Introduction to Philosophy Lecture 8 Epistemology #1 By David Kelsey

Epistemology Epistemology: Some epistemological questions include: 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?

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

Knowledge and justification Knowledge: is also more than mere true belief. The Chargers win: 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.

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.

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.

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 it is true 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…

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. (‘A’) A is Justified: Smith is justified in holding A because: Smith is justified in holding F A is entailed by F Smith makes the proper inference from F to A. Brown in Barcelona: now imagine that both Jones doesn’t own a Ford and that Brown really does live in Barcelona. JTB without knowledge…

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…

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.

Externalism Here’s an example of an Externalist theory of justification: S is justified in believing that P iff S’s belief that P is closely correlated with P’s being true. I’m justified in believing P iff: In most cases in which P is true, I believe P. In most cases in which P is false, I disbelieve P. Lecture example… So Justification doesn’t come from inference but correlation…

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. Infallible evidence: is just really good evidence, which couldn’t be wrong because you were deceived or mistaken for some reason.

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. No Defeaters: Knowledge is justified true belief where there’s no true information “out there” in the world that would defeat your justification for p, were you to learn of it. If you come across a defeater for (some justification of) P, then you didn’t know P.

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 with Gettier cases on the bottom end of it…