I've been trying to wrap my head around the justified true belief analysis of knowledge along with the fallibly justified, true belief analysis of knowledge; and there is something that keeps bothering me with the analyses. The matter that keeps bothering me is the absence of a "feeling" of knowledge.

Let's take the following example:

  1. Let's presume it's a fact that a world external to the mind exists.
  2. Let's presume that I believe that a world external to the mind exists.
  3. Let's presume that I have justification in some form for that belief.

I'm a hard skeptic, but let's presume those things as true. And, I would not be surprised if there were times when my skepticism went away and I came to believe (if beliefs can actually exist) that a world external to my mind exist; and I suppose there was some justification involved.

For any and all times, I deny that I ever felt like I had knowledge. I've been reading more into epistemology, and it seems to me that something that touches on this matter are what are called, and please correct me if I'm wrong, "luminous mental states."

I don't having a feeling of awareness, or certainty, that something is true (regardless of whether or not I believe in it. Why is it, then, that supposedly (if the things presumed are taken as true) that I know something. Shouldn't there be a feeling of certainty associated with knowing something? Has anyone ever covered this topic in philosophy?

Let's take presume that a fallibly justified, true belief is a form of knowledge.

Now, let's imagine I have a fallibly justified belief. Let's argue that this is "mental state fjb1." Let's further this by thinking that my belief is the belief that the basement light switch on. But, for this example, the switch is currently off.

Now, let's say I start thinking more about the matter and my belief changes. Now I hold the belief that the light switch is off.

I have a different mental state. But why is it, since my mental state now exists as a fallibly justified, true belief I don't have a feeling of accuracy despite having knowledge of the light switch being off?

This differs with touching something hot and holding a true belief that the thing being touched is hot. There is a corresponding mental state.

  • To a great extent, "knowledge" is just a word, with cognates in other languages (e.g. ratio cognoscendi), as well as rough synonyms in the same language. If you have an intuition that you don't "know" something, it's less that you're not aware of the thing or that you lack meaningful evidence, etc. and more that you're sensitive to the (many) uses of the word "knowledge" and are sorting through them per application. Commented Jun 17, 2023 at 18:31
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    Contingent truths are never certain. And analytic/necessary truths are content-free tautologies, ie circular. To say that a triangle is 3 sided is no different than saying a triangle is a triangle. Ie it's true without your needing to know anything about triangles
    – Rushi
    Commented Jun 17, 2023 at 18:57
  • What we call 'True', is overwhelmingly what we find useful. Is money 'real'? Our collective imagining that it is a true store of value, makes it so, yet, it's reality is not subjective, but intersubjective. See 'Why is a measured true value “TRUE”?' philosophy.stackexchange.com/questions/81655/…
    – CriglCragl
    Commented Jun 17, 2023 at 19:21
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    All beliefs have some level of uncertainty. Given this, you have two choices for the word "knowledge": (1) never use the word at all because you are always somewhat uncertain. (2) redefine the word to just mean confidence above a certain threshold, such as 95%, but still short of 100%. Of the two options (2) is the more pragmatic and useful.
    – causative
    Commented Jun 17, 2023 at 19:21
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    @causative That seems to be a false dichotomy where you have denied the existence of knowledge being possible. Commented Jun 18, 2023 at 1:05

3 Answers 3


There are these heuristic rules of discussion, called Gricean maxims, that relate to the issue of neg-raising for statements like, "I don't believe that F." Since the average judge presumably lacks countless beliefs about various things, it can seem "pragmatically inefficient" to "go out of one's way" to signal a lack of a specific belief, so we tend to read, "I don't believe that F," as interchangeable with something like, "I do believe that not F."

Now, we're not quite so inclined to switch from, "I don't know that F is true," to, "I do know that F is false." Per the pragmatics, and even in disputes with ourselves internally, the use of "know" is as a sort of question-stopper: we feel that we know something when we feel that we have no grounds for continuing to question that something in relevant ways. If we find that some questions never seem to go away, no matter what evidence or proof we think we have besides, then we experience this persistent gap between our desire to "know" and the achievement of such a goal.

