Is knowing a mental event?

[ACB]

What do you think about the following as a definition of knowledge to avoid the Gettier problem?

Knowledge is JTB, provided that:
No state of affairs that is (a) consistent with the belief and (b) is J or T or B
excludes the possibility of any other such state of affairs.

Applying this to the Smith/Jones example:

0. "The man who will get the job has 10 coins in his pocket" is JTB [I'll admit it's "believed" for the purpose of this argument]

1. "The man who will get the job, Jones, has 10 coins in his pocket" is consistent with (0) and is J and B

2. "The man who will get the job, Smith, has 10 coins in his pocket" is consistent with (0) and is T

(1) excludes (2), and vice versa.

Hence Smith does not know (0).

[Emil]

Originally Posted by paulhanke

... it seems to me that a theory of knowledge based upon JTB has been shown to be inconsistent by Gettier ... that is, Gettier demonstrates that according to the JTB theory of knowledge (0) can be classified both as knowledge and not knowledge ... it is knowledge because applying the JTB criteria to (0) succeeds; and it is not knowledge because applying the JTB criteria to (1) (from which (0) is derived) fails ... the question is with respect to turning a theory of knowledge based upon JTB into a consistent theory ... the ellipses simply reflect the way this stuff pops into my head ...

You have misunderstood the Gettier objections to JTB. They show that the analysis is false, not inconsistent. There is no contradiction with JTB theory AFAIK but it is widely agreed to be false by epistemologists, I'd say. Ken can perhaps confirm this.

---------- Post added 11-22-2009 at 05:33 AM ----------

Originally Posted by ACB

What do you think about the following as a definition of knowledge to avoid the Gettier problem?

Knowledge is JTB, provided that:
No state of affairs that is (a) consistent with the belief and (b) is J or T or B
excludes the possibility of any other such state of affairs.

Applying this to the Smith/Jones example:

0. "The man who will get the job has 10 coins in his pocket" is JTB [I'll admit it's "believed" for the purpose of this argument]

1. "The man who will get the job, Jones, has 10 coins in his pocket" is consistent with (0) and is J and B

2. "The man who will get the job, Smith, has 10 coins in his pocket" is consistent with (0) and is T

(1) excludes (2), and vice versa.

Hence Smith does not know (0).

I don't understand this either. (I'm not drunk or anything tonight.)

[paulhanke]

Originally Posted by Emil

You have misunderstood the Gettier objections to JTB. They show that the analysis is false, not inconsistent. There is no contradiction with JTB theory AFAIK but it is widely agreed to be false by epistemologists, I'd say. Ken can perhaps confirm this.

... ah - if no epistemologists actually buy into the JTB theory, then the point is moot ... so what are the accepted criteria for knowledge these days? ...

EDIT: or maybe I misunderstood and you're just reiterating that "it is widely agreed to be false by epistemologists" that the Gettier analysis is false ... in which case, is it false due to some flaw in Gettier's logic, or false simply because the JTB criteria produce a false positive?

[Zetherin]

Originally Posted by Emil

The moderators are not doing a good job of separating different information threads (i.e. conversations) in a forum thread.

Often times it's not best to separate discussions, especially if a tangential discussion is helping to clarify important points, points which may not be understood without going a tad off-topic. I find this to be especially true in many of these logic and epistemology threads, as not everyone has that the same understanding of formal logic as people like you do. The discussion in this thread, as you can see, has taken many turns, but I don't consider this a bad thing; it seems to be helping most of us here. If you disagree, let me know. And if it's agreed upon that some tangential discussion is intruding, I'll remove or move to another thread.

Thanks for your understanding,

Z

[paulhanke]

Originally Posted by ACB

What do you think about the following as a definition of knowledge to avoid the Gettier problem?

Knowledge is JTB, provided that:
No state of affairs that is (a) consistent with the belief and (b) is J or T or B
excludes the possibility of any other such state of affairs.

Applying this to the Smith/Jones example:

0. "The man who will get the job has 10 coins in his pocket" is JTB [I'll admit it's "believed" for the purpose of this argument]

1. "The man who will get the job, Jones, has 10 coins in his pocket" is consistent with (0) and is J and B

2. "The man who will get the job, Smith, has 10 coins in his pocket" is consistent with (0) and is T

(1) excludes (2), and vice versa.

Hence Smith does not know (0).

... unfortunately, it appears that what we're proposing has been attempted by Dretske (and later revised by Nozick), but the results were unpalatable:

"This is a troubling account however, since it seems the first statement I see a barn can be inferred from I see a red barn, however by Nozick's view the first belief is not knowledge and the second is knowledge." (Gettier problem - Wikipedia, the free encyclopedia)

[Emil]

Originally Posted by paulhanke

... ah - if no epistemologists actually buy into the JTB theory, then the point is moot ... so what are the accepted criteria for knowledge these days? ...

Some epistemologists presumably think that JTB is a true analysis or at least that Gettier's examples are not counter-examples to JTB.

I don't know what the most believed analysis of knowledge is. Perhaps just the analysis sketch of JTB+. Though externalistic accounts seem to be gaining in popularity. (One cause is that they are affiliated with theism.)

EDIT: or maybe I misunderstood and you're just reiterating that "it is widely agreed to be false by epistemologists" that the Gettier analysis is false ... in which case, is it false due to some flaw in Gettier's logic, or false simply because the JTB criteria produce a false positive?

AFAIK there is wide agreement that Gettier disproved the JTB analysis.

