But of course, we could reply here that you "know it to be true" just in case you have a justified belief that it is true, and it is true. I don't think that answers J's question though, because we still have to assume the "it is true" part. — Count Timothy von Icarus

Yes. Or if not assume, at least spell out some criteria that don't merely repeat the J criteria.

Well, no. If S is some sentence that satisfies the criteria JTB, then by that very fact it is true — Banno

Surely not. This is the absurd "deduction" I was addressing above. Satisfying the JTB criteria is not what makes a sentence true. It's not the "very fact" we're looking for. What makes a sentence true will be, let's say, some version of Tarski-truth.

Or to put it another way, what makes a sentence true is satisfying T; you don't need to bring in J and B at all. The question is, Can we imagine a situation in which T would be apparent to me -- not to a hypothetical anyone, but to me, the user of the JTB criteria -- on other grounds than the J?

The circularity, so far as there is one, is in your then asking "But is it true?" — Banno

Perhaps the right question, then, is "Who knows it to be true?" Does the person applying the JTB criteria have to know this? Or is it sufficient for it merely to be the case, with no one knowing it? This leads back to my concern about the use of all this.

Hence, in most ordinary circumstances, one will affirm knowledge of what one will do later on in the day (or else of when one’s airplane will arrive), this serving as one example among many. — javra

Knowledge of what one will do later in the day is not quite the same as having intentions or plans for what one will do later. — Ludwig V

@Banno kindly already replied. But to make it maybe less tricky an issue, I’ll change the example to knowledge of a future event that is not mostly contingent on one’s intentions or plans.

Suppose one watches a regular TV series that always starts at 6pm. Does one merely believe that the series will air later on during the day at 6pm or does one know this? In commonsense speech, if one says “I believe it will air at 6pm” in reply to a question, and this without any sarcasm, one then communicates that, although one assents to the reality that it will, one nevertheless does not have reason (this, here, being sufficient justification) to be psychologically certain that it will. And why not?

On the other hand, when told that the series starts at 6pm and replying to this “dude, I know” or something to the like, one conveys that one is psychologically certain (notice that I’m not here claiming being epistemically certainty) that it will, and this because one can justify that it will via any number of means without there being any credible alternatives to the contrary. This doesn’t then imply that its impossible for this upheld knowledge to be mistaken and, thereby, to in fact not be knowledge. Maybe there will be a city-wide outage at 5:55pm that prevents the show from being aired, maybe this and maybe that, but, nevertheless, one will have no reason to find any such alternative (whose possibility could be theoretically justified) credible and thereby plausible. So one then knows the show will air later on in the day at 6pm. And when it does, one's knowledge is confirmed by factual events.

If one instead prefers to remain on the safe side, one can instead simply declare it as a belief one has. — javra

There is no safe side. One may prioritize avoiding believing something false, but that raises the risk of failing to believe something true. — Ludwig V

True. I’m guessing it should come as no surprise that the living of life is risky, even when we’re not consciously aware of it, and irrespective of how risk-adverse one might be. Every choice we make has its potential opportunities and potential costs and, hence, its risks. This is where I take personal responsibility steps into play (and maybe why making reasoned decisions we can justify given the contexts of what we are aware of during the moment of choice if often best … but hey, spontaneity sometimes is also good). With this personal responsibility then including our choosing what we deem to be knowns and what we don’t. We take our risks in life and reap the consequences, but are the risks justified? At least that's how I look at it.

This is the absurd "deduction" I was addressing above. Satisfying the JTB criteria is not what makes a sentence true. — J

Due, what's the "T"? If a sentence satisfies JTB, then it is true. Further, from "B", those who say that it satisfies the JTB account agree that it is true.

I'm genuinely at a loss to make sense of what you are saying.

That's why I say the J, T, and B are more loaded than they might first appear.

...

A "justification," of claims to be in contact with reality (in possession of knowledge) on the basis of appearances needs some metaphysics of how appearances relate to reality. If this linkage doesn't exist, I am not sure how J ever falls into place or how T would ever show up in our experience. But if J is about the private and communal imputation of status in the first place, and not about a relationship between the knower and known, how could it ever bridge the gap? — Count Timothy von Icarus

Good post. :up:

This is what I was pointing up earlier with the pool analogy. If J and T are conceived of along the lines of that analogy, then the "task" that @J has set before him is impossible by definition. None of it is as mysterious as it is being made out to be. If one's anthropology precludes the mind from knowing things, then truth will be inaccessible and any theory with a T—including JTB—will fail. For example, if T is not traditional-T but rather pragmatic-T or communal-T, then of course JTB is undermined.

Sorry if I wasn't clear. Satisfying the JTB criteria is how we know a sentence is true, supposedly. What makes it true would be some version of Tarski-truth. I was saying that one could point to a JTB-verified sentence and say, "Well, since it's a JTB, I know it's true." But this kind of knowledge doesn't involve any meaningful justifications on my part. It's a kind of reliance on authority, the authority of having passed the JTB criteria.

Possibly I also haven't been clear about why the PoV matters -- who is doing all this. The phrase "point to" is meant to raise this question. If I am the one who declares a sentence to be a JTB, then presumably I have satisfied myself, as best I can, about the T part, and provided my own justifications. But if you tell me it's a JTB, I haven't. All I can do is accept the "deduction" that, if it is indeed a JTB, then it must be true. I think you've been assuming, in this discussion, that a single person is taking all these steps, but there's nothing in JTB that requires that. We don't ask, "Have I verified that this sentence is true?" but rather "Is this sentence true?"; we don't ask "Have I provided good justifications?" but rather "Are there good justifications?"

Is this what JTB is for?

And thanks for your patience with this.

This is a false dilemma. John's subjective truth will be conditioned by his understanding of what mathematical truth is, which he has learnt through interaction with others who teach him. Unless that has happened John may have a subjective opinion, but it doesn't count as a mathematical opinion. — Ludwig V

Yes, the keyword here is interaction - more specfiically John's ongoing interactions with his environment that maintains a correlation between his conditioning and external truth-makers. The critical importance of ongoing interaction is both overlooked, and many would argue incompatible with, the traditional epistemological notion of apriori, intentional belief states that we are supposed to believe can make semantic and epistemological contact with truth-makers before interaction. For it isn't feasible that a propositional attitude with respect to a future-contigent proposition, can access the truthmaker of the proposition in advance of the actual interactive use of the proposition.

As Wittgenstein might have put it, both the meaning and truth of a future-contigent proposition are up in the air, because the referential semantics of a future-contigent proposition cannot decided before the truth of the proposition is evaluated, which critically undermines the traditional epistemological concept of intentional belief states that are naively presumed to consist of a teleological mental state holding in mind a possible outcome of the future before it happens.

Hence emphasising interaction rather than beliefs can resolve the dilemma of semantic-externalism or trivialism in the same way thay Bayesian Statistics does - pragmatically through making it clear that beliefs are not intentional mental states, but conventions used for interpreting and controlling behavioural conditioning, in a sense that rejects the traditionally internalist and static epistemological notion of belief states.

I'm not convinced that Wittgenstein accepted JTB, in the way Sam26 seems to think. I read him in On Certainty more as pointing out that if we do accept JTB then these are the consequences - there are for instance things that we might casually say we know that are rules out as knowledge by the JTB account. We can't know how a dog that has been run over feels. — Banno

My account of JTB+U is not the same as traditional JTB, it's more refined using Wittgenstein's methods from his later thinking. I'll partly sum it up in the following:

Extending JTB Through Wittgensteinian Methods

The classical model of knowledge—justified true belief (JTB)—says that a person knows p when three conditions are met: the belief is true, the subject believes it, and it is justified. That triad has stood since Plato, but its weak point has always been justification: what exactly counts as good reasons, and how are they grounded?

