"All x are not y" - what does this mean to you??

[Wallenstein]

In this post (http://boards.straightdope.com/sdmb/showpost.php?p=12335953&postcount=406) Fuzzy Wombats is talking about whether a group of Iraqis are armed or not.

The phrase used is "Now, from my viewing of that video, I can clearly see weapons. All of them are not armed, but there are a few."

That phrase "All of them are not armed" seems to mean the exact opposite to what is meant?

As a Brit I take "All of them are not armed" to mean "None of them is armed", which doesn't appear to be the intention behind it. In fact it's the complete opposite - i.e. some of them are indeed armed.

Likewise I've also seen a similar phrase used in defence of the catholic clergy: "All priests are not abusers", which surely means "There are zero priests who are abusers" which is not the intention either.

In each case I would have used "Not all of them are armed", and "Not all priests are abusers".

So is this just a case of sloppy writing by Fuzzy Wombats, or have I got my grammar confused? :confused:

[Johanna]

Thank you-- I'd been hearing that syntax in TV commercials for ages ("All fluoride toothpastes are not alike (http://www.straightdope.com/columns/read/2603/whats-the-best-toothpaste)!") and it drives me crazy. Too bad they don't teach basic logic until the college level, and even then I doubt more than a few people even study it a little bit, or we wouldn't have this syntactical embarrassment.

[panache45]

You're right, of course, and I've been hearing it too . . . along with the use of "less" when they mean "fewer." You'd think that professional journalists would have a grasp of the English language.

[Gary T]

Sloppy writing. I've seen similar variances in meaning and resultant confusion with respect to the particular placement of "only," as well.

[Wallenstein]

Is this an American thing (like "I could care less"), or is it standard english outside the UK?

[Capt. Ridley's Shooting Party]

It's got nothing to do with logic (and translating English into a formal language, or back again, is fraught with all sorts of difficulties). It's just proof that the semantics of English aren't really compositional, and the meaning of one sentence can change depending on its context. Taken in context, it's easy to see what the sentence means. Even the OP had to focus on a fragment of a sentence to get a contradiction, the second half of the sentence clears up the meaning.

[Wallenstein]

It's got nothing to do with logic (and translating English into a formal language, or back again, is fraught with all sorts of difficulties). It's just proof that the semantics of English aren't really compositional, and the meaning of one sentence can change depending on its context. Taken in context, it's easy to see what the sentence means.
I agree that from context it's possible to work it out, but that's making the reader work harder than required, hence my feeling that's it's lazy writing.

[Ace309]

My first instinct was to parse it as {If X, then ~Y}. Of course, I've been teaching formal logic to kiddos lately and the text we use is quite careful to differentiate "All X are not Y" from "Not all X are Y <=> Some X are not Y".

[wayward]

Those sentences don't sound right to me either, but at least they have a respectable precedent in "All that glitters is not gold". What's really been grating me recently is the use of "anymore" to mean "these days". I just always have to re-read the sentence to understand it. I seem to almost exclusively see it used here, but that's probably just because it's the main place I see informal US English.

[Nava]

wayward, I think what's been cropping up all over the place is a misspelling: people apparently don't know the difference between "anymore" and "any more".


As for the sentence in the OP, I do tend to parse it as the speakers intended. I see "all bananas are fruits, but not all fruits are bananas" and "all bananas are fruits, but all fruits are not bananas" as equivalent, although I'd be more likely to use the first construction.

[tdn]

I understood it right off the bat. Not from any sort of logic, but just because I've seen that construction so often that I barely notice it any more.

[elfkin477]

wayward, I think what's been cropping up all over the place is a misspelling: people apparently don't know the difference between "anymore" and "any more". No, it's a regionalism (http://www4.uwm.edu/FLL/linguistics/dialect/staticmaps/q_54.html) and "supposed to" be written that way. We have several dopers here from the area of the US that uses it. Drives me batty as well, but not as much as [object] needs [past tense verb].

I'm wondering now if leaving out the word "not" in phrases the OP mentioned is a regionalism too. I haven't heard anyone phrase things like that outside a logic class, anyway.

[Chessic Sense]

You're right, of course, and I've been hearing it too . . . along with the use of "less" when they mean "fewer." You'd think that professional journalists would have a grasp of the English language.

We've covered this. "Less" is perfectly fine when used to mean "lower quantity of", according to any online dictionary that I've looked at.

[MeanOldLady]

Funny, when I saw the thread title "All x are not y" I thought it meant that some y that are x, but not all of them. When I read the sentence in question, half way through I interpreted it to mean they're all unarmed, but upon reading the whole thing, I see he meant some are.