Consider, for example, C. S. Peirce's pragmatic theory (or description) of truth in general:

All the followers of science are fully persuaded that the processes of investigation, if only pushed far enough, will give one certain solution to every question to which they can be applied.…The opinion which is fated to be ultimately agreed to by all who investigate, is what we mean by the truth. (1878 [1986: 273])

So if knowledge is non-accidental true belief (if that's the point of wanting to "know" things, to have true beliefs but not "by happenstance"), then the will to know is the will to resolve our (always evolving) set of questions about things as such. Evidence is typically incomplete, and formal proofs are more like clever hypotheticals, so either kind of knowledge-supporting factor does tend to leave open lots of questions, and so the pressure of inquiry continues, and we can end up going back and forth about our feeling of knowing various things (our feeling of "certainty").

But note, then, that active skepticism weakens itself when applied to itself (it doesn't have to be taken to be completely self-defeating, but to hold its own in the dialectical battle, it can't just weaken itself over and over again but has to find purchase at least in a retreat to passive skepticism, the pure "suspension of belief"). At the very least, doubting the existence of questions in general is useless when we will go on to ask questions anyway, or then when doubting is itself questioning already. But so we also often find that we didn't before understand our own lack of understanding sometimes, and a question that we stopped asking because we felt like we had it well-answered then turns into another question that we know that we don't have such a stable reply to.

Eventually, the important difference is not so much between the absence and presence of knowledge but between trivial and nontrivial, but either way present, knowledge. And since it is socially easy to slide from trivialities like, "Some truth is absolute," to absurdities like, "All truth is absolute," it is that much harder to recognize how important that difference is.

Imagine saying, "I'm not certain about what certainty is," or worse, "I know that I'm uncertain about certainty." If, in the back of your mind, you've made certainty into part of knowing in the first place, how could you be uncertain about the nature of uncertainty? It could be more reasonable, then, to just drop use of the word "certainty" (or even "knowledge") as such, or to settle on a stipulative definition.

  • I appreciate the response, but I feel that it doesn't resolve my absence of feeling that I know something if, supposedly, I know something, according to the JTB and "fJTB" analyses of knowledge. Commented Jun 17, 2023 at 23:12
  • @DennisFrancisBlewett it's not really meant to resolve a feeling, which is a more subjective issue that is inconsistent with PhilosophySE parameters for posted questions (we request that questions be posted that can be answered more by citations). Commented Jun 17, 2023 at 23:40
  • I don't feel your answer was relevant, then. Your answer did not answer my question well enough. For instance, there a failure to address if some kind of feeling, if but mental state, of certainty should be had if someone knows something. Also, I think people needing citations is elitism/"intellectual circle-jerking." Commented Jun 18, 2023 at 0:07
  • @DennisFrancisBlewett the only thing I could think to cite with regard to certainty specifically, was the SEP article on certainty, although I think that semantic intuitions are feeling-ish so mentioning Grice/related topics was then pertinent. As far as this site being about citation-supported answers, well, that's just how the site (the whole SE network, really) is intended. Philosophy is fairly elastic so there's a lot of leeway for tangents and caveats here and there, but it's still preferable to try to ask a relatively particular question per main post. Commented Jun 18, 2023 at 0:22
  • Actually, though, I was technically wrong, subjective questions are admissible when set up a specific way, although see also this help center page for broader considerations. Commented Jun 18, 2023 at 0:26

Almost everything about knowledge is contested, including the JTB itself. I shall try to signal where something is contested.

One reply is that your psychological feeling of certainty is no guide to the truth or otherwise of anything, and no guide to whether your justification is sound or not.

A qualification - Axioms and introspective knowledge are often regarded as exceptions, but not everyone would accept that they count as knowledge. The main ground for that is that you can't be wrong. Knowledge essentially involves risk (even deductive knowledge, though some people would strongly disagree - but mistakes are possible even there.)

