Well Vogel seems to think that there's a difference between Al's and Betty's epistemic circumstances. From what I can gather Al is more confident than Betty with regard to the current location of their car.

We're being put in a situation where we are told that we KNOW. Here is the truth, period. This is the way it is and now you KNOW it. We're not in that situation. Yes, sometimes we know more than others, but there is always room for possible error. So, we use the word know and this word can be very effective, distinguishing situations where there is a better chance our belief is incorrect. It's not a hard and fast category but one we place things in that we have very good reasons for believing. If we were friends with these people, we would think - before finding out otherwise - that they knew. Yes, what we consider knowledge may not be correct. But it's a pretty effective category for many people. So, on the ground, as a person in the world of those scenarios, I wouldn't consider having said one or both of them knew where there car was as some big error should it turn out that the car is not there. Because when I say 'know' it doesn't mean 'cannot possibly be revised stuff'.

A distinction should be made between what we know, based on what we are told, and what Al knows or doesn't know. What he does not know is if his car has been stolen. If by knowledge we mean infallibility, then he does not know where his car is. But knowledge about the world is never infallible. What we hold to as something known can change over time.

Why frame Betty's case in a parallel universe? There is nothing here that precludes it happening in the same universe or even same parking lot as in Al's case. Betty knows no more or less than Al does until she discovers that her car is missing.

1. Yes.
2. No.
3. No.
4. No.
5. K = JTB.
1. Al's memory Justifies his Belief as to the location of his car, and his belief is True.
2. Al has no Justification for Believing his car to have been stolen, only for considering it possible.
3. Betty has a Justified Belief, that turns out to be Not True.


The situation would change if the crime rate was so high that it was reasonable to expect that one's car would be stolen, in which case one would presumably take extra precautions, or expect trouble.

Lets try another tact. Do the people deductively know where their car is at that moment, or are they making an induction?

The only thing they could know is, "I left my car at X spot." Do they deductively know their car is there still when they walk away? Of course not. Its an induction. An induction based on logic, reason, and memory, but an induction none-the less.

You're just bringing up the old justified true belief balderdash without calling it that. Pretty soon you'll get to the Gettier problem. JTB is the appendix of the philosophical world. Appendix as in that small, useless organ that is attached to our intestines. It keeps hanging around for no particular purpose and just pops up every now to cause trouble.

Having said that, I won't interrupt your thread anymore.

Al knows where he parked his car. He doesn't know whether it was stolen.

JTB is the appendix of the philosophical world. Appendix as in that small, useless organ that is attached to our intestines. It keeps hanging around for no particular purpose and just pops up every now to cause trouble. — T Clark

Not at all. It's very intuitive and would probably only be denied by certain externalists who believe knowledge reduces to behavior.

What this high-lights is that we rely on a whole heap of assumptions in deciding what is true, or may be true, or isn’t true. But when we are reminded of them, we pause and question them and this can change our minds. Gathering evidence for all of them is impractical, so it is hard to see that this can be avoided. One might draw two conclusions from this.

1. There is an element of luck in all our knowledge claims, which makes it more difficult to distinguish lucky guesses, which most people would classify as not knowledge, from knowledge. To be honest, I’m not sure what to say about this.

2. Knowledge can be fallible. Or rather, it is obvious that knowledge claims are fallible. The question is whether a knowledge claim that fails because it is wrong is still to be classified as knowledge or whether it should be re-classified as belief, (until and unless an infallible, conclusive claim is established). It may be that this is just a linguistic question and doesn’t really matter. But if one accepts that knowledge (as opposed to a claim to knowledge) is fallible, I don’t see what distinguishes it from belief, so I’m inclined to the latter option.

This case is is too simple to do more than start considering the problem. We should consider a variety of cases. For example, consider another risk that Al has not taken into account, that his car may be smashed by a falling meteorite. Does that mean he doesn’t know about his car? Again, suppose Al’s car has a sun-roof. Rain is not certain, but has been forecast. Does Al know his car is safe?

Each of these cases is different. Do the differences make any difference? I’m not sure, but we should consider whether the question “Does s/he know?” is appropriate in the sense that it can really be answered.

Vogel seems to think that there's a difference between Al's and Betty's epistemic circumstances. — Agent Smith

The problem is set by the similarity between the two, which suggests that their epistemic classification should be the same, and the difference in their circumstances (i.e. the fact that Betty’s car has been stolen), which strongly suggests that it is different. So the fact that Betty’s car has been stolen makes me classify her as believing and rather than knowing. Conclusion – knowledge is not just about the psychological state of the knower. Hence, for example, how confident they each are is irrelevant.

