Everyone is female... Therefore ... ?

[Speakpigeon]

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.

Excellent. I'm impressed.

Collins, for "sibling", has "a. a person's brother or sister", and I would assume it is the implicit interpretation most people make.

According to this interpretation, I take it you accept the argument is valid?
EB

[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.

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

You can snow the jury by using a dictionary in a courtroom, but you’re gonna confuse neither the other attorneys nor the judge—nor the others who have acclimated to specialized word usage. See, it doesn’t mean a hill of beans what “kidnapping” means when it comes to whether or not the accused is guilty of ‘kidnapping’.

You are clearly wanting to use the terms in non-technical ways, yet you continue to explicitly qualify your usage as being logical, yet that creates the ambiguity between “logically valid” and (written identically) “logically valid.” The first is your sense where insight can only be gleaned from a dictionary—and the latter from a glossary.

[Speakpigeon]

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.



Indeed.

I just realised you don't argue.
EB

You can snow the jury by using a dictionary in a courtroom, but you’re gonna confuse neither the other attorneys nor the judge—nor the others who have acclimated to specialized word usage. See, it doesn’t mean a hill of beans what “kidnapping” means when it comes to whether or not the accused is guilty of ‘kidnapping’.

You are clearly wanting to use the terms in non-technical ways, yet you continue to explicitly qualify your usage as being logical, yet that creates the ambiguity between “logically valid” and (written identically) “logically valid.” The first is your sense where insight can only be gleaned from a dictionary—and the latter from a glossary.

I rest my case.
EB

[ronburgundy]

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

It is not deductively valid. It becomes valid only if one adds the premise "Female siblings are always sisters."

While this premise may seem so obviously true by definition that we normally would not verbalize it, deductive validity is determined only upon explicitly stated information.

[Bomb#20]

Excellent. I'm impressed.

Collins, for "sibling", has "a. a person's brother or sister", and I would assume it is the implicit interpretation most people make.

According to this interpretation, I take it you accept the argument is valid?

Some speech communities use the word "valid" for a property the argument has; other speech communities use the word "valid" for a property the argument does not have. I'm not going to get into a debate over which speech community rightfully owns the word. Linguistics is a descriptive science, not a prescriptive one.

[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

It is not deductively valid. It becomes valid only if one adds the premise "Female siblings are always sisters."

While this premise may seem so obviously true by definition that we normally would not verbalize it, deductive validity is determined only upon explicitly stated information.

Ok, but what do you think people mean here when they say it is valid? Do you think they mean "not deductively valid"?

You seem to understand the reasoning behind the assessment that the arguent is valid. Isn't it enough to make the distinction between valid simpliciter and formally valid? It seems to me that you are talking about formal validity, whereby we require all premises to be made explicit...
EB

[Speakpigeon]

Excellent. I'm impressed.

Collins, for "sibling", has "a. a person's brother or sister", and I would assume it is the implicit interpretation most people make.

According to this interpretation, I take it you accept the argument is valid?

Some speech communities use the word "valid" for a property the argument has; other speech communities use the word "valid" for a property the argument does not have. I'm not going to get into a debate over which speech community rightfully owns the word. Linguistics is a descriptive science, not a prescriptive one.

Sorry, I'm not sure I understand the subtext of that. Could you spell out what "community" would deem the argument not valid?
EB

[Bomb#20]

Some speech communities use the word "valid" for a property the argument has; other speech communities use the word "valid" for a property the argument does not have. I'm not going to get into a debate over which speech community rightfully owns the word. Linguistics is a descriptive science, not a prescriptive one.

Sorry, I'm not sure I understand the subtext of that. Could you spell out what "community" would deem the argument not valid?
EB

Whoever it is the OED is talking about who use "valid" as a synonym for "sound".

https://www.lexico.com/en/synonym/valid

[Speakpigeon]

Some speech communities use the word "valid" for a property the argument has; other speech communities use the word "valid" for a property the argument does not have. I'm not going to get into a debate over which speech community rightfully owns the word. Linguistics is a descriptive science, not a prescriptive one.

Sorry, I'm not sure I understand the subtext of that. Could you spell out what "community" would deem the argument not valid?
EB

Whoever it is the OED is talking about who use "valid" as a synonym for "sound".

https://www.lexico.com/en/synonym/valid

You must be too clever for this world.
EB

[fromderinside]

He's Mighty Mouse.