I don’t think I can overestimate how important epistemology is in evaluating beliefs and systems of belief, especially in our modern society where we’re being challenged at every turn. We are flooded daily with claims—political, scientific, technological, and now artificial intelligence—all competing for our assent. Without a clear framework for what counts as knowledge, we risk confusing conviction with truth or mistaking repetition for justification. Epistemology provides the tools to sort through this noise: to ask whether a belief is backed by reasons that are testable, whether those reasons stand up to defeaters, and whether the belief is grounded in understanding rather than mere assertion. In a culture where misinformation spreads quickly and skepticism often takes the form of indiscriminate doubt, epistemology steadies us by distinguishing between genuine inquiry and idle challenge. It reminds us that knowledge is not simply having a belief that happens to be true, but having reasons that others can check, refine, and correct.

Another important aspect of this epistemology comes from Wittgenstein’s Philosophical Investigations: knowledge is not something we locate inwardly, as though we could point to a private object called “knowing” or consult an inner meter. Knowledge shows itself in our practices—what we say, how we check, and how we act in the world. To imagine that knowledge is an inner state is to confuse conviction with justification. Conviction is inward, but knowledge is public: it lives in criteria that others can test, in language that is shared, and in practices that display whether someone truly understands what they claim.

And yet today it is common to hear people speak as though knowledge is simply whatever they take knowledge to be. To put it more sharply: many equate knowledge with conviction. If I am sure of something, then in my own eyes I “know” it. But this collapses the difference between subjective certainty and objective certainty or knowledge. Conviction may be powerful, even immovable, but it is not an epistemic use of the word know. Knowledge requires more: truth, belief, justification that can be publicly tested, and understanding in use. Without these, what someone calls “knowledge” is merely the strength of their assurance, not the possession of reasons that could stand up in a public arena.

our epistemic practices require certainties that are not proved from within the practice but make proof possible. — Sam26

Maybe not “certainties”? So “proof” is aspirational, or ideal. But the metaphysic outlined - namely, proof sites within epistemic practice, and so proving cannot be applied to the grounds (certainties) underlying the epistemology - sounds right to me.

Much of the literature treats Gettier as a mortal wound to JTB. I don’t. Gettier cases work only if we confuse seeming justified with being justified. If the support for a true belief essentially depends on a false ground, the belief fails the J-condition, full stop. I mark this with an anti-false-grounds constraint: justification must not essentially rely on falsehood. That preserves the classical core without endless epicycles. — Sam26

I agree 100%. K=JTB remains instructive. Useful under Wittegenstein as it is under Plato, and for many others.

hunt for one essence of justification; I look for overlapping patterns that guide our reasoning. — Sam26

Why isn’t the process of hunting for one essence the exact same process as looking for overlapping patterns that guide? I never understood the need to rebel against the notion of intelligible essence - whatever emerges and however it emerges that we call “knowledge,” it always still involves a “what it is to be.” K=JTB. Essence is what K speaks of. If K can ever be Justified as True, then Believing K is as much a possession of an essence as it is any other act that would demonstrate what one believes one knows. What is known, is what can be spoken; what can be spoken, distinguishes the essence of some thing spoken about. (But this may all be an unnecessary can of worms)

Truth and justification remain conceptually distinct, two different “grammars” in Wittgenstein’s sense, even though, in practice, our only route to truth runs through justificatory methods.

Truth: how the world is (a world constraint on speech acts).

Justified: whether one’s reasons meet the public standards of the operative language-game (science, law, everyday perception, math).

We don’t reduce truth to justification, and we don’t pretend justification is free of truth. We couple them so that justification tracks truth (anti-false-grounds + practice-safety), and Wittgensteinian hinges stop the regress (and circularity) that would make any coupling impossible. — Sam26

I agree.

I see them each contributing to knowledge as like a verb and a noun contribute to an assertion. True and justified may seem to do similar work, but if we keep one as the verb and the other the a noun, we see the two functions they fulfill. “True” references “how the world is” - a truth, there in the world, like a noun is fixed in sentence. “Justified” is a the process of matching reasons with the public standards and quality of the game play - this is a process, like a verb.

