Epistemology Midterm 1 (chapter 3)

Gettier's two points

1. It is possible for a person to be justified in believing a proposition that is in fact false. 2. For any proposition P, if S is justified in believing P, and P entails Q, and S deduces Q from P and accepts Q as a result of this deduction, then S is justified in believing Q.

Structure of Gettier examples

1. True Evidence -- Smith's extensively good reasons to believe x. 2. False 1st Conclusion -- (x) Nogot ... owns a Ford. 3. True 2nd conclusion -- (y) Someone ... owns a ford. --The final conclusion is true "by coincidence".

The Justified Falsehood Principle (JF)

It is possible for a person to be justified in believing a false proposition. *A person can be justified in believing the odd-numbered propositions even though they are false.

Answer to Q1

Knowledge requires justified true belief that does not essentially depend upon a falsehood.

The No False Grounds Theory (NFG)

A belief may depend upon a falsehood if there is a false proposition among the grounds or reasons for belief. NFG. S knows p = df. 1. S believes p 2. p is true 3. S is justified in believing p 4. All of S's grounds for believing P are true. *Having all true grounds is an additional condition for knowledge, but not a condition for justification. Defenders of NFG agree that the victims of the Gettier examples are justified in their beliefs. This response says that knowledge cannot depend on any false grounds. -- In each example Smith does have false grounds for his final belief. NFG seems to avoid Gettier-style counter examples.

The Grabit Case

Black sees her student Tom Grabit stick a tape in his coat pocket and sneak out of the library. She knows Tom took the tape. Now, imagine that Tom's crime is reported to Tom's mother in her room at the psychiatric hospital. And she replies that Tom didn't do it, that it was his twin brother Tim. And imagine further that he has no twin, that this is just another one of her delusions. Black is ignorant of all this. p: Tom took the tape. D: Tom's mother said that Tom's Twin Tim took the tape, not Tom. 10. Tom's mother said that Tom's twin too the tape. 10 is true even though what the mother said is false. Condition 4 is not necessary for knowledge after all.

Gutter's response to Chisholm and Ayer

Chisholm: S knows that P IFF (i) S accepts P, (ii) S has adequate evidence for P, and (iii) P is true. Ayer: S knows that P IFF (i) P is true, (ii) S is sure that P is true, and (iii) S has the right to be sure that P is true. Both of these fail if "has adequate evidence for" or "has the right to be sure that" is substituted for "is justified in believing that" throughout.

Defeater

D defeats S's justification for p = df. D is a proposition such that, if S were justified in believing D, then S would not be justified in believing p.

Defending TAK

Doubt is usually based on the idea that the person in the example is not justified in believing the final proposition and thus does not really have a justified true belief. This relies on rejecting JF or JD.

Essential dependence

EDF. S know p = df. (i) p is true. (ii) S believes p. (iii) S is justified in believing p. (iv) S's justification for p does not essentially depend on any falsehood. A useful working definition of knowledge with which we can proceed. By adding (iv), EDF makes an important modification to the TAK, while retaining the heart of the traditional view, because it retains the idea that knowledge requires justified true belief. It simply adds another condition.

What idea Feldman prefers

Feldman prefers "no falsehoods" idea. -- (iv) S's justification for p does not essentially depend on a falsehood.

Grounds for belief

G1: The grounds for a belief include just those other beliefs that are explicit steps in the chain of inferences leading to the belief. (narrow account) If clause (iv) of (NFG) makes use of this account of grounds, then Example 3.4 refutes the theory. It is a Gettier case in which explicit steps of reasoning include no falsehood. G2: The grounds for belief include all beliefs that play any role in the formation of the belief, including "background assumptions" and presuppositions. If Clark uses (G2) in explaining clause (iv) of his account of knowledge, then Example 3.4 does not refute it. This is because there is a false background assumption in the example (3). Thus the theory has just the right result here: it says that Smith does not know that someone in his office owns a ford. *There can be knowledge even when some of one's grounds are false.

