Philosophy: Basic Questions; Prof. Boedeker; handout on Descartes #1
Meditation I: Rational doubt
A. Knowledge:
Definition 1 (“knowledge”): I know that p = I know that p is ______true
From Def1, we can conclude:
C1: If p is not certainly true, then I ______know that p.
Def2 (“certain truth”): p is certainly true = there’s no good reason that p might be ______
From Def2, we can conclude:
C2: If there is a good reason that p might be false, then p is ______certainly true.
From C2 and C1, we can conclude:
C3: If there is a good reason that p might be false, then I ______know that p.
B. The method of doubt:C3 gives Descartes a ______for eliminating those of his beliefs that he doesn’t really ______. All he has to do to show that he ______know a class of beliefs is to show that there’s a good reason why those beliefs might be ______. Note that this is a much easier task than showing that these beliefs ______false.
C. Applying the method of doubt to classes of beliefs:
1a. Class of beliefs (1): The exact testimony of the senses, i.e., that things are just as they ______to the senses.
1b. Reason to doubt beliefs (1): I have made perceptual ______in the past, and I don’t know that I’m ______making a similar perceptual error ______.
2a. Class of beliefs (2): The (physical) objects that seem to be given to me through my senses ______(even though they might not be just as they appear).
2b. Reason to doubt beliefs (2): I have been misled to believe in existence of the really non-existent objects of my ______, and I don’t know that I’m not ______now.
3a. Class of beliefs (3): Purely intellectual matters (such as ______) are just as they seem to my mind when I clearly and distinctly perceive the ______involved (thus, for example, not when I’m just being ______).
3b. Reason to doubt beliefs (3): I ______know that my mind and all of my experiences weren’t created by an evil ______(i.e., an omniscient, omnipotent, but malevolent ______). Being evil, this genius might want to deceive me by making intellectual matters that I clearly and distinctly perceive ______true to my mind, whereas they were in fact ______. (Thus, for all I know, 1 + 1 really might ______equal 2.)
Meditation II: Descartes’ first certainty
A. Descartes’ of knowledge also give him a way to recognize what, if anything, he actually ______.
From Def1 and Def2, we can conclude:
C4: I know that p = I know that there’s no good reason that p might be ______
And from C4, we can conclude:
C5: If I know that there’s no good reason that p might be false, then I know that ______.
Thus if Descartes can discover something for which there’s no good reason why it might be ______– i.e., something that can’t be rationally ______– then Descartes knows that it must be ______.
B. So what is this first certainty?
P1 (“principle of the substantiality of thought” = “I think; therefore I am” = “cogito ergo sum”): If I engage in a mental act, then it follows logically that I ______as a thinking mind.
P2: ______that p is engaging in a mental act.
From P2 (substituting “I exist” for “p”) and P1 (substituting “I doubt that I exist” for “I engage in a mental act”), we can conclude:
C6: If I doubt that ______, then it follows logically that I ______as a thinking mind.
P3 (“principle of the transparency of thought”): If I engage in a mental act, then I ______that I engage in that mental act.
From P2 (again substituting “I exist” for “p”) and P3 (substituting “I doubt that I exist” for “I engage in a mental act”), we can conclude:
C7: If I doubt that I exist, then I ______that I doubt that I exist.
P4 (“principle of closure”): If I know that q, then I know everything that follows ______from q.
From P4 (substituting “I doubt that I exist” for “q”), we can conclude:
C8: If I know that I doubt that I exist, then I know everything that follows logically from my doubting that ______.
From C8 and C6, we can conclude:
C9: If I know that I doubt that I exist, then I know that I ______as a thinking mind.
From C7 and C9, we can conclude:
C10: If I doubt that I exist, then I ______that I ______as a thinking mind.
C10 entails that I know that there’s no good reason to ______that I exist as a thinking mind. Thus from C10 and C5, Descartes concludes his first certainty:
C11: I know that I ______as a thinking mind.
Meditation IV: Error
- What is responsible for my errors?
P1: If I’m forced to err, then God – my creator – ______me.
P2: A deceives B only if A is either ______, ______, or ______-______.
P3: God is ______(= omniscient, omnipotent, and [omni]benevolent).
From P2 and P3, we can conclude:
C1: God does not ______me.
From P1 and C1, we can conclude:
C2: I’m not forced to ______.
P4: If person P does action A, but P is not forced to do A, then P does A out of P’s metaphysically ______.
From P4 (substituting “I” for “P” and “err” for “does action A”) and C2, we can conclude:
C3: When I err, I do so out of my metaphysically ______.
Error is thus an ______of our metaphysically free will to make ______judgments – i.e., to judge false ideas to be true.
Thus judgment (=______) is a function of the metaphysically free will.
B. How to avoid errors: the principle of clear and distinct perception:
P5: If there’s any idea that I clearly and distinctly perceive, then I’m ______to judge it to be ______.
From P5, we can conclude:
C4: If there’s any false idea that I clearly and distinctly perceive, then I’m forced to judge a ______idea to be true.
Def1 (“mistake”): I make a mistake = I err = I judge a ______idea to be ______
From Def1, we can conclude:
C5: If I’m forced to judge a false idea to be true, then I’m forced to ______.
From C5 and C2, we can conclude:
C6: I’m ______forced to judge a false idea to be true.
From C4 and C6, we can conclude:
C7: There’s no ______idea that I ______and ______perceive.
From C7, we can conclude the principle of clear and distinct perception:
C8: Every idea that I clearly and distinctly perceive must be ______.
In giving me the ability to judge only those ideas that I clearly and distinctly perceive, God has given me the ability ______to make errors.
I ______my ______when I judge something true that I don’t clearly and distinctly perceive.
This gives Descartes a method for never making an ______:
Never judge an idea ______unless you clearly and distinctly perceive it.
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