[Thudlow Boink]

When I read, "All X are not Y," I think it should mean "Every single X is not Y." "There is no X which is Y." "The set of X is disjoint from the set of Y."

However, I am aware that many people use this construction to mean "Not all X are Y."

So, in practice I treat the phrase as ambiguous and hope I can figure out from the context which they mean.

[runcible spoon]

Maybe it's regional, but I've never encountered anyone using it to mean 'no x are y'. In my experience, it's strictly 'not all x are y', so that's immediately how I interpret it.

[Thudlow Boink]

Maybe it's regional, but I've never encountered anyone using it to mean 'no x are y'.But that's what it "should" mean. A statement that begins "All X are..." logically ought to say something about all X. "All of them have beards" would be a statement about all of them; analogously, "All of them are not armed" ought to be a statement about all of them.

[Indistinguishable]

It's got nothing to do with logic (and translating English into a formal language, or back again, is fraught with all sorts of difficulties). It's just proof that the semantics of English aren't really compositional, and the meaning of one sentence can change depending on its context. Taken in context, it's easy to see what the sentence means. Even the OP had to focus on a fragment of a sentence to get a contradiction, the second half of the sentence clears up the meaning.
Man, you said everything I was going to say. Now what am I going to do?...

(That having been said, I often mentally stumble when confronted with this phrasing as well. C'est la vie.)

[Mangetout]

Is this an American thing ..?

I started a thread asking this a while back and I think it was resolved that it's an English thing that has fallen more quickly out of common use in the UK than in the US. Consider: 'All that glisters is not gold (Shakespeare) and 'All is not lost' (Milton)

ETA: Outside of well-established examples such as the above, I often have problems parsing it properly.

[Ximenean]

I agree that from context it's possible to work it out, but that's making the reader work harder than required, hence my feeling that's it's lazy writing.
I disagree. If you want to say that none of them are armed (or, if you insist, is armed), the usual way to say it is just that, "none of them is/are armed". Nobody would say "all of them are not armed" to convey that idea, regardless of logic, so I don't think it does need context to clarify it. It just needs familiarity with common usage.

[Wallenstein]

Nobody would say "all of them are not armed" to convey that idea, regardless of logic, so I don't think it does need context to clarify it. It just needs familiarity with common usage.

Well from my view this side of the pond nobody would say "all of them are not armed" to convey the idea that some but not all of them are carrying arms, so context is arguably required to clarify intention. The common usage most English speakers are familiar with is surely "not all of them are armed" which needs no context to be understood?

Anyway, looks like it's a common enough American usage so ignorance fought.

I disagree. If you want to say that none of them are armed (or, if you insist, is armed), the usual way to say it is just that, "none of them is/are armed".

FWIW I would tend to say "none of them are armed" in normal speech, but you get some nitpicking grammar pedants on these boards so wanted to be on the safe side ;)

[Celyn]

...
As a Brit I take "All of them are not armed" to mean "None of them is armed", which doesn't appear to be the intention behind it. In fact it's the complete opposite - i.e. some of them are indeed armed.

Likewise I've also seen a similar phrase used in defence of the catholic clergy: "All priests are not abusers", which surely means "There are zero priests who are abusers" which is not the intention either.

In each case I would have used "Not all of them are armed", and "Not all priests are abusers".
...

I agree with you entirely. I had begun to think that I might be the only person in the world annoyed by that phrase, preferring" the "not all x are y" version. Like some others here, I often have to remember "all that glisters is not gold" in order to force myself to accept it, albeit grudgingly.

Sadly it doesn't really work, because the next step is me muttering to myself "I don't care if Bill Shakespeare did write it. I still don't like it. And didn't Shakespeare have clocks striking in Julius Caesar, and a silly line in Macbeth saying "he has killed me, Mother"? Grumble grumble, grumble". I should probably give up talking to myself, because it is never the holliest of conversations. :D

[Wolverine]

The difference is all about where you pause or break the sentence.

Consider the difference:

"All X are not" + "Y" means that not every single X is Y. e.g Not every person is armed.
"All X are" + "not Y" matches up with the OP's understanding. Every person is unarmed.

I think that both are correct readings and the reader needs context to understand what the writer wanted. However, the use of "All X are not" makes more sense to me than "All X are." The second interpretation seems more forced and unnatural to everyday speech. It is easier to say "Every X is" for that usage.

[BigT]

I agree that from context it's possible to work it out, but that's making the reader work harder than required, hence my feeling that's it's lazy writing.

