Such person would consider the meaning of all words to be vague (including the meaning of the word "vague" ), and think that actually we do not know what we are talking about (including this sentence itself ) even though we feel that we know very well about what we are talking about. Therefore all of our knowledge presented in the form of language is nonsense (including this sentence itself).

For example:
A: Truth is some statement that corresponds to the reality.
B: What does "correspond" mean? What does "reality" mean? What does "statement" mean?
A: "Correspond" means XXX, "reality" means XXX, and "statement" means XXX.
B: Then what does XXX mean?
A: ...
(And B would even question the meaning of his own sentences.)

It seems to me that such absolute-skepticism is invincivle. Is it possible to argue against this?

  • The only known cure for that condition is rigorous contrarianism. Anytime he say something, deny it. If he says "I think I'll have a beer", tell him he doesn't and require him to prove his assertion, to define "I" or "beer".
    – user6726
    Jun 4, 2015 at 16:12
  • 2
    The important point is that the existence of people denying an argument, because they (in a fit of self-contradiction) refuse to accept the validity of language or reason, does not in any way mean the argument is invalid. It's ok to shrug and walk away... at that point, it's not much different than arguing with your dog. Jun 4, 2015 at 17:40
  • Sounds a bit like (the late) Wittgenstein Jun 5, 2015 at 5:49
  • 1
    Listen to Feynman: "We can't define anything precisely. If we attempt to, we get into the paralysis of thought that comes to philosophers... one saying to the other: you don't know what you are talking about! The second one says: what do you mean by talking? What do you mean by you? What do you mean by know?"
    – Sensebe
    Jun 5, 2015 at 17:02
  • @MauroALLEGRANZA, user6726, kbelder: All of you seems to "escape" from the problem, instead of solving it. It is not about arguing here, it is about truth.
    – Sensebe
    Jun 5, 2015 at 17:07

6 Answers 6


First of all this would be a paradox as; if everything B knows is opened and undefined then the argument can not begin. Whether, B accepts an argument or not does not matter.

But, the paradox is that B seems to know what "meaning" is as he questions the meaning of every proposition. So, it seems B is not entirely purely skeptical; this provides us a beginning.

  • And then B would question the meaning of "meaning"...
    – user5938
    Jun 5, 2015 at 11:40
  • @user5938 True enough, but, B does seem to know that entities and propositions have some meaning. It seems then that B is not entirely skeptical rather he is just disagreeing with whatever argument is put up to him. Jun 5, 2015 at 11:49
  • If B was truly skeptical and did not accept the meaning of any thing (including 'meaning' itself) then he would not know any sort of language whether formal, mathematical or any other. We would then have no means of communication with him, therefore, the argument could not begin inside any known system. Jun 5, 2015 at 11:53
  • This leaves open the possibility that, yes, he is lying about really being skeptical of all meaning, but he insists it is possible and believes that approaching it is a reasonable goal and he is pursuing getting closer to this state. This is Pyrrhonism applied to argumentation -- he wants to trust only the things he can really see, or that are really so completely natural that he cannot question them.
    – user9166
    Jun 8, 2015 at 17:54
  • This needs to be broken down by some argument like Montaigne's, Wittgenstein's or the late Academics'. It is not a reasonable goal, it is an illusion, because all meaning is primarily consensual and not based solely upon observation and reason.
    – user9166
    Jun 8, 2015 at 17:59

Every definition uses undefined words and so definitions can't be used to securely found our knowledge. This was noted by Karl Popper in "Conjectures and Refutations" Chapter 3 and on many other occasions. But knowledge doesn't need foundations. We can create knowledge by guessing solutions to problems, criticising the guesses until only one is left and it has no known criticisms, and then we look for a new problem. For more details see

Is everything just an opinion?.

Definitions should be read as summaries of ideas for convenience of reference, not as foundations for knowledge. For example, rather than saying "negatively charged particle with a mass of 9.11 x 10^(-31) kg etc.", physicists say "electron". And trying to understand stuff in terms of definitions is a mistake because the definitions only make sense in the context of an explanation. For example the electron definition makes no sense unless you know something about electromagnetism, atoms and other physics. Doing everything in terms of definitions makes ideas less clear, not more clear.

