Ambiguity Fallacy

TrappedPrior (RotE) writes:

I consider equivocation to be a fallacy where:

• a term has multiple definitions
• more than 1 (usually 2) of these definitions are used in the argument
• they are passed off as being equivalent

Example: "The poster says 'do something nice for someone'. I'm someone, so do something nice for me!"

(The first sense of 'someone' is 'a person other than yourself'. The second sense of 'someone' is 'a specific person'. Both senses are deployed in the argument, but treated as being the same, making for a misleading argument.)

The  ambiguity fallacy  does not require you to switch between multiple senses of the same word; it just means the operant terms are not defined, so it is unclear whether the premises support the conclusion.

Example: "If you support equality, then there's no reason to oppose affirmation action. Historically marginalised groups deserve representation."

(The operant is 'equality', which is not defined by the speaker. Thus, they are able to smuggle their ideological assumptions into the argument. The interlocutor or audience might have a different concept of 'equality' to the speaker. Equality for whom? Equality of what? You could also argue that 'affirmative action', which refers to a broad set of policies aimed at levelling the playing field for the disadvantaged, is also too wide to be meaningful when used in this argument.)

TrappedPrior (RotE) writes:

I agree that  equivocation  is one form of the  ambiguity fallacy. 

T. Edward Damer would classify both as 'acceptability fallacies', as they both fail to meet the acceptability criterion for a sound argument (since they rely on linguistic confusion).

Darren writes:
[To Rationalissimus of the Elenchus]

I looked at the T. Edward Damer book, which had an interesting discussion on this issue.   He divides fallacies according to 5 criteria for what constitutes a good argument, one of which is Acceptability (which is very broadly defined).   Ambiguity, as you point out, is in the Acceptability section.

Fallacies are, of course, defined differently by different sources; this is how Damer parses Ambiguity and Equivocation:

Equivocation is where a word  or phrase with 2 or more meanings is used in different ways in the premises of an argument, but appear to have the same meaning throughout.  Note that he doesn't distinguish between words and phrases; either can be Equivocation.   This is a different interpretation than what Jorge wrote below and (I believe) a different interpretation than this website, which seems to distinguish between words and phrases in attributing the Equivocation vs Ambiguity fallacy.

He talks about two different types of Ambiguity fallacies based on semantic vs syntactic ambiguity.  Semantic ambiguity is where the ambiguity is in the meaning of the word or phrase used.   An example he gives deals with driving instructions:   if the driver is told "turn right here",   the speaker might have meant turn right away (and was pointing to the left),  whereas the driver interpreted "right" to mean the direction to go.  This is not the same as Equivocation, since this isn't a case where the same word or phrase is used in different ways in the same argument, but rather, the single use of the word or phrase is ambiguous.  

The other type of ambiguity is syntactic ambiguity, which is where the word or phrase is not inherently ambiguous but becomes ambiguous because of poor use of grammar or syntax  (this is referred to as "Amphiboly").  An example he gives is:  "Fred never argues with his father when he's drunk" (does this mean--when Fred's drunk, or when his father's drunk)?   The ambiguity isn't in the meaning of the words but because it's not made clear who "he" is.

If I were doing the Taxonomy, I'd use "Equivocation" for either a word or phrase being used in more than one ways in the same argument.   "Ambiguity Fallacy" would be a catch-all for all types of fallacies (including Equivocation) where an argument can be interpreted in two or more ways because of ambiguity in the terms.   For those who want a separate name for each variation of fallacy, I'd divide these into semantic ambiguity and Amphiboly.   I think the latter, at least, deserves its own entry.

 

TrappedPrior (RotE) writes:
[To Darren]

Good points. Perhaps 'ambiguity fallacy' is a bit...um...ambiguous, too much so to be a useful entry.

It could be split into three fallacies - equivocation (switching the sense in which the same word/phrase is used, so the argument is misleading), semantic ambiguity (word/phrase itself is unclear) and syntactic ambiguity or amphiboly (word/phrase is unclear due to poor grammar).

That said, Dr Bo might not feel it's worthwhile to add separate entries for the last two types, when they could just be given as different variations on the Ambiguity Fallacy, rather than getting rid of the latter entry altogether. After all, Appeal to Emotion is also...um...ambiguous, yet it has its own entry.

(But in counter to that, so do some of the various forms of it!)

Darren writes:

Thanks.

This website makes the distinction you make between single terms vs phrases in defining equivocation and ambiguity fallacy.   I was wondering if you've seen that distinction anywhere else (most sources define "equivocation" as a word or phrase.)      

Jorge writes:

[To Darren]

I responded without perhaps understanding your two points. Let me try this again. Here's what you wrote:
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(1)  using a phrase more than once but with different meanings (similar to equivocation) or

(2) using an ambiguous phrase once, but the listener might misinterpret it (due to its ambiguity).
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I contend that equivocation and ambiguity can be used interchangeably because the idea behind their classification is equivocation, or "equal in voice" but not necessarily in meaning. 

With that said, I like classifying things. So having equivocation dissected in two fallacies is interesting. It would be like having a computer and wanting to know some of its architecture I guess. You can still use the computer but maybe knowing some of its architecture can help you program differently. Perhaps the linguist or psychologist can make a better use with the equivocation-to-ambiguity distinction. But we still know what we mean when we use them, even interchangeably: there was an error in reasoning and that happened because of equivocation.

As to your points, the first one I think is what it's meant by the strict definitions on this website. To your second point, the fallacy would be committed by the listener if the listener forms a conclusion by misinterpretation, even it was done by accident. This is because we can re-write information and courses of action in the form of an argument.

Example: 
Sarah: Pete, I'll see you at the movies.
Pete: Ok Sarah.
Pete then goes to the movies but doesn't look for Sarah and they don't meet. The next day:
Sarah: What happened? I said I'll see you there!
Pete: Yes, and you didn't look for me!

Pete used the phrase "I'll see you" to mean "I'll look for you" when in reality Sarah meant to say that they have to look for each other. An error in thinking was made and perhaps by accident. We can re-write Pete's course of action as a response to the information as follows:

1. Sarah said that she'll see me at the movies.
2. If Sarah will see me at the movies, then I don't have to look for her.
C. I don't have to look for her.

Maybe my example sounds outdated because of smartphones and stuff but suppose that Pete didn't pay attention to his phone because he was in the arcades.

rx7man writes:

It could also be that either one of them SAW the other at the movies, but didn't approach or acknowledge each other

Jorge writes:
[To rx7man]

It could be. But suppose that it didn't happened that way. Suppose that Pete truly believed that Sarah was gonna look for him and he just didn't worry about that. And suppose that Sarah really did look for him but couldn't find him. Then they missed each other because Pete's misunderstanding. This ambiguity fallacy can still be committed by Pete even if Sarah ends up finding Pete or even if Pete bumps into Sarah. Pete's reasoning was still faulty.