Sept. 12, 2013
Descartes II – Beyond Doubt: the Reconstruction of Knowledge
Descartes’ three stages of doubt: perception (local), dream (general), demon (general
I should suspend all information that I perceive through my sense because they’re
deceived me before, and therefore, are dubitable
Demon = Evil Genius (has God-like powers which he uses to deceive me)
1. Descartes’ proof of the physical world
1. a) Beyond doubt I: Dream skepticism, experiential coherence (end of M6)
1. b) Beyond doubt II: passivity of ideas plus divine benevolence (and again coherence)
o I exist at least as a thinking thing -that’s one belief which can withstand the
inception of the Evil Genius
o This is my Necessary Truth – indubitable starting point
o 2 proofs of God – the very fact that I have an idea of God – the cause of the idea
has to be adequate to what it is – omnibenevolent and must exist to be perfect.
o If I have an idea of perfection, it must exist. That existence is God.
o He’s proved his existence, he’s proved God’s existence, what about my beliefs?
o Passivity of ideas: my ideas are caused by sensations. The only way to avoid
sensation is to block my senses, otherwise I cannot avoid perceiving.
o Divine Benevolence: God would not deceive me – he has given me knowledge to
2. Descartes’ legacy: Foundationalism, rationalism, infallibilism
3. A) Problem 1: tension in application of the standard: certainty is required to restore
trust in general reliability of senses, and b