Knowledge is not true justified belief

Knowledge is defined as:

x knows y means x believes y and x believes that x will believe y in the future.

Knowledge is distinguished from assume:

x assumes y means x believes y and x believes that x might not believe y in the future.

Assume also has a second meaning:

x assumes y means x believes y and x believes that x cannot justify y.

The most popular definition of knowledge comes from Plato: x knows y means y is true and x believes y and x must be able to justify y.

But there are problems with this. It seems that anyone who subscribes to this definition believes that true corresponds to reality. We cannot be certain that we will not discover that our knowledge will later turn out to be wrong. If we draw up a list of 10,000 facts, in 100 years at least one of those facts will be wrong, if not more. Second, not all knowledge need be justified. Take the following sentence:

Something exists.

Let’s now demonstrate that that sentence cannot be justified. To justify a sentence means to show that it follows necessarily from certain unjustified sentences, also known as axioms and definitions. Given that definition, we cannot know axioms because axioms are defined as those sentences which cannot be justified. Further, we cannot define every word we use since that would lead to an infinite regress. There must be some words which are indefinable. Existence is one such word. So the standard definition of knowledge cannot verify the following sentence:

I know that something exists.

We will now show that that sentence leads to a contradiction. Replacing ‘know’ with true justified belief we get:

I believe that something exists. It is true that something exists. I am able to justify that something exists.
I am not able to justify that something exists.

That isn’t how I define it.

Which is why I don’t believe;

Then how do you define it?

Any definition of ‘know’ is merely conventional. In English, to ‘know’ means to hold a belief that has strong empirical support, i.e., ‘true belief’. It is not possible to speak of two people having contradictory knowledge. Charles cannot ‘know’ that tomorrow is Wednesday when at the same time and the same place, Wendy ‘knows’ that tomorrow is Friday. One or both of them is wrong.

Maybe you’re operating under the following fallacy, James:

  1. I can define words any way I want.
  2. x defines knowledge as y.
  3. I do not define knowledge as y.
  4. Therefore, x is wrong.

The problem with this fallacy is that there are sentences whose truth value all rational people agree on. We will call these true sentences. We need to define our terms so that they justify the true sentences.

I know I existed five minutes ago.

is one such sentence. Now of course it’s logically possible that I did not exist 5 minutes ago but the point is that I believe that I am not going to believe that I did not exist 5 minutes ago in the future.

So come up with your definition of ‘know’ and we’ll see if it verifies true sentences.

Surely, you jest.

You just declared your version of what you called “a definition” (which actually wasn’t a definition at all). I said that I didn’t believe what you said. And then you accuse ME of making up definitions??? :open_mouth:

Just out of curiosity, how did you gain supreme authority to form “true definitions”?

x knows y means x believes y and x believes that x will believe y in the future.

is a definition. A definition has on side of the equation the term to be defined and on the other side of the equation the several sentences it reduces to. So here knowledge is defined in terms of belief and future.

No. By stating: “That isn’t how I define it. Which is why I don’t believe;” the only way that statement can justify an argument is with the following reasoning:

  1. If I don’t believe x then x is not true. or
  2. If I don’t define x as y, then x is not defined as y.

Both of which are fallacious.

If one’s definitions can verify sentences whose truth value all rational people agree on, then the definitions are correct. Here is what I mean by verify. You put the words together into a sentence and using the definition of the words you break the sentence down. If the reduced sentence is not contradictory and the contrary is contradictory then the definitions verify the sentence. So come up with your own definition of knowledge and we’ll see if it leads to contradictions when using it to verify sentences whose truth value we both agree on. Alternatively, you can try to show that my definition contradicts a sentence that all rational people believe.

You merely declared a substitution for the word “knows” with “believes”.
A) It is merely your supposition that those terms are identical for the entire population (having not categorized within what realm such might be true).

B) A single word substitution is not an explanation of the concept and thus not actually a definition anyway.

C) I am not aware of anyone in any realm that believes your extension of always believing the same thing as a prerequist for someone “knowing”.

D) The word “knowledge” is related to the word “knows”, but neither would be a definition for the other. They aren’t even the same grammatical type (noun vs passive verb).

