Typically knowledge is formulated as justified, true, belief. Is there a word for an unjustified, true, belief?

Edit: Lets say for a moment that you think that all Asians are martial artists. This is a false and therefore not something you can use to justify something else. However, because of that, you conclude that because Jackie Chan is Asian, Jackie Chan is a martial artist. It happens to be true that Jackie Chan is a martial artist. You believe it and it's true, but it's not properly justified.

  • Comments are not for extended discussion; this conversation has been moved to chat.
    – tchrist
    Apr 22, 2017 at 18:58
  • Belief: "an acceptance that something exists or is true, especially one without proof." Jun 13, 2019 at 0:39

11 Answers 11


Maybe a "lucky guess?" This phrase is often used when someone gets the right answer, but we know they have no idea why it's correct.

  • 3
    Yup, with the coordinate terms blind or dumb luck describing the completely unjustified nature of the answer's selection.
    – lly
    Apr 13, 2017 at 16:26
  • 5
    +1 I wonder if you knew this or had a lucky guess.
    – vickyace
    Apr 13, 2017 at 16:33

Is there a word for an unjustified, true, belief?

Depends how unjustified you mean. Below are a bunch of terms that might fit. Off-hand, it seems like postulate, conjecture, speculation, or faith might fit, depending on what you mean by "unjustified".

  • definition: Defined as true, mostly used to refer to a trivially simple concept.

  • axiom: Defined as true, mostly used to refer to non-trivial concepts.

  • postulate: Believed to be true, supported by a strong sense of analytical correctness.

  • law: Believed to be true, supported by overwhelming evidence.

  • theorem: Believed to be true, supported by strong evidence.

    • In logical fields (e.g. math; logic; computer science), proof is more analytical and generally regarded as irrefutable unless there's a major paradigm shift in understanding.

    • In sciences, a theory is a very strongly evidenced belief, but not quite as strong as a law.

  • hypothesis: Suspected to possibly be true, but yet unproven.

    • Often implies a desire to seek further evidence.
  • conjecture: Quite plausibly true, but unproven and may be doubted.

  • speculation: Plausibly true, but significant reason to doubt.

    • motivated speculation: Plausibly true, plus some reason to suspect it.
    • unmotivated speculation: Plausibly true, without reason to suspect it.
  • faith: Believed to be true, but no evidence nor logical motivation.

  • false belief: Believed to be true, but strong evidence against.

  • delusion: Believed to be true, but overwhelming evidence against.

  • falsehood: Not believed to be true.

  • 3
    That's a lovely chain of definitions. It doesn't really fit this post at all, where OP is specifically asking for unjustified but accurate belief, but you should repost it when a more fitting topic comes up.
    – lly
    Apr 14, 2017 at 2:21
  • in another of its meanings faith should go on the top of this list with "faith: Defined as true, mostly used to refer to a non-trivial, complex concept." You know, like religious faith and stuff. Apr 14, 2017 at 7:24

tl;dr- In math jargon, a "howler" is a correct result obtained through unsound reasoning. However, this usage appears to be jargon, and the same term can be interpreted different ways.


In math, a correct result arrived at through an unsound method has been called a howler:

  1. Mathematical errors occur in many different forms. In his short treatment of the topic, E. A. Maxwell distinguished the simple mistake, which may be caused by ‘a momentary aberration, a slip in writing, or the misreading of earlier work’, from the howler, ‘an error which leads innocently to a correct result’, and the fallacy, which ‘leads by guile to a wrong but plausible conclusion’ (Maxwell, 1959, p. 9).

    We might gloss this preliminary taxonomy of mathematical error as correlating the (in)correctness of the result to the (un)soundness of the method, as in Table 1.

                   |  True Result    False Result
      Sound Method |   Correct         Fallacy
    Unsound Method |   Howler          Mistake

    Table 1. A Preliminary Typology of Mathematical Error

    –"Learning from our Mistakes—but Especially from our Fallacies and Howlers", Andrew Aberdein (PDF)

  2. Howlers

    Examples exist of mathematically correct results derived by incorrect lines of reasoning. Such an argument, however true the conclusion, is mathematically invalid and is commonly known as a howler.

    "Mathematical fallacy", Wikipedia

"Howler (error)", Wikipedia, discusses the word. Apparently howler isn't commonly understood in the sense cited above, so this may be regarded as math jargon.

Note: There probably isn't a non-jargon alternative.

Apparently "howler" was coined in 1959, in "Fallacies in Mathematics" by Edwin A. Maxwell.