So, on the ground, as a person in the world of those scenarios, I wouldn't consider having said one or both of them knew where there car was as some big error should it turn out that the car is not there. Because when I say 'know' it doesn't mean 'cannot possibly be revised stuff'. — Bylaw

It is certainly true that philosophers often get very dogmatic, especially about knowledge. I deduce that you would say that both of them know, except that Al’s knowledge is correct (so far) and Betty’s knowledge is not correct and hence should be revised. I think that does reflect how we actually use the word. When she finds out her car has been stolen, she will know that. Would that be a fair summary?

May I ask what would you say to this possible outcome? Her car is stolen but only for a joy ride, and the thief, being cautious, took the trouble to return her car to its place and managed to do so before she came back to retrieve it. So she never knew her car was stolen and believed it had been safely parked all the time.

But knowledge about the world is never infallible. What we hold to as something known can change over time. — Fooloso4

You’re right. The parallel universe is a bit over the top. I based this on Jennifer Nagel’s version of it (I couldn’t find the original). You’re also right that we only know what the example chooses to tell us, and that is usually very limited, which can be frustrating.

Surely, we can sometimes be conclusively right. For example, one could say that Al and Betty both have fallible knowledge. But then, when they get back to the cars and drive back home, they will know conclusively, won’t they?

The situation would change if the crime rate was so high that it was reasonable to expect that one's car would be stolen, in which case one would presumably take extra precautions, or expect trouble. — unenlightened

The situation would change if the crime rate was so high that it was reasonable to expect that one's car would be stolen, in which case one would presumably take extra precautions, or expect trouble.
Your point that Al has no justification for believing that his car has been stolen is a good one. Until she discovers that her car has been stolen, the same is true of Betty, of course. That’s a key problem, of course. Justification can be less than conclusive.

An induction based on logic, reason, and memory, but an induction none-the less. — Philosophim

Quite right. I’m not sure whether you think that induction can never result in knowledge because it is always uncertain or not. Certainly, in this case, it is an induction that can be replaced by certainty – when they get back. Though actually, I would say that unless one embraces full-blown scepticism, induction can also justify certainty. What is less clear is when we reach that point. I suspect that philosophers would be much less optimistic than everyday people.

Pretty soon you'll get to the Gettier problem. — T Clark

That's unlikely. I've been there and done that. But epistemology is perhaps in an impoverished state because all the big questions have been spun off into distinct philosophical fields. If you're not interested, that's fair enough.



I have to say, the only alternative to the JTB that I've come across is the "knowledge first" idea. That might have something so recommend it, but I haven't caught up with it yet.

The problem is set by the similarity between the two, which suggests that their epistemic classification should be the same, and the difference in their circumstances (i.e. the fact that Betty’s car has been stolen), which strongly suggests that it is different. So the fact that Betty’s car has been stolen makes me classify her as believing and rather than knowing. Conclusion – knowledge is not just about the psychological state of the knower. Hence, for example, how confident they each are is irrelevant. — Ludwig V

Then I don't understand Vogel. Full steam ahead!

I have to say, the only alternative to the JTB that I've come across is the "knowledge first" idea. That might have something so recommend it, but I haven't caught up with it yet. — Ludwig V

JTB is knowledge internalism, which asserts that in order to count as having knowledge, a subject must have access to some justification.

Knowledge externalism just denies that.

Quite right. I’m not sure whether you think that induction can never result in knowledge because it is always uncertain or not. — Ludwig V

No, induction can never result in knowledge. However, certain inductions could be considered more reasonable or cogent than others. That is the problem of induction. What standard can we used to determine which types of inductions are more reasonable to hold than others? You mentioned you might take a look at my paper; I cover that there.

Your point that Al has no justification for believing that his car has been stolen is a good one. Until she discovers that her car has been stolen, the same is true of Betty, of course. That’s a key problem, of course. Justification can be less than conclusive. — Ludwig V

Of course it can. we are fallible. I always keep my keys in my right pocket so I always know where they are, unless I forgot to empty the pockets when I changed my trousers. In that case, I discover that I did not know where my keys were after all. Or unless there was a hole in my pocket, or someone has stolen them, or they have been dissolved by the alien key dissolving ray, or God has done a miracle, or I hallucinated having keys, or...

But meanwhile, I know where my keys are. Knowledge is provisional and fallible - if the car isn't there when Betty gets back she cannot have known it was there, but she thought she did until she learned better. This is only problematic for the pope, who is supposed to be infallible. You're not the pope, are you?

So the paradox is that one's intuition is to say Al knows where his car is, but not that it has not been stolen... an apparent contradiction. If the car has been stolen then Al does not know it's location.

