Part of the Standard Definitional Dispute runs as follows:

    Albert:  "Look, suppose that I left a microphone in the forest and recorded the pattern of the acoustic vibrations of the tree falling.  If I played that back to someone, they'd call it a 'sound'!  That's the common usage!  Don't go around making up your own wacky definitions!"

    Barry:  "One, I can define a word any way I like so long as I use it consistently.  Two, the meaning I gave was in the dictionary.  Three, who gave you the right to decide what is or isn't common usage?"

    Not all definitional disputes progress as far as recognizing the notion of common usage.  More often, I think, someone picks up a dictionary because they believe that words have meanings, and the dictionary faithfully records what this meaning is.  Some people even seem to believe that the dictionary determines the meaning—that the dictionary editors are the Legislators of Language.  Maybe because back in elementary school, their authority-teacher said that they had to obey the dictionary, that it was a mandatory rule rather than an optional one?

    Dictionary editors read what other people write, and record what the words seem to mean; they are historians.  The Oxford English Dictionary may be comprehensive, but never authoritative.

    But surely there is a social imperative to use words in a commonly understood way?  Does not our human telepathy, our valuable power of language, rely on mutual coordination to work?  Perhaps we should voluntarily treat dictionary editors as supreme arbiters—even if they prefer to think of themselves as historians—in order to maintain the quiet cooperation on which all speech depends.

    The phrase "authoritative dictionary" is almost never used correctly, an example of proper usage being the Authoritative Dictionary of IEEE Standards.  The IEEE is a body of voting members who have a professional need for exact agreement on terms and definitions, and so the Authoritative Dictionary of IEEE Standards is actual, negotiated legislation, which exerts whatever authority one regards as residing in the IEEE.

    In everyday life, shared language usually does not arise from a deliberate agreement, as of the IEEE.  It's more a matter of infection, as words are invented and diffuse through the culture.  (A "meme", one might say, following Richard Dawkins thirty years ago—but you already know what I mean, and if not, you can look it up on Google, and then you too will have been infected.)

    Yet as the example of the IEEE shows, agreement on language can also be a cooperatively established public good.  If you and I wish to undergo an exchange of thoughts via language, the human telepathy, then it is in our mutual interest that we use the same word for similar concepts—preferably, concepts similar to the limit of resolution in our brain's representation thereof—even though we have no obvious mutual interest in using any particular word for a concept.

    We have no obvious mutual interest in using the word "oto" to mean sound, or "sound" to mean oto; but we have a mutual interest in using the same word, whichever word it happens to be.  (Preferably, words we use frequently should be short, but let's not get into information theory just yet.)

    But, while we have a mutual interest, it is not strictly necessary that you and I use the similar labels internally; it is only convenient.  If I know that, to you, "oto" means sound—that is, you associate "oto" to a concept very similar to the one I associate to "sound"—then I can say "Paper crumpling makes a crackling oto."  It requires extra thought, but I can do it if I want.

    Similarly, if you say "What is the walking-stick of a bowling ball dropping on the floor?" and I know which concept you associate with the syllables "walking-stick", then I can figure out what you mean.  It may require some thought, and give me pause, because I ordinarily associate "walking-stick" with a different concept.  But I can do it just fine.

    When humans really want to communicate with each other, we're hard to stop!  If we're stuck on a deserted island with no common language, we'll take up sticks and draw pictures in sand.

    Albert's appeal to the Argument from Common Usage assumes that agreement on language is a cooperatively established public good.  Yet Albert assumes this for the sole purpose of rhetorically accusing Barry of breaking the agreement, and endangering the public good.  Now the falling-tree argument has gone all the way from botany to semantics to politics; and so Barry responds by challenging Albert for the authority to define the word.

    A rationalist, with the discipline of hugging the query active, would notice that the conversation had gone rather far astray.

    Oh, dear reader, is it all really necessary?  Albert knows what Barry means by "sound".  Barry knows what Albert means by "sound".  Both Albert and Barry have access to words, such as "acoustic vibrations" or "auditory experience", which they already associate to the same concepts, and which can describe events in the forest without ambiguity.  If they were stuck on a deserted island, trying to communicate with each other, their work would be done.

    When both sides know what the other side wants to say, and both sides accuse the other side of defecting from "common usage", then whatever it is they are about, it is clearly not working out a way to communicate with each other.  But this is the whole benefit that common usage provides in the first place.