If making the reader "work harder than required" is an example of sloppy writing, then pretty much every classic piece of literature is sloppy writing.

And I don't see why it's logically wrong. All of them are not armed, however, some of them are armed. If you want to say otherwise, you say "None of them are armed" or "All of them are unarmed."

ETA: Or to take it Wolverine's way: There's a difference in accent: "All of them are not armed." vs "All of them are not armed."

Oh, and anymore and any more are two different words for different cases, like anyway and any way. "I'm not making any more cookies." vs. "She make cookies anymore." or "Anymore, she can't get help."

[Eyebrows 0f Doom]

Is this an American thing (like "I could care less")

That's not an American thing, that's a stupid person thing.

[njtt]

I am British and I think "All of them are not armed," to convey that only some of them are armed is perfectly fine, and not particularly ambiguous.*

Indeed, I would not use that form to say that nobody in some group is armed, both because it is an awkward way to say that and because for me it most immediately evokes the meaning intended by Fuzzy Wombats. I would say either "None of them are armed," or "All of them are unarmed."

*Actually, I think that in speech it would be disambiguated by intonation. If the all and the not were heavily stressed then it would mean that none were armed. If it were said with a falling inflection and no stress on the not it would mean that only some of them were armed. To me, the latter, without the rather deliberate stressing, is the most natural way to read it when written.

[Capt. Ridley's Shooting Party]

Indeed, I would not use that form to say that nobody in some group is armed, both because it is an awkward way to say that and because for me it most immediately evokes the meaning intended by Fuzzy Wombats. I would say either "None of them are armed," or "All of them are unarmed."


This highlights an interesting quirk of language, as "all of them are not armed" seems to be causing confusion, yet "all of them are unarmed" is cited as unambiguous. So, is "unarmed" defined as "not armed", or not? ;)

[wayward]

Oh, and anymore and any more are two different words for different cases, like anyway and any way. "I'm not making any more cookies." vs. "She make cookies anymore." or "Anymore, she can't get help."
That's not quite the issue though, it's not the compound word that bugs me. It seems perfectly natural to me to use "any more" in a "these days" type context for negative statements, "He's not able work any more"; "She doesn't make cookies any more". There it's acting as a synonym for "any longer". It seems to be in the last few years that it has begun to be used for positive statements too.

Don't get me wrong, I can see how it happened, I understand that language is constantly changing and evolving and I know that I use plenty of idioms that don't make literal sense. I suppose it just stands out to me because I've seen it spread without actually using it within my peer group.

Sorry for the hijack.

[Wallenstein]

This highlights an interesting quirk of language, as "all of them are not armed" seems to be causing confusion, yet "all of them are unarmed" is cited as unambiguous. So, is "unarmed" defined as "not armed", or not? ;)

"Unarmed" = "not armed"... can it be defined any other way?

"All of them are unarmed"
"All of them are not armed"

I honestly can't see how they can mean different things.

"All of them are unarmed"
"Not all of them are armed"

Same words but totally different meaning (IMO, obviously).

There's a good reason I put this in IMHO as clearly some people have no problem with this usage, but to me it just grates horribly... in my humble opinion.

[Mangetout]

There are words where the 'un~' prefix doesn't render quite the same meaning as prefixing with 'not' - usually where 'un' indicates that some state has been reversed (as opposed to the state just never having happened). Consider:

Dead. 'They are not dead' vs 'They are undead'
Tied. 'The boat's mooring rope was not tied' vs 'the boat's mooring rope was untied'

In the case of armed, I suppose some people might interpret 'unarmed' to mean 'doesn't own a weapon' and 'not armed' to mean 'not carrying a weapon, right now'

[Wallenstein]

In the case of armed, I suppose some people might interpret 'unarmed' to mean 'doesn't own a weapon' and 'not armed' to mean 'not carrying a weapon, right now'
In which case the sentance would mean "All of them are not carrying a weapon", which to my ears still implies that no guns are present? Rather than "Not all of them are carrying a weapon" vs "None of them are carrying a weapon".

Part of the reason Shakespeare opted for "All that glisters is not gold" is presumably that it fits his chosen metre better than alternatives?

Wikipedia (http://en.wikipedia.org/wiki/All_that_glitters_is_not_gold) makes an interesting point:

The statement "All that glitters is not gold" may seem literally incorrect, gold itself serving as a counterexample (gold glitters, but is gold). However, panning for gold often results in finding pyrite, nicknamed fool's gold, which reflects substantially more light than authentic gold does. Gold in its raw form appears dull and does not glitter.

"Not all that glitters is gold" is an alternate formulation.