My proposal is to extend JTB with a Wittgensteinian emphasis. I call this JTB+U, where the “+U” stands for understanding. Genuine knowledge requires not only justification in some abstract sense but also competence with the relevant concepts. That competence shows itself in the correct public use of words, within the language-games and forms of life that give them their meaning. In other words, to “understand” is to be able to navigate the practices that make justification possible in the first place.

This move does two things at once:

Re-locates justification: It is not a freestanding relation between belief and evidence, but an activity carried out within specific language-games. What counts as “good reasons” is inseparable from the public standards and forms of life that sustain them.

Builds in uptake: To count as knowledge, a claim must not only be justified but also be grasped conceptually by the knower. A person may parrot a valid argument form, but without knowing the terms in use—say, “HbA1c” in a medical report—they cannot be said to know.

Traditional epistemology often treats justification as context-free, but justification lives and breathes inside particular practices. Courts, laboratories, and ordinary conversations each operate with their own standards, which are intelligible only against their background forms of life. Language-games set the grammar for justification, and hinge propositions—the arational certainties that stand fast—mark its limits.

I part ways with Wittgenstein on one important point: he treated language as bounded by insurmountable limits. I disagree. Language-games and forms of life are more open-textured than he allowed, and they evolve in ways that allow language to surpass those boundaries. Our epistemology should therefore preserve Wittgenstein’s insight into the contextual life of justification without accepting his strict metaphysical ceilings.

The upshot is a framework that is at once traditional and supple. JTB remains the core, but it is further strengthened by grounding it in the Wittgensteinian recognition that meaning, justification, and understanding are functions of practice. Knowledge claims are tested along multiple routes—testimony, logic, sensory experience, linguistic training, and pure logic—but always within the river-bed of language-games that give these routes their force.

Look, don't think:

Wittgenstein’s reminder “look, don’t think” is not an anti-intellectual gesture, but a methodological one: when philosophy drifts into abstraction, we should return to the actual use of words, to the practices in which meaning and justification live. It is a call to examine the grammar of our language-games before theorizing about their essence.

In terms of JTB+U, the maxim sharpens both justification and understanding:

For justification (J):
Traditional JTB risks treating justification as a timeless relation between belief and evidence. “Look, don’t think” tells us to attend instead to the public criteria in use: how testimony is corroborated, how sensory anchors are cross-checked, how logical inference operates in practice. Rather than imagining some metaphysical essence of justification, we look to the rules and error-signals that actually govern our language-games.

For understanding (+U):
Understanding is shown not in private conviction but in our capacity to use concepts correctly. To know is not merely to assent to a true and justified proposition, but to handle the relevant terms in the way our form of life requires. Here Wittgenstein’s maxim is the corrective: don’t speculate inwardly about what a concept really is; look outward at how the concept functions in actual practice. If someone says they “know what DNA is” but cannot use the term competently in the language-game of biology, they fail the +U condition.

In this way, “look, don’t think” guards JTB+U against two perennial errors:

Essentialism (believing knowledge must rest on some hidden inner property);

Private conviction masquerading as knowledge (thinking “I feel sure” is equivalent to being justified).

Instead, the maxim keeps our eyes on use, on the lived background where justification gets its grip and understanding is displayed.

So, in short: “Look, don’t think” is the Wittgensteinian brake on abstract theorizing that keeps JTB+U tethered to practice. It ensures that both justification and understanding are grounded in observable criteria within language-games.

For example, it would be odd for a typical westerner to say "though I believe it, I don't know whether I will eat anything tomorrow". — javra

A good example of how different people work with "know." I would in fact say just that, perhaps precisifying it: "I strongly believe that I will eat tomorrow, though there is a very slight chance that I won't." Would I also claim knowledge? This is where it really starts to get murky. According to JTB, I can't, since I don't (yet) know if "I will eat something tomorrow" is true. It may be true, in which case my claim at T1 is knowledge -- the problem is, I can only be aware of that in retrospect. In practice, however, and leaving aside the somewhat bizarre (to me) requirements of JTB, I'd rate the statement pretty low on the knowledge scale. Any number of things might prevent me from eating tomorrow, sickness especially. Whereas "The sun will rise tomorrow" gets an enthusiastic thumbs-up from me as a piece of knowledge, despite the fact that it too is not certain -- there are defeaters, as I proposed to @Janus (who wasn't impressed!).

Once again, though, we have to remember that a philosophical question such as "What is knowledge?" or "What counts as knowledge?" can be taken in at least two different ways. We can be asking, "What is the correct way to understand what knowledge is?" If we answer that, then we can go on to ameliorate the incorrect understandings and usages. The other way is to ask, "How is the word 'knowledge' used? What range of situations and applications does it cover?" If we answer this, we're no longer trying to say which (one) of the usages is correct. In fact, if it turns out that many people use "knowledge" in a manner, or in situations, that don't fit a proposed correct understanding of what knowledge is, this may, and should, give us pause. It may suggest to us that a "one size fits all" construal of knowledge is misguided. This doesn't mean that Total Chaos is now rampaging. It just means that the question is nuanced, and often depends on interpretation.

Would I also claim knowledge? This is where it really starts to get murky. According to JTB, I can't, since I don't (yet) know if "I will eat something tomorrow" is true. — J

Why not?

As I and others have pointed out in previous posts, ontological truths occur, i.e, ontological correspondence/conformity to that which is, was, or will be actual do occur. Implicit in every belief is an assent to that which is true. So when one's belief of what is true is one and the same with what is ontologically true, one's belief is true. Justification then comes into play in the following manner: if my justifications for X being true are contradictory, then they are invalid. If they are not contradictory in any way, then, irrespective of how strong or weak, there will be no reason whatsoever for me to presume my belief to not be true. This then implies that one knows in a JTB sense that one will eat something tomorrow.

I so far presume implicit in all of this an emotive desire to obtain a state wherein all possible risks of being wrong are 100% avoided. And this state of an absolute guarantee of being in no way wrong about what is ontologically true is technically termed infallibility. I don't believe that an individual ego's omniscience is possible - a different issue to this thread which I won't pursue to justify. But I do find that the only way infallibility of anything could hypothetically be obtained is if the individual ego in question happened to be omniscient - thereby having perfect awareness of all past, present, and future events in all aspects of the cosmos. And no human is.

It may suggest to us that a "one size fits all" construal of knowledge is misguided. This doesn't mean that Total Chaos is now rampaging. It just means that the question is nuanced, and often depends on interpretation. — J

Fully agree. For one example, the proposition "I know that I know X" can at least be interpreted to specify two utterly different types of knowledge at play: knowledge-by-acquaintance of having JTB knowedge regarding X.

Continuing the Explanation of JTB+U

To extend the picture, I need to clarify what the “+U” adds, how justification itself must be situated in language-games, how the five routes interlock, and how this framework addresses familiar rivals. Each step reinforces the claim that knowledge is not only a matter of true belief with reasons, but of uptake within the forms of life that make reasons intelligible.

1. The role of +U
The “understanding” condition guards against the illusion that one can count as knowing simply by repeating words linked to justification. A student may recite that “HbA1c above 6.5 signals diabetes,” but unless they understand what HbA1c measures and why that threshold matters, their belief does not rise to knowledge. The difference lies in the correct public use of concepts. Understanding is shown in practice, not in private conviction. This is why Wittgenstein reminds us to “look, don’t think”: look to the use of terms in their home setting, not to an imagined essence behind them.

