect, I may make mistakes: I do always not "contain the will"
• If I judged only matters that were clear and distinct, I would be always right, but I sometimes will to judge matters that are not clear and distinct
• Even if my own intellect is very limited, I can at least avoid error by not willing to assert anything not clear and distinct

Implications of Meditation IV for the philosophy of mind

• The separation of mind and body are augmented by the notion of judgment and will
  • Judgment sits back from the world and decides
  • Will is absolute -- the body and world are wholly separate from all decision making except that they send to the mind and will messages
  • The body and its skills are nowhere part of the story of understanding and other mental capabilities
• The doctrine of error and of using clear and distinct as a standard cohere well with the preeminence that Descartes gives to introspection.