Introduction to Philosophy Lecture 8 Epistemology #1

1. Introduction to PhilosophyLecture 8Epistemology #1 By David Kelsey

2. Epistemology • Epistemology: • the theory of knowledge. • analyzes concepts such as belief, truth, knowledge, justification and opinion. • Some epistemological questions include: • What is knowledge? • Which of my beliefs do I know? • How do I know them?

3. Defining Knowledge • Knowledge: is often contrasted with mere opinion or mere belief. • Beliefs without knowledge: But knowledge is more than just belief for I can have beliefs about all sorts of things without knowing them. • True Belief: so for a belief to count as knowledge the belief must be true.

4. Knowledge and justification • Knowledge: is also more than mere true belief. • Example: • Justified beliefs: to count as knowledge, my true beliefs must be justified. • A held belief is justified: just when one has a reason to hold that belief.

5. Knowledge as JTB • Knowledge as JTB: we might try to define knowledge as justified true belief then. • Thus, S knows that p if and only if: • S believes that p and • P is true and • S’s belief that p is justified • Individually Necessary: Each of these three conditions is necessary for S to know that p. • Jointly sufficient: together the 3 conditions are jointly sufficient for S to know that p.

6. Gettier & Knowledge • Edmund Gettier • Born in 1927 • Philosophy professor at University of Massachusetts Amherst since 1967 • In his article Is Justified True Belief Knowledge? Gettier argues that something’s being justified true belief is not a sufficient condition for it’s being knowledge. • Thus, he argues that one can have a justified true belief and yet not have knowledge. • Gettier provides two counterexamples to prove his point.

7. Smith, the job &10 coins • Smith, the job & 10 coins: Smith believes that • Jones is the man who will get the job and Jones has 10 coins in his pocket. • Smith is justified in this belief: • The company president and counting… • Smith infers: so Smith infers that The man who will get the job has ten coins in his pocket. • He is justified given closure and because he validly inferred it… • Smith gets the job: unbeknownst to Smith, not only will he get the job but he also has 10 coins in his pocket. • So not only is Smith justified in his belief that the man who will get the job has ten coins in his pocket, but this belief is true. • But Smith doesn’t know it…

8. The Ford &Barcelona • Now Smith gains evidence for the proposition: That Jones owns a Ford (‘F’) • Smith remembers and Jones drives up in a Ford… • Brown is where: Smith has another friend named Brown of whose whereabouts Smith is totally ignorant. • Smith then believes: Either Jones owns a Ford or Brown is in Barcelona. (‘H’) • A is Justified: Smith is justified in holding H because: • Smith is justified in holding F • H is entailed by F • Smith makes the proper inference from F to H. • Brown in Barcelona: now imagine that both Jones doesn’t own a Ford and that Brown really does live in Barcelona. • JTB without knowledge…

9. Replies to Gettier • Denying the assumptions: The first way we might reply to Gettier is to deny some of the assumptions he makes. He assumes that: • It is possible for a person to be justified in believing a proposition that is false • Closure: for any proposition P, if S is justified in believing P & • P entails Q & • S deduces Q from P & • S accepts Q as a result of this deduction, then • S is justified in believing Q. • Snowing so Freezing… • The first assumption is uncontroversial really • But maybe we can deny the second assumption…

10. Denying Closure • Denying closure: We could deny Closure by holding an Externalist theory of justification. • Externalism is so called because Externalists are not interested in what’s going on internally, I.e. in your head, when you know something. • Inference doesn’t guarantee justification: the Externalist can deny that the mental state of inferring can justify one’s beliefs.

11. Externalism • Here’s an example of an Externalist theory of justification: • S is justified in believing that P iff P is formed by a reliable belief forming process. • So Justification doesn’t come from inference but reliability…

12. More replies to Gettier • Accepting the counterexamples: We might also reply to Gettier by accepting his counterexamples to the traditional definition of knowledge. • Finding another analysis: In this case we are then out to find a more adequate analysis of KNOWLEDGE. • Infallible evidence:S knows that p iff S believes P, P is true and P is justified for S by infallible or absolutely certain evidence.

13. Other possible definitions of knowledge No false steps: Knowledge is justified true belief where the reasoning your belief is based on doesn’t proceed through any false steps. • A false step: is just some belief you hold in your pattern of reasoning which is false.

14. Last thoughts on defining knowledge • Knowledge is a graded concept: • Conceptual analysis is impossible: This reply is more a reply to being able to define concepts at all. • Some people think that finding adequate definitions for our concepts is near impossible. • Some people go so far as to say conceptual analysis is impossible in and of itself. • Graded: One reply to this kind of worry is to say that concepts have a graded nature. • Knowledge is of a scale…