2. Justification in language-games
What counts as justification is not determined once and for all, but by the grammar of the practice in which the claim is made. In law, justification rests on admissible evidence and procedural safeguards; in science, on reproducibility, statistical thresholds, and peer scrutiny; in everyday life, on testimony that lacks defeaters. Each form of life sets its own standards. To ask for justification without reference to a language-game is to float free of the river-bed. JTB+U insists that we situate reasons where they belong, not in abstraction but in practice.

3. The five routes working together
My method recognizes five primary routes of justification: testimony, logic, sensory experience, linguistic training, and pure logic. Each has its own integrity, but they rarely operate in isolation. Testimony is checked by sensory anchors; logic binds testimony and perception into argument; linguistic training disciplines our terms, keeping them clear of confusion; pure logic secures consistency at the boundaries. When these routes converge, belief gains strength. When they diverge, we look for defeaters. This interlocking structure keeps justification tied to the lived world.

4. Answering rivals
Seen in this light, the JTB+U framework offers replies to classic objections. Gettier’s puzzles lose force because a belief that is true by accident but not conceptually taken up within the relevant practice fails the +U condition. Relativism is resisted because language-games are not arbitrary; they are bound by hinges—what stands fast in our shared form of life. Dogmatism is resisted as well, because defeater screening and practice-safety remind us that no claim is beyond correction.

The result is not a rejection of JTB but a strengthening of it. By insisting on public uptake, contextual justification, and interlocking routes, JTB+U places knowledge back where it belongs: within the activities and forms of life that give our words and reasons their grip.

Here’s a related issue:

Ought we take all affirmations of “I/you/they/etc. did, are, or will do X”, “X happened, is happening, will happen”, “X was, is, or will be Y”, and so forth to implicitly affirm mere beliefs regarding facts or statements of JTB knowledge regarding facts?

Certainly, depending on statement and its conceivable justifications, to differing degrees any such statement could be theoretically wrong. If one assumes that JTB must be absolutely devoid of any possibility of being wrong, then we all communicate all the time via beliefs which we don’t know to be true.

How would this not then result in a societal chaos of sorts wherein most all trust goes down the drain?

That said, when you tell me, “this person went there,” I always take this to be a statement regarding your knowledge of events. This unless you preface the statement with, “I believe that,” or else “I think that,” which would both, each in their own subtly different ways, convey that you cannot gather sufficient justification for the affirmation to maintain psychological certainty in its truth and, thereby, uphold it as knowledge.

Can this knowledge be mistaken? Of course. But at least here you implicitly convey that, to your own best appraisal, you can justify its ontological truth to me were I to so inquire (maybe needless to add, this without any contradictions).

Bridge: From JTB+U to Hinges

Even with justification clarified and understanding secured, the model of JTB+U does not by itself remove the regress problem. Reasons can always be asked for in turn, and if the structure were required to justify itself endlessly, no claim could ever rise to knowledge. At some point, justification reaches a stopping place—not because of a failure in reasoning, but because practices rest on certainties that are not themselves up for doubt or proof. This is where Wittgenstein’s remarks on hinges enter.

Hinge certainties function as the river-bed of thought: “I have two hands,” “the earth has existed for a long time,” or more primitively, the unreflective assurance that the ground will hold us when we walk. Such claims do not stand as ordinary propositions requiring evidence; they are the background that makes doubt and evidence possible in the first place. To doubt them globally would be to lose our footing in the very language-games that give meaning to knowledge claims.

In my own work I have drawn a parallel between these hinges and Gödel’s incompleteness theorems,
just as Gödel showed that no consistent formal system strong enough for arithmetic can prove all the truths it contains or even establish its own consistency from within, Wittgenstein shows that epistemic systems rest on unprovable certainties. Both reveal a structural limit on internal justification. Far from undermining knowledge, these limits are enabling conditions: mathematics requires axioms it cannot justify, and our epistemic practices require hinges that stand fast without proof.

Placing JTB+U against this background allows us to see its proper scope. Justification, truth, belief, and understanding all operate within practices bounded by hinges. Knowledge becomes possible not because every step can be proven, but because certain things are exempt from doubt—bedrock elements of our form of life. To see this is to shift from asking for an impossible universal ground to recognizing the lived certainties that make reasoning, language, and knowledge possible at all.

The craving for generality: Wittgenstein warned against the philosopher’s temptation to seek a single formula that captures the essence of every case. He called this the “craving for generality”: the urge to believe that a concept must rest on one hidden feature common to all its uses. But not all generality is illusion. There is a legitimate kind, which describes the recurring patterns and family resemblances that hold our practices together without reducing them to one rigid essence. The tripartite model of truth, belief, and justification belongs to this latter kind. It does not disclose the secret essence of knowledge but highlights a recurring structure that marks off knowledge from mere conviction. Adding +U strengthens that pattern, keeping it tied to competent application in practice and guarding against the mistake of treating a guiding framework as if it were an eternal definition.

Mastery of a technique: Wittgenstein often compared understanding to mastering a skill or technique. To know how to play chess is not merely to recite the rules but to make the right moves in practice. Likewise, to know a mathematical proof is not just to memorize it but to apply it under variation, extend it, and recognize mistakes. Knowledge claims, on this view, require more than stating the right words: they require competent use within a practice. This aligns perfectly with the +U in JTB+U—understanding shown in skillful use of concepts.

When Wittgenstein uses “know” epistemically, his examples remain squarely within the orbit of what the tradition would call justified true belief. He does not propose a radically new category of knowledge but reminds us that the sense of “know” always comes to light in use, and its grammar reveals the conditions of truth, belief, and justification. If I say, “I know he was on the train,” my claim is factive (it presupposes truth), I am committed to it as a belief, and I expect to be able to give reasons—tickets, eyewitnesses, timetables—if challenged. In this respect Wittgenstein does not undo the JTB model, he re-situates it: he wants us to notice the practices that give “justification” its shape in the first place.

What he strips away is the illusion of a context-independent essence. The temptation of classical epistemology is to imagine justification as a single property that attaches to beliefs in the same way across all cases. Wittgenstein shows that what counts as justification shifts with the language-game. In a courtroom, “I know” calls for evidence that can be entered into the record; in daily conversation, it may be enough that I saw it with my own eyes; in science, the standards are replication and peer review. Each of these is still JTB, but the J is made concrete only in its practice. This is why he counsels “look, don’t think”: instead of theorizing what justification must be, examine how it functions in the life of language.

On this point, Wittgenstein’s contribution is not to propose another model of knowledge beside JTB, but to dissolve the demand for an ultimate account of justification outside our forms of life. The factivity of know remains untouched, as does its commitment to belief. What changes is our view of justification: no longer a timeless condition, it is an activity rooted in our shared background. When Wittgenstein says that “knowledge is in the end based on acknowledgment” (OC §378), he is not abandoning JTB but pointing to the human practices in which justification has its weight.

Thus the upshot is clear: there is no distinct epistemic use of “know” in Wittgenstein’s later philosophy that lies beyond JTB. What he uncovers is that every epistemic use is JTB-like, yet always practice-bound. The hinge or convictional uses fall outside epistemology altogether, but the genuinely epistemic ones do not float free of the traditional model. They fall comfortably within JTB once we recognize that justification lives inside language-games, and your +U condition makes that insight explicit. To know is still to believe what is true with justification, but it is also to understand the grammar of the concepts in play, and that is what JTB+U secures.

For example, if T is not traditional-T but rather pragmatic-T or communal-T, then of course JTB is undermined. — Leontiskos

I was thinking rather the opposite. The reason people fiddle with T is to make it so that we can possess "knowledge" and access "truth" while still maintaining a view of J (and B) that makes it impossible to possess knowledge and have access to truth in their traditional sense.

