The Monkey argument: Valid? not valid?

Do you accept the Monkey argument as valid?

  • Yes, I accept it is valid.

    Votes: 1 14.3%

  • No, I think it is not valid.

    Votes: 6 85.7%

  • I don't know.

    Votes: 0 0.0%

  • The argument doesn't make sense.

    Votes: 0 0.0%
  • Total voters
    7
  • Poll closed .
Speakpigeon

Speakpigeon

Valued Senior Member
Here is an argument. Please take all the time necessary to make up your mind about it...

No monkey is a giraffe;
No giraffe is an elephant;
No elephant is a squid;
No squid is a monkey;
Joe is either an elephant, a monkey or a squid;
Joe is neither an elephant nor a giraffe;
Therefore, Joe is a monkey.​

Once you think you have it figured out, thank you to vote to say whether you accept this argument as valid or not (i.e. logically valid).

Please note I'm interested in whether you personally accept the argument as valid.

Thank you for your answers.

Please no comment without vote.
EB
 
Speakpigeon said:
Joe is either an elephant, a monkey or a squid;
​
Click to expand...

It is not clear whether the above is intended to be a premise or a conclusion.​

I suspect it is intended as a premise - i.e. the argument asserts that Joe is one of those three.
Is this correct?
 
DaveC426913 said:
It is not clear whether the above is intended to be a premise or a conclusion.​

I suspect it is intended as a premise - i.e. the argument asserts that Joe is one of those three.
Is this correct?
Click to expand...
The natural assumption in #1 surely is that all lines bar the last one are specified conditions. Only the last line then can be the argument purporting to reconcile those preceding specified conditions/relations. It fails imo to do so and is therefore false. Annoying if it turns out Speakpigeon has failed to mention additional assumptions turning it into a trick question.
 
Q-reeus said:
First four lines are redundant. Sixth line eliminates only elephant from three initial options in fifth line, hence Joe is a monkey OR squid. Too easy.
Click to expand...
Sorry about that but I need to check what the baseline is!

Maybe you could give your view on this one too:

A squid is not a giraffe
A giraffe is not an elephant
An elephant is not a squid
Joe is either a squid or a giraffe
Joe is an elephant
Therefore, Joe is a squid​

What do you think? Valid/Not valid/Don't know/Doesn't make sense?

Q-reeus said:
The natural assumption in #1 surely is that all lines bar the last one are specified conditions. Only the last line then can be the argument purporting to reconcile those preceding specified conditions/relations. It fails imo to do so and is therefore false. Annoying if it turns out Speakpigeon has failed to mention additional assumptions turning it into a trick question.
Click to expand...
LOL, you're ready for the worse!
No, the argument of course is what it is. Additional premises would make it a different argument.
The argument is made up by the whole seven lines,
The "last line" is the called the "conclusion".
And what you call "specified conditions" are also and more usually called the premises.
EB
 
Speakpigeon said:
A squid is not a giraffe
A giraffe is not an elephant
An elephant is not a squid
Joe is either a squid or a giraffe
Joe is an elephant
Therefore, Joe is a squid
Click to expand...


"premise" : An elephant is not a squid
"premise" : Joe is an elephant
"conclusion" : Joe is a squid

"Please take all the time necessary to make up your mind about" your "premises" and "conclusion" prior to Posting

Hint : you may have omitted a "not" in "premise" #5
 
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Speakpigeon said:
Sorry about that but I need to check what the baseline is!

Maybe you could give your view on this one too:

A squid is not a giraffe
A giraffe is not an elephant
An elephant is not a squid
Joe is either a squid or a giraffe
Joe is an elephant
Therefore, Joe is a squid​

What do you think? Valid/Not valid/Don't know/Doesn't make sense?


LOL, you're ready for the worse!
No, the argument of course is what it is. Additional premises would make it a different argument.
The argument is made up by the whole seven lines,
The "last line" is the called the "conclusion".
And what you call "specified conditions" are also and more usually called the premises.
EB
Click to expand...
In #1 argument, the opening word 'Therefore' in line seven clearly distinguished it as different in nature from the preceding six lines - viz conclusion/argument vs declarations/premises. I made no fine distinctions there between conclusion and argument, or between (declarations = specified conditions/relations) and premises. It seems you do.
Key feature is there are no logical contradictions in any of the premises/declarations/specifications. Merely a faulty conclusion.

In #6 you present a schizophrenic situation where the last two premises/declarations/... are outright contradictory. Rendering the conclusion meaningless imo. Joe is in Wonderland. Have fun.
 