Your argument is fallacious and does not represent the case in question and thus is a “strawman”.

So you are in authority to actually know what all rational people agree upon?
Can I ask how you ascended to such a superior level?

Although I would have called that a good direction and effort, it isn’t actually true.
It is a logical fallacy to think that because something is not contradictory, it is true.
Truth verification requires a bit more than that.

Red ≡ Whatever Joan calls “red”.

Joan calls her apple red.
Joan calls her apple [whatever Joan calls red].

Do those conflict? No.
Therefore it is true that red ≡ whatever Joan calls red???
I don’t think anything has been verified concerning the definition.

Besides, Joan also calls her car “red”.
Therefore her car is an apple??? :confused:

If I said: x knows y means x believes y, then I would merely declare a substitution for the word “knows” with “believes”, but I did not do that.

It is not a mere supposition. It is a definition for which there is no counterexample. A definition is correct if there are no counterexamples to it.

As I already stated, I did not make a single word substitution.

James does not know anyone that believes x, therefore x is false is a fallacy.

This is how know and knowledge are related:

If x knows y, then y is knowledge.

“Your argument is a strawman” does not prove my argument is a strawman. You have to quote my argument and show how that misrepresents what you really said.

Do you deny that the following are sentences that all rational people agree on:

  1. Something exists.
  2. It is false that if x knows y then x does not believe y.
  3. If x believes y provisionally then x does not know y.
  4. If x believes that it is highly likely that x will revise belief y in the future then x does not know y.
  5. Humans can think.
  6. People can read.
  7. Possibilities can become actual.

Let’s now assume the contrary:
There are no true sentences that all rational people agree on.

If that were true, then communication would not even be possible. Therefore, there must be true sentences that all rational people agree on. We need to find a way to justify those sentences.

You did not represent my argument correctly. I said: "If the reduced sentence is not contradictory and the contrary is contradictory then the definitions verify the sentence. Thus you have built up a strawman.

This proves that your definition of red is false, not that my theory of verification is false.

This proves that red is not synonymous with apple nothing more.

I read all the posts and I have to be frank I am impressed at the logical deductive process interpreted in all conjectures. Simply explained I would state that knowledge is arbitrary and could be false or not false (true), or mayhap enlightening altogether with elements that are abstract in nature or alien in origin. True justified belief pertains to ‘ultimate truth’, or in common layman terms, rational scientific based truths that withstand the tests of scrutiny. Having ‘knowledge’ does not equate to true justified belief simply for the fact that it is arbitrary in origin and it could be erroneous in nature or maybe only partially complete.

knowledge /= true justified belief → which withstands the impositions of questionings and scrutiny methodically with all available knowledge.

In other words, knowledge is not interchangeable with true justified belief because one is accrued blindly and the other is tested and validated. My best debate to this question would revolve around picking up the English Oxford Dictionary to answer all questions pertaining to definition. If a clash in definition exists than by all certainty the statement(s) cannot hold.

English is a beautiful language.

This is getting kind of silly. :laughing:

Why not just use the dictionary?

Note that neither references the other.

Knowledge is a “thing”.
Believing is a behavior (acceptance of the thing).

They are not synonymous.
And neither necessarily associated with truth.

Because the dictionary is circular and makes no effort at getting around the problem of circularity.

Rocks are things too. This definition does not help us distinguish rocks from things.

This just moves the problem around. We’re now stuck with what acceptance is. Belief is indefinable. Here is how we prove that beliefs are indefinable. In order to communicate with another there are several requirements. Two people must agree on a finite set of symbols. Second, two people must agree what the symbols stand for. Three, we can’t just string the symbols together in any order we need to string them together in a correct way. Once we have a correct way of stringing the symbols together we need to call that something. I call it a belief.
They are not synonymous.
And neither necessarily associated with truth.

In what way is it “circular”?

Let’s now use the same dictionary to look up trust, I assume you’re using the freedictionary.

Let’s now look up ‘place confidence in’:

And now we are in a circle.