So the ‘justified’ part of JTB is the process, and the ‘true’ part is an end goal achieved by that process.

This is why it makes sense that it is circular but not collapsing (it is sort of self-affirming, making something self-evident within the community).

And the reason ‘justified and true’ can seem unsatisfyingly circular comes from the sense that we can make nouns of verbs and verbs into nouns (I think). Instead of “justified” (verb) “true” (adjective for the noun) belief, we could abuse language a bit and talk about “truing up” (verb, process) a “justified” (adjective) belief. So as long as we keep process and target separate, justification and truth do not consume each other but are shown as distinct moments inside knowledge.

the real issue lies in how we understand justification. — Sam26

Yes.

It is more than simply a person thinking they are justified. — Sam26

Yes.

when a defeater arises that overturns what seemed to be justified, we recognize that the claim was never knowledge to begin with, but only something that masqueraded as such. — Sam26

But doesn't this raise, again, the problem of the independence of justification from truth, and vice versa? If something can only be knowledge if it's true (along with J and B, and perhaps your U), what are the criteria for knowing when it is true, apart from those very justifications?

We have every (public and private) justification for believing the sky is blue (with all the usual qualifications about colors). If a defeater arose, such that we understood that the sky was not in fact blue, what has happened? You say, "The claim was never knowledge to begin with." But I say, "Yes, it was, on the JTB definition, because there was never an independent criterion for blueness apart from our justifications for believing the term applies to 'sky'. And that won't do, because we don't want an explanation of what knowledge is to leave room for that kind of error." This is a problem with JTB, not your very thorough argument that tries to rehabilitate it.

Here's another way to state the objection. How does a defeater work? It demonstrates that a previously held belief is untrue. How does it do this? By showing that the previously held justifications are inadequate to establish the truth of the belief. It can't talk about truth apart from the justifications. If we could know, or even think we know, truth apart from justifications, why would we need justifications to be part of knowledge? We could just "know the truth" and leave it at that.

In short, JTB is onto something important, but as formulated, it doesn't give us enough clarity about how truth and justification may be conceptually separated.

it includes understanding (+U): You grasp the concepts involved and know how to apply them correctly, avoiding confusion in how words or ideas are used. — Sam26

Traditional JTB does not require fully grasping the ideas. I insist on it, so you demonstrate knowledge by using concepts properly. — Sam26

Just curious: If I believe something without fully understanding it, and I'm asked to give an account of what I say I believe, can I do it? Or would this reveal that the B of JTB in fact doesn't apply? - that I literally don't know what I believe.

Seems to me that folk read JTB as the claim that in order to know something, we must know that it is true. It's hard to get across that this is not what the JTB account is saying. It's not that the proposal is justified, believed and known to be true, but that it is justified, believed and true.

Hence, It seems to me, 's reservations.

We cannot know things that are not true. Despite what so many hereabouts supose.


___________
There is a tension in work on JTB.

On one side we have an account of knowledge as justified true belief, which we can treat as either a stipulation, or as a theory as to the nature of knowledge. If it's a stipulation, then that's mostly an end to the discussion. If it's a theory, then we should look to our use of "knowledge" to see how well the theory works.

Alternately, can go after account of the use of "knowledge" in our various language games - don't think, but look, as Wittgenstein extolled.

And when we look, we do find uses of "knowledge" that do not quite fit the JTB account.

But to be sure, at the core, we do not know things that are not true, we do not know things that we do not believe, and we ought be able to give an account as to why we know some proposal.

What might be problematic here is some expectation that there be no exceptions, no fuzziness as to what counts as knowledge and what doesn't.

The spectre of essentialism hangs over such expectations.

Hence, It seems to me, ↪J's reservations. — Banno

Yes. Though maybe more in my post directly above that one.

But to be sure, at the core, we do not know things that are not true, we do not know things that we do not believe, and we ought be able to give an account as to why we know some proposal. — Banno

Right, there's something basically correct and useful about the JTB concept. I'd modify "an account as to why we know some proposal" to "an account as to why we believe or say we know some proposal."

