I am wondering if there is a name for the following theory of truth, which I might call "persuasionism."

Truth, for an individual, is the set of beliefs that individual would eventually, in the limit, be persuaded of, given unlimited evidence and unlimited time to consider.

This theory may be compared to Charles Sanders Peirce's pragmatist theory of truth:

Truth is that concordance of an abstract statement with the ideal limit towards which endless investigation would tend to bring scientific belief, which concordance the abstract statement may possess by virtue of the confession of its inaccuracy and one-sidedness, and this confession is an essential ingredient of truth. (Peirce 1901).

Distinguishing "persuasionism" from pragmatism:

  • Persuasionism puts the emphasis on what would persuade the individual, not a "community of inquirers." The rationale is that it does not matter to an individual what might persuade others in the community, unless it also convinces that individual.
  • Persuasionism does not restrict the domain of truth to scientific belief; it might be applied as well to philosophical questions such as evaluating the truth of moral claims.
  • Which individual ? It has been shown that some people won't budge even in face of damning evidence. Worst, they get more engaged into their ridiculous belief. This definition does not account for the biases our very imperfect brains struggle with.
    – armand
    Jan 31, 2021 at 9:40
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    Unlimited evidence, unlimited time to consider, unlimited capacity to process all that (and that's not enough, some cognitive actions can not be performed individually even with unlimited time) would turn this individual into a generic ideal reasoner stripped of any individuality. Or at least it is unclear what "individual" would be left in such a being. There is a reason Peirce had to resort to a community (actually, an unlimited succession of communities) to make this work. Its point is not so much in introducing "others" but in making what your "individual" is supposed to do more palatable.
    – Conifold
    Jan 31, 2021 at 9:42
  • armand - when I am selecting my own beliefs, the individual in question would be me; when you are selecting yours, the individual in question would be you. So it doesn't matter if some third party is irrational. We do have to idealize the individual's reasoning process somewhat, however, since humans can't biologically have "unlimited time." Conifold, what could be more palatable to me than the beliefs I myself would arrive at? Or more palatable to you than the beliefs you would arrive at.
    – causative
    Jan 31, 2021 at 9:52
  • I'd also like to remark: a rational person would wish to believe right now, what he himself would in the future believe after considering more evidence. Because being better informed is preferable for the purpose of forming beliefs over not being so informed. By the way, the "community of inquirers" suffers from the same problem of irrationality you point to in the individual; groups of people are not rational.
    – causative
    Jan 31, 2021 at 9:56
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    @causative: so is this a "you have your truth, I have my truth" type of thing? I would not be so worried about the irrationality of a third party, but more about my own, and so should be each individual.
    – armand
    Jan 31, 2021 at 13:06

2 Answers 2


You have to identify necessary truths from contingent truths first. For necessary truths, some are fairly intuitive like principle of non-contradiction (PNC), whose truth value cannot be fully justified in any sufficient way no matter how much time passes or how much individual's capability has in this contingent world, even approaching infinite, its value transcends us and thus hidden forever to us even it really exists.

For contingent truths, as most modern philosophers would agree, justified true belief (JTB) is the standard epistemic definition of knowledge human can possibly achieve and this seems is what you want to reach. But there're still modern philosophical arguments against justified truth (knowledge) such as Gettier problem. The problem lies in how sufficiently a justification can be satisfied for JTB to be really our contingent truth. I guess it doesn't need infinite time or capacity since we can already do sufficiently many experiments within a short time via modern technology, such as the view espoused by scientific Positivism. For me a serious intrinsic issue would be what if the contingent truth itself will change as time passes, such as some geological, biological or even physical laws? Then even given infinite time with infinite individual capacity, one still won't approach a convergent limit of such truth as you wished.