Another qualification - Religious beliefs are another special case. People sometimes say they believe that God exists and sometimes that they know that God exists. I class such cases as special, and I'm certainly not including them in what follows.

Back to certainty. The JTB has the consequence that you cannot, on your own, validate your own beliefs as knowledge or not. ("I know that horse will win the race" says no more than "that horse will win the race" and expresses your conviction that it will. Nothing follows about whether you knew or not.) The T clause in "JTB" means that a claim to knowledge needs to be validated by other people. Similarly, whether you are justified in your belief/knowledge also needs to be validated by other people.(There's a lot of debate about what standard of justification should be applied, but that's a different issue.)

That interprets your question as "If I'm certain about something, does it follow that I know it." But I think that what you are really asking is "If I'm uncertain about something, does it follow that I do not know it." The short answer is, no. But there is a complication. If you are uncertain about something, it may well follow that you do not believe it and so do not know it. So let's look at the relation between belief and certainty.

If you have conclusive evidence that p, you are entitled to be certain that p. (There is a lot of argument about what "conclusive" means in that sentence, but let's suppose it is possible.) Then you can say not only "I believe that p" but also "p is certain". But in using "believe" you are acknowledging the possibility you might be wrong, and so you are misleading me. You should say "I know that p", but not because you are certain of it, but because you have conclusive evidence.

If you have some evidence that p, you may well decide, that, on balance, p is most likely true. Then you can say (without misleading me) "I believe that p" and "on balance, p", not because you do not feel certain, but because the evidence available to you is not conclusive. If you were to say "I know that p", you would be misleading me. What if you turn out to be right? H'm. See below.

Now, quite often, we form beliefs on very scanty evidence, which is inadvisable in academic and legal pursuits, but in practice is sometimes necessary and sometimes merely convenient. In those cases, you would be right to say that your belief is little better than a guess, but you can say "I believe that p" and "p is uncertain". What if you turn out to be right? Again, see below.

Now, I think we are getting to the really tricky bit, and not everyone agrees (though I also think that a lot depends on the details of each example, and a global answer is unreliable) Suppose we ask the way to X, and our respondent replies with "Yes - I think you take the first left, no, the second left, and then right - or is it straight on - no, it's the first right ...." we would, rightly, be very reluctant to say that they knew the way. But suppose we finally extract a coherent set of instructions and, for lack of anything better, we follow them, and it turns out that the instructions were correct. There is good reason to say that they knew, after all. I qualify that because circumstances may altet the conclusion. If, for example, it turns out that this is their first visit to the area and they were purely guessing, of course they didn't know.)

Another kind of case is this one. Someone in a supermarket is answering customer queries "Where can I find x?", "What is the price of y?" and after ten minutes of this I ask you whether they know their stuff. They have hesitated quite often, so they seem a bit uncertain. But, assuming they give the right answer consistently, I maintain that you would be justified in saying they do.

Summary, with knowledge, getting it right is more important than being justified or being certain. To put it another way, in the JTB account, T trumps J and even (in some cases) an uncertain belief.

Philosophy can induce bewilderment. Which is fine, because the questions are often bewildering and that motivates the philosophy. But it is possible to carry on an ordinary life around it.

I'm sorry this is so long, but I couldn't think of a shorter way.


You have to be strong in terms to answer such questions.

The term "knowledge" is not properly understood by you. You mix data and information with that.

Knowledge is about rules. More rules you know, more knowledeable you are. We as in all thinking beings get lots of data through our senses, arrange them to have information so our mind can work on them. Then extract rules from that. The rules make our knowledge-base.

Mathematics, physics and all sciences, philosophy even arts is about finding out the rules.

Should you be comfortable about what you know? Only when the rules you have covers all the data. If some data is left outside then you cannot feel comfortable - unless you are doped or disillusioned.

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