What might be problematic here is some expectation that there be no exceptions, no fuzziness as to what counts as knowledge and what doesn't. — Banno

I've objected to the unclarity around justification vs. truth, but this is important too. As you say, we can just stipulate what "knowledge" will mean, and get on with it, but that's not very satisfying. The fuzziness around "knowledge" and "knowing" is what JTB tries to de-fuzz. If we agree that we can know things that aren't certain, then there may be room for degrees of knowledge as well. If the justification-truth circle is indeed a vicious one, as I suspect it may be, then we may have to settle for a less-than-perfect conception of what it means to know something,

And when we look, we do find uses of "knowledge" that do not quite fit the JTB account. — Banno

There are uses of know that don't fit the JTB account, but I would maintain they're not epistemic uses. Are you saying that there are epistemic uses that don't fit the JTB model? If that's what you're claiming, and I'm not sure that you're claiming that, give an example. There is a use of know, for example, that's just an exclamation of a conviction. In other words, it's just an expression without epistemic force behind it.

The spectre of essentialism hangs over such expectations. — Banno

There is no one essence that fits JTB, there are just a series of language games that demonstrate how we justify beliefs in various ways. If we "look" as Witt would say, we can see these uses in practice via forms of life. I've added the +U because I think it captures the essence of this. The “+U” is what makes the difference plain. Traditional JTB can sound as if all you need is a true belief and some reason that looks like justification. But without understanding, justification can collapse into parroting words or leaning on a method you don’t really grasp. +U requires that the knower demonstrate competence in the concepts at play. That means being able to apply the idea correctly in practice, to handle nearby counterexamples without confusion, and to explain the checks that make the claim public.

I'm not seeing a difference between a justification and an understanding. In both cases what we know should fit in with our other explanations.

It's an appeal to consistency, or perhaps in Davidson's terms, to holism.

"Knowledge" doesn't have an essence. Whatever an essence is.

If the justification-truth circle is indeed a vicious one... — J

There, perhaps, is the problem.

Sentences are true or they are false, regardless of any justification.

Again,

Seems to me that folk read JTB as the claim that in order to know something, we must know that it is true. — Banno

You say that we have knowledge and that it may be overturned by new evidence. You say what we believed we knew is overturned, in which case it wasn't knowledge at all but belief.

Whether a belief is thought to be justified or not is a matter of how rigorous or extreme are the criteria we want to stipulate for our use that determine what counts as justification.

We have knowledge of how to do things, but that kind of knowledge is not true belief, whether justified or not, but rather understanding what to do and how to do it, and that kind of knowledge cannot be overturned but can be improved upon.

You know the saying "seeing is beleiving" well I prefer to say that seeing is knowing. If I am looking at a tree, I know I am seeing a tree (radical skeptical scenarios like I might be dreaming or being deceived somehow aside).

And I don't think any knowledge is absolute, it is all contextual.

Returning to your 'raining' example, would you have said that you know it is raining?
— Janus

Not if I accept JTB as the standard of knowledge. I can't say I know it's raining unless it's true that it's raining; truth is the third leg of the tripod. — J

Right, but I wasn't asking whether you would now, when you know it was not raining, say that you knew it was raining, but whether when you thought it was raining you would have said you knew it was raining. This relates to what I said above to Sam about the paradox involved in saying that we have knowledge, but that it may be overturned by further evidence.

On the strength of this paradoxical situation I would say we can only justifiably claim to have knowledge when we are certain that we do. I think this obtains when we can directly observe something to be the case, and also with analytic truths as in mathematics. But I am not saying any knowledge is absolute, so any certainty is contextual.

I have to be able to be justified yet wrong. — J

I agree. but then why say we have knowledge, rather than merely belief, if we are not certain? (And I repeat that I am referring here specifically to propositional knowledge, not to know-how).

A good question. Again accepting JTB, the answer has to be no, unless you're wanting to tweak how we understand "possess." — J

I was thinking about it in the context of JTB. The idea was to question the idea of justification. I imagine a situation in which I believe something to be the case on grounds that would count as justifiable, but I am nonetheless not confident enough to think I know, and unbeknownst to me what I believe is actually true.

