Logic quiz

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Arm-Chair Logic

(93% here. Seems logical enough.)

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>Seems logical enough
I think the text is on very shaky grounds.
e.g. (13)Not a single animal uses language
The premise appears to be that humans are not considered as animals. We know that they are animals, but the premise is undermined by the doubt raised by the phrasing.
I was thinking of raising a similar point about Kangaroos. If asked I would call them “marsupials” rather than “mammals” “invertebrates” or ‘chordates” which I think they are.
That is, by using an intermediate description the premise clouds the discussion.

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Remember, this quiz is not about individual statements being true/correct or false/wrong. Within the context of the quiz, the statements a), etc. are givens, we do not need to question them (some are obviously false/wrong but we should ignore that).
Instead, we have to decide whether the conclusion follows logically from the premises.

(I think the last one, #15, is rather doubtful)

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I found this fairly easy, but we had a whole module on this stuff when I did my degree in Philosophy!

StuartR

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> (I think the last one, #15, is rather doubtful)

“Therefore we can predict”

Well, yes.
If it was “Therefore we can predict with 100% accuracy” ….

I mean.
“I predict that I’ll earn $5,000,000,000,000,000,000 tomorrow” is valid.
I do, indeed predict that.
But unless Stuart comes to claim his prize ……

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>”I predict that I’ll earn $5,000,000,000,000,000,000 tomorrow”

Selling your cat Chris ???

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>>”I predict that I’ll earn $5,000,000,000,000,000,000 tomorrow”
> Selling your cat Chris ???
That’s my prediction …..

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I think that the human brain is geared to make use of every scrap of information. Tests on babies show that they can differentiate between 1, 2 and 3.

The story about human development of counting runs:

I need a cave to shelter for the night.

Two bears go into a cave and one comes out.
Should I enter the cave?

Two bears go into a cave and two come out.
Should I enter the cave?

Two bears go into a cave and two scurry out.
Should I enter the cave?

In the last two cases the mathematics are the same (2-2=0), but the use of the word “scurry” conveys extra information regarding my safety.

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100% for me although #15 made me think for a bit

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#15 was the one that stumped me. A wrong guess.

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93% also. I got #10 wrong, because the question must contain the (unspecified) assumption that there is only one “Paris” for the logic to be valid.

Alan

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Alan,

They ALL have similar assumptions, #1 assumes there is only one Donald and #3 assumes there is only one Gary for example. You need to think of these labels as being like variables in a programming language, not the names of real people and places.

StuartR

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OK, in that case I’ll give the quiz some latitude and award myself 100%.

Alan

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It is an assumption behind all these questions that if the same word is used in both statements it means the same thing each time.

If you replace Paris with XX you would take it for granted that XX refers to the same place each time.

Reword this as:
Question 10.
a) Jenny lives in XX.
XX is in New Zealand.

Conclusion
Therefore Jenny lives in New Zealand.

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93%. I got no. 13 wrong. The answer is followed by this statement: “But we can say that ‘not all’ reasoning beings employ generalisations.” If this is the case then surely some do? So why is the answer then not valid?

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The conclusion “Therefore reasoning beings employ generalisations” says that *all* reasoning beings employ generalisations.
But *some* reasoning beings are animals ©, hence they don’t use language (, so they don’t employ generalisations (a).

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Yeah but……. oh well never mind!!!

Great quiz though. One to email to everyone tomorrow.

Regards

Graeme

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Try:

1) If every boy likes some girl and every girl likes some boy,does every boy like someone who likes him?

2) A chocolate bar is better than nothing.
Nothing is better than eternal happiness.
Therefore, a chocolate bar is better than eternal happiness

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Jezza

That makes sense. However, I think my Missus might argue that “a chocolate bar is better than eternal happiness ” is valid on some days!

How’s your leg?

Regards

Graeme

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There’s nothing like a good analogy. And that’s nothing like a good analogy!

Alan

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Agreed. And had the assumption been explicitly stated, then there would be no room for ambiguity in interpretation.

Alan

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