The Justified Deduction Principle (JD)

If S is justified on believing p, and p entails q, and S deduces q from p and accepts q as a result of this deduction, then S is justified in believing q. *The second proposition is justified because it is deduced from the first.

Rejecting JF

If a proposition is false, then a person must not have good enough reasons for that belief. This implies that Smith is not justified in believing the false proposition (odd #). If he is not justified in believing the false proposition then he is not justified in believing what he deduces from it. His belief in the even # proposition is not justified either. Gettier examples are not JTB. They do not refute TAK. Rejecting JF implies that hardly anyone is ever justified in believing anything.

The Same Evidence Principle (SE)

If in two possible examples there is no difference at all in the evidence a person has concerning some proposition, then either the person is justified in believing the proposition in both cases or the person is not justified in believing the proposition in both cases. If (SE) is true and (JF) is false, then virtually nothing is justified. --That violates our basic assumption that we know things. So this first defense of TAK is no GOOD.

JD and JF

If the three examples are possible and these two principles are true, then the TAK is mistaken. The two principles do seem correct. Thus, it looks like we have a strong case against TAK.

Rejecting JD

If you start with a false belief, as in the Gettier example, and correctly draw a conclusion from it, then the resulting belief is not justified. This view also requires rejecting SE. Rejecting JD is not a good way of defending the TAK from Gettier examples.

Michael Clark's No False Grounds Theory (class)

NFG. S knows that p = df. 1. S believes that p. 2. p is true 3. S is justified in believing p *4. All of S's grounds for believing p are true NFG adds a 4th condition that also has to be satisfied to explain why the person doesn't know in Gettier. 4 is not a condition for justification. This condition is for knowledge. Clark's assumptions a) In all Gettier cases the believer has a false ground. b) There are no instances of knowledge in which the believer has a false ground. *There are reasons to deny both claims. NFG works only if there are no cases of knowledge in which there are falsehoods among the person's grounds.

The No Defeaters Theory (Peter Klein)

S knows that p = df. 1. S believes p 2. p is true 3. S is justified in believing p 4. There is no true proposition t such that, if S were justified in believing t, then S would not be justified in believing p. (No truth defeats S's justification for p). Long: *4. There is no defeater of S's justification for p. (This is a condition on knowledge not justification. ex: That thing I'm looking at is not a sheep. ex: Jones is not the man who will get the job not an ex: Nogot does not own a Ford. -- he would continue to think that someone in the office owns a Ford even if he learned that Nogot does not own one.

The Sheep in the Field

Smith goes for a drive in the country. He looks off in a nearby field and sees what looks exactly like sheep. So he justifiably believes: 5. That animal in the field is a sheep. Smith's son is in the back seat reading a book and not looking at the field. The son asks if there are any sheep in the field they are passing. Smith says "Yes," adding: 6. There is a sheep in the field. Smith is justified by what he sees in thinking that (5) is true. (6) follows from (5), so he is justified in believing (6) as ell. As it turns out, (5) is false. What Smith sees is a sheep dog. But (6) as it happens, is true anyway. Out in the field, out of view, there is a sheep. So, Smith has a justified belief in (6), and it is true. But e does not know it. It is only by luck tat he is right about (6).

The Extra Reasons Case

Smith has two independent sets of reasons for thinking that someone in his office owns a Ford. One set has to do with Nogot. Nogot says he owns a Ford, and so on. As usual, Nogot is merely pretending. But Smith also has equally strong reasons having to do with Havit. And Havit is not pretending. Habit owns a Ford, and Smith knows that he owns a Ford. In this ex, Smith does not know that someone in the office owns a ford. His reasons having to do with Havit are good enough to give him knowledge. Yet his reason having to do with Nogot is false. *You can still have knowledge even if there is some falsehood somewhere in the picture. *Clark's way of fixing the TAK does not work. The mere fact that there is a falsehood among one's reasons for a belief does not show that one lacks knowledge.