    Why would you argue about the meaning of a word, two sides trying to wrest it back and forth?  If it's just a namespace conflict that has gotten blown out of proportion, and nothing more is at stake, then the two sides need merely generate two new words and use them consistently.

    Yet often categorizations function as hidden inferences and disguised queriesIs atheism a "religion"?  If someone is arguing that the reasoning methods used in atheism are on a par with the reasoning methods used in Judaism, or that atheism is on a par with Islam in terms of causally engendering violence, then they have a clear argumentative stake in lumping it all together into an indistinct gray blur of "faith".

    Or consider the fight to blend together blacks and whites as "people".  This would not be a time to generate two words—what's at stake is exactly the idea that you shouldn't draw a moral distinction.

    But once any empirical proposition is at stake, or any moral proposition, you can no longer appeal to common usage.

    If the question is how to cluster together similar things for purposes of inference, empirical predictions will depend on the answer; which means that definitions can be wrong.  A conflict of predictions cannot be settled by an opinion poll.

    If you want to know whether atheism should be clustered with supernaturalist religions for purposes of some particular empirical inference, the dictionary can't answer you.

    If you want to know whether blacks are people, the dictionary can't answer you.

    If everyone believes that the red light in the sky is Mars the God of War, the dictionary will define "Mars" as the God of War.  If everyone believes that fire is the release of phlogiston, the dictionary will define "fire" as the release of phlogiston.

    There is an art to using words; even when definitions are not literally true or false, they are often wiser or more foolish.  Dictionaries are mere histories of past usage; if you treat them as supreme arbiters of meaning, it binds you to the wisdom of the past, forbidding you to do better.

    Though do take care to ensure (if you must depart from the wisdom of the past) that people can figure out what you're trying to swim.

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    23 comments, sorted by Click to highlight new comments since: Today at 11:01 PM

    Very sensible. I never could understand why people made such a fuss about whether the tree made a sound or not. (The best answer I saw was a cartoon of the fallen tree saying quietly to itself, "Oh, shit.")

    Perhaps this also has relevance to the classic omnipotence paradox - "Can an omnipotent being (or God) create a rock so heavy that that being can't lift it?" Since few people want to redefine omnipotence (if we did, we'd soon want another word that meant what "omnipotent" used to), the answer is simple: the omnipotent being will be able to create such a rock, and then just lift it anyway, while still being unable to.

    It doesn't make sense, but the thing is, it doesn't have to. The words "omnipotent", "rock", "heavy", "can't", still mean what we understand them to mean. And we understand pretty well what "paradox" means, too. A paradox is obviously a problem for human reason, but would be no problem at all for divine omnipotence.

    Well, the "does a tree make a sound when it falls in the forest with nobody there to hear it?" question is really about a different issue than this matter of what is the truth-value of dictionary definitions of words. When Bishop Berkeley posed that original question and said "no," he was asserting an idealistic philosophical perspective that I doubt few of the readers of this blog are particularly sympathetic with, although a lot of mathematician readers are probably bigger Platonists than they might be willing to admit (Did you "discover" that proof?).

    Regarding dictionaries and common usage and Caterpillar assertions of "I can make a word mean whatever I want it to mean," well, certainly dictionaries do ultimately simply report reasonably common usages, with the possibility of these simply expanding for any given word. Most of the time these new usages simply evolve in spontaneous and oddly linked ways through similarities between the newer and the older usages.

    Things get a bit odd when we have consciously made changes of meaning a la the Caterpillar. Sometimes these are ironic or hip or whatever, often playing off or against an established meaning ironically. This can lead to confusion if the new meaning gets added on with the older ones, especially if the new meaning is somehow logically or factually at odds with older meanings. This means that users of the word will have to be careful about contexty and audience, if they wish to avoid confusion. Sometimes this is conscious, such as "bad" meaning "really coolly good," although I doubt that usage has made it to the OED, if it ever will. Others with deeper historical roots are mysteries. Thus, why do both "inflammable" and "flammable" mean the same thing? And then we have words that have evolved to mean just the opposite of their original meaning, such as "pretty," whose Old English root, "praetig," apparently meant more like "ugly," although I may be slightly off on that one. But, such cases are definitely out there. Should the original person to use some form of "pretty" to mean what it does today have been punished, and why did his or her listeners go along with such an extreme change of meaning (which probably happened sort of gradually anyway)?