This is the same problem as above, I think. What counts as "justified" is slippery. Also, your phrasing is a little ambiguous: Do you mean "turn out to be wrong that what we believed was justified" or "turn out to be wrong that what we named as a justification was incorrect"?

EDIT: Sorry, the last phrase should be "turn out to be wrong that what we named as a justification was correct." — J

I meant the latter―that what we thought counted as a justification was not. The very idea of justification for a belief must rely upon other beliefs which we take to be knowledge, even certain knowledge, because if we took them to be mere beliefs it would then be belief all the way down, meaning no knowledge.

The so-called “Gettier problem” rests on a sleight of hand. It trades on the difference between thinking one is justified and actually being justified. — Sam26

This is a profound problem. Of course I acknowledge a logical distinction between feeling certain and being certain, and between feeling justified and being justified, and I have raised this very point many times before on these forums. The problem is that if we cannot be certain about being justified, if there is no observable state of affairs or logically self-evident criterion for justification then what we have is really a house of cards.

Then we can only be said to know something if we can be certain (as opposed to merely feeling certain
) that we are justified in counting it as knowledge. Whenever the truth is not obvious, then we cannot be certain that we know what it is.

I'm not sure, but you seem to think that if knowing isn't absolute, it isn't knowledge. This is a classic misunderstanding of what knowledge is. — Sam26

I come back to this because I'm not sure whether by 'absolute' you mean 'certain' or 'context-free'. No knowledge is context free because it is couched in language for a start, and language is obviously itself a context.

On the other hand, I say that within the appropriate contexts anything that counts as knowledge must be certain, because if it could be refuted then it could not count as knowledge. You might say that I'm showing "a classic misunderstandings of what knowledge is" but the reality is I would just be advocating a different understanding than yours, and I think mine makes more sense. You of course don't have to agree, but if you cannot see the possibility of different perspectives on this then you are playing the dogmatist.

I think that all your very pertinent questions come down to versions of the same issue, which @Banno has also picked up on, namely whether the T in JTB is doing any useful work.

(I was asking) whether when you thought it was raining you would have said you knew it was raining. — Janus

Not if I was a proponent of JTB. Since, at that time, I had no way of knowing whether the "raining" statement was true apart from the cogency of my justifications, I would/should have said, "I believe I am justified in saying it's raining."

But this raises the deeper problem. When do I ever know something is true apart from having the right justifications? How can we make truth independent of justification -- make J and T genuinely separate criteria? Even the truth of analytic statements can be justified, indeed must be. Perhaps the idea is that some justifications cannot be insufficient or misguided. We can somehow know beforehand that there cannot be any defeaters.

And this connects with your questions about knowledge and certainty. I understand why JTB, taken rigorously, suggests that knowledge must be certain. Otherwise, how do we get "true" to do anything that "justified" isn't already doing? But if we decide to equate "true" with "certain," we get a possible answer.

The only issue with any of this is that it doesn't fit the way we actually think and talk about knowledge. I know the sun will rise tomorrow, in spite of being able to imagine defeaters. We'd have to say I didn't, on this view. Keeping J and T separate isn't worth paying this price, it seems to me.

namely whether the T in JTB is doing any useful work. — J

There are some folk on TPF who do not actually believe in truth or knowledge, and you are the foremost. This has been pointed out quite a few times. So it's no coincidence that you wonder whether "the T in JTB" is doing any useful work, or, "When do I ever know something...?"

This is related to a recent discussion with @Relativist:

If one locks the subject within their own beliefs, then knowledge is impossible. — Leontiskos

The other question has to do with the modern move where the subject is cut off from reality by fiat of premise. For example, if we can never get beyond our attitudes and make truth- and knowledge-claims that are not merely belief- or attitude-claims, then of course a kind of Cartesian skepticism will obtain. If every knowledge-claim is rewritten as a matter of the subject's attitude or nominalistic beliefs, then realism has been denied a hearing. — Leontiskos

-

The objection to JTB seems to be this:

<JTB means that there are three independent ingredients to knowledge, and once we have harvested all three we will be able to bake the knowledge cake. So we go find our Justification, and we go find our Truth, and we go find our Belief, and then we put them together in our mixing bowl, mix, and bake. Voila! We have knowledge. But where does Truth exist in isolation? Or Justification? Or Belief? They don't exist in isolation, to be harvested at will; therefore JTB fails.>

...That's a pretty wild understanding of JTB. The whole notion is incoherent, given that it presupposes that one can have knowledge of J independently of T and B (and knowledge of T independently of J and B, and knowledge of B independently of J and T). The "three independent ingredients" approach actually contradicts the whole epistemic notion of JTB.