The Ten Coins Case

Smith is justified in believing: 1. Jones is the man who will get the job and Jones has ten coins in his pocket. The reason Smith is justified in believing (1) is that he has just seen Jones empty his pockets, carefully count his coins, and then return them to his pocket. Smith also knows that Jones is extremely well qualified for the job and he has heard the boss tell the secretary that Jones has been selected. On the basis (1), Smith correctly deduces and believes another propositions: 2. The man who will get the job has ten coins in his pocket. Smith is justified in believing (2) on the basis of this inference. In spite of Smith's evidence, (1) is not true after all. The boss misspoke when he said that Jones was going to get the job. In fact, the job is going to the company vice president's nephew, Robinson. Coincidentally, Robinson also happens to have ten coins in his pocket. In this example (2) is true even though (1) is false. Smith was justified in believing (1), correctly deduced (2) from (1), and believed it as a result. So, Smith was also justified in believing (2). And (2) is true. So smith's belief in (2) is justified and true. But clearly Smith does not know (2). It is just a coincidence that he is right about (2)

The Radio Case

Smith is sitting in is study with his radio off and Smith knows that it is off. At the time, Classic Hits 101 is playing the great Neil Diamond's great song "Girl, You'll be a Woman Soon." If Smith had the radio on and turned to that station, Smith would hear the song and know that it is on. Smith knows: 8. The radio is off. Conditions (i) - (iii) of the TAK are satisfied. But it does not satisfy (iv). 9. Classic Hits 101 in now playing "Girl, You'll be a Woman Soon." If smith were justified in believing 9, he would not be justified in believing 8. The only way S can know 9 is if his radio is on. Klein's theory implies that Smith does not know p. ND is false because there are too many Defeaters.

The Nogot/Havit Case

Smith knows that Nogot, who works in his office, is driving a Ford, has Ford ownership papers, is generally honest, etc. On this basis he believes: 3. Nogot, who works in Smith's office, owns a Ford. Smith hears on the radio that a local Ford dealership is having a contest. Anyone who works in the same office as a Ford owner is eligible to enter a lottery, the winner receiving a Ford. Smith decides to apply, thinking he eligible. After all, he thinks that (3) is true, so he concludes that: 4. There is someone who works in (my) Smith's office who owns a Ford. (There is at least one Ford owner in Smith's office.) It turns out that Nogot is a Ford faker and (3) is false. However, (4) is true because some other person unknown to Smith, Havit, works in his office and owns a Ford. So Smith has a justified true belief in (4), but he does not know (4). It is just a lucky coincidence, resulting from Havit's having it, that makes him right about (4).

The Alternate Route

Smith notices that Nogot is driving a Ford, has a Ford ownership certificate, and so on. But instead of drawing a conclusion about Nogot, Smith draws the following conclusion: 7. There is someone who works in Smith's office who drives a Ford, has Ford ownership papers, etc. On the basis of (7), Smith draws the same final conclusion as before: 4. There is someone who works in Smith's office who owns a Ford. The difference between the two examples is that in the original version Smith explicitly reasoned through a false step to get to his true conclusion, and in the new version he takes an alternate route to get to the same conclusion. (pg. 31) N. Nogot, who works in Smith's office, drives a Ford, has Ford ownership papers, etc. 7. There is someone who works in Smith's office who drives a Ford, has Ford ownership papers, etc. 4. There is someone who works in Smith's office who owns a Ford. (N) and (4) are still true, but now the middle step, (7), is also true. So in this version, Smith does not reason through a false proposition. Yet Smith still does not know (4). It is still a Gettier case. *Thus, not all Gettier examples rely on a person deriving a truth from a falsehood.

Gettier's response to TAK

TAK: S knows that P IFF (i) P is true, (ii) S believes that P, and (iii) S is justified in believing that P. This is false in that the conditions stated therein do not constitute a sufficient condition for the truth of the proposition s knows that P.

A modest proposal

The Gettier problem remains unsolved. In all Gettier cases there is a false proposition involved that makes it the case that the person lacks knowledge. The justification depends on this falsehood. The key thing in all Gettier cases is that, in some sense, the central belief "essentially depends upon a falsehood."

Gettier Objection

The TAK is insufficient for knowledge. JTB is insufficient for knowledge.