Logical conditional statements -- confusion about the word "only"

BBNinetyOneBBNinetyOne Member
in General 6 karma

Hi all,
Helpful insight would be appreciated; I am practicing my "translating" my Sufficient & Necessary conditional statements.

"Only" is a "group 2" operator that introduces the necessary condition, but I'm finding it difficult to figure out why this matters in certain simplistic contexts.

Consider the statement: "Only cats meow."

M --> C
/C --> /M

But with "only" sentences, it seems like the reverse logical operation is also true.

C --> M
/M --> /C

Am I simplifying it too much? In other words, is this logical reasoning or rule only relevant when ideas are more complex?

Thanks,

Comments

  • _megana__megana_ Member
    edited November 2021 64 karma

    Let's look at the original statement first: "Only cats meow." Do Dogs meow? No. Do cows meow? No. Only cats meow.

    Ok, so then we know if an animal meows, it must be a cat. Hence, the translation rule:
    M --> C (If meow, then cat).

    Now looking at C --> M (if cat, then meow), we can't infer this from the statement "Only cats meow." For all we know, our particular cat could bark. Just because you are a cat, that doesn't mean you meow. We just know from our statement that Only cats meow, not dogs, not cows, only cats.

    I hope that clarifies some confusion!

  • gabes900-1gabes900-1 Member
    855 karma

    @s00anderson said:
    Let's look at the original statement first: "Only cats meow." Do Dogs meow? No. Do cows meow? No. Only cats meow.

    Ok, so then we know if an animal is meows, it must be a cat. Hence, the translation rule:
    M --> C (If meow, then cat).

    Now looking at C --> M (if cat, then meow), we can't infer this from the statement "Only cats meow." For all we know, our particular cat could bark. Just because you are a cat, that doesn't mean you meow. We just know from our statement that Only cats meow, not dogs, not cows, only cats.

    I hope that clarifies some confusion!

    Was going to respond too, but this is a great explanation!

  • _megana__megana_ Member
    64 karma

    @gabes900 said:

    @s00anderson said:
    Let's look at the original statement first: "Only cats meow." Do Dogs meow? No. Do cows meow? No. Only cats meow.

    Ok, so then we know if an animal is meows, it must be a cat. Hence, the translation rule:
    M --> C (If meow, then cat).

    Now looking at C --> M (if cat, then meow), we can't infer this from the statement "Only cats meow." For all we know, our particular cat could bark. Just because you are a cat, that doesn't mean you meow. We just know from our statement that Only cats meow, not dogs, not cows, only cats.

    I hope that clarifies some confusion!

    Was going to respond too, but this is a great explanation!

    Thanks! Feel free to add on as well!

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