When do I ever know something is true apart from having the right justifications? — J

That's kinda the right question and kinda the wrong question. The J in JTB is supposed to exclude cases of epistemic luck: the truth of your belief, if the belief was not formed in the right way, is not enough for us to count it as knowledge.

The issue isn't whether you know your belief is true — which in most cases amounts to knowing that you know — but whether your reasons for believing something is the case are connected in the right way to its being the case. That's what the J is meant to capture, and it leaves room for epistemic bad luck, where your belief turns out false but anyone would have formed the same belief, and it was a one in a million chance that in this case the evidence misled you.

The point about luck is not incidental: luck is not a strategy. In most cases, a strategy is only likely to produce the result we want, but it's not a guarantee. (Pareto dominance is the exception.) The question is the same with post-hoc justification, whether your strategy was likely to have produced knowledge; the question of whether it did in this case, is different, and must be judged differently.

That's what the J is meant to capture, and it leaves room for epistemic bad luck, where your belief turns out false but anyone would have formed the same belief, and it was a one in a million chance that in this case the evidence misled you. — Srap Tasmaner

The counterargument could be phrased this way:

1. Truth is always known via justification, and ensured by justification
2. Justification can never overcome the possibility of the one-in-a-million anomaly
3. Therefore, truth is never certain

This form of skepticism is a bit like the claim that epistemology is like a game of pool and no matter how good you are, there is always a chance that your shot will not pocket the 9-ball. Accidental contingencies are always involved, and therefore the best one can hope for is a good probability (or an ). Such a skeptic would say, "The only way to guarantee that the 9-ball is pocketed would be to pick it up with your own hand and place it into the pocket directly, but that would be cheating."

This is why I see the Gettier literature as a long detour. It multiplies refinements to patch a problem that dissolves once we keep the standard for justification strong. By “strong” I mean publicly checkable, defeater-sensitive, and free of false grounds. If a justification fails those checks, it does not count as justification. Once that is clear, Gettier’s cases lose their force: they are examples not of knowledge, but of its counterfeit—instances where someone takes themselves to know but does not in fact know. — Sam26

I think Gettier would just provide you with a case where the erroneous clock is publicly checkable and defeater-sensitive. For example: a case where multiple public clocks are all simultaneously erroneous.

Regarding the "false grounds," the key to the Gettier case is the difference between a material conclusion and a formal conclusion. So suppose we have two different cases:

Case 1:

J1. John looks at his clock which reads "2:00."
J2. John assumes that his clock is working but in fact it is not.
J3. John infers that it is in fact 2:00.
4. It is, objectively, 2:00.

Case 2:

B1. Ben looks at his clock which reads "2:00."
B2. Ben assumes that his clock is working.
B3. Ben infers that it is in fact 2:00.
4. It is, objectively, 2:00.

Case 1 and case 2 are identical except for the second proposition, and the Gettier case turns on the premise that knowledge should not be able to be had by accident or by sheer luck.

When I say "material" vs. "formal" conclusion I mean that both arguments "reach" (4) in a material sense, but only Ben reaches it in a formal sense. If we conceive of (4) as a kind of goalpost that someone must reach, and it doesn't matter how he reached it, then John has reached it. But if we conceive of (4) as a goalpost that someone must reach, and the reaching of which depends upon the means by which they arrived, then John has not reached it given the means in question. John has reached (4) materially but not formally, whereas Ben has reached it both materially and formally. ...Taken further we might say that a valid conclusion is different from a sound conclusion, and therefore John and Ben have reached different conclusions.

The same thing applies to propositions more generally, including J3 and B3.