The problem I see is that this just seems like equivocation. The problems of global fallibilism appear to go away because "knowledge" and "truth" have been redefined, but they aren't actually being dealt with. Now we can say things like: "I know p, but of course p might be false."



Might this not risk instrumentalizing knowledge? But the purpose of at least some knowledge isn't to do anything, or demonstrate any competency.

Also, how might this apply to moral knowledge? If one discovers that the dominant norms of one's society are, in fact, evil, how does one end up demonstrating this understanding? Pretty much by definition, one's community will think you are in error (violating U). But it does seem possible to be right about what is just, or choiceworthy, when everyone around you is wrong, and deems you to be in error, and "misusing language." For example, when Saint Gregory of Nyssa first began making a concrete Christian justification for the total abolition of slavery, this was a pretty wild claim. When he said "slavery is unjust," arguably he could be accused of misusing the term "just" in his context. And yet we tend to think he was absolutely correct here, and that his society would later come to agree with him and largely abolish slavery because he was correct.

It ensures that both justification and understanding are grounded in observable criteria within language-games. — Sam26

What about shifting contexts? As a Marxist, I might be able to justify and demonstrate understanding of the labor theory of value to other Marxists. I might also believe the theory is true. However, we have pretty good reason to think the labor theory of value is false. Can I know something that is false?

More problematically, suppose I have become versed in both Protestant and Catholic/Orthodox language games. Can I both understand and know that the Eucharist is the real body and blood of Christ, and that it is not the real body and blood of Christ because I can justify both and demonstrate a competent understanding of both?

Obviously, we might object that I cannot actually believe both (barring some sort of power of self-hypnosis perhaps), so I fail the B criteria on at least one of these. However, it seems possible that I could act like I believe both. The B criteria here seems ineluctably private, and so not "observable."

The problem I see with grounding J in current practice is that many forms of J do not seem to secure, or even lead towards truth. Some seem to positively block access to truth. So, referring back to current practice and use doesn't secure T. This would mean that knowledge exists just in case current practice and use corresponds to what is true (I think it's fair to say that no one except for the relativist vis-á-vis truth thinks this is always the case). But then there still needs to be some linkage between justification, use, and practice (@J's issue if I understand it right). Just because current practice requires that I cut out a victim's heart to keep the sun from going out won't make my justified belief, through which I demonstrate mastery of the relevant language game, true; it must also be true that this practice actually keeps the sun from going out.

But then J and U must have something to do with truth, or else they seem irrelevant, and likewise if B and U can be arbitrarily related to T, they will only ever accidentally line up with it. Presumably, J links them. But sometimes J requires that we contravene established practices that demonstrate U as well. We might decide that we have to start speaking about DNA or justice differently, before we have convinced anyone else.

I think this relates to another question. Practices and language clearly evolve over time. What causes them to change the way they do? Presumably, this is how J might relate to T and U.

In my own work I have drawn a parallel between these hinges and Gödel’s incompleteness theorems,
just as Gödel showed that no consistent formal system strong enough for arithmetic can prove all the truths it contains or even establish its own consistency from within, Wittgenstein shows that epistemic systems rest on unprovable certainties. Both reveal a structural limit on internal justification. Far from undermining knowledge, these limits are enabling conditions: mathematics requires axioms it cannot justify, and our epistemic practices require hinges that stand fast without proof. — Sam26

I am not sure about this comparison, axioms are justified and questioned all the time. If you tried to present a system with arbitrary axioms, or ones that seemed prima facie false, no one is likely to take them seriously. The gold standard is that they seem self-evident (arguably, a sort of justification). There have been intense debates over axioms, which can take place because "justification" is not itself bound by any axiomatized system. Afterall, what are the axioms for English, German, or Latin? Axioms are assessed by intuition, consequence, coherence, explanatory success, or even aesthetics, etc. Reasons/justifications are given.

But the same is true vis-a-vis these examples of hinge propositions in philosophy. They are challenged and justified. That's the whole history of philosophy. And I wouldn't want to accuse Kant and Hegel of misusing language (torturing the reader perhaps), but maybe just of being wrong or unjustified in their conclusions (particularly Kant!).

Plus, even if we accept that we must accept some things as true to engage in justification, this does not seem to entail that they are true. So the linkage between belief and truth still remains an open question.

On this point, Wittgenstein’s contribution is not to propose another model of knowledge beside JTB, but to dissolve the demand for an ultimate account of justification outside our forms of life. The factivity of know remains untouched, as does its commitment to belief. What changes is our view of justification: no longer a timeless condition, it is an activity rooted in our shared background. When Wittgenstein says that “knowledge is in the end based on acknowledgment” (OC §378), he is not abandoning JTB but pointing to the human practices in which justification has its weight. — Sam26

This account is right in line with the shifting meaning of "justification." But it seems to me to leave open the same question.

The history of "justification" as a theological term turned philosophical is itself telling here. To be "justified" was originally an internal process, a change in that which is justified. It meant "to be made righteous." With Luther, it is displaced to external divine judgement, an imputation. Then it ends up becoming a philosophical external imputation that devolves down to either the community or the individual. A "justification," of claims to be in contact with reality (in possession of knowledge) on the basis of appearances needs some metaphysics of how appearances relate to reality. If this linkage doesn't exist, I am not sure how J ever falls into place or how T would ever show up in our experience. But if J is about the private and communal imputation of status in the first place, and not about a relationship between the knower and known, how could it ever bridge the gap? — Count Timothy von Icarus

How might this apply to moral knowledge? If one discovers that the dominant norms of one's society are, in fact, evil, how does one end up demonstrating this understanding? Pretty much by definition, one's community will think you are in error. But it does seem possible to be right about what is just, or choiceworthy, when everyone around you is wrong, and deems you to be in error, and prehaps "misusing language." For example, when Saint Gregory of Nyssa first began making a concrete Christian justification for the total abolition of slavery, this was a pretty wild claim. When he said "slavery is unjust," arguably he could be accused of misusing the term "just" in his context. And yet we tend to think he was absolutely correct here, and that his society would later come to agree with him and largely abolish slavery because he was correct. — Count Timothy von Icarus

On my account, moral knowledge is possible in the same way any knowledge is possible: it requires truth, belief, justification, and understanding, situated within the language-games and forms of life that give “justification” its meaning. The claim that “slavery is unjust” is not just convictional; it is epistemic when it can be shown to cohere with the deeper grammar of moral language—justice as fairness, dignity, and reciprocity—even if the society around you has not yet taken up that use.

Objectivity without Absolutism
Objectivity in morality means that claims can be tested by public reasons, not just private conviction. Even when one’s contemporaries reject those reasons, the reasons can endure defeater screening over time. Gregory’s claim survived challenges and proved practice-safe; rival justificatory schemes (naturalizing slavery, theological rationales for domination) eventually collapsed. The enduring stability of the abolitionist claim shows that it was not merely cultural preference but a true moral proposition grasped with understanding.

The Role of +U
This is where the “+U” condition is critical. Gregory did not simply parrot “slavery is unjust”; he understood the concept of justice in a way that exposed contradictions in existing norms. To demonstrate such understanding is to handle the concept rightly, even in the face of communal resistance. Moral knowledge is thus not a matter of majority assent but of correctly grasping and applying the concepts in a way that survives both internal scrutiny and the defeater tests of history.

What about shifting contexts? As a Marxist, I might be able to justify and demonstrate understanding of the labor theory of value to other Marxists. I might also believe the theory is true. However, we have pretty good reason to think the labor theory of value is false. Can I know something that is false?

