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Quick Review

A. To build a foundation for scientific knowledge, Descartes wants of rid himself of any beliefs about which he cannot be certain. Hence anything of which he cannot be certain he will reject until he can deduce it from more basic premises of which he is certain.

1. What of beliefs that come through the senses? Sometimes they are wrong (pencil bending in water); but other times they seem so correct (this is a hand in front of my face) I cannot reasonably doubt them.

a. Still, in my dreams things have seemed just as real as this hand in front of my face, but I have been mistaken. So I cannot now be certain that I am dreaming.

1) But cannot I be certain about parts of my dreams -- can't I be certain that the fundamental elements which make up my dreams (color, shape, quantity, etc.) are real?

b. Perhaps, but how can I know that God has not brought it to pass that everything I see, hear, smell, touch, and taste is not really here? I cannot understand why an all-powerful and supremely good being would do this, but neither can I understand why such a Being EVER lets me be deceived.

But I am deceived sometimes...how can this be?

1) NOTE: to those of you who don't believe in God, you're worse off than me...at least for we believers, the possibility exists that God will save us from deception; non-believers don't have such an option.

c. Given that I cannot rule out the possibility that I am deceived about everything, I cannot be certain of anything. So to keep me from reverting to accepting my old beliefs, I shall assume that an evil genius is always deceiving me.

II. O.K. Bouwsma -- "Descartes' Evil Genius"

A. Two Scenarios -- paper world vs. fully illusory world

1. CRITICAL QUESTION: What does it mean to be deceived?

BOUWSMA: A person can only be deceived if it is conceptually possible for her to detect the illusion. ("Conceptually" here means "logically possible").

a. So in the paper world scenario,

"That the paper flowers are illusory is revealed by the recognition that they are paper....What is required, of course, is that he know the difference between flowers and paper, and that when presented with one or the other he can tell the difference." [245]

2. If so, then Descartes' evil genius cannot deceive me in the sense it appears Descartes is suggesting. Where it is impossible by use of our senses to detect an illusion, no illusion exists.

This a tricky point, so here it is again: Bouwsma is claiming that where it is logically impossible for a person to detect an illusion, that person is incapable of being deceived.

a. Hence the evil genius knows he has created an illusion because he has a sense (cerpicio) which allows him to detect the illusion. He is not deceived for this reason. But a human being, however, who lacks this extra sense, is incapable of being deceived by the evil genius's illusion for just this reason. What the evil genius calls a thick illusion of a flower -- something which looks, smells, feels, tastes, and sounds like a flower -- just is (for us) a flower.

Question: "Doesn't this mistake by the evil genius show that he is not a true genius, because he is making such a mistake? And if this is so, then isn't this case of Bouwsma's an unfair representation of Descartes' evil genius hypothesis?"