Unformatted text preview: Knowledge
Internalism and Externalism What is Knowledge? Uncontroversially: Knowledge implies truth I know that it's Monday --> it's Monday What is Knowledge? Uncontroversially: Knowledge implies truth I know that it's Monday --> it's Monday Almost as uncontroversially: Knowledge is a kind of belief I know that it's Monday --> I believe that it's Monday Plato Knowledge = true belief? Plato Knowledge = true belief? But a belief might be true accidentally Examples? Warrant Knowledge = Truth + Belief + __________ Call the property that has to be added to true belief to get knowledge warrant By definition, Knowledge = warranted true belief What is warrant? Knowledge = warranted true belief Belief: Internal--the kind of mental state knowledge is Truth: External--connects that mental state to the world Is warrant internal or external? Internalism Warrant is internal We already know what
Warrant Belief kind of mental state knowledge is So, warrant must be a relation to other mental states Truth Internalism How to distinguish knowledge from other mental states (belief, desire, hope, wonder, doubt, etc.)? I know the Longhorns will win I think the Longhorns will win I want the Longhorns to win I hope the Longhorns win I wonder whether the Longhorns will win I doubt whether the Longhorns will win Internalism Internalism: distinguish knowledge in terms of truth and things inside the mind: the character of the state itself and Its relations to other mental states Externalism Warrant is external We already know that the belief must be true; it matches the world now So, warrant must be a matter of how that belief arose Belief Truth Warrant Externalism To distinguish knowledge from other mental states, We must invoke relations between mental states and the world Knowledge = true belief formed by a reliable process of belief formation Not necessarily transparent to knower Plato's Internalist Definition Knowledge = justified true belief, belief with an account We must be able to give reasons Justified true belief Theaetetus. That is a distinction, Socrates, which I have heard made by some one else, but I had forgotten it. He said that true opinion, combined with reason, was knowledge, but that the opinion which had no reason was out of the sphere of knowledge; and that things of which there is no rational account are not knowable--such was the singular expression which he used--and that things which have a reason or explanation are knowable. Foundationalism You can know something only if you can justify your belief, that is, explain why it must be true Your explanation must rely on other things you know You must have explanations of them in terms of prior things you know Regress stops: there must be a foundation of basic items ("the given") known directly Foundationalism The Given Plato's Dilemma for the Given If knowledge rests on a foundation of basic items, do we know them? If not, how can knowledge rest on the unknown? If so, how can they be justified and yet basic? Plato's Argument If knowledge is justified true belief, it has a foundation justifying everything else Items in the foundation are not justified But they are known-- more directly than anything else So, knowledge is not justified true belief Plato's Argument Knowledge > Justification The given is known But it's not justified The Given Three Options Classical foundationalism: the given justify themselves Direct realism: sensations can justify knowledge without being knowledge Coherentism: knowledge has no foundation; there is no "given," no level of ultimate justifiers Classical Foundationalism The given is self-evident; it justifies itself The Given Direct Realism The given = sensation The Given: Sense Experience Coherentism Knowledge has no foundation Web of belief: Internalist definition Knowledge = justified true belief What is justification? Justification Beliefs may be justified: Inferentially: following from other justified beliefs Intrinsically: selfjustifying, self-evident Direct realism: by sensation Intrinsic justification Are there beliefs that justify themselves? If so, what are they? Self-evident truths? I think I am Everything that thinks exists Self-evident truths? That's black That looks black That looks black to me now I'm being appeared to blackly It seems that I'm being appeared to blackly Self-evident truths? You ought to seek the good You ought to avoid evil Inference A belief can be justified by being inferred from other justified beliefs What is a good inference? What is an argument? Transparency Justification is internal: following from other justified beliefs So, justification is transparent to the knower: if you are justified, you [can] know it Chisholm: "If a person S is internally justified in believing a certain thing, then this may be something he can know just by reflecting upon his own state of mind." KK Thesis KK thesis: if you know, you [can] know that you know I am I know I am I know I know I am I know I know I know I am. . . . Problems with internalism Attacking internalism Knowledge Too narrow Knowledge = justified true belief? Too narrow (necessity): knowledge that isn't justified? Too broad (sufficiency): justified true belief that isn't knowledge? Too broad Justified true belief Too Narrow? Internalism: knowledge = justified true belief Is justification really necessary? Can you know something without being able to justify it? Pop Quiz What's the capital of Malaysia? State the numerical value of to two decimal places. Who invented the cotton gin? In what year did Lee surrender to Grant at Appomattox? Who is Lisa Simpson's teacher? Is Justification Necessary? Can you justify any of those answers? Can you give reasons? So, who needs justification? The Gettier Problem Too broad Justification is NOT enough! We can be Justified Right But right by accident The Gettier Problem Homer and Ned both apply for a job Homer has strong evidence that Ned will get the job Homer also has strong evidence that Ned has 10 coins in his pocket The Gettier Problem Homer concludes And is justified in concluding that The man who will get the job has 10 coins in his pocket The Gettier Problem But in fact Homer will get the job And Homer has 10 coins in his pocket