More problematically, suppose I have become versed in both Protestant and Catholic/Orthodox language games. Can I both understand and know that the Eucharist is the real body and blood of Christ, and that it is not the real body and blood of Christ because I can justify both and demonstrate a competent understanding of both?

Obviously, we might object that I cannot actually believe both (barring some sort of power of self-hypnosis perhaps), so I fail the B criteria on at least one of these. However, it seems possible that I could act like I believe both. The B criteria here seems ineluctably private, and so not "observable."

The problem I see with grounding J in current practice is that many forms of J do not seem to secure, or even lead towards truth. Some seem to positively block access to truth. So, referring back to current practice and use doesn't secure T. This would mean that knowledge exists just in case current practice and use corresponds to what is true (I think it's fair to say that no one except for the relativist vis-á-vis truth thinks this is always the case). But then there still needs to be some linkage between justification, use, and practice (@J's issue if I understand it right). Just because current practice requires that I cut out a victim's heart to keep the sun from going out won't make my justified belief, through which I demonstrate mastery of the relevant language game, true; it must also be true that this practice actually keeps the sun from going out.

But then J and U must have something to do with truth, or else they seem irrelevant, and likewise if B and U can be arbitrarily related to T, they will only ever accidentally line up with it. Presumably, J links them. But sometimes J requires that we contravene established practices that demonstrate U as well. We might decide that we have to start speaking about DNA or justice differently, before we have convinced anyone else.

I think this relates to another question. Practices and language clearly evolve over time. What causes them to change the way they do? Presumably, this is how J might relate to T and U. — Count Timothy von Icarus

1. Can I know something that is false?

No. Knowledge is factive. If a belief turns out false (like the labor theory of value as an account of price and markets), then however justified and understood it may have seemed at the time, it was not knowledge but a case of apparent knowledge. JTB+U preserves this: the T condition (truth) is non-negotiable. What you had was a justified, understood belief that later collapsed under defeaters. That does not mean JTB+U failed—it means knowledge claims are always defeasible.

2. Can I know contradictory things?

The Eucharist example is instructive. You might be able to understand both the Catholic/Orthodox and Protestant language-games, and you might be able to justify each within its practice. But you cannot believe both simultaneously in the epistemic sense. At most, you can role-play or act as though you believe both. Since JTB+U requires belief, one of these would fail the B condition. If you suspend belief and simply track the grammar of each tradition, that is competence, not knowledge. Knowledge needs commitment to one truth-claim, not simultaneous acceptance of contradictories.

3. Isn’t justification sometimes corrupt or truth-blocking?

Yes—and this is why in JTB+U justification is not free-floating but checked by practice-safety and defeater screening. A practice like Aztec human sacrifice may have had an internal logic, but the claim “cutting out hearts keeps the sun alive” cannot survive defeater screening. It conflicts with what we now know through other interlocking routes (astronomy, physics, biology). So J is not whatever counts as justification in the moment, but justification that can hold up under the pressure of cross-checks and error-signals. That’s the linkage between J, U, and T: justification is only adequate if it is safety-preserving and defeater-resistant relative to truth.

4. How do practices evolve?

Practices evolve because defeaters accumulate, because rival routes converge on better explanations, and because conceptual understanding exposes contradictions. This is why J and U are not sealed off from T: language-games are porous. A community can be wrong for a time, but over the long run, practices shift under the weight of correction. That is why Gregory’s abolitionist claim, once dismissed as misuse, later became the new grammar: it better aligned justification and understanding with what is true.

5. The big picture

So the framework looks like this:

Truth (T): non-negotiable; one cannot know falsehoods.

Belief (B): requires genuine commitment, not role-playing.

Justification (J): tied to practices but must be defeater-safe and truth-conducive.

Understanding (U): demonstrated by conceptual uptake, not parroting.

Together, JTB+U explains why false theories don’t count as knowledge, why contradictory beliefs can’t both be known, why corrupt practices don’t ground knowledge, and how evolving practices eventually bend toward truth.

On this point, Wittgenstein’s contribution is not to propose another model of knowledge beside JTB, but to dissolve the demand for an ultimate account of justification outside our forms of life. The factivity of know remains untouched, as does its commitment to belief. What changes is our view of justification: no longer a timeless condition, it is an activity rooted in our shared background. When Wittgenstein says that “knowledge is in the end based on acknowledgment” (OC §378), he is not abandoning JTB but pointing to the human practices in which justification has its weight.
— Sam26

This account is right in line with the shifting meaning of "justification." But it seems to me to leave open the same question. — Count Timothy von Icarus

You’re right that the question remains—what secures justification if it shifts with use? My point is not that justification becomes arbitrary, but that its weight lies in the river-bed of practices that give it sense. That river-bed is not static, but neither is it untethered.

What Wittgenstein helps us see is that justification is always bound to what stands fast for us at a given time: the certainties we do not doubt, the error-signals we attend to, the ways we check one another’s claims. That is why he can say knowledge rests on acknowledgment. To acknowledge is not simply to nod assent; it is to recognize a claim as fitting the grammar of our form of life.

So yes, the question presses: what if those practices are distorted, or what if our forms of life themselves evolve? Here is where JTB+U offers a refinement. Justification is not only public uptake, but uptake tethered to understanding. One can parrot reasons that “fit” in the moment, but without grasping their grammar, one does not know. Understanding functions as the hinge between practice and truth: it is what allows us to detect when a justification, though accepted, is hollow, or when a claim, though rejected, is nonetheless aligned with the deeper use of our concepts.

The open question then is not whether justification needs grounding beyond practice, but how practices themselves can be judged as truth-conducive. My answer is that they are judged over time by defeater screening, by convergence across routes of justification, and by whether they prove practice-safe when tested against the world. Practices shift because error-signals accumulate. In that shifting, knowledge does not lose its footing; it shows that our grasp of justification is corrigible, but never free-floating.

By the way, I've finished my first book, and I'm starting my second book called "Why Christianity Fails
(Weak Testimony, Fragile Evidence, and the Collapse of a Belief System). This book will probably take a while to finish, and it will be much longer (300-350 pages). I go after the core belief in Christianity, the resurrection, and demonstrate the weakness of the testimonial and historical evidence.

:up:

I think that's a good answer. A difficulty in epistemology that I think is often under addressed is that the idea that knowledge "progresses" (e.g., "scientific progress," "moral progress," etc.) needs to be justified itself. The original Enlightenment justification for this was theological, and so if it is adopted in a secular naturalist context it needs another sort of justification. However, historically, it does not seem that technological, scientific, moral, or philosophical progress is assured. They don't seem to have always occurred; periods of regression show up as well. The early secular narratives that put forth the idea that only "superstition" blocks the path to progress seem too simplistic to account for this (they seem like downright ideological propaganda a century on TBH).

However, there are still plenty of issues. What constitutes an "error" or "failure" is itself dependent on goals and understandings that are always shifting. Consider the contemporary traditionalist critique that crashing fertility rates are a sign that exclusive humanism is maladaptive. Well, if it really does go extinct because its population falls by more than half each generation, and the dominant paradigm a century from now is something more in line with the traditionalist ethos, shall it thus be true that secular exclusive humanism was discovered to be a sort of error? From the exclusive humanist perspective, this would not prove it was in error; its own extinction would not be evidence of the truth of religion, tradition, etc., only of those traditions' reproductive value (indeed, anti-natalists would probably argue that religion is reproductively successful precisely because it is false). But this shows that "success" might arguably correlate with falsehood not truth.