In which case this would support the view that either it's incorrect gramatically or that it's highlighting the point that "if it glitters / glisters it's not gold".

[Mangetout]

In which case the sentance would mean "All of them are not carrying a weapon", which to my ears still implies that no guns are present? Rather than "Not all of them are carrying a weapon" vs "None of them are carrying a weapon".I agree in this case, and to my British ears, 'all are not armed' sounds like a universal.

Part of the reason Shakespeare opted for "All that glisters is not gold" is presumably that it fits his chosen metre better than alternatives?Maybe, but I think it's more likely that the usage was simply more common in English at that time - English subsequently split into UK and American variants, and a different subset of things fell out of common usage on either side ('gotten' is another example of this)

I think the Wiki link is just explaining it for anyone who happens to stumble over the usage, as we are wont to do,.

[Mangetout]

This link seems to confirm what I'm saying:

http://alt-usage-english.org/excerpts/fxallnot.html

Since Chaucer said very much the same thing before Shakespeare, it looks like maybe Shakespeare was just using an alread-common idiom of his day. The linked article gives a number of other early uses of the construction (and notes that there appear no 'not all...' counterexamples back that far)

Tis just the way we used to speak. Brits largely stopped doing it - Americans continued.

[Wallenstein]

Ah well - I guess that's the general rule with grammar issues. Often it's just the way it is. :)

[tr0psn4j]

Right, they should add a "not" to the beginning of those sentences.

[septimus]

I think it's just a language ambiguity in English. (Some languages may avoid this, but might be more ambiguous in other ways. It would be interesting to learn about language-dependent ambiguity; unfortunately we mustn't pose the question to linguists who are, without doubt, the Most Pedantic and Self-Righteous of any scientific specialty.)

An even simpler example of ambiguity is "You can not smoke." It means smoking is forbidden but parses as meaning that not-smoking is allowed. Even Thai (usually far more ambiguous than English) avoids that problem, since it allows "not" to be placed either before or after the "can."

[Johanna]

unfortunately we mustn't pose the question to linguists who are, without doubt, the Most Pedantic and Self-Righteous of any scientific specialty.
To make such a statement takes some profound ignorance of what the field of linguistics actually is.

[septimus]

To make such a statement takes some profound ignorance of what the field of linguistics actually is.

Are you a linguist, Johanna? If so, since there's very little relation between your statement and mine, I'll take yours as another datapoint in my favor. :cool:

[Jamaika a jamaikaiaké]

Are you a linguist, Johanna? If so, since there's very little relation between your statement and mine, I'll take yours as another datapoint in my favor. :cool:

How is she being self-righteous and pedantic? You (ignorantly, and without provocation) insulted all the linguists on this board.

Thank you-- I'd been hearing that syntax in TV commercials for ages ("All fluoride toothpastes are not alike!") and it drives me crazy. Too bad they don't teach basic logic until the college level, and even then I doubt more than a few people even study it a little bit, or we wouldn't have this syntactical embarrassment.
It's variation, man. It doesn't jibe with my idiolect, either, but it is well-established usage. (Cite: Shakespeare, Chaucer, etc.)
-Jaj, Logician.

My first instinct was to parse it as {If X, then ~Y}. Of course, I've been teaching formal logic to kiddos lately and the text we use is quite careful to differentiate "All X are not Y" from "Not all X are Y <=> Some X are not Y".
Just out of curiosity, you do make a big-assed caveat stating that formal Logic isn't the same as ordinary English, right? I mean, as soon as we hit the seemingly simple word "OR" we've already diverged from ordinary English. I'm a mathematician by trade, and I've always wondered how others deal with this.

This highlights an interesting quirk of language, as "all of them are not armed" seems to be causing confusion, yet "all of them are unarmed" is cited as unambiguous. So, is "unarmed" defined as "not armed", or not?
That's pretty awesome.
You're right, of course, and I've been hearing it too . . . along with the use of "less" when they mean "fewer." You'd think that professional journalists would have a grasp of the English language.
What's the deal with airline food?

[Spectre of Pithecanthropus]

All X are not Y to mean X and Y are mutually exclusive is somewhat of a colloquialism, acceptable in everyday usage. This is what I first thought it always meant. I didn't encounter the meaning that Y may be a subset of X until being exposed to academic or formal discourse.

[Indistinguishable]

I would think the meaning "X and Y are mutually exclusive" is the academic or formal reading of "All X are not Y", while the colloquialism is the reading of "All X are not Y" as meaning "X is not a subset of Y (i.e., not all X are Y)".