  • I don't make any assumptions about how they arrive at their beliefs. Whether they use PNC or not is up to them; there are some philosophies such as Zen Buddhism that make heavy use of contradictions, and PNC does not hold in fuzzy logic. Yes, if a truth changes over time due to changing contexts, then perhaps there is no limit of belief for it, and therefore we would not say it is absolutely true or false. The answer is to fully contextualize the proposition, e.g. not "it is raining" but "at X absolute time and Y absolute location, it is/was/will be raining."
    – causative
    Mar 31, 2021 at 23:05
  • By the way, the answer to the Gettier problem is to say knowledge is true belief whose justification is also true at every premise and step of reasoning. But JTB is a separate question from the OP. I am not trying to define "knowledge" here, only "truth."
    – causative
    Mar 31, 2021 at 23:20
  • @causative thx for ur feedback! Per ur own quoted definition above "Truth, for an individual, is the set of beliefs", as understood in public language, seems you exactly meant your truth is a kind of belief, and implicitly it needs to be true and justified, otherwise one can believe anything one likes...So I do think JTB (modern knowledge in philosophical context) is exactly the kind of truth OP was interested in. Mar 31, 2021 at 23:31
  • I am defining truth, so I can't say that truth is justified true beliefs; that would be circular. Yes, the individual may believe whatever they like. The idea is that in the limit as they reason more and see more evidence, "whatever they wish to believe" would converge towards a limit, at least for certain beliefs.
    – causative
    Mar 31, 2021 at 23:38
  • @causative Admittedly public language is not FOL and full of traps to misunderstand in a subtle way. So based on your own definition of truth above (only a set of beliefs, which may not need to be justified and true, personally I'll just use a set of beliefs, no need for a new "truth" concept here), u wish to predict if some belief(s) will emerge as JTB? Well, I think our scientific world seem just such a case, under rational choice theory in economics, this is what positivism claims and hopes to reach. . Apr 1, 2021 at 0:10

Truth, for an individual, is the set of beliefs that individual would eventually, in the limit, be persuaded of, given unlimited evidence and unlimited time to consider.

This is not a theory of truth. We all know what we all mean by "truth" and this isn't it.

This is not a theory of truth. This is a definition, and it is a redaction of the definition of truth everybody has in mind. This is on a par with so-called Justified True Belief.

So, this "theory" may be a theory of something, but it is not a theory of truth.

I could also define truth as whatever I believe and run with that definition. Many philosophers try to redefine the common notion of truth simply because they want to be able to claim that we know something about the physical world.

A statement is either true or false. Whatever we believe in this respect is irrelevant.

Different people believe different things about the world. We try to arrive at a common view through argument, ideally logical argument based on empirical evidence. Whether we succeed is irrelevant to whether what we believe is true. We have to live with that. We live our lives according to our beliefs. Isn't that good enough? It seems to be working rather well so far.

Another aspect of this question is that being given an unlimited time to consider (the unlimited evidence) is not a method to arrive at the truth. The history of ideas shows how little truth comes out of the lengthy consideration of things. I guess the missing ingredient is called "intelligence", although this in itself doesn't say much. Another way to say it is the ability the solve problems, which is the only definition of intelligence that makes sense. Clearly, humans have such an ability but just as clearly not all in the same amount. The fact is that most people given an infinite time to consider an infinite amount of evidence would still not arrive at the truth.

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    Most of the more prolific epistemologists of the last 70 years agree that this whole "Truth (capital T) talk" is meaningless. Your appeal to common sense fails since this position is logically inconsistent, as Putnam has shown and Tim Buttons beautifully formalised in The Limits of Realism. You are the one stating something arbitrarily without further justification here.
    – Philip Klöcking
    Jan 31, 2021 at 12:41
  • I agree that truth ought to be something universal - which means that with enough time and evidence, any reasonable person ought to come to the same conclusion. However, even if truth is universal, the problem remains: some beliefs are true and some are false. Beliefs correspond to physical patterns in the brain. How do we relate the abstract, universal truth to a physical brain pattern?
    – causative
    Jan 31, 2021 at 16:47
  • @PhilipKlöcking which epistemologists are those? And what do you mean by "capital T"? Are you saying that the more prolific epistemologists of the last 70 years would deny that facts like "my glasses are on my table" can have an absolute truth value? Or do you say that they only deny that certain propositions have an absolute truth value?
    – causative
    Jan 26, 2022 at 20:30
  • @PhilipKlöcking 1. "agree that this whole "Truth (capital T) talk" is meaningless." I don't know how that relates to my answer. I can't read your mind. 2. "Your appeal to common sense fails" No, it doesn't and you have no argument that it does. The only notion of truth that withstood the test of time is the ordinary, commen-sense notion of truth. 3. "this position is logically inconsistent, as Putnam has shown and Tim Buttons beautifully formalised in The Limits of Realism." So your only argument is to drop names? Am I supposed to search this book to find what exactly is your argument? Jan 27, 2022 at 11:28
  • @PhilipKlöcking "You are the one stating something arbitrarily without further justification here." Whoa. Arguing from common-sense is to state something arbitrarily?! I'm very nearly speechless. Did you say that the common-sense notion of truth is meaningless? This would be one way indeed of arbitrarily dismissing the overwhelming empirical evidence that all human beings abide everyday by it, including in fact yourself. Isn't that true? Jan 27, 2022 at 11:34

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