I think your response works best in terms of technological questions where "success" is fairly easy to define. Either a plane crashes or it doesn't. It becomes much more difficult in political, social, moral, philosophical, etc. questions. For example, arguably the main liability to Scholastic thought in the early modern period was not its apparent falsity (or its dogmatically asserted "dogmatism") but that it absolutely did not lend itself to pamphlets aimed at a common audience, the new dominant market for philosophy, and that its institutions became prime targets for political violence and expropriation.

So, there is the issue that past "successes" and "errors" are being defined in terms of current practice. There is a bit of a "history is written by the victors" problem. There is also the problem posed by Hoffmann's "Fitness Beats Truth Theorem" and similar arguments, where selection-based approaches to belief do not ensure that beliefs are true. Fitness does not seem to be equivalent with truth in how information (or beliefs/memes) replicate. But then if our justification for our own beliefs rests on a selection model, this ends up being self-refuting. If our selection theory is true, we ought not believe our own beliefs are true, because their fitness is only loosely related to their truth.

Nonetheless, I think selection can be an important factor in explaining progress, just not the only factor. The other issue here is that it would only suggest that knowledge will be produced in the long run, not that we have it now. But if we aren't likely to have true beliefs now, then we ought not believe in our own progress narratives (a similar sort of issue). Hence, I think a stronger linkage is needed.

As I and others have pointed out in previous posts, ontological truths occur, i.e, ontological correspondence/conformity to that which is, was, or will be actual do occur. Implicit in every belief is an assent to that which is true. — javra

Before I reply in any detail, let me be sure I understand you. Are you saying there are ontological truths about the future? That is, the future exists now in such a way that statements about it are, at this moment, either true or false? (I think this is what you mean by an ontological truth?)

If one assumes that JTB must be absolutely devoid of any possibility of being wrong, then we all communicate all the time via beliefs which we don’t know to be true.

How would this not then result in a societal chaos of sorts wherein most all trust goes down the drain? — javra

I'm not sure that societal chaos would follow, but I agree with your point about JTB. That's part of why I'm hesitant to accept it as a good description of knowledge.

Sometimes it helps to pull back from the intricate details and ask ourselves, What are we trying to say about knowledge and truth? JTB seems to be saying, "You can only know something if it's true." Or wait . . . maybe it's saying, "You can only know something if, right now, you are sure it's true." Which is it? There seems to be support on this thread for the former construal: All that matters is that Statement P is true, not whether I can know that to be the case.

I think that, for JTB to be worth using, it ought to take us closer to the second construal: My claiming that P is true ought to say something about what I actually do have some surety about. And this is not a binary judgment. Our justifications will vary in strength. How strong does a J have to be in order to cross the "sure" barrier? I don't know if that's answerable. It's a bit like the old "heap" problem. Is there some line we can name, below which I'm not quite sure, and above which I am? (Notice that I'm using "sure" instead of "certain" or "have knowledge," because I don't want the potential circle to confuse this question.)

The who in JTB is most reliant on the belief. That's where the propositional attitude enters, and so the person who has the attitude.

Hence if you know something, then by that very fact you believe it.

If someone says we know such-and-such, it remains up to you to decide if they are correct - to decide if you believe them.

Still not seeing much here. I'll read the rest of the stuff from overnight.

I think that's a good answer. A difficulty in epistemology that I think is often under addressed is that the idea that knowledge "progresses" (e.g., "scientific progress," "moral progress," etc.) needs to be justified itself. The original Enlightenment justification for this was theological, and so if it is adopted in a secular naturalist context it needs another sort of justification. However, historically, it does not seem that technological, scientific, moral, or philosophical progress is assured. They don't seem to have always occurred; periods of regression show up as well. The early secular narratives that put forth the idea that only "superstition" blocks the path to progress seem too simplistic to account for this (they seem like downright ideological propaganda a century on TBH).

However, there are still plenty of issues. What constitutes an "error" or "failure" is itself dependent on goals and understandings that are always shifting. Consider the contemporary traditionalist critique that crashing fertility rates are a sign that exclusive humanism is maladaptive. Well, if it really does go extinct because its population falls by more than half each generation, and the dominant paradigm a century from now is something more in line with the traditionalist ethos, shall it thus be true that secular exclusive humanism was discovered to be a sort of error? From the exclusive humanist perspective, this would not prove it was in error; its own extinction would not be evidence of the truth of religion, tradition, etc., only of those traditions' reproductive value (indeed, anti-natalists would probably argue that religion is reproductively successful precisely because it is false). But this shows that "success" might arguably correlate with falsehood not truth.

I think your response works best in terms of technological questions where "success" is fairly easy to define. Either a plane crashes or it doesn't. It becomes much more difficult in political, social, moral, philosophical, etc. questions. For example, arguably the main liability to Scholastic thought in the early modern period was not its apparent falsity (or its dogmatically asserted "dogmatism") but that it absolutely did not lend itself to pamphlets aimed at a common audience, the new dominant market for philosophy, and that its institutions became prime targets for political violence and expropriation.

So, there is the issue that past "successes" and "errors" are being defined in terms of current practice. There is a bit of a "history is written by the victors" problem. There is also the problem posed by Hoffmann's "Fitness Beats Truth Theorem" and similar arguments, where selection-based approaches to belief do not ensure that beliefs are true. Fitness does not seem to be equivalent with truth in how information (or beliefs/memes) replicate. But then if our justification for our own beliefs rests on a selection model, this ends up being self-refuting. If our selection theory is true, we ought not believe our own beliefs are true, because their fitness is only loosely related to their truth.

Nonetheless, I think selection can be an important factor in explaining progress, just not the only factor. The other issue here is that it would only suggest that knowledge will be produced in the long run, not that we have it now. But if we aren't likely to have true beliefs now, then we ought not believe in our own progress narratives (a similar sort of issue). Hence, I think a stronger linkage is needed. — Count Timothy von Icarus

I agree that narratives of inevitable progress, whether Enlightenment or later, tend to oversimplify. Knowledge does not advance in a straight line. There are periods of regression, distortion, and even collapse of practices. What JTB+U gives us is not a guarantee of progress but a way of making sense of how correction is possible when progress does occur.

The key is to separate two things: (1) the sociological fact of which beliefs or practices dominate, and (2) the epistemic status of claims. The fact that a tradition survives or reproduces more effectively does not by itself prove truth. Fitness can select for falsehood as easily as for truth. The “Fitness Beats Truth Theorem” makes this plain. But epistemic justification is not reducible to fitness. A belief counts as knowledge only if it is true, believed, justified, and understood. That standard is higher than survival-value alone, which is why extinction or dominance cannot by themselves settle the matter.

Still, practices evolve. And they evolve in part because defeaters accumulate: rival routes of justification expose contradictions, or experience undercuts established norms. Scholasticism did not vanish simply because it lacked pamphleteers; it lost its grip on the justificatory practices of the time. Competing frameworks proved more effective at handling error-signals and sustaining inquiry in new conditions. That does not mean the older framework was false because it disappeared, but that its justificatory practices could not carry forward.

So I would put it this way: JTB+U does not assure progress, but it explains what progress consists in when it happens. A belief that is true, justified within its language-game, and understood conceptually can survive the test of defeaters across time. Sometimes it will be suppressed, sometimes ignored, sometimes distorted. But when it resurfaces and proves practice-safe under renewed scrutiny, that is a mark of epistemic progress.