    Words are used within our minds because we don't have the computational resources to duplicate association-bundles every time we want to think about something. It's far cheaper to use pointer variables. We bind a reference to the bundle to a much simpler name and then store the name in memory instead.

    As for the omnipotence-with-rocks argument, the solution is to recognize that the question is nonsense because the concepts it uses are self-contradictory. What happens when an immovable object meets an irresistible force?

    "As for the omnipotence-with-rocks argument, the solution is to recognize that the question is nonsense because the concepts it uses are self-contradictory. What happens when an immovable object meets an irresistible force?"

    Well said. The question is no different in principle to asking, "What happens when a number is both 2 and not 2 at the same time?"

    Or, Can an omnipotent being create a black calico cat?

    When an irresistible force meets an immovable object, it goes through without leaving a hole.

    Mr. Rosser,

    AFAIK, "flammable" is a shortening of "inflammable," which confused some people -- they thought the "in-" part was a prefix of negation. Consequently, some people might have employed insufficient caution around large fuel containers marked "inflammable." Most people seem to more easily understand "flammable" as meaning burnable, by analogy with "flame," than "inflammable" by analogy with "to inflame."

    Specifically, what Berkeley was asserting was that the existence of the acoustic vibrations (although I don't think he knew that they were vibrations) was dependent upon the existence of the auditory experience. It wasn't an argument about definitions at all! It was a peculiar kind of solipsism which, as Rosser guessed, I have little sympathy with.


    Thanks for the correction r.e. "inflammable" and "flammable." Of course you are right. Not a contradiction between those two.

    I never could understand why people made such a fuss about whether the tree made a sound or not.

    Because the sense in which this question is being used as an example here is not the real question that bishop Berkeley had in mind.

    It's really a question about epistemology. It's related to the "grue" paradox, which is a bit easier to explain. The grue paradox first notes that ordinarily we have good reason to believe that certain things (grass, green paint, copper flames) are green and will continue to be green after (say) 1 January 2009. It then notes that every piece of evidence we have supporting that belief also supports the belief that these things are "grue", which is defined as being green before 2009 and being blue after that date. On the face of it, we should be equally confident that green paint etc will be blue after 2009.

    Much has been written, but the important point is that nobody has ever experienced 2009 (except you lurkers who read posts from previous years. Just change 2009 to a date that's still in your future, or have they forgotten how to do that in the future?)

    A similar condition applies with Berkeley's paradox. Tautologically, nobody has ever heard a tree fall that nobody heard. (Planting a tape recorder or radio transmitter and listening to that counts as hearing it) So when we guess that the falling tree makes a sound, we are extrapolating. There is no way to test that extrapolation, so how can it be justified?

    I recommend David Deutsch's Four threads of reality for some intelligent and not too wordy comments on how, among other interesting topics he covers.

    FYI all: I originally touched on the point that the classic sense of the falling-tree argument is Berkeleyan, but, as noted, I've seen the argument get started without wandering anywhere near Berkeley. Or the problem of induction. "Fully naive", I said.

    A few comments:

    A dictionary is vastly more than a "history of past usage." It is a cultural touchstone. This may not be apparent to those without high degree of mobility, but the existence of dictionaries (and especially inter-language dictionaries) is critical to the ability of complete strangers (even in the cultural sense) to interact. I think we universally underestimate the extent to which our culture enables our "meaningful" interaction.

    Your last sentence is right on the mark - we can start inventing all sorts of new definitions but we need to be very careful that we don't stray too far into our own language. We might corrode our ability to interact meaningfully with life-giver "society."

    I have noted a very large number of multi-meaning words in english - note, interestingly, that Japanese has multiple kanji representations of words with similar, but not equivalent, meanings and same readings - e.g. 見るvs.観る both being read "miru" and the first meaning "to see" (e.g. to see a tree) with the second meaning "to watch" (e.g. to watch a movie).

    By this point the intellectual community (and especially the philosophical) is sufficiently diffuse that very very important words (e.g. "context," "content," "concept," "abstraction") have lost their meaning or become tremendously blurred.

    Your point that the fight to define a word is really the fight to assert a moral position/worldview/what-have-you is extremely interesting. I hadn't thought about it that way.

    It immediately brings to mind the question of "how do we define definition?" which is infinitely interesting. If we define "definition" then we must necessarily be doing so in a context that is removed from the context in which we are defining "definition." This immediately implies that there is no universal sense in which words can be "defined" but that there are infinite senses in which words can be "defined." When two entities conflict on a definition they are both thinking in contexts which are removed from the context in question (e.g. the characters thinking about the tree are arguing about the correct procedure for creating a common-usage definition). But most people do not think in this meta-context often which is why they have woefully underdeveloped vocabularies and theories w/r/t it. Thus, frustration. Thus, anger. But it's just a silly tree!