Seems to me that there is a play on two senses of "know" going on here. In (1) Al knows where his car is, since he has a justified true belief, and that is the sense in which "know" is being used. But in (2), "know" is being used in the place of "is certain that...", and not in the sense of "has a justified true belief that...".

Al has a justified, true belief that his car is in Ally A; but he cannot be certain that it is in Ally A.

The paradox is that Al has a justified true belief as to were his car is, but is not certain of it. So what is interesting here, and much more fun than Gettier, , is that the argument shows a difference between knowing and being certain.

And Betty, who just as easily might have been in the very same city as Al (no need for parallel universes here), can feel certain of where her car is, but is mistaken, and hence does not know where it is.

Make sure my name is on the paper when it's published.

Seems to me that there is a play on two senses of "know" going on here — Banno

And the distinction between "knowing" and the feeling of knowing. When I follow the proof of a theorem I know the theorem is true according to the rules of the game, and I have a feeling of knowing. But when I park my car out of sight I only feel that I know where it is. So it is conditional knowledge. Most of life is lived in a complex of probabilities.

But then I have the feeling of knowing what I have written is of no consequence in this forum. :roll:

1. Someone (call him Al) has parked his car on Avenue A (out of sight now) half an hour ago. Everything is normal, the car is still there, Al has a good memory. Does he know where his car is?

2. Every day, a certain percentage of cars gets stolen. Does Al know, right now, that his car has not been stolen and driven away since he parked it?

3. Meanwhile, in a parallel universe with a similar crime rate, Betty has parked her car on Avenue B half an hour ago. Betty is cognitively very similar to Al (just as good a memory, just as much confidence about the location of her car). Her car, unfortunately, was stolen and driven away. Does Betty, who believes that her car is on Avenue B where she parked it, know that her car is on Avenue B?

4. Having answered all three questions, would you like to revise your answer to any of them?

5. Why? — Ludwig V

Al knows where he parked his car. That's it. You might say he knows there is a better chance that it is still there than not, given the statistical likelihood of having your car stolen (I have never had a car stolen in over 50 years of driving). I think this points to the inadequacy of JTB, because, according to ordinary criteria of belief justification, it seems that Al is justified in believing his car is where he parked, and if the car is there then on that basis we would say that he knows that it is there. But if it is not there then he would not be said to know it was there. This seems too arbitrary to justify switching from saying there is knowledge to saying there is not knowledge.

I would not revise my answer because the way I see it we only know that which we can be certain of (not feel certain of, mind, which is not the same). I only know my car is there when I see it there. The old chestnut, "seeing is believing" should be "seeing is knowing".

And the distinction between "knowing" and the feeling of knowing. When I follow the proof of a theorem I know the theorem is true according to the rules of the game, and I have a feeling of knowing. But when I park my car out of sight I only feel that I know where it is. So it is conditional knowledge. Most of life is lived in a complex of probabilities.

But then I have the feeling of knowing what I have written is of no consequence in this forum — jgill

For me what you said does have consequence. You are equating knowledge with certainty, and drawing a distinction between being certain and merely feeling certain, and that is exactly the point I have made. But I know what you mean: it won't be of any consequence to the JTB dogmatists. :wink:

1. Someone (call him Al) has parked his car on Avenue A (out of sight now) half an hour ago. Everything is normal, the car is still there, Al has a good memory. Does he know where his car is? — Ludwig V

A posteriori, he does, but not as a necessary fact.

This problem was devised by Jonathan Vogel.

1. Someone (call him Al) has parked his car on Avenue A (out of sight now) half an hour ago. Everything is normal, the car is still there, Al has a good memory. Does he know where his car is?

2. Every day, a certain percentage of cars gets stolen. Does Al know, right now, that his car has not been stolen and driven away since he parked it?

3. Meanwhile, in a parallel universe with a similar crime rate, Betty has parked her car on Avenue B half an hour ago. Betty is cognitively very similar to Al (just as good a memory, just as much confidence about the location of her car). Her car, unfortunately, was stolen and driven away. Does Betty, who believes that her car is on Avenue B where she parked it, know that her car is on Avenue B?

4. Having answered all three questions, would you like to revise your answer to any of them?

5. Why? — Ludwig V

1. Yes, Al believes his car is where it is.
2. If he believes it has not been stolen, and it has not been stolen, then yes, he knows it has not been stolen.
3. No, because her belief is not true.
4. No
5. There is no issue I see.

I second what and both say as well.