This also clarifies why “success” in the practical sense (planes flying, vaccines working) and “success” in the moral or philosophical sense look so different. In technology, error-signals are immediate and decisive. In moral and political life, error-signals can be deferred, resisted, or disguised. That makes progress slower and less assured, but not impossible. Over the long run, justification and understanding are forced to adjust as contradictions mount. The abolition of slavery or the recognition of human rights are not simply products of fitness; they are instances where justification and truth finally aligned, and practices evolved to acknowledge it.

In that sense, knowledge does not march inevitably forward. But when it advances, it is not because victors wrote the history, but because some beliefs endured defeater screening while others failed. That is the “stronger linkage”: progress is not guaranteed, but possible because truth exerts pressure over time through the interlocking routes of justification.

Before I reply in any detail, let me be sure I understand you. Are you saying there are ontological truths about the future? — J

Yes.

That is, the future exists now in such a way that statements about it are, at this moment, either true or false? — J

No.

Future actualities that are not yet actual int he present will happen. If one's belief of what will be a future actuality conforms/correlates to what will in fact be a future actuality, then one's current belief in the present is true by definition of truth. Hence, the "sun will rise again tomorrow" is either true or false, this being contingent on whether or not it will.

TB seems to be saying, "You can only know something if it's true." Or wait . . . maybe it's saying, "You can only know something if, right now, you are sure it's true." Which is it? — J

Why not both at the same time? The first by entailment. The second only due to the valid, and hence non-contradictory, justifications one could provide for its ontological truth granting one the sureness that it is true. As far as I can tell, both are necessary for any JTB form of knowledge.

OK. Is there any activity that you see as a non-physical activity? Unless there is, you've deprived "physical activity" of its meaning. — Ludwig V

I'll be convinced of that when you can point to a non-physical activity. I say all activities involve energy, and I count energy as being physical.

If say I am certain that something is the case, then I mean that there cannot be any doubt about it. Then I would say I know it to be the case. If I think something is the case but there is any possible doubt it, then I would say that I believe it to be the case, but do not know it to be.
— Janus
There is a difference between the possibility something might not be the case and it actually not being the case. You are treating mere possibilities as if they were actual. — Ludwig V

I'm not treating mere possibilities as though they are actual at all. I've already said I have no truck with radical skepticism that is based on the mere logical possibility that I might be deceived. All I'm saying is that I will not claim to know something is the case if I see any possibility of its not being the case. Depending on how I gauge the likelihood of the possibility that it not be the case, I might nonetheless believe it to be the case—that is provisionally accept that is the case.

For example I will say I know I am typing at this computer, or that I see the towel on the line outside my window being moved by the breeze, because I see no possibility of reasonable doubt about those.

Why? Where does it say that it is not possible to know something but not to know that you know it? It isn't like a pain or a taste, where what I say determines the truth. I suspect that you are thinking of the first person "I know that I know..." But it is perfectly possible for me to say "Janus knows that p, though he thinks that he believes it." — Ludwig V

I'm not saying it is "said anywhere", but that the idea of knowing something yet not knowing that you know it makes no sense to me, except in cases where I may not recall that I knew something. Even there, can I be said to know something I previously knew if I can no longer recall knowing it? Knowing that you know something consists in being able to explain how you know it, in my view.

Can the justifications for thinking it true be themselves true even if the theory is false?
— Janus
Yes, if the justification is not conclusive - i.e. not sufficient. — Ludwig V

How do we ever know when the justifications are sufficient to warrant thinking something is true? That is the problem that leads me to think that if it is a matter of justification, then we are talking about belief, not knowledge. If I am certain I don't require justification.

I see why this is attractive. "Possible doubt" is the question, though. Is it possible that the sun will not rise tomorrow? — J

It is logically possible that the laws of nature might change and the Sun burns itself out in seconds rather than taking billions of years. But that is, if all our scientific understanding is correct, not physically possible. The alien race scenario may or may not be physically possible, but it seems so vanishingly unlikely that it would be perverse to take it as a reasonable doubt. So I would say that I do know the Sun will rise tomorrow because I cannot see any possibility of reasonable doubt that it will.

Right, and to restate my point, J's objection holds against any theory of knowledge which takes truth to be a necessary condition of knowledge, and this is not just JTB, it is pretty much every theory of knowledge. — Leontiskos

I am not sure about that implication of what @J has been arguing, but I think truth is a necessary condition of knowledge, and I also think knowing the truth and knowing how you know it is also a necessary condition of knowledge. That said, I am not claiming that we cannot think we have knowledge and yet be wrong.

As I have said in the past, I would want to use the words valid/invalid and sound/unsound for justifications, and true/false for propositions. That itself clears up part of your conundrum, albeit not all of it

Regarding Evolution, I think it is clear that the theory of Evolution is not knowledge in the strictest sense (scientia), and therefore it is not demonstrable. The theory of Evolution involves precisely the sort of probabilistic guesses that some take all knowledge to be bound up with. — Leontiskos

I take the ToE to be a way of understanding, like all scientific theories. We can say it differently and say theories are ways of knowing, but that is a different sense of knowing than "knowing that", or propositional knowledge. I would not say that we know the ToE (as opposed to evolution as such) to be wholly true, it may have parts that will be superceded, for example. One example of this is that the "central dogma" (that acquired characteristics cannot be inherited) has turned out to be thought to be not strictly true with the development of epigenetics.

Whereas "The sun will rise tomorrow" gets an enthusiastic thumbs-up from me as a piece of knowledge, despite the fact that it too is not certain -- there are defeaters, as I proposed to Janus (who wasn't impressed!). — J

I responded to this example of yours for the first time in this very post, so I'm not sure what you mean when you say I was "not impressed'. As you will see if you read the above I agree with you that I think it is reasonable to say we know the Sun will rise tomorrow.

I was thinking rather the opposite. The reason people fiddle with T is to make it so that we can possess "knowledge" and access "truth" while still maintaining a view of J (and B) that makes it impossible to possess knowledge and have access to truth in their traditional sense. — Count Timothy von Icarus

Right, I am saying the same thing.

The problem I see is that this just seems like equivocation. The problems of global fallibilism appear to go away because "knowledge" and "truth" have been redefined, but they aren't actually being dealt with. — Count Timothy von Icarus

Yes, and my point is that if one rejects the traditional sense of truth then JTB in its traditional sense naturally falls. Perhaps I should have not spoken about 'T' in the way that I did, since what I said could be read as claiming that someone who replaces traditional T with some other T will thereby reject JTB in the non-traditional sense. That's not quite what I was meaning to say, but I think it is also true.

I think this relates to another question. Practices and language clearly evolve over time. What causes them to change the way they do? Presumably, this is how J might relate to T and U.

In my own work I have drawn a parallel between these hinges and Gödel’s incompleteness theorems,
just as Gödel showed that no consistent formal system strong enough for arithmetic can prove all the truths it contains or even establish its own consistency from within, Wittgenstein shows that epistemic systems rest on unprovable certainties. Both reveal a structural limit on internal justification. Far from undermining knowledge, these limits are enabling conditions: mathematics requires axioms it cannot justify, and our epistemic practices require hinges that stand fast without proof.
— Sam26

I am not sure about this comparison, axioms are justified and questioned all the time. If you tried to present a system with arbitrary axioms, or ones that seemed prima facie false, no one is likely to take them seriously. The gold standard is that they seem self-evident (arguably, a sort of justification). There have been intense debates over axioms, which can take place because "justification" is not itself bound by any axiomatized system. Afterall, what are the axioms for English, German, or Latin? Axioms are assessed by intuition, consequence, coherence, explanatory success, or even aesthetics, etc. Reasons/justifications are given. — Count Timothy von Icarus

I think that axioms are a misleading interpretation of Wittgenstein's hinges.

i) Axioms are typically used to represent truth-apt empirical hypotheses.
ii) Axioms are stated in advance of proving theorems.
iii) Axioms are detachable and optional parts of a reasoning system .

i suspect that neither i,ii,or iii are generally true of Wittgenstein's hinges. To think this way would be to construe Wittgenstein as being committed to traditional foundationalist epistemology built upon logical atomism, as naturally embodied by the intended interpretation of an axiomatic system, which most Wittgensteinians think to be a gross misconstrual of his later ideas.

