Everyone is female... Therefore ... ?

[Speakpigeon]

Here is an interesting logical argument:

Everyone is female;
Therefore, any siblings are sisters.

Do you personally think this argument is logically valid?

Thank you to cast a vote before posting any comment.

Please note you can vote for several options.
EB

 

[ruby sparks]

I voted no.

Sisters would only be children who have the same mother, so it does not follow?

Oh bollocks, I screwed up your poll. I should have said yes. AArrhggh. Sorry!

 

[DBT]

As the conclusion does follow from the given premise, the conclusion is logically valid in relation to the given premise. It appears that the premise is false.

 

[Tigers!]

As noted by DBT the argument is logically valid given the premise but the premise is the problem.

 

[Speakpigeon]

As the conclusion does follow from the given premise, the conclusion is logically valid in relation to the given premise. It appears that the premise is false.

Excellent, so you don't seem "confused" between validity and soundness, as some of our mathematically trained experts here have implied.

...

 

[Speakpigeon]

I voted no.

Sisters would only be children who have the same mother, so it does not follow?

Oh bollocks, I screwed up your poll. I should have said yes. AArrhggh. Sorry!

Again... And I'm not sure I understand your explanation.

Still, you should be able to vote a second time, no?
EB

 

[Speakpigeon]

...

 

[Politesse]

Here is an interesting logical argument:

Everyone is female;
Therefore, any siblings are sisters.

Do you personally think this argument is logically valid?

Thank you to cast a vote before posting any comment.

Please note you can vote for several options.
EB

Well, we all start our lives as biological sisters to our siblings, anatomically speaking. But I assume you were after philosophical, not empirical, validation.

 

[fromderinside]

Everyone is female;
Therefore, any siblings are sisters.

EB

No.

It fails logical limitation necessary to attribute everyone group. Is it everyone present is female, everyone everywhere are female? If it is everyone observed is female then then are the siblings product of the females present only? and are all the siblings of one parent or are the siblings are just those found in a group that was all female with other females who may have been mothers, grandmothers, daughters, or granddaughters.

 

[fast]

As the conclusion does follow from the given premise, the conclusion is logically valid in relation to the given premise. It appears that the premise is false.

Excellent, so you don't seem "confused" between validity and soundness, as some of our mathematically trained experts here have implied.

...

If educated people out of an entire field of study, collectively over time, appropriates a couple terms to denote a very specific technical meaning, the plain Jane common usage is likely divergent from its technical usage.

The terms “valid” and “sound” are technical terms, and when used in accordance to their technical use, they don’t even apply for inductive arguments—a category error, it makes. So, while you may use the terms in the same way Larry, Moe, Curly, Shemp, and Joe use it when discussing inductive arguments, the technical usage has no place.

But, you’re making a deductive argument, and while the five stooges can use the terms in common yet non-technical ways, just as they can with inductive arguments, the technical terms’ technical usage often trumps common usage when the discussion pertains to a technical field. No one really care how the almighty dictionary defines “kidnapping” while inside a courtroom. It’s technical usage is what then matters.

A sound argument is a valid argument with true premises. That’s how it’s used by trained logicians. Coming in and using it like the everyday dictionary explains its usage intentionally creates ambiguity where there should be none.

Validity doesn’t imply soundness whereas soundness implies validity — in accordance to technical usage.

A sound argument is superior to an argument that is merely valid.

 

[Speakpigeon]

Here is an interesting logical argument:

Everyone is female;
Therefore, any siblings are sisters.

Do you personally think this argument is logically valid?

Thank you to cast a vote before posting any comment.

Please note you can vote for several options.
EB

Well, we all start our lives as biological sisters to our siblings, anatomically speaking. But I assume you were after philosophical, not empirical, validation.

I didn't say "philosophical validity". I said "logical validity". Is the argument logically valid do you think?

Can you explain why you voted "the question doesn't make sense"?
EB

 

[Speakpigeon]

Everyone is female;
Therefore, any siblings are sisters.

EB

No.

It fails logical limitation necessary to attribute everyone group. Is it everyone present is female, everyone everywhere are female? If it is everyone observed is female then then are the siblings product of the females present only? and are all the siblings of one parent or are the siblings are just those found in a group that was all female with other females who may have been mothers, grandmothers, daughters, or granddaughters.