A posteriori, he does, but not as a necessary fact. — Wayfarer

It is a curious consequence of JTB knowledge that one may be certain, but one never knows that one knows - one always knows absolutely of the hypothetical Al's and Betty's whether they know or not, because the truth is stipulated in the hypothesis, but one's own knowledge or another's in real life... Philosophers put themselves in the position of the conjuror revealing where the queen really is after taking the sap's money. It's probably over-compensating for their own gullibility. :wink:

As Hume described, there is no reason to expect, never mind know, that the future will be like the past, except the desperation that one has nothing whatsoever else to go on.

Lets try another tact — Philosophim

'Tack' is the expression. From what yachts do when they need to change course. (Sorry for being pedantic. I suppose it wasn't very tackful :-)

I tried googling Vogel's paradox. Null result. :chin:

I tried googling Vogel's paradox. Null result — Agent Smith

Try ChatGPT on Vogel's paradox!

Try ChatGPT on Vogel's paradox! — javi2541997

Gracias for the suggestion. Will consider.

I actually didn't now that Wayfarer, so thank you! I've been using it for years assuming tact was short for "tactic".

You're welcome, quite an understandable misread.

1. Someone (call him Al) has parked his car on Avenue A (out of sight now) half an hour ago. Everything is normal, the car is still there, Al has a good memory. Does he know where his car is?

2. Every day, a certain percentage of cars gets stolen. Does Al know, right now, that his car has not been stolen and driven away since he parked it?

3. Meanwhile, in a parallel universe with a similar crime rate, Betty has parked her car on Avenue B half an hour ago. Betty is cognitively very similar to Al (just as good a memory, just as much confidence about the location of her car). Her car, unfortunately, was stolen and driven away. Does Betty, who believes that her car is on Avenue B where she parked it, know that her car is on Avenue B?

4. Having answered all three questions, would you like to revise your answer to any of them?

5. Why? — Ludwig V

Funny thing is, often reality is more accurate than fiction. In an ordinary conversation, we often pre-qualify our statements by saying -- "I left it there an hour ago, so I don't know if it's still there..." or "I saw your keys on the table at the conference hall when I left two hours ago, maybe someone took it to the front desk for lost item."

That (!) is a normal conversation.

But when we post a epistemelogic probing question, we want to highlight the idea that people are gullible about their own memory or knowledge of things so we post a leading question such as the above. My point is, this is not how we do things in actuality and we should give humans a lot of credit for their minds.

But then I have the feeling of knowing what I have written is of no consequence in this forum. :roll: — jgill

This whole forum is of no consequence, so that's fine.

Your post put me in mind of computer assisted proofs. I was playing with ChatGPT, asking it to disprove a few theorems in modal logic, which it happily did. When I pointed out its errors, it politely corrected itself.

If you have a computer assisted proof, do you know the result? Suppose it is a proof that you cannot follow; is the feeling of certitude necessary for the claim that you know the answer?

eg:

Show □(p→q) → □p→□q is invalid

Now see this tree.

But ChatGPT replied:

The statement □(p→q) → □p→□q is not always true in modal logic, and thus it is invalid. A counterexample can be constructed by considering a model where p is true at some possible world w, q is true at another possible world v, and there is no path from w to v. In this model, □(p→q) is true at world w (because there is no world where p is true and q is false), but □p→□q is false at world w (because there is no path from w to a world where q is true).

This proceeded:

Me: But □(p→q) → □p→□q is valid

ChatGPT: You are correct. The statement □(p→q) → □p→□q is actually valid in modal logic. I apologize for my previous response. This can be shown using the following argument:

Suppose □(p→q) is true at a world w and □p is true at w. Then, at all possible worlds v accessible from w, p is true (by the definition of □p), and thus either q is true at v or p is false at v (since □(p→q) is true at w). But since p is true at w and there is a path from w to v, it follows that p is true at v. Therefore, q is true at v (since p is true at v and □(p→q) is true at v), and hence □q is true at w. Since this argument holds for any world where □(p→q) is true and □p is true, we can conclude that □(p→q) → □p→□q is valid in modal logic.

Both Betty and Al know where their cars are when they exist them. When Betty's car is stolen it is no longer the case that she knows where it is, but did she continue to know it up until that moment? Or is there some moment when both Al and Betty no longer knew where their cars were? Is this moment when the car is no longer in sight? Suppose they round the block and are able to see their cars again. Did they know then no longer know and then know again where their cars are?

If someone asks Al where his car is and Al says that he does, is he mistaken?

Arguably, once they had left the ally, neither had a justified belief as to the location of their car. The conclusion in (1) is based on the seperate assumption that

Everything is normal, the car is still there — Ludwig V

I hit enter before completing the post. I resubmitted it.

neither had a justified belief as to the location of their car. — Banno

When Al returns and his car is still where he left it is his belief then justified? Is there any justification for him to look somewhere else?