That view would imply that if someone told me he had a headache, his authority would not be strong enough to warrant my knowing he has a headache.

With your example, the person you ask, presumably, has direct access to how they feel. And, as far as I understand it, that person is the most reliable authority figure in regards to how they feel.

But is this analogous, in terms of justification, with a professor knowing something within his field of expertise, relaying that to a student, and then telling the student that he (the student) knows said thing?

A professor of geography tells a student two things:

1.) You know I have a headache. (after he tells the student he has a headache)
2.) You know Quito is the capital of Ecuador. (after he tells the student Quito is the capital of Ecuador)

It seems that there is more room for argument for the latter (#2), as the professor does not have direct access to that piece of knowledge. And, although his being possibly mistaken about #2 does not mean he doesn't know #2, his being a justifier that the student knows he (the student) knows #2 looks slightly more suspect.

Of course, my exploration here rests on the acknowledgement that the professor is epistemically certain about his knowing he has a headache, and not epistemically certain that Quito is the capital of Ecuador. If we agree that no one is epistemically certain about anything, then just disregard all of this.

But there may be limits for justification from authorities. I don't think there are so, but there may be.

Yes. But there may be limits for justification from authorities. I don't think there are so, but there may be.



Yes.

There are limits on authorities, but I don't understand what you mean by limits on justificaton by authorities.

P-cats are mammals

When you say, "I know P," you are not only saying that you know P, but you are also saying by implication that you have knowledge, so you are saying 1) you have knowledge and 2) you have knowledge that P. The latter implies the former, but the former doesn't imply the latter, so if you have knowledge that P, then you have knowledge, but just because you have knowledge, that doesn't imply that you have knowledge that P.

If you know that P is true; hence, if you have an adequately justified true belief that cats are mammals, then just how much of a leap am I taking to think that you know what a cat is or what a mammal is, given that you have adequate justification for thinking P is true?

---------- Post added 12-15-2009 at 04:39 PM ----------

I don't think that.

Two things. Firstly, if I was correct in taking you to think that knowing can be seen as a dispositional mental state, I don't see how you could come up with a formulation of this without involving articulation in some way. "S knows P iff he were to be asked the truth value of P, he would give a correct and appropriately justified answer." After all, when we talk about dispositional mental states we are talking about dispositions to behave in certain ways.

More important than the above is what it is possible to believe, and what it is possible to believe with justification in general. Beliefs are propositional attitudes, attitudes that certain propositions are true; it seems to me that if one had never heard of the word know, or heard it in use before, one would not know the syntactic rules governing it's use. 'Know' might be a proper name for all you know, so the only attitude you could adopt to a proposition in the form of "I know P", is an attitude of confusion as to whether it is a proposition or not; it may have the same syntactic form as "I Santa Clause P", which is not a proposition, or even a sentence.

Perhaps you might deduce, after a few circumstances of hearing its use that a statement in the form "I know P" is a declarative sentence that is true or false, but still you have no idea of the semantics of the language that would furnish us with the statement's truth conditions. If one is to know that one knows something then one must believe a statement in the form of "I know P", it must be true, and one must be justified in believing it. Now how can you possible be justified in believing such a statement if you don't even know the conditions under which it is true? Any attitude you take towards the truth or falsehood of "I know P" would be completely arbitrary. You need at least some guide for the use of 'know' in order to justify your use of it, the most simple I can think of is if a philosophy professor (whose research is in epistemology) tells a fresh faced student who has never studied philosophy before, "You know that there is no King of France." Here, the professor has furnished his student with a new semantic rule: "A statement in the form of 'I know P' is true when P is the proposition 'There is no King of France'".

Statements are not the only things which can be known. I don't know why you think this. I am not talking about knowing statements, and I don't understand why you think I am.



But who's talking about statements containing the word "know"? Not me! I'm talking about knowing that I know.

I don't have to believe any statements to know that I know something. None at all.

Well, you thought you knew things, and maybe you did know things, but that doesn't mean you knew that you knew things. If you didn't know the things, then you most certainly didn't know you knew things, but now that you know what it means to say you know something (and are not mistaken about it), then you know that you knew--as opposed to merely believing you knew things. And yes, I know that you disagree, but don't worry, I might disagree with me soon too.