Q-reeus said:
In #1 argument, the opening word 'Therefore' in line seven clearly distinguished it as different in nature from the preceding six lines - viz conclusion/argument vs declarations/premises. I made no fine distinctions there between conclusion and argument, or between (declarations = specified conditions/relations) and premises. It seems you do.
Click to expand...
I'm merely following the usual conventions. I think we all understand arguments such as: "No monkey is a fish. That's a fish. Therefore, it's not a monkey."
Q-reeus said:
Key feature is there are no logical contradictions in any of the premises/declarations/specifications. Merely a faulty conclusion.
Click to expand...
We agree on that.
Q-reeus said:
In #6 you present a schizophrenic situation where the last two premises/declarations/... are outright contradictory. Rendering the conclusion meaningless imo. Joe is in Wonderland. Have fun.
Click to expand...
Nothing really schizophrenic, only a bunch of contradictory premises.
But apparently, you can't say whether you think it is valid or not.
EB
 
Speakpigeon said:
No monkey is a giraffe;
No giraffe is an elephant;
No elephant is a squid;
No squid is a monkey;
Joe is either an elephant, a monkey or a squid;
Joe is neither an elephant nor a giraffe;
Therefore, Joe is a monkey.​
Click to expand...
Premises 1 to 4 don’t add much to the argument, other than to state what each animal is not, but there is nothing contradictory in these 4 premises.
Premise 5 states Joe to be an elephant, monkey, or squid, while premise 6 excludes Joe from being an elephant or a giraffe. Again, nothing contradictory: Joe could be a monkey or a squid and still comply with both those premises.
Hence the conclusion, that Joe is a monkey, is invalid, as it is possible that Joe is a monkey.
I.e. all the premises could be true yet the conclusion could be false. Thus invalid.
 
Speakpigeon said:
Nothing really schizophrenic, only a bunch of contradictory premises.
Click to expand...
Which fits my idea of schizophrenic, but not worth arguing over nuances.
But apparently, you can't say whether you think it is valid or not.
Click to expand...
So 'Rendering the conclusion meaningless imo' is unclear? Well to home in further, of your four poll options, only the second and fourth are worth choosing between:
2: No, I think it is not valid.
4: The argument doesn't make sense.

I'll go with the fourth one as it effectively encompasses the second one but is stronger in nailing contradictory propositions as nonsensical not merely incorrect.
 
I'm not sure how far down the rabbit hole this can go, but how many assumptions must we make?
Premise: No monkey is a giraffe.
Does it immediately follow that no giraffe is a monkey? Are they assumed to be mutually exclusive?

If it were, instead, no mammal is a giraffe, it would not follow that no giraffe is a mammal.
 
DaveC426913 said:
Premise: No monkey is a giraffe.
Does it immediately follow that no giraffe is a monkey? Are they assumed to be mutually exclusive?
Click to expand...
As this relates back to logically coherent premises in #1 'argument', how could it be otherwise?
If it were, instead, no mammal is a giraffe, it would not follow that no giraffe is a mammal.
Click to expand...
Speakpigeon's premises in #1 are not of this type. I supect he is either a sadist (get respondents tied up in needless quandaries), or overdosing on certain stimulants. Or something mysterious known only to himself. I just know this will finish with an amazing 'a ha' moment for all involved. Or not. Covered all bases. Hopefully.
 
He's littered this site with numerous threads of this type, across numerous sub-fora: posting a question, taking a poll, but never actually engaging in conversation / discussion of the matter, never actually giving his own view of the question he asks.
 
Q-reeus said:
As this relates back to logically coherent premises in #1 'argument', how could it be otherwise?
Click to expand...
I'm simply drawing attention to the fact that we are assuming all the items in the first four premises are mutually exclusive (i.e. both directions).

We assume that 'no M is a G' implies that 'no G is an M'. That one is not a superset of the other.
 
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Sarkus said:
Premises 1 to 4 don’t add much to the argument, other than to state what each animal is not, but there is nothing contradictory in these 4 premises.
Premise 5 states Joe to be an elephant, monkey, or squid, while premise 6 excludes Joe from being an elephant or a giraffe. Again, nothing contradictory: Joe could be a monkey or a squid and still comply with both those premises.
Hence the conclusion, that Joe is a monkey, is invalid, as it is possible that Joe is a monkey.
I.e. all the premises could be true yet the conclusion could be false. Thus invalid.
Click to expand...
Thanks for voting.
EB
 
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