  • This is a bit prescriptive for anyone even moderately skeptical of language to take seriously.
    – user9166
    Jun 8, 2015 at 18:13
  • "But knowledge doesn't need foundations." I don't agree with this view. Of course you can say that knowledge is something that survives criticisms, but at least your criticisms need some foundation, otherwise I can just give whatever criticism I like.
    – user5938
    Jun 9, 2015 at 9:13
  • And I think you have misunderstood my question partly. The question is not about "definition". It is about "do we really know what we are talking about?"
    – user5938
    Jun 9, 2015 at 9:16
  • No criticisms don't need foundations. A criticism needs to have some connections to other ideas if it's going to succeed as a criticism. As a result the criticism will have implications for issues other than those it was originally intended to solve and so there will be ways in which it could be criticised by pointing out false implications or other problems related to those other issues.
    – alanf
    Jun 9, 2015 at 9:17
  • The question is about knowing what you're talking about, so it is about knowledge. As such, if asking "what do you mean by X?" is a bad strategy for creating knowledge, it is a bad strategy for knowing what you're talking about.
    – alanf
    Jun 9, 2015 at 9:24

A Ciceronian Academic position, or, at a different level of subtlety, a strong late-Wittgenstein stance addresses your friend's position. The position is perfectly logical, but it makes all other stances entirely irrelevant at the cost of its own meaning, if one takes it quite literally. It is kind of a hard-line stance against stances.

Strong positions for skepticism ultimately contradict absolute nihilism. So writers like Cicero, Montaigne or an honest version of Wittgenstein take the route that your first comment suggests -- "reductio ad absurdum". By agreeing with him, you can deduce that it is absurd for him to still be alive.

After all, he is correct. We do not know what we are talking about. It seems obvious. Nobody does. But we are talking. So we must think we know. OK, so we do realize, at some level, that we really do not know, and that everyone else knows that, too. But even if we know that we do not know, we have decided to play this game of pretending we know. Is there any other choice? How would one find out? So there isn't.

We think we know what meanings are because our words have effects, or we realize that the game is what gives certain words effects. If this is the best you can manage, why bother disputing it? Simply follow the words' effects to learn the rules of the game, and ignore their supposed meaning. If you are trapped in an infinite puzzle your entire life, knowing it is infinite, why resist? Just play as well as you can comfortably manage, and attempt to discern why the other players are playing.

If you attempt to escape from all language-games entirely, that includes economics, child-rearing and romance, not just philosophy. You have no effect. You are isolated and lose traction on all social activity. You enter the realm of schizophrenia or monasticism. So then why take part in any argument? To remain in a situation where the impossible is necessary seems crazy. So accept the necessity and minimize the relevance of the impossibility.

If you insist on harping on the meaninglessness knowing that meaninglessness is essentially mandatory, you are either cheating, or you are just a bad player.

This argument does not criticize philosophical debate. It gave us science after all. What it criticizes is the notion that one can arbitrarily take a position outside a game and comment reasonably on that game by breaking its rules.

Things have meaning in context, and that meaning is always backed by something other than sheer logic. Most 'deep' philosophical questions arise when we try to inject maneuvers proper to a different context wherever we want and take the result too seriously.

This particular kind of skepticism is one of those 'deep' approaches. It takes the 'game' of learning language and tries to use its rules to evade full participation in the 'game' of deduction or transmission of knowledge. It is not a legitimate way to argue. It is not based on any particular false premise, but it is tone-deaf to what is useful and productive.

Fleshing that out, learning a language presumes someone knows it, but he is denying that anyone knows it, so asking definitions is just silliness. If he is truly skeptical of language, he should want sensory or other proof, not definitions.

But just agreeing on what that proof should be, would have to be negotiated in some terms. So he can evade alanf's arguments indefinitely as well, in the same way Lakatos's commentary on Kuhn imagines incompatible theories can avoid admitting one another's evidence indefinitely.

So there is no point in backing away from the argument to find middle ground. It is correct, and it proves he should just go die. If he can ignore it, so can you.