I think what the Gettier case shows is that there are at least some conclusions which are material rather than formal, and knowledge of these conclusions is never certain. But his point isn't applicable to justification tout court. It is only applicable to those situations in which luck or accident plays a role. ...Of course the skeptic will argue that luck and accident play a role in every situation (i.e. that every conclusion is material), and that seems to be the crux.

The so-called “Gettier problem” rests on a sleight of hand. It trades on the difference between thinking one is justified and actually being justified. — Sam26

We could construe it as saying that every valid justification can be unsound, and that we can only know that a justification is valid, not sound. Such a perspective might simply argue that not all unsound reasoning has defeaters.

I have to be able to be justified yet wrong. — J

The problem is that you want to make sound justification and unsound justification identical, as if they were the same thing, as if they were interchangeable. You are assuming that the 'J' signifies justification regardless of whether that justification is sound or unsound. You want to say that the person who is justified yet wrong is justified with the same justification of the person who is justified and therefore right.

The crux is that, following Sam26's thought, there needs to be some space between justification and truth in order for JTB to really be a three-legged tripod. — J

...And you think that if we distinguish between sound justification and unsound justification then there is no difference between 'J' and 'T', which is incorrect. This goes back to the "three separate ingredients" strawman.

Aristotle is rather precise on this point in the second chapter of the Posterior Analytics, where he says that scientia proper requires that one knows the explanation for the thing in question. One must know what explains it; why it came to be. One must not merely have an explanation that incidentally lines up with some particular aspect of its existence. One must have more than an unsound argument with a true conclusion in order to have demonstrative knowledge. If one's understanding of 'J' does not take these distinctions into account then they will not be able to make JTB workable.

The J in JTB is supposed to exclude cases of epistemic luck: the truth of your belief, if the belief was not formed in the right way, is not enough for us to count it as knowledge. — Srap Tasmaner

Yes. I took that to be understood. My question -- the "right question" part, I guess -- was what sort of answer a person would give if they were asked why X was true but also told, "You may not give your justifications." We feel there should be some answer to this, since after all it isn't our justifications that make a state of affairs true.

But JTB is not about what makes something true, but how I can say I know it to be true. The truth or falsity of the proposition under discussion remains what it is, no matter what I know or don't know. But my knowledge, according to JTB, depends on three things, two of which -- J and T -- seem viciously circular in this context, which again is epistemological, not substantive about the world. (And I raised, above, the question of whether even B can stand up, if I think I have a justification for something I don't actually understand: "If I believe something without fully understanding it, and I'm asked to give an account of what I say I believe, can I do it? Or would this reveal that the B of JTB in fact doesn't apply? - that I literally don't know what I believe." This connects with @Sam26's proposed criterion of "understanding.")

PS -- offline till Monday . . .

When do I ever know something is true apart from having the right justifications? How can we make truth independent of justification -- make J and T genuinely separate criteria? — J

We know analytic statements are true. Given competence we know that mathematical proofs are true. We know that true propositions about directly observable states of affairs are true (if we observe them).

The problem with relying on justifications is that we would need to know the justifications are true in order to be valid as justifications, which would seem to introduce an infinite regress.

But JTB is not about what makes something true, but how I can say I know it to be true. [ my bolding, your italics ] — J

I'm not sure this is right.

If we say, a person S knows that P when P is the case, they believe that P, and their belief that P is "justified," in whatever sense we give that word, then what S says or is entitled to say about their possible knowledge that P just doesn't enter into it ― unless you tie justification directly to (even to the point of identifying it with) what S says about how they know that P. That's not crazy, for a lot of reasons, but it's also not forced on us.

And there are cases where we wouldn't want to do that. You might know that the capital of Arkansas is Little Rock, but not even remember how you came to believe it, much less provide an account of that process that would convince a doubter. (Looking it up now in a source trusted by the doubter only proves that you were right, not that you weren't guessing.) There are all sorts of cases.

In general, what you say is going to reflect what you think you know, so sometimes that'll be spot on and sometimes it won't. Just as your confidence is an indicator of the truth of your claims, but a somewhat limited one, so what you offer in the way of reasons and justifications ― what you say ― is likewise only an indicator. Putting too much weight on it will lead us to include cases we oughtn't and exclude cases we oughtn't.