You can know something and write it out as a proposition, and you can also know a proposition. But what I know need not be written out as a proposition. I need not articulate what I know in language, is what I mean.

If he knows that the premises P, and if P then Q, entail the conclusion Q, then I don't think it would be incorrect to say that he knows that modus ponens is a valid inference rule.

I think a lot of the potential for worry about this kind of thing lies in the difference between the linguistic and the logical. Say for example that it is true that S knows that Mount Everest is the highest mountain in the world; it also seems reasonable to say that S knows that Qomolangma (the Tibetan name for Everest) is the highest mountain in the world. From a logical point of view, both statements of knowledge seem to say the same thing, that S has a justified true belief that a certain relation holds between one particular mountain, and all of the other mountains. The 'particular mountain' being the one that is referred to by the two different names. We might say that names are the grammatical subjects of expressions, but particular objects are the logical subjects of expressions. On the other hand, S may have no idea that Qomolangma is the same thing as Everest, so if we were to ask S "Is Qomolangma the highest mountain in the world?" he might reply "No, Everest is."

My inclination is to say that S does know that Qomolangma is the highest mountain in the world, reasoning as follows:
Premises
S knows Everest is the highest mountain in the world.
Everest = 'Qomolangma'

Conclusion
S knows Qomolangma is the highest mountain in the world.

The worry arises because S does not know that Everest = 'Qomolangma'. This seems like a circumstance where it might be appropriate to say S does not know that he knows that Qomolangma is the highest mountain in the world, while in the original case it would make sense to say that one did not know that one knew that modus ponens is a valid inference.

This seems to raise an issue with iterated knowledge. If we use the above reasoning, which seems to be sound, to say that S does not know that he knows that Qomolangma is the highest mountain in the world; it still seems possible for S to know that he knows that Everest is the highest mountain in the world. This would certainly seem to be the case in the following exchange:
Q. Is Qomolangma the highest mountain in the world?
A. No, Everest is.
Q. Do you know that Everest is the highest mountain in the world?
A. Yes, I do know this.

However, in this case, there also seems to be a sense in which we may also say that S knows that he knows Qomolangma is the highest mountain in the world. The logical sense, in which we mean that S has a justified true belief that his belief about a relation that obtains between a particular mountain (the one that is picked out by the names 'Everest' and 'Qomolangma') and all the other mountains is true and justified.

Apparently the rules governing how we may use the word 'know' are very very subtle.

If the above deduction is correct, what about the following?

1. S knows that every statement in his geography textbook is correct. (His well-qualified geography teacher has told him: "I have checked this book carefully, and everything in it is correct". The teacher is right, and S believes him.)

2. One of the statements in the textbook is that Quito is the capital of Ecuador.

3. Therefore, S knows that Quito is the capital of Ecuador, even if he has never heard of Quito or Ecuador.

This doesn't seem right to me. What do you think?

This is an interesting point. Is there a minimum level of understanding that someone must have in order to derive justification from an authority? For example, if you are completely ignorant of music theory, and a qualified musician tells you: "A tritone is an augmented fourth or a diminished fifth", are you justified in believing it? You do not have a clue what it means, except that it is something to do with music. Imagine the following exchange:

Layman (L): What are you talking about?
Musician (M): I'm talking about intervals.
L: What are they?
M: The distances between two notes.
L: You mean, like when two players stand five feet apart...
M: No, you fool, I mean like when you play two different notes on the piano.
L: Oh, I see. So what is this 'fourth' and 'fifth' stuff? That's more than two.
M: No, you have to count up from the bottom note...
[Some minutes later]
L: Ah, I'm beginning to understand you now. So an augmented fourth sounds the same as a diminished fifth.
M: Yes, that's right.
L: But what the hell is a tritone? Three tones? How can that be the same?
[Some minutes later]
L: Ah, I understand. Now I believe your original statement.
M: But why didn't you believe it in the first place? I'm an expert in music theory, and you know I wouldn't lie to you.