---------- Post added 11-22-2009 at 06:46 AM ----------

Originally Posted by Zetherin

Often times it's not best to separate discussions, especially if a tangential discussion is helping to clarify important points, points which may not be understood without going a tad off-topic. I find this to be especially true in many of these logic and epistemology threads, as not everyone has that the same understanding of formal logic as people like you do. The discussion in this thread, as you can see, has taken many turns, but I don't consider this a bad thing; it seems to be helping most of us here. If you disagree, let me know. And if it's agreed upon that some tangential discussion is intruding, I'll remove or move to another thread.

Thanks for your understanding,

Z

I think that is is obvious that many of the things debated in this thread had (close to) nothing to do with whether knowing is a mental event. This discussion of the JTB analysis per se is on the edge, perhaps over the edge.

A benefit of having many threads with topics smaller in scope is that it is easier for new participants to join in. Often people will not join a thread that has more than one page.

Another benefit is that it is easier to single out a single discussion in the thread. Suppose I wanted to link to that discussion in my writings, etc.

I'm always happy ( ) to be told that "not everyone has that the same understanding of formal logic as people like you do". I'm sure Ken is delighted too (and whoever else "people like you" referred to).

[ACB]

OK, I'll revise my wording:

Belief in a proposition X constitutes knowledge if it is a justified true belief, provided that:
No proposition Y that (a) implies X and (b) is justified or true or believed
contradicts any proposition Z that (a) implies X and (b) is justified or true or believed.

Applying this to the Smith/Jones example:

X. "The man who will get the job has 10 coins in his pocket" is a JTB [I'll admit it's "believed" for the purpose of this argument]

Y. "The man who will get the job, Jones, has 10 coins in his pocket" implies X and is J and B

Z. "The man who will get the job, Smith, has 10 coins in his pocket" implies X and is T

Y contradicts Z.

Hence Smith does not know X.

The above argument may need some fine-tuning, but basically what I am saying is that (if it is accepted that he believes X) the detail that Smith specifically believes and is justified (i.e. that Jones will get the job) contradicts the detail that is specifically true (i.e. that Smith will get the job). Such a contradiction should be incorporated as a caveat in any definition of knowledge.

[Emil]

Originally Posted by ACB

OK, I'll revise my wording:

Belief in a proposition X constitutes knowledge if it is a justified true belief, provided that:
No proposition Y that (a) implies X and (b) is justified or true or believed
contradicts any proposition Z that (a) implies X and (b) is justified or true or believed.

Applying this to the Smith/Jones example:

X. "The man who will get the job has 10 coins in his pocket" is a JTB [I'll admit it's "believed" for the purpose of this argument]

Y. "The man who will get the job, Jones, has 10 coins in his pocket" implies X and is J and B

Z. "The man who will get the job, Smith, has 10 coins in his pocket" implies X and is T

Y contradicts Z.

Hence Smith does not know X.

The above argument may need some fine-tuning, but basically what I am saying is that (if it is accepted that he believes X) the detail that Smith specifically believes and is justified (i.e. that Jones will get the job) contradicts the detail that is specifically true (i.e. that Smith will get the job). Such a contradiction should be incorporated as a caveat in any definition of knowledge.

By "contradicts" I take it that you mean "is inconsistent with".

I don't think (Y) is believed by the person in Gettier's example. This doesn't change the end result though.

[paulhanke]

Originally Posted by ACB

OK, I'll revise my wording:

Belief in a proposition X constitutes knowledge if it is a justified true belief, provided that:
No proposition Y that (a) implies X and (b) is justified or true or believed
contradicts any proposition Z that (a) implies X and (b) is justified or true or believed.

Applying this to the Smith/Jones example:

X. "The man who will get the job has 10 coins in his pocket" is a JTB [I'll admit it's "believed" for the purpose of this argument]

Y. "The man who will get the job, Jones, has 10 coins in his pocket" implies X and is J and B

Z. "The man who will get the job, Smith, has 10 coins in his pocket" implies X and is T

Y contradicts Z.

Hence Smith does not know X.

The above argument may need some fine-tuning, but basically what I am saying is that (if it is accepted that he believes X) the detail that Smith specifically believes and is justified (i.e. that Jones will get the job) contradicts the detail that is specifically true (i.e. that Smith will get the job). Such a contradiction should be incorporated as a caveat in any definition of knowledge.

... I think what is needed here is a theory of knowledge that makes it such that if Y is J and B and is the specific source of the more general statement X, then X is knowledge if and only if Y is knowledge ... such a criterion essentially means X is simply shorthand for Y, but perhaps that's the kind of generalization operator a theory of knowledge requires ... and maybe that's just another way of saying what you have said ...

[kennethamy]

Originally Posted by ACB

I will come back to this point, but first I would appreciate your view on a problem I am having about what constitutes knowledge.

Imagine I have a friend who lives in Paris. I believe, with strong justification, that he is currently in Paris (he has told me that he has important business there today). But, unknown to me, he has actually left Paris and gone on a visit to Switzerland. The question is this:

At what point did I cease to know he was in France?

Was it immediately he left Paris? Was it when he was approaching the Swiss border? Or was it not until he actually crossed the border? Would it make any difference if he did not plan to cross the border at all, but only decided to do so at the last moment? And if he then came back to Paris, would I know once more that he was in France (and Paris)? Would it make any difference how long he had stayed in Switzerland, and how long he had been back?

The more I think about it, the more it strikes me that "knowledge" is a vague term.

When he was no longer in France. Obviously. And you ceased to know he was in Paris when he was no longer in Paris. I don't see the problem.