Epistemology

1. Epistemology

2. Epistemology – Study of Knowledge • How do you know when you know something to be true?

3. Epistemology – Study of Knowledge • How do you know when you know something to be true? • Knowledge as: • Justified • True • Belief

4. Knowledge – justified true belief? • Justification – what makes a belief justified? • Is it your experience? • Is it how reliable the belief is at getting a true claim? • We usually consider justification as an activity; here we will view justification as a property of a belief, just as appearing blue may be a property of your jacket.

5. Knowledge – justified true belief? • Possible sources of evidence for your beliefs: • Perception • Introspection • Reason • Memory

6. Knowledge – justified true belief? • True - false propositions don't count as knowledge • directions example (I thought I knew how to get there…) • Deduction - a type of reasoning, with it you can be as sure of conclusion as you were of what you started with • Deduction is truth preserving (I am home, therefore someone is home)

7. Knowledge – justified true belief? • Belief – a proposition you hold to be true • a priori - before experience • For instance – All bachelors are unmarried. • a posteriori - requires experience • For instance – All bachelors are taxed differently from married men in the US.

8. Knowledge • Foundationalism – our system of knowledge is justified through a pyramid of beliefs.

9. Knowledge • Foundationalism – our system of knowledge is justified through a pyramid of beliefs based on our basic beliefs. • Basic beliefs - beliefs justified in themselves. Those beliefs upon which all other beliefs are based. We build on these to get our other beliefs. • Consider – if your perceptions are basic beliefs that would be how you justify many further beliefs. (i.e. this shirt is blue, that cup is red, etc.)

10. Knowledge • Foundationalism – our system of knowledge is justified through a pyramid of beliefs. • Criticism • Why think these 'basic' beliefs lead us to truth? • Why think such ‘basic’ beliefs exist at all?

11. Knowledge • Coherentism – our knowledge is justified through a web of beliefs, a whole set of beliefs where each relies on others with none as basic.

12. Knowledge • Coherentism – our knowledge is justified through a web of beliefs, a whole set of beliefs where each relies on others with none as basic. • Primary alternative to Foundationalism • No basic beliefs back up your other beliefs. Justification is holistic, the whole system works together to justify each of your beliefs. • Each belief is related in various ways to your other beliefs like the strands of a spider web.

13. Knowledge • Neurath's boat example • you can't step outside of your belief system. • Revisions to your beliefs have to occur within the system of your beliefs.

14. Knowledge • Berkeley (as an example of a coherent set of beliefs) • Idealist (there is no physical substance, only mind) • His work is metaphysics because he is primarily making statements about how the world is, not what we can know about it. • He has a coherent set of beliefs quite different from the way we normally view the world.

15. Knowledge • Coherentism – our knowledge is justified through a web of beliefs, a whole set of beliefs where each relies on others with none as basic. • Criticism • Circular Arguments – assume the truth of what is supposedly being proved. (i.e. begging the question) • The smaller the loop of beliefs, the less informative. • You’re punching a wall. • Someone asks why. • You say you’re angry. • Someone asks why. • You say your hand hurts. (we never learned what we sought) • Can a big enough circle of beliefs possibly make everything okay? • Raft analogy – big enough and it won’t capsize.

16. Knowledge – Criticism of JTB • Gettier examples - cases of justified true beliefs that we would still not count as knowledge. • illustrate a flaw in the account of knowledge as justified true belief. • if we have justified true belief but don't think it's knowledge, the JTB definition is incomplete.

17. Knowledge – Criticism of JTB • Gettier examples - cases of justified true beliefs that we would still not count as knowledge. • Say we agree that beliefs need to be true and justified to count as knowledge – this is not enough. • Gettier's examples show that for knowledge, using justified true belief leaves room for someone to make mistakenly include things which are not knowledge. An important part of this is that we can justifiably believe false things.

18. Knowledge – Gettier examples • At a party you recognize your friend Steve and come to believe: “Steve is drinking champagne.” As it turns out, you see your friend's twin brother Jake drinking ginger ale. It is possible that accidentally you are still correct since your friend Steve is downstairs drinking champagne. • Say I believe falsely (but justifiably) that Shane owns a kayak. On the basis of this I believe: “Either Shane owns a kayak or Shane is in Canada.” It turns out that Shane (unknown to me) is in Canada, but is renting the kayak. This makes my Shane/Kayak/Canada belief is a justified true belief but NOT knowledge, because my belief is accidentally true. • In both of these you have a justified, accidentally true belief that we would hesitate to call knowledge.