Since Maxwell did his PhD dissertation in Math at the University of Cambridge, and published a book on mathematical fallacies, I assume that he'd be well-aware of any preexisting term for a "howler" if one had existed and just used that. Since he didn't, this seems to strongly suggest that there isn't (or at least wasn't) a non-jargon alternative.


  1. I haven't been able to find a good term for the same searching on Google just now.

  2. The above sources, including Wikipedia, don't mention any alternatives.

For these reasons, it seems unlikely that there's a non-jargon alternative to "howler" for a correct result arrived at through unsound reasoning.

Therefore, non-jargon terms for this concept will likely need to be constructed using multiple words.

  • I previously answered this question, but looking back at it, it seems that the question was clarified in an edit. This answer is meant to address the clarified version of the question.
    – Nat
    Jun 11, 2019 at 23:49
  • I wish this had been addressed on math.SE. I have never heard of 'howler' used in math as 'true but unsoundly supported'. If anything 'howler' might be applied to a terribly mistaken proof attempt of an otherwise established theorem only because it is something 'obviously wrong to everyone else' (which is what a 'howler' is. 'Badly supported truths' are a very small subset of howlers in math. I distrust that the sentence in wikipedia faithfully represents what is in the reference. What is a howler is the erroneous process, not the truth being proven.
    – Mitch
    Jun 12, 2019 at 13:25
  • 1
    @Mitch: The Wikipedia page did appear to relate what the 1959-book described a "howler" as in its "Chapter 1: The Mistake, The Howler, and the Fallacy". That said, it did seem like an odd usage, and it looks like both of the references cited above (the PDF and Wikipedia article) have been taken down (though Wikipedia retains a sub-section for "howler" in a different article). Might update/delete this answer later.
    – Nat
    Oct 9, 2022 at 11:26

For some values of religious belief, faith is going to be a term applied to an accurate assessment of G-d and Its relation to mankind without any solid rational basis for that assessment.

Obviously, atheists and/or Wittgenstein would take exception to the application of the word "true" to the knowledge being claimed.

  • Comments are not for extended discussion; this conversation has been moved to chat.
    – tchrist
    Apr 13, 2017 at 22:40
  • @tchrist That's fine, but the post with the link to the OED entry could've stayed. In any case, @ others, the OED cite is available via the link in T. Christ's message.
    – lly
    Apr 14, 2017 at 2:16
  • The definition of faith your reasoning using is only 1 of at least 6 definitions for the word. I find that irresponsible and your post to be unnecessarily demeaning of those who have faith. You could stick to the facts. Mentioning atheism to help define your word is a polemic.
    – ErikE
    Apr 23, 2017 at 20:00
  • @tchrist Can we get this insecure whinge shunted to chat with the rest? or am I able to do that myself somehow?
    – lly
    Apr 24, 2017 at 7:55
  • A more serious objection to this answer is that 'faith' may be misplaced in certain situations: faith in a person who then lets you down, say. Unsubstantiated and not 'true_. Jun 12, 2019 at 12:48

A Gettier Case. Your knowledge or lack thereof is 'Gettiered' when it fails to correspond to JTB theory.


It would appear1 that there is no single word that encompasses the meanings of both "lacking in justification" and "true". Therefore, a phrase must be used, and I would suggest "unsubstantiated" as the most appropriate word for the first part. Thus you could say that "Jackie Chan is a martial artist" is an unsubstantiated truth (or ...fact or ...belief).

This is, in my opinion, a better phrase than unjustified truth/belief/fact since I believe that latter carries connotations of being wrong in asserting the truth (or holding the belief etc.). Unsubstantiated just says we haven't shown it to be true or false.

The OED's entry for unsubstantiated links to the second sense of "un-":

un, prefix

  1. Prefixed to past participles, forming adjectives expressing the fact that the specified action has not been carried out.

and its entry for substantiated:

substantiated, adj.

That has been substantiated (in various senses of the verb); given substance, made real. Now usually: (of a fact, claim, etc.) verified, justified with evidence.

(Emphasis mine in both cases). So an unsubstantiated fact or opinion is one where verification or justification has not happened. It does not imply that either cannot happen.

On the other hand, the OED's two most appropriate entries for unjustified are:

unjustified, adj


a. Of a person, group, etc.: lacking or unable to demonstrate good justification for an action, opinion, etc.; not vindicated or shown to be in the right; not exonerated from a charge, criticism, etc. Cf. justify v. 2a, 7a.

b. Of an action, opinion, etc.: not clearly right, proper, or appropriate; lacking justification or good cause; unwarranted.

