DEPARTMENT OF PHILOSOPHY
University of Toronto at Mississauga
PHL105Y5Y: Introduction to Philosophy Fall 2016
B. D. Katz
Epistemology: Topics for Review
1. Explain what is meant by the term ‘proposition’. How, if at all, do propositions differ from sentences?
2. In light of your explanation of the term ‘proposition’, critically evaluate each of the following claims, giving
examples where appropriate:
a) A proposition is neither true nor false until we have some evidence for or against it.
b) A proposition is neither true nor false until someone is thinking about it.
c) A proposition may be true for one person and not for another—e.g. ‘I frequently have migraine
headaches’ may be true for me but not you.
d) A proposition may be true at one time and not at another—e.g., ‘Currently, Jones is mayor of the city’
may be true at one time but not another.
e) A proposition may be true in one place but not another—e.g. ‘It is raining here’ may be true in one
place but not another.
3. Analyze the meaning of the word ‘true’, or ‘truth’, in each of the following sentences:
a) She is a true friend.
b) He is true to his wife.
c) The character in the film was true to way people of that kind behave in actual life.
d) The true way of solving this problem is . . ..
e) This line is not true plumb.
f) The true meaning of democracy is . . ..
g) It’s the truth that hurts.
4. What, if anything, is wrong with the following definitions of truth:
a) A proposition is true just in case I believe that proposition.
b) A proposition is true just in case most people believe that proposition.
c) A proposition is true just in case there is evidence for that proposition.
d) A proposition is true just in case there is overwhelming evidence for that proposition.
5. Suppose that English had evolved differently so that the numeral ‘five’ was the label not for the sum 2 + 3 but
for the sum 2 + 2. In those circumstances, would the senetnce ‘Five is a prime number’ have been true? In those
circumstances, would it have been a truth of arithmetic that five is a prime number? Explain.
6. Giving examples, explain what is meant by knowledge of method.
7. Giving examples, explain what is meant by knowledge by acquaintance.
8. What does it mean to say that factual (or propositi onal) knowledge is justified, true belief? What are the
reasons for characterizing knowledge in this manner?
9. A man who knows a sheep when he sees one says, ‘The re is a sheep’. It turns out, however, that it is not a
sheep; rather it is dog that looks like a sheep. The man alsosees an object farther away, which he thinks is a dog
but in fact is a sheep that looks like a dog. Thus, the mnoes in fact see a sheep, he believes that he sees a sheep,
and he is justified in believing that he sees a sheep. Butwhat he takes to be a sheep is a dog, while what he takes
to be a dog is a sheep. Does the man know that he sees a sheep? Why, or why not?
10. A person is asked, What is the decimal expansion of pi to four places? He says, “I don’t know”. A few
minutes later he remembers and says, “I do know; it is 3.1416". Did the person know the first time, even when
he said he didn’t?
11. What is meant by the term ‘skepticism’?
12. Suppose that a skeptic says that she does not know she has a hand in front of her. Does she know in spite
of what she claims.
13. Do you require anything other than your presen t experience, plus knowledge of what the words mean, to
know whether the propositions expressed by the following sentences are true?
a. I have a toothache.
b. I ate breakfast this morning.
c. I hope that it rains tomorrow.
d. I think that it will rain tomorrow.
e. It will rain tomorrow.
14. What exactly is Descartes’ method of systematic doubt? What is the purpose of adopting this procedure?
What is Descartes’ criterion for assessing beliefs?
15. Descartes thinks that only propositions that meet the foregoing criterion can be considered knowledge. Do
you agree with this? Do we know things that do not meet this standard? Explain.
26. What is Descartes’s argument for rejecting the prinp clie that sense experience is always reliabl