So, Homer is right! But not in the way he thinks The Gettier Problem Homer believes that the man who will get the job has 10 coins in his pocket He's right He justified But does he know? Murderhorn Homer believes he'll plant a flag on the top He has justification (PowerSauce bars) He's right-- but not for the reason he thinks Does he know? A Possible Solution Homer infers the truth from something false (that Ned will get the job; that he'll get there) Inferential justification: following from other justified beliefs Maybe we should say: following from other things known Following only from true information Loss of transparency Then we can't judge justification internally We lose transparency We can't tell when we're justified We can't tell whether we know Too Narrow? Suppose we don't know anything based on not even a bit of false information Won't this exclude much of our knowledge? Fake Barn Country Homer sees what appears to be a barn in the field He infers that there's a barn in the field He's right He has a belief, it's justified, and it's true-- and, everything he bases it on is true and known Fake Barn Country But, unbeknownst to Homer, most barns in this area are fake Does he know that there's a barn? Cardboard Cops Smyrna, TN, and Pflugerville, TX, use cardboard photos of police officers to slow traffic You see an officer holding a radar gun Do you know you see an officer, if there are more cardboard officers than real ones, and you can't tell them apart? Externalism Externalism Replace internal, transparent justification with something external, opaque, linked to the world Knowledge = true belief produced by a reliable process Reliable processes What is a reliable process? It produces mostly true beliefs When used normally, In normal situations Perception Perception is a reliable process We perceive most things accurately When using our sense organs normally In normal situations So, accurate perception --> knowledge Perceptual mistakes We don't perceive everything accurately
Illusions Distorting glasses and mirrors Strange lighting But those cases are anomalous Inference Inference is also a reliable process We draw conclusions accurately When reasoning normally In normal situations So, inference --> knowledge Deductive inference An inference: Premises Conclusion An inference is deductively valid if the truth of the premises guarantees the truth of the conclusion Deductive inference Examples: All men are mortal Socrates is a man Socrates is mortal Aristotle tutored Alexander Aristotle tutored someone Inductive inference An inference is inductively strong if the truth of the premises makes the truth of the conclusion probable Example: All ravens we've observed are black All ravens are black Common sense inference An inference is defeasibly valid if the truth of the premises makes it reasonable to accept the conclusion, in the absence of further information Common sense inference Examples: Birds fly Tweety is a bird Tweety flies Birds fly Penguins don't fly Penguins are birds Tweety is a penguin Tweety doesn't fly Anything else? Perception + inference Everyone agrees these are reliable sources of knowledge But are there others that don't reduce to them? Memory Memory is a reliable process? We generally remember accurately When our memories And the situation are normal Memory --> knowledge Testimony Testimony is a reliable process? What we learn through testimony is mostly accurate From normal witnesses In normal situations Testimony --> knowledge Gettier problem Reasoning with false premises-- that Ned will get the job-- isn't reliable Homer's process of belief formation isn't reliable So, Homer doesn't know Fake barns Perception is generally reliable So, if Homer sees a barn in the field, he knows there's a barn in the field But in Fake Barn Country, that perception is unreliable So, Homer doesn't know Attacking externalism Knowledge Too narrow Knowledge = justified true belief? Too narrow (necessity, false negatives): knowledge that isn't reliably produced? Too broad (sufficiency, Too false positives): reliably broad produced true belief that isn't knowledge? Reliably produced true belief Context How do we select the appropriate context? In this field, barns are real In this county, barns are generally fake In this part of the state, barns are generally real In this state, barns are generally fake. . . . Indian Externalism Two Hindu darshanas, Nyaya (logic) and Vaisesika (particularism), merged around 1000 in the work of Udayana Proponents are Nyayayikas Earliest work: Nyaya-sutra, by Gautama (200) Pramanas Pramana = means (source) of knowledge Perception Inference Analogy Reliable testimony Knowledge is true belief produced by a reliable means of knowledge (pramana) Perception Perception is synthetic, veridical, and definite Sutra 4: Perception is the cognition resulting from sense-object contact [and which is] 'not due to words', 'invariably related' [to the object] and is 'of a definite character'. Analogy We use analogy, especially in knowing language Sutra 6: Comparison is the instrument of the valid knowledge of an object derived through its similarity with another well-known Testimony Sutra 7: Verbal testimony is the communication from a 'trustworthy person'. Bhasya: A trustworthy person is the speaker who has the direct knowledge of an object and is motivated by the desire of communicating the object as directly known by him. Inference Sutra 5: Next [is discussed] inference, which is preceded by it [i.e., by perception], and is of three kinds, namely, inferring the effect (i.e. having the antecedent as the probans), inferring the cause (i.e. having the consequent as the probans) and inferring the rule (i.e. where the general law is ascertained by general observation). Kinds of inference Inferring the effect We know cause (e.g., lightning) We expect effect (e.g., thunder) We know effect (e.g., thunder) We infer the cause (e.g., lightning) We know instances and generalize (e.g., lightning causes thunder) Inferring the cause Inferring the rule ...
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This note was uploaded on 03/19/2008 for the course PHL 301 taught by Professor Bonevac during the Fall '08 term at University of Texas.
- Fall '08