While these definitions do not explicitly state that verification/proof is not possible, the tone is far less neutral than for unsubstantiated. In addition, the etymology of unjustified points to the first sense of "un-":

un, prefix

  1. Prefixed to adjectives to express a negative sense, forming adjectives (and derived nouns).

Together, these all point to unsubstantiated being the better word to express the lack of evidence (one way or another), whereas unjustified has strong connotations of their actually being evidence to the contrary.

1 Based on no one having found evidence so far for such a word. Of course, lack of proof is not proof of a lack.

  • 1
    There's possibly no single-word answer that addresses both 'unjustified' and 'true'. This covers 'unjustified'. Jun 12, 2019 at 10:58
  • @EdwinAshworth Probably true. You would have to use unsubstantiated fact, ...truth or ...belief.
    – TripeHound
    Jun 12, 2019 at 11:02
  • I was wondering about downvoting, but somebody else has done it; one downvote is enough to engender wariness. Jun 12, 2019 at 12:51
  • @EdwinAshworth I'm happy to delete if that's the consensus... For my future education, although the title/body ask for "a word", it isn't tagged as single-word-request. If, as seems the case, there isn't a single word to cover exactly what the OP wants, is it wrong to suggest a two-word answer?
    – TripeHound
    Jun 12, 2019 at 12:59
  • I'd only do so if I thought that the answer was really (one of) the best possible ways to express something. There have been discussions on Meta about the point you raise. I think that the English language comes before ELU, but ELU comes before some of the poor stuff that appears here. I've been disappointed with the answers here (though I doubt an appropriate single-word answer exists): if a longer phrase were allowed, OP's 'unjustified [but] true belief' would take some beating. Jun 12, 2019 at 13:35

In philosophy and logic we distinguish (after Aristotle):

  • Valid argument: argument that if premises are true so is conclusion. For example 'Earth is flat. If earth was flat people sailing would felt off the world. Therefore Columbus would felt off the edge' (note - no one - at least no one educated or familiar with sailing - actually believed in Columbus days that Earth is flat).
  • Sound argument: argument that if premises are true so is conclusion and premises are true.
  • Invalid argument: argument that is, well, invalid regardless if the premises/conclusions are true or not.
  • Unsound argument: argument that is not sound so either premises are not true or the chain of logic is not true.

Conversely I'd describe the believe as "unsound but true". I assume that this is an answer you seek as you tagged by 'philosophy' and not 'single-word'.

  • Hello, Maciej. Can you add a linked and attributed reference supporting the above? If you can, will you add it, please? Jun 12, 2019 at 10:56
  • @EdwinAshworth I added links. I'm too lazy to go to the original Aristotle to give exact reference. Jun 12, 2019 at 23:05

I think you're looking for "Axiom". An axiom is statement that's assumed to be true.

An axiom is generally used as a basis for further logical reasoning.

  • 2
    Yes, in the sense that there is no justification given for the axiom, even though usually there is much justification given for it for it to be considered a useful axiom.
    – Mitch
    Apr 13, 2017 at 18:21
  • 6
    The axiom's being assumed to be true isn't the same as its actually being true, which is what was being looked for here I think.
    – lly
    Apr 13, 2017 at 19:22
  • I don't think "an axiom is statement that's assumed to be true". P ≠ NP is widely assumed to be true but it is not an axiom of complexity theory. Axiom is quite literally the closest thing to justified truth in system as possible. Apr 14, 2017 at 8:07

Belief, if it was justified it could be called a 'measurement' or 'observation', or even 'scientific proof'.

  • 1
    OP is looking for that which is unjustified. How does your post answer the question has to be explained.
    – vickyace
    Apr 13, 2017 at 22:37
  • Especially in philosophy believe can have a bit different meaning then in everyday world or even mainstream science. I'm close to Bayesian viewpoint so for me 'measurement', 'observation' and 'scientific proof' are type of believes, in Bayesian sense. Assuming OP was looking for domain-specific word belief would be quite confusing. [To clarify - yes, my believe in theory of evolution is close to 100% while my believe in celestial teapot is close to 0%] Apr 14, 2017 at 8:16

I would say it is a "hypothesis". A hypothesis is just an idea without anything to substantiate it, so I would say this is accurate. But I am willing to be wrong.

  • A hypothesis can be the basis for further knowledge but in and of itself is just a guess, you're right... but the term doesn't imply any truth behind its guess, only the belief that it's potentially the right answer to some problem or question.
    – lly
    Apr 13, 2017 at 19:24

Sometimes when referring to religious people the term 'fundamentalist' is used as a sort of synonym to 'false believer'.

  • Please include a source for the definition that supports your answer.
    – vickyace
    Apr 13, 2017 at 19:59

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