    To respond to Caledonian's question: "What happens when an immovable object meets an irresistible force?"

    The result will be to rename one of the two. I'd bet on the immovable object to "win" merely on a hunch that maximum inertia beats maximum momentum. (I'm only half kidding, though I have no proof or even a plausible hypothesis to support my bald-faced assertion.)

    You're close, I think, to what would happen if there really was an immovable object about to be struck by an unstoppable force.

    If such an event were ever to occur, and we could study it, we'd get to find out whether an immovable object is truly immovable, and whether an unstoppable force is truly unstoppable.

    My guess is that they would cancel each other out - the immovable object would move, and the unstoppable force would stop. Like a rocket sled hitting a concrete wall. Wall goes bust, sled stops moving.

    The other option lies in the reason the two are immovable or unstoppable - if an unstoppable force is unstoppable because it does not interact with matter, then the immovable object remains unmoved and the unstoppable force remains unstopped.

    In truth it's a silly contradiction with the lack of information posed in the question, and, as Caledonian said, as such it is almost pointless to think about. The best answer you can come up with is "I don't know".

    Though do take care to ensure (if you must depart from the wisdom of the past) that people can figure out what you're trying to swim.

    Somehow I missed this the first time. Hilarious.

    I'm surprised that translation between languages isn't mentioned as a more simple example of where misinterpretation of meaning can arise.

    Additionally, most people will now be aware of the variation in symbolic meaning between cultures (ie finishing all food on your plate being a compliment in some countries, and a sign that you weren't given enough food in others).

    It's almost as if there is a requirement to have a constant reality-check process operating within the mind to ring alarm bells if the received response is against expectation. If this were operating effectively within both members of the tree-falling arguement they would more rapidly discover the arguement lay in the meaning of the word "noise" and not a failure of logical processing.

    Why would you argue about the meaning of a word, two sides trying to wrest it back and forth?

    Because I'm bored.

    I understand dictionary just keep track of how people in a culture use a word. But many people including me, consider that ,we should use dictionaries to know "how a word was used until now" and keep using it that way, instead of creating your own language, which is how humans work now. Now you live in a world with as many languages as people speak, and while you can't really change that, you can definitely highly reduce the differences. That could be achieved by using a pilar of reference. Why is this not the most productive position?

    THis kind of needs a reference to the thing that periodically comes up in social justice circles, where, for example, 'sexism' has a different definition, specifically including only gender discrimination by the more powerful gender against the less powerful one. Infortunately, this sometimes results in every possible word to describe prejudice being redefined.

    Quick note - the sentence "If you want to know whether blacks are people, the dictionary can't answer you," in comparison to the sentence "Or consider the fight to blend together blacks and whites as 'people'," unnecessarily normalizes whites as people (though, historically, that is how the fight felt from the white perspective). I don't know if you should change this, but I just wanted to point it out.

    Altogether, good post!

    I think most of the conflict escalates from the dichotomy that arises when two conflicting definitions are lumped together. It wouldn't be so hard to argue about trees in a forest and sound if the arguers made up their own words and associated definitions. E.g. "When a tree falls in a forest it makes a WASAD" and "When a tree falls in a forest it does not make a FORFAN". No contradiction there.

    I find it strange why humans find it difficult to accept that words have no absolute meaning. Furthermore, why is it that when both parties are already aware that the other has a different definiton, they instead choose to start a political argument on who "has the right definition" rather than change the word and continue the original topic?

    It so happens that Eliezer offers a possible answer in this very sequence.

    Of course, one or both parties may know this answer and choose a more political/rhetorical approach in the hope of changing someone's behavior, not their factual beliefs.

    There is descriptive linguistics and prescriptive linguistics (and that applies, in particular, to lexicography); but to make sense, to create rules people will not immediately and fully ignore (merely somewhat in some relatively rare cases as the language changes), prescriptive linguistics feeds on descriptive linguistics to prescribe something not too different (which does not say "the same"). Thus to create a dictionary which will unify common usage you need to describe common usage first - not to be too astray.

    Unfortunately, in English tradition this is also blurred by having no usual distinction between prescriptive grammars (and lexicons) and style guides.