Nevetheless, the later Wittgenstein's epistemological views still come across as immature and lacking in sophistication when compared to the detailed accounts of scientific knowledge and justification by Carnap and Quine. To me, Wittgenstein sometimes comes across as a descriptive Carnapian, in the sense that like Carnap, Wittgenstein seemed to think (as in OC) that it was useful to delineate the internal questions of truth and justification that make sense from within a particular linguistic framework, from the external questions concerning the choice of linguistic framework. But unlike Carnap, I don't think that Wittgenstein saw the internal-external distinction as having prescriptive epistemological value, for essentially the same reasons as Quine; namely due to rejecting the analytic-synthetic distinction.

If Wittgenstein had fully rejected the logical atomism of the Tractatus, and if he wasn't comitted to the picture theory of meaning and the accompanying idea of intentional propositional attitudes that the picture theory of meaning is wedded to, and if Wittgenstein wasn't committed to the analytic synthetic distinction, then presuambly Wittgenstein's later epistemological views were closer to Quine's confirmation holism, in which case hinges are merely entrenched but revisable assertions, even if they are fixed for all intents and purposes within specific cases of reasoning.

I think that is a fair reading. IIRC, Godel was something of a platonist, so his reading of axioms would also not be that they are unjustified.



:up:



Well, if you acknowledge that regression can occur, then it seems that defeaters can appear to pile up against a position, and yet this is itself a sort of illusion or product of pathological justification. So my question then is: "how do you know that what you think are defeaters and are progressive evolution really are?"

For instance, scholasticism didn't disappear. It still has a fairly robust presence in philosophical publications, perhaps more than a century ago. How are you sure that your identification of errors and defeaters is correct?

Or in the religion example, you seem to accept that no matter if it comes to be affirmed, it will be false. But if it comes to be affirmed, surely people will be able to argue, with justification, that defeaters and errors piled up within the secular naturalist/ exclusive humanist paradigm, and they will claim that this is precisely why it collapsed. Indeed, plenty of thinkers (and not just religious ones) do claim that errors and defeaters against naturalism have indeed piled up, and that it is on its way out. The fact that evolutionary narratives of knowledge seem to be self-refuting is precisely one of the issues here.

JTB seems to be saying, "You can only know something if it's true." Or wait . . . maybe it's saying, "You can only know something if, right now, you are sure it's true." Which is it?
— J

Why not both at the same time? — javra

Because they aren't asserting the same thing, or at least we need an argument to show that they do. The first speaks of the truth of a statement ("something") irrespective of whether I know it to be true. The second brings me into the picture, insisting that I have to be sure it's true.

Otherwise, it's all circular. "I know X" becomes the same thing as "I know that X is true." But this presupposes that "knowing X" involves a definition of knowledge that include knowing that X is true. Isn't this what JTB was supposed to demonstrate?

Filling in with an example:

1 - "I know that I live in Maryland"
2 - "I know that 'I live in Maryland' is true"

What is our warrant for claiming that 1 and 2 assert the same thing? Doesn't it involve a stipulation or presupposition about what it means to know something -- specifically, a stipulation involving the term "true"? Statement 2 talks about what is true, statement 1 does not. But isn't this the very thing JTB is supposed to give us? -- a reason to include the truth of a statement as part of the knowledge claim?

But also, see my previous comments about the inquiry into "What is knowledge?" JTB wants to pin down the correct use of "I know"; I'm suggesting that it might be more profitable to look at the ways we actually use "I know." I don't think they correspond to JTB. There are many things I believe I know, but am not certain they are true. JTB would argue that, therefore, I'm using "know" incorrectly. Whereas I'm saying that it's JTB that needs correction, not me. This latter position lacks punch, of course, unless the "me" can be turned into "us" with sufficient frequency. We need a fairly widespread agreement on the faults of JTB in order to claim that it doesn't capture our common practice.

EDIT: I agree that it isn't possible to claim 1 without also claiming 2, and vice versa. Perhaps that's all you mean by "Why not both?" If so, it's fine. My argument above is that they are nonetheless different claims. And consider a 3rd statement: "'I live in Maryland' is true." This can be the case even if I don't know I live in Maryland.

Well, if you acknowledge that regression can occur, then it seems that defeaters can appear to pile up against a position, and yet this is itself a sort of illusion or product of pathological justification. So my question then is: "how do you know that what you think are defeaters and are progressive evolution really are?" — Count Timothy von Icarus

My system fixes the regression problem. I said that "there are periods of regression," just as there are periods where one thinks that a particular conclusion is knowledge, but later it's found to have flaws/defeaters.

Your question "how do you know that what you think are defeaters and are progressive evolution really are?" is the right question to ask, because it highlights the difference between thinking one has a defeater and actually having one. JTB+U is built precisely to keep that distinction clear.

A defeater is not just whatever I take to undermine a claim. It has to stand up within the interlocking routes of justification and not collapse under cross-examination. Suppose I call something a defeater—say, new evidence, or a conceptual contradiction. The question is then whether that supposed defeater is itself truth-conducive, practice-safe, and able to endure scrutiny across language-games. If it turns out to be mistaken, then it was not a genuine defeater but an apparent one.

The same applies to what looks like “progressive evolution.” The fact that practices change does not mean they are evolving toward truth. What secures progress is not the mere shift but whether the change holds up under defeater screening, survives error-signals, and continues to cohere with the deeper grammar of our concepts. Many shifts are later revealed as regressions—false starts that fail the test of time. Others, like the recognition of human rights, survive repeated challenges and show themselves to be knowledge rather than temporary consensus.

So my answer is: I do not “know” in advance that this or that shift is progress. What I can do is apply the JTB+U framework as best as I can—testing for truth, justification, belief, and understanding, and watching to see whether putative defeaters actually endure. Progress is visible in retrospect when claims prove stable across scrutiny and when rival justifications collapse. That is what makes them knowledge rather than mere opinion.

Your question "how do you know that what you think are defeaters and are progressive evolution really are?" is the right question to ask, because it highlights the difference between thinking one has a defeater and actually having one. JTB+U is built precisely to keep that distinction clear. — Sam26

Isn't understanding the same thing as justification? I'm not sure what the U adds to JTB, given that we assess understanding in terms of justifications.

As for deciding whether a refutation is valid or not, this rests upon the truth of one's auxiliary hypotheses. So unless those can also be tested, one cannot know whether the refutation is valid, which is the staple criticism of Popper's falsificationism - that individual hypotheses are impossible to test, since their validity stands and falls with the truth of every other hypothesis. So the bridge from practical refutation in everyday life, which often involves the testing of individual hypotheses under the assumption of true auxilliary hypotheses, doesn't withstand skeptical scrutinty and the standards demanded by scientific epistemology - an essentially unattainable standard, relegating JTB to the realm of the impossible, or to the realm of semantics that is epistemically vacuous.

Justified True Beliefs, isn't that mostly rhetorical clothing for our instincts? Reasons are post-hoc rationalizations of our drives. A life-preserving fiction that looks backwards at that which has already been done. And doesn't change that fact whether justified or not. Who needs to believe when one can simply create and affirm that which is created?