The fact that you can pick a word that they haven’t ensured can’t be merely traced back to that same word, means nothing. You are making the circle despite options. But I am not saying that they are perfect. They certainly aren’t.

The definitions that they provided were not in themselves circular. If you know no English at all and thus must look up every word, you very well might end up back where you started.

Do you really need to look up the term “place confidence in” or “place trust in”?
Those were related to “believe in”.

Note that “knowledge” had nothing to do with placing confidence. It had to do with awareness. The only confidence related to it is the confidence that your awareness is functioning properly (which in itself should be dubious these days).

Knowing is not the same as believing. They are related because if one knows, then one believes. But if one believes, they might not know. You cannot conflate them freely.

In English, that is not how “know” is used at all. If x believes y and believes that they will continue to believe y, but y is false, we don’t say they “know” that - we say they “believe” that. No-one says “the patient knows that he is Napoleon Bonaparte”. There is implicit reference in the use of the word to a match with reality. Ornello’s point above is another clear counterexample.

In addition, we ask “how do you know?” but “why do you believe?” They refer to different relations between statement and reality.

If your argument is that we have no access to reality besides through belief, that’s one thing. But that is not the way the English language (or any language I’m aware of) uses the (equivalent) word “to know”. Some languages use different verbs for knowing by direct experience and knowing by being told. But those also have words for believing something that is not the case.

@ 117938Aa

English for beginners:

If you say “x knows y means x believes y and x believes that x will believe y in the future”, then you mean “x knows that y means that x believes y and x believes that x will believe y in the future”, do you?

When you say ‘y is false’ you seem to be adopting some correspondence theory of truth which is fallacious. We cannot know if our beliefs correspond to reality, we can only hope that is the case. Draw up a list of 10,000 facts which you believe are true and in 100 years at least one of them will turn out to be false. I want to make a very controversial claim:

All of our beliefs are true

When we find out our beliefs are false, we no longer believe them but replace them with new beliefs which we believe are true and which we believe correspond to reality but again this is just a mere hope. We can never be certain. To demonstrate that all of our beliefs are true observe that every utterance we make we can always insert the words ‘it is true that’ in front of it. To take your example of the patient that believes they are Bonaparte, we can easily say: It is true that x is not Napoleon. As for the patient himself if he says: ‘I know I am Bonaparte’, then we simply do not believe him. A more realistic example would be the following: if you spoke with Einstein in 1905 and he said: ‘Time slows down as you approach the speed of light’ and you had no understanding of Maxwell’s equations then you would dismiss him as a madman and you would not believe him and you would say that he does not KNOW what he’s talking about. However, 20 years later the physics community more or less universally agreed that Einstein was right and they believed that they would not change their belief in the future.

Correct, no one says this because no one believes this in the present and if you do not believe something in the present then you have not met the first condition of knowledge.

Let me also point out that perhaps I was not sufficiently clear about the meaning of the word belief. It is indefinable but sometimes it is also synonymous with the definition for assume that I laid out above.

But we can’t be certain that our beliefs match with reality. We can only disbelieve them when we find out that they do not match with reality. But what we believe now is almost always subject to change. Case in point everyone in 1995 believed they knew that Pluto was a planet. They were wrong.

I don’t see anyone named Ornello above. Maybe one of those guys has a different name that I do not KNOW about. The reason why I use the word know in that context is because I do not have a belief about anyone named Ornello so that fails to satisfy the first condition of know which is we must believe it.

You seem to be claiming that we have access to reality. Sure, we have access to it but not infallible access. The example of Pluto is a case in point.

This is just information about other languages.

So you believe.

Yet by your own belief, you cannot know to be true.

If you believe that you can only believe, then you can know that you know nothing.

James, I have decided that debating with you can no longer serve a useful purpose for the following reasons. When I posted the following:

You did not respond to my claims or answer any of my questions. Instead you talked about the necessity of referring to the dictionary. This leads me to believe that you’re not interested in engaging in rational discussion so as to learn something but are only saying anything you can think of so that you will not admit that you’re wrong. There is no point in dialoguing with such a person because they’re not interested in truth but just saying anything to make themselves look good.