The reasons people say what they do might be somewhat more loosely coupled to what they know and how they know it than philosophers would prefer.

But JTB is not about what makes something true, but how I can say I know it to be true. — J

No, that's not right. JTB is not meant to provide you with a recipe for knowledge-cakes. JTB is a descriptive theory, not a normative theory. It is something like an attempt at a definition of knowledge, not an attempt at a recipe for knowledge. It is a set of conditions that is supposed to track when knowledge is present, not a strategy for gaining knowledge.

Like, someone cannot sit down and say, "Ah, I have ten minutes to spare. I'm going to get me some knowledge. I'm going to know that Jupiter is the largest planet in the solar system. So for 'true' I will ask ChatGPT. Check. It is true that Jupiter is the largest planet. Now I need to check the justification box, so I'll look up some arguments for the idea. Check. Now I need to believe it. I think I do believe it, but to make sure I'm going to sit here and repeat to myself the mantra, 'I believe Jupiter is the largest planet, I believe Jupiter is the largest planet...' Okay, well it looks like I now know that Jupiter is the largest planet, given that I have checked all three boxes. Four minutes to spare... what else should I learn today?"

JTB creates so much confusion that I think it may be more trouble than it's worth.

Must I again point out the difference between "P is true" and "I know that P is true".

These are not the same.

The link between them is that one cannot know things that are not true.

which Banno has also picked up on, namely whether the T in JTB is doing any useful work. — J

Of course it is doing useful work.

When do I ever know something is true apart from having the right justifications? How can we make truth independent of justification — J

See how, again, this asks how you know that P is true, and not whether P is true?

But the T in JTB is dependent on P's being true, not on the circularity of your knowing that P is true.

Am I misunderstanding you in some way? You seem to miss this very obvious point.

which Banno has also picked up on, namely whether the T in JTB is doing any useful work.
— J

Of course it is doing useful work. — Banno

The distinction between something's being true and our knowing it to be true is of necessary and useful―it is useful to know whether we do know something is true or not― it's better than thinking we know something is true if we don't.

A question remains though― what use is something's being true if we don't know it.

You prefer utility to truth?

Do you think you can maintain that distinction? The truth doesn't care about what is useful.

↪Janus You prefer utility to truth? — Banno

No, I didn't mean that. I don't know how you got to that conclusion.

For example, we don't know whether there is sentient life on other planets, and it is good to know that we don't know that. The other day I was at a local market and one of the stalls selling aloe vera and other herbs displayed a Raëlian poster claiming that we need to prepare for the return of the Elohim. Raëlianism is the belief that humanity was created by an advanced extraterrestrial species known as the Elohim.

It is good to know that we don't know whether there are advanced extra-terrestrial species, but the actual truth or falsity regarding that is meaningless to us, since it cannot be (currently) determined.

The truth doesn't care about what is useful. — Banno

Actually the truth presumably doesn't care about anything.

Ok, I must be misunderstanding you. We know that we don't know whether there is sentient life on other planets...

A question remains though― what use is something's being true if we don't know it. — Janus

Well we could ask whether the 'T' in JTB is "accessible" truth or "inaccessible" truth. Isn't it pretty obvious that it is "accessible" truth? Or is there some JTB proponent I am unaware of who thinks "inaccessible" truths are per se important and also central to the JTB approach?

Again, the JTB approach does not claim that truths are known independently of justification and belief. The whole point of JTB is that nothing is known independently of justification and belief.

(This is why 's concern that one must be able to explain why X is true without giving any justification is a kind of ignoratio elenchus.)

I agree that we know that we don't know in the case re alien species...There are also many truths we do know. The problem I see is that if we know something is true we must know it cannot be false, from which it seems to follow that knowledge is not defeasible.

The problem I see is that if we know something is true we must know it cannot be false — Janus

If we know something is true we must know it is not false. That's not the same as that it cannot* be false. It's not knowledge that is defeasible, but belief. Everything we know is true - just like every fact is true. Some things we think we know, are false - and therefore we do not know them.

If we think we know it's true, but it turns out it is false, then we didn't know it was true in the first place.

See how it works?


*Are we going to look at modality again? Let's not.