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I. Epistemological Theories:

Skepticism: we cannot know anything for certain. If there are absolute truths, we do not have access to them.
Relativism: there are no absolute, certain truths. Knowledge is always a matter of (cultural or individual) perspective.
Rationalism: reason is the primary source of all knowledge, superior to sense evidence. Only reason can distinguish reality from illusion and give meaning to experience.
Empiricism: all knowledge ultimately derives from sense experience, and all meaningful ideas can be traced to sense data.
II. Descartes: a rationalist.
The method of doubt:
“Reason now leads me to think that I should hold back my assent from opinions which are not completely certain and indubitable just as carefully as I do from those which are patently false. So, for the purpose of rejecting all my opinions, it will be enough if I find in each of them at least some reason for doubt. And to do this I will not need to run through them all individually, which would be an endless task. Once the foundations of a building are undermined, anything built on them collapses on its own accord; so I will go straight for the basic principles on which all my former beliefs rested.”
1. What is the goal of doubt for Descartes? (252)
2. What is the actual method? (253)
Which of the following beliefs do you think passes the method of doubt test? How are these beliefs different?
  1. I am in the classroom now
  2. I am having the experience of being in the classroom now.
This gives us a very strict standard for knowledge. Why did Descartes think he needed it? (250)
The Stages of Doubt (253-4)
In the three stages of doubt, Descartes applies his method. In each case, he finds some reason to doubt his belief, so he decides he must withhold his assent to the truth of the belief. See page 253 for the three groups of beliefs that come into doubt.
1. The argument from illusion
Most knowledge seems to come through the senses, but sometimes our senses deceive us.
Three questions:
  1. What lesson can we draw from this?
  2. What is the common-sense reply?
  3. How does it lead to the next stage of doubt?
2. The argument from dreams
Morpheus in The Matrix: “Did you ever have a dream you were so sure was real?” [He means: true.  Of course the dream is ‘real’ in some sense. But it is false in the sense that a dream is an experience caused by something other than what is actually being experienced.]
Three questions:
  1. How does Descartes’ dreaming argument go?
  2. What is his conclusion now? Remember the goal! It’s not total negativity/nihilism
3.     So far, many, but not all, types of beliefs have been called into question. Which types of beliefs are affected and which are not?  Why?
A priori truths: known “prior” to experience. Example: mathematical truths
A posteriori truths: those that rely on experience for verification. Example: elephants are gray.
How does this distinction drive us to the third stage of doubt? (See Lawhead p. 253)
3. The evil genius
Two questions:
1.     What is the point here? Does Descartes “believe in” an evil genius?
2.     What additional beliefs are in question now?
The Cogito Argument (254)

In this use of the method, Descartes finds something that he can discover no reason to doubt, so it must be true
Suppose an evil genius is deceiving me. Then I must exist [to be deceived.]
So, we turn the skeptic’s argument against him:
  1. The skeptic agrees that we’re in doubt.
  2. I am doubting.
  3. Therefore, I must exist.
Use the method of doubt here: try to doubt that you exist. The act of doubting your existence confirms it. So, since doubting is a kind of thinking, “I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind.”
The ‘self’ (you: the seat of your own experience) after this argument:
What am I after the cogito argument? I exist as a thinking thing (a mind.) But a mind is not necessarily the same thing as a brain. I am not yet sure that I am a physical being at all. All I know for certain is my thoughts. This is the problem of solipsism. (255) Solipsism is the view that there is no reality outside one’s own mind. Descartes spends the next three chapters of his book trying to retire this worry. We will pick him up again after he has argued that the external world exists and that he does in fact have a body.
Making a long story short:
Descartes is not a solipsist! He does believe we can know the world outside our own minds, and that he can prove its existence using mathematical proofs as a model. In other words, he thinks that our (correct) beliefs about abstract objects (the self, triangles, God - as a concept) are the most certain. Using these, he 'proves' the existence of the external world (and consequently of our bodies - see p. 259-60. Hume will call his proofs into question.)
Hume: an empiricist, and a skeptic.
1. Classification of mental items according to Descartes, Hume:
Hume reverses Descartes' hierarchy of mental items. To see this, we must understand what he means by an impression and by an idea.
1. What are impressions, for Hume? (336)
2. What are ideas?
Table of Mental Items
Descartes: Privileged [certain]: what I "clearly and distinctly perceive" (abstact ideas)
Confused [doubtable]: sense preceptions
Privileged [good for knowledge]: impressions Less vivid [bad for knowledge]: abstract ideas
Why does Hume think ideas are worse for knowledge than impressions?
2. Two kinds of Inquiry (337-8)
Fill in the table below:
type of inquiry object of knowledge
relations of ideas
matters of fact
3. The Empirical Criterion (339)
How do we use ideas carefully?
Hume attacks the cherished metaphysical ideas of the rationalists:
1. Substance (339) For Descartes, we are the union of two different substances: mind and body. A substance can be thought of as a thing that has properties but is not itself a property. (A rock is hard, gray, solid, angular in shape, etc. But what is this 'thing' that has these properties?)
2. The self: (the knowing subject; 340)
3. Causality (340-42)
What are the three phenomena you experience when you conclude that A caused B?
How does Hume use the empirical criterion to raise skeptical doubts about cause and effect? (341)
How does he respond to the objection that some regularities are just too “regular?”
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