View Poll Results: Do you think all these arguments are valid, only some are, or none of them?

Voters
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  • All these arguments are valid

    1 16.67%
  • Only some of these arguments are valid

    1 16.67%
  • None of these argument is valid

    3 50.00%
  • I don't know

    1 16.67%
  • These arguments don't make sense.

    0 0%
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Thread: All; therefore some?

  1. Top | #51
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    Quote Originally Posted by Speakpigeon View Post
    Ah, here is a very interesting piece of logic. I give the general form of the argument first, and then three straightforward applications of the general form.

    All A's are/have F;
    Therefore, some A is/has F.
    All angels have wings;
    Therefore, some angel has wings.

    All politicians are liars;
    Therefore, some politician is a liar.

    All imaginary beings have serious existential problems;
    Therefore, some imaginary being has serious existential problems.
    Thank you to say whether you think all these arguments are valid, or only some, or none.

    Thank you to cast your vote before posting any comment.
    EB
    I didn't vote, because to my understanding there is a difference between valid formal logic, which all the syllogism have, and a valid argument, which is what your question asks about, and which depends not just on the validity of the formal logic but on the truth or accuracy of the premises.
    However, it is not clear to me whether you are not just using "argument" as a synonym for "formal logic".

  2. Top | #52
    Contributor Speakpigeon's Avatar
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    Quote Originally Posted by jab View Post
    I didn't vote, because to my understanding there is a difference between valid formal logic, which all the syllogism have, and a valid argument, which is what your question asks about, and which depends not just on the validity of the formal logic but on the truth or accuracy of the premises.
    However, it is not clear to me whether you are not just using "argument" as a synonym for "formal logic".
    Definition
    A valid argument is a logical argument in which the premises provide conclusive reasons for the conclusion.

    When a proof is valid, we may say one of the following:

    • The conclusion follows from the premises;
    • The premises entail the conclusion;
    • The conclusion is true on the strength of the premises;
    • The conclusion is drawn from the premises;
    • The conclusion is deduced from the premises;
    • The conclusion is derived from the premises.


    https://proofwiki.org/wiki/Definition:Valid_Argument
    I hope this will be helpful.
    EB

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