The Fallacy of Vagueness or/and Ambiguity

The Fallacy of Vagueness or/and Ambiguity.

This fallacy has come up in another thread. I invite Bbarr to explain what this fallacy in general means.

Other debators are of course welcome to join in and give their thoughts.

Originally posted by ivanhoe
The Fallacy of Vagueness or/and Ambiguity.

This fallacy has come up in another thread. I invite Bbarr to explain what this fallacy in general means.

Other debators are of course welcome to join in and give their thoughts.

Uh, Ivanhoe, these are two different fallacies. 'Vagueness', in this context, means employing a term that fails to have precise application conditions. 'Ambiguity', in this context, means employing a term with more than one meaning. Now, just employing a term that is vague does not constitute a fallacy. For instance:

All bachelors are male
Royal Chicken is a bachelor
Hence, Royal Chicken is male

Now, even the term 'bachelor' is vague. We take it to mean unmarried male, but that can't be quite right. Infant boys are not really bachelors. So, perhaps we can revise our definition so that 'bachelor' means unmarried male of marriageable age. But wait, Catholic priests often satisfy these conditions, and they aren't really bachelors either. The term 'bachelor' has something to do with being available or willing to engage in certain behaviors. But how available and how willing must one be? There is no way other than by stipulation to settle this question, because our concept BACHELOR just isn't that fine grained. The point is that even with the simplest term like 'bachelor' there is vagueness. Nevertheless, the above argument is does not suffer from this vagueness. The vagueness at the boundaries of the application conditions of 'bachelor' do not give us any reason to doubt the argument above because the bachelor being mentioned is so very clearly a bachelor.

Is this clear so far?

Originally posted by bbarr
Uh, Ivanhoe, these are two different fallacies. 'Vagueness', in this context, means employing a term that fails to have precise application conditions. 'Ambiguity', in this context, means employing a term with more than one meaning. Now, just employing a term that is vague does not constitute a fallacy. For instance:

All bachelors are male
Royal Ch ...[text shortened]... e because the bachelor being mentioned is so very clearly a bachelor.

Is this clear so far?

Carry on ......

Originally posted by ivanhoe

Carry on ......

Well, I wanted to give you a chance to ask questions. You have any questions? You see, if I were you, I would be asking the following question:

"So, just when is vagueness problematic?"

Don't you think that's a good question, Ivanhoe?

Don't sleep in class, Ivanhoe! 😠

I asked you a question!

Originally posted by ivanhoe
The Fallacy of Vagueness or/and Ambiguity.

This fallacy has come up in another thread. I invite Bbarr to explain what this fallacy in general means.

Other debators are of course welcome to join in and give their thoughts.

I've read that all informal fallacies are really fallacies of ambiguity.

And the fallacy occurs when an argument uses the ambiguity of a term to shift it's meaning as it occurs at different points in an argument.

An ambiguous term or statement can have more than one meaning. When you change the meaning of a term as you use it in an argument, that is the fallacy of ambiguity.

I would think a vague term could be easily used in a similar fallacious manor. If you keep your arguments purposely vague, it gives you more room to change the meaning as you go.

The important point, in order to avoid a fallacy, any key term you use an an argument should always have the same meaning throughout the argument. By giving clear definitions, you protect your argument from assault.

Specific definitions help avoid the fallacy of ambiguity, but vauge or undefined terms don't necessarily cause a fallacy.

Originally posted by Coletti
I've read that all informal fallacies are really fallacies of ambiguity.

And the fallacy occurs when an argument uses the ambiguity of a term to shift it's meaning as it occurs at different points in an argument.

An ambiguous term o ...[text shortened]... , but vauge or undefined terms don't necessarily cause a fallacy.

Yeah, the fallacy you describe is often called the fallacy of equivocation, switching between senses of a word during an argument, like this:

Man the only rational animal.
No woman is a man.
Hence, no woman is a rational animal.

Originally posted by bbarr
Well, I wanted to give you a chance to ask questions. You have any questions? You see, if I were you, I would be asking the following question:

"So, just when [b]is vagueness problematic?"

Don't you think that's a good question, Ivanhoe?[/b]

A very good question indeed.

Do carry on.

Bbarr: "Uh, Ivanhoe, these are two different fallacies."

Uh, Bbarr, but they are related and sometimes closely related. That's the reason why they are often mentioned together.

Please, notice how carefully I formulated the thread's title .....

Originally posted by ivanhoe
The Fallacy of Vagueness or/and Ambiguity.

This fallacy has come up in another thread. I invite Bbarr to explain what this fallacy in general means.

Other debators are of course welcome to join in and give their thoughts.

Good article on vagueness.

Vagueness is to be distinguished from ambiguity, though rather fittingly the distinction is vague!

http://www.fallacyfiles.org/vaguenes.html

🙂

Originally posted by ivanhoe

A very good question indeed.

Do carry on.

That's better. I thought you were dozing.

Here is an argument I take to problematically vague, where that means that some key terms need to clarified before the argument can be assessed:

God is love
Love is good
Hence, God is good

Now, if somebody presented this argument to you, what terms would you want clarified?

Originally posted by ivanhoe
Bbarr: "Uh, Ivanhoe, these are two different fallacies."

Uh, Bbarr, but they are related and sometimes closely related. That's the reason why they are often mentioned together.

Please, notice how carefully I formulated the thread's title .....

No, this is incorrect. Those folk who are running these fallacies together are obscuring the very important distinction mentioned above. Here is how you can tell the difference between the two fallacies: Vague terms are those that do not have well defined application conditions at the margins. Ambiguous terms are those with two different meanings. Some terms may be both vague and ambiguous, but an argument relying on such a term will be guilty of two errors, not just one.

Originally posted by bbarr
That's better. I thought you were dozing.

Here is an argument I take to problematically vague, where that means that some key terms need to clarified before the argument can be assessed:

God is love
Love is good
Hence, God is good
...[text shortened]... esented this argument to you, what terms would you want clarified?

What terms do you want clarified ?

Originally posted by bbarr
That's better. I thought you were dozing.

Here is an argument I take to problematically vague, where that means that some key terms need to clarified before the argument can be assessed:

God is love
Love is good
Hence, God is good

Now, if somebody presented this argument to you, what terms would you want clarified?

I'd want to know what your definition of "is" is.

Originally posted by ivanhoe
What terms do you want clarified ?

I want you to identify those terms that you think are in need of clarification. I am an advocate of experiential learning, so if you are really interested in learning about these fallacies, I'm going to walk you through some arguments that suffer these flaws and ask you questions about them. I've found that it is easier to learn about logic and inference when you actually try to do some logic and draw some inferences. Besides, it will be instructive for those folk following along.