At what point would L become justified in believing M's original statement? At the beginning? At the end? Or at some point in between? Is the acquisition of justification an all-or-nothing affair, or can it be incremental? Can any clear rules be formulated about this?

Or am I looking at this the wrong way? Should the question be, not "when would L first have justification for believing the statement", but simply "when could he first believe the statement"?

Any thoughts would be welcome.

Propositions are not written in any language. You are confusing sentences with propositions. Sentences are not propositions and propositions are not sentences.

I was using this definition:

"A proposition is a sentence expressing something true or false."

A proposition, as I understood it, was a kind of sentence. This is incorrect? If so, please clarify for me what the above means.

By the way, I'm only going to quote this, because everything I think I don't understand revolves around your comment here.

Yes it is incorrect. Philosophypages.com:
[INDENT]What is conveyed by a declarative sentence used to make a statement or assertion. Each proposition is either true or false, though in a particular instance we may not know which it is. [/INDENT]

Ah, the proposition is what is conveyed, not the sentence that does the conveying. I see. Well, that about clears it up. It was an inaccurate definition on my end.

Thank you.

PS: Don't you think the Wikipedia entry is a bit misleading?

This is an interesting point. Is there a minimum level of understanding that someone must have in order to derive justification from an authority? For example, if you are completely ignorant of music theory, and a qualified musician tells you: "A tritone is an augmented fourth or a diminished fifth", are you justified in believing it? You do not have a clue what it means, except that it is something to do with music. Imagine the following exchange:

Layman (L): What are you talking about?
Musician (M): I'm talking about intervals.
L: What are they?
M: The distances between two notes.
L: You mean, like when two players stand five feet apart...
M: No, you fool, I mean like when you play two different notes on the piano.
L: Oh, I see. So what is this 'fourth' and 'fifth' stuff? That's more than two.
M: No, you have to count up from the bottom note...
[Some minutes later]
L: Ah, I'm beginning to understand you now. So an augmented fourth sounds the same as a diminished fifth.
M: Yes, that's right.
L: But what the hell is a tritone? Three tones? How can that be the same?
[Some minutes later]
L: Ah, I understand. Now I believe your original statement.
M: But why didn't you believe it in the first place? I'm an expert in music theory, and you know I wouldn't lie to you.

At what point would L become justified in believing M's original statement? At the beginning? At the end? Or at some point in between? Is the acquisition of justification an all-or-nothing affair, or can it be incremental? Can any clear rules be formulated about this?

Or am I looking at this the wrong way? Should the question be, not "when would L first have justification for believing the statement", but simply "when could he first believe the statement"?

Any thoughts would be welcome.

As for you, ACB, I'd like to see if anyone can give you an intelligent, meaningful response. I am just as curious about this as you are.

As for you, ACB, I'd like to see if anyone can give you an intelligent, meaningful response. I am just as curious about this as you are.

I'll try! Some things can't be transmitted from one person to the next like a shopping list.

Some things you have to figure out for yourself. For these things, the teacher points to what there is to be figured out. He can't drill a hole in the student's skull and pour in the info. He can be encouraging.. he can share what ways of thinking helped him.

You respond to authority according to your nature. What does it mean to say I believe the authority without understanding what it is I believe?

fast;111569 wrote:

P-cats are mammals[/SIZE]


When you say, "I know P," you are not only saying that you know P, but you are also saying by implication that you have knowledge, so you are saying 1) you have knowledge and 2) you have knowledge that P. The latter implies the former, but the former doesn't imply the latter, so if you have knowledge that P, then you have knowledge, but just because you have knowledge, that doesn't imply that you have knowledge that P.

If you know that P is true; hence, if you have an adequately justified true belief that cats are mammals, then just how much of a leap am I taking to think that you know what a cat is or what a mammal is, given that you have adequate justification for thinking P is true?

[QUOTE=Emil]I don't think what you says supports the conclusion. Please show the argument more formally.

You don't think that a person who says, "I know P" is at least saying she has knowledge? Why not?

That's not what I meant. I meant that what you wrote does not support the conclusion that K(K(P)) implies K(X).