The premise "Everyone is female" does"t read "Everyone present is female".

The premise "Everyone is female" does"t read "Everyone observed is female".

The premise "Everyone is female" just reads "Everyone is female".

Maybe I should put that in bigger size.
EB

 

[Speakpigeon]

the technical terms’ technical usage often trumps common usage when the discussion pertains to a technical field.

Sure, but "often trumps" won't be enough here.

And you would have to justify your implicit notion here that mathematical logic is the correct way to do logic as people not trained in mathematical logic think of it. I think I have demonstrated it's not.

Consequently, there is zero good reason to use mathematical logic's notion of validity when discussing logic.

A sound argument is a valid argument with true premises. That’s how it’s used by trained logicians. Coming in and using it like the everyday dictionary explains its usage intentionally creates ambiguity where there should be none.

Validity doesn’t imply soundness whereas soundness implies validity — in accordance to technical usage.

A sound argument is superior to an argument that is merely valid.

That's entirely irrelevant to this thread since I asked about validity. It is also entirely irrelevant to my comment to DBT. I hope you're not suggesting DBT is confused about soundness and validity?

I use the term "soundness" as most people understand it and we all understand enough of the difference between sound and valid to talk competently about it. And that's what I'm interested in anyway.

 

[fast]

You asked “is the argument logically valid?”

When you specifically use the term “logically” to describe a particular sense of validity when discussing an argument, not only will Larry, Curly, Moe, Shemp, and Joe refrain from using “valid” in a layman sense as explained in dictionaries, they will (like most all logicians) turn to a glossary specific to the field of logic as used by those who study logic.

‘Logic’ need not even resemble “logic.” ‘Valid’ need not resemble “valid.”

 

[fromderinside]

The premise "Everyone is female" just reads "Everyone is female".

Maybe I should put that in bigger size.
EB

Ah the reason I left out because it is so obvious that I constructed instances for possibly logical true applications of everyone is female. It is demonstrably false that Everyone is female which would make you last comment really embarrassing for you. If it is demonstrably false it cannot be logically true.

 

[Bomb#20]

The conclusion doesn't follow from the premise. "Everyone" means "every person". "Sibling" means "one of two or more individuals having one common parent", not "one of two or more individual persons having one common parent". So everyone being female doesn't imply ducks don't have brothers.

 

[DBT]

Maybe in that little universe all males were killed off and females took up the practice of cloning.....consequently, 'everyone is female?'

 

[Speakpigeon]

The premise "Everyone is female" just reads "Everyone is female".

Maybe I should put that in bigger size.
EB

Ah the reason I left out because it is so obvious that I constructed instances for possibly logical true applications of everyone is female. It is demonstrably false that Everyone is female which would make you last comment really embarrassing for you. If it is demonstrably false it cannot be logically true.

How can you be so utterly ignorant?

Still, I didn't ask whether the premise was true, or indeed "*logically true*", whatever you may mean by that.

I ask about the argument, and I asked whether it was *logically valid*, not whether it was logically true.

But I guess your answer goes a long way to explain how you don't understand anything I say.
EB

 

[Speakpigeon]

Maybe in that little universe all males were killed off and females took up the practice of cloning.....consequently, 'everyone is female?'

DBT 1 - FDI 0.
EB

 

[Speakpigeon]

You asked “is the argument logically valid?”

When you specifically use the term “logically” to describe a particular sense of validity when discussing an argument, not only will Larry, Curly, Moe, Shemp, and Joe refrain from using “valid” in a layman sense as explained in dictionaries, they will (like most all logicians) turn to a glossary specific to the field of logic as used by those who study logic.

LOL. This is preposterous. You are talking from ignorance.

Beside, you can see for yourself that Joe does use "valid" to refer to logical validity. Everybody does. You should try it.

You keep up the pretence that logic is only mathematical logic. Aristotle came 2,300 years before any mathematical logic and described logic as he saw it in the argument of philosophers at the time and indeed in the way people in general used language.

‘Logic’ need not even resemble “logic.” ‘Valid’ need not resemble “valid.”

Indeed.

I just realised you don't argue.
EB