  • 1
    As far as I can see, your opinion is like this: such standpoint is perfectly logical, but we can pretend we know the meaning and keep playing the game of philosophy research. But is this approach just a sort of "refusing to accept the skepticism"? And if I attempt to escape from the game entirely, I don't have to stop all social activities; I just stop talking about philosophical question and other things go as usual.
    – user5938
    Jun 6, 2015 at 12:13
  • 1
    There is a continuum of rejection of meaning running from Stoicism, to Cynicism, to Skepticism to nihilism. If you want to live, you have to choose some point farther up the scale from absolute nihilism, or you have to just accept the hypocrisy of staying alive, which removes all the force from your rejection of anyone else's decisions.
    – user9166
    Jun 6, 2015 at 22:57
  • You can recuse yourself from this game, but every other social interaction is equally a game. Economics is a game, family life is a game, all productivity is bound up in games. None of it is possible to do in a truly authentic way that does not presume meaning where it is obviously vague. So why choose this one to leave and not all the others? If vagueness is an absolute part of all understanding, then why require some interactions to be clear, such as philosophy, and let others be unclear? That some activities are optional? But all activities are optional, if you just die.
    – user9166
    Jun 6, 2015 at 23:09
  • My issue with this argument is that economics and social interaction seem to have explicit purposes and practical ends in their "game", whereas philosophical debate - of the type that late Wittgenstein criticizes - seeks to offer explanatory power on the basis of pure introspection.
    – Yang
    Jun 7, 2015 at 1:00
  • In other words, it seems perfectly possible to take a non-nihilistic stance where some things have meaning, and still be skeptical of the notion that philosophical debate itself is helpful for explaining or discovering any of these interesting things.
    – Yang
    Jun 7, 2015 at 1:01

This question was systematically addressed in Alfred Korzbyski's book Science and Sanity . Make sure you also read about Jacques Derrida view of Heidegger's concept of sous rature.

  • 4
    For the sake of someone like me who's uninitiated, can you summarize the argument briefly? Jun 8, 2015 at 20:51
  • Can you recommend some books (or other sources) about Derrida's view?
    – user5938
    Jun 11, 2015 at 10:22

After such an "argument" you could reply nonsensically. Doing so demonstrates the absurdity of his question since he understood it enough to ask what something meant (and has a meaning to the phrase "what does _ mean".

You could combine that with stating (he will understand this statement as he understood your last one) that words convey specific meanings and while there may be disagreements over the meaning of words that does not change the underlying meaning of what is attempted to be conveyed.

More practically, someone might use this tactic (to a lesser degree) to argue over your interpretation of something based on the word you used (and he pointed out). Thus, you could substantiate with an argument explaining why someone corresponded, or lied, etc.

You may also run into issues of conflict with legal words and layman words. For example, a court may require proof of "extreme negligence" but you would need substantiation (likely court precedent or legal definition) to avoid perceived conflation of the legal term with layman negligence.


Such solipsist positions are logically unassailable. That's the point when I reach for my copy of Marx's Theses on Feuerbach:

VIII - All social life is essentially practical. All mysteries which lead theory to mysticism find their rational solution in human practice and in the comprehension of this practice.


XI - Philosophers have only interpreted the world, in various ways; the point is to change it.

So, to argue with a person who states, in principle, that all arguments are useless, is to argue with a person that acts in bad faith. If they really believe that all arguments are useless, then they should not argue. If they argue, it means that they don't really believe all arguments are useless. Their practice contradicts their "theory"; they are dissemblers.

Anyone who has philosophical convinctions should make at least some effort to live by them. If someone is a Tomist, then they should try to live as a Tomist should live. Conversational solipsists do not do that. They do not try to live by their philosophical "convictions", which they use as a mere tool to discredit everybody else. But they know that our world knowledge, provisional as it is, is working knowledge. They know they shouldn't drink the hemlock, jump from a window at the seventh floor, or cross the street without looking both sides, and they abide by this knowledge. So they, themselves, refute their own points: while those may be "correct" in a completely abstract way, concretely they know better and behave as if they don't believe in them. It is a lazy "philosophy", designed to extricate their proponents from the problems posed by good faith people.

So, I would propose a counter-question: even if it is possible to argue against someone as described in the Question, what is the use of it?

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