Is this argument valid?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP

up vote
1
down vote

favorite

Is this argument valid?

  1. No one under 18 is permitted to vote.
  2. No faculty member is under 18.
  3. The philosophy chairperson is a faculty member.
  4. Conclusion: The philosophy chairperson is permitted to vote.

My answer was it is not valid because the conclusion don’t follow from the premises.

share|improve this question

New contributor
Abdullah O. Alfaqir is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

  • Wait. Philosophy chairperson is a faculty member -> philosophy chairperson is 18 years old or older -> philosophy chairperson is permitted to vote. The argument is sound. And “the conclusion don’t follow from the premises.” is not what validity means.
    – rus9384
    5 hours ago

  • I’m sorry, to avoid gamesmanship here on the forum… are you asking about the argument ending in “Then the philosophy chairperson…” ? or the one ending in “My answer was it is not…”?
    – elliot svensson
    5 hours ago

  • I’m asking if my answer was correct or not
    – Abdullah O. Alfaqir
    5 hours ago

  • What you might need to add is why the conclusion does not follow from the premises, not just assert that it doesn’t follow from the premises. What were your reasons? Welcome to this SE!
    – Frank Hubeny
    1 hour ago

up vote
1
down vote

favorite

Is this argument valid?

  1. No one under 18 is permitted to vote.
  2. No faculty member is under 18.
  3. The philosophy chairperson is a faculty member.
  4. Conclusion: The philosophy chairperson is permitted to vote.

My answer was it is not valid because the conclusion don’t follow from the premises.

share|improve this question

New contributor
Abdullah O. Alfaqir is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

  • Wait. Philosophy chairperson is a faculty member -> philosophy chairperson is 18 years old or older -> philosophy chairperson is permitted to vote. The argument is sound. And “the conclusion don’t follow from the premises.” is not what validity means.
    – rus9384
    5 hours ago

  • I’m sorry, to avoid gamesmanship here on the forum… are you asking about the argument ending in “Then the philosophy chairperson…” ? or the one ending in “My answer was it is not…”?
    – elliot svensson
    5 hours ago

  • I’m asking if my answer was correct or not
    – Abdullah O. Alfaqir
    5 hours ago

  • What you might need to add is why the conclusion does not follow from the premises, not just assert that it doesn’t follow from the premises. What were your reasons? Welcome to this SE!
    – Frank Hubeny
    1 hour ago

up vote
1
down vote

favorite

up vote
1
down vote

favorite

Is this argument valid?

  1. No one under 18 is permitted to vote.
  2. No faculty member is under 18.
  3. The philosophy chairperson is a faculty member.
  4. Conclusion: The philosophy chairperson is permitted to vote.

My answer was it is not valid because the conclusion don’t follow from the premises.

share|improve this question

New contributor
Abdullah O. Alfaqir is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

Is this argument valid?

  1. No one under 18 is permitted to vote.
  2. No faculty member is under 18.
  3. The philosophy chairperson is a faculty member.
  4. Conclusion: The philosophy chairperson is permitted to vote.

My answer was it is not valid because the conclusion don’t follow from the premises.

logic

share|improve this question

New contributor
Abdullah O. Alfaqir is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

New contributor
Abdullah O. Alfaqir is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

share|improve this question

edited 5 hours ago

Eliran H

4,02521133

4,02521133

New contributor
Abdullah O. Alfaqir is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 6 hours ago

Abdullah O. Alfaqir

84

84

New contributor
Abdullah O. Alfaqir is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

New contributor

Abdullah O. Alfaqir is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

Abdullah O. Alfaqir is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

  • Wait. Philosophy chairperson is a faculty member -> philosophy chairperson is 18 years old or older -> philosophy chairperson is permitted to vote. The argument is sound. And “the conclusion don’t follow from the premises.” is not what validity means.
    – rus9384
    5 hours ago

  • I’m sorry, to avoid gamesmanship here on the forum… are you asking about the argument ending in “Then the philosophy chairperson…” ? or the one ending in “My answer was it is not…”?
    – elliot svensson
    5 hours ago

  • I’m asking if my answer was correct or not
    – Abdullah O. Alfaqir
    5 hours ago

  • What you might need to add is why the conclusion does not follow from the premises, not just assert that it doesn’t follow from the premises. What were your reasons? Welcome to this SE!
    – Frank Hubeny
    1 hour ago

  • Wait. Philosophy chairperson is a faculty member -> philosophy chairperson is 18 years old or older -> philosophy chairperson is permitted to vote. The argument is sound. And “the conclusion don’t follow from the premises.” is not what validity means.
    – rus9384
    5 hours ago

  • I’m sorry, to avoid gamesmanship here on the forum… are you asking about the argument ending in “Then the philosophy chairperson…” ? or the one ending in “My answer was it is not…”?
    – elliot svensson
    5 hours ago

  • I’m asking if my answer was correct or not
    – Abdullah O. Alfaqir
    5 hours ago

  • What you might need to add is why the conclusion does not follow from the premises, not just assert that it doesn’t follow from the premises. What were your reasons? Welcome to this SE!
    – Frank Hubeny
    1 hour ago

Wait. Philosophy chairperson is a faculty member -> philosophy chairperson is 18 years old or older -> philosophy chairperson is permitted to vote. The argument is sound. And “the conclusion don’t follow from the premises.” is not what validity means.
– rus9384
5 hours ago

Wait. Philosophy chairperson is a faculty member -> philosophy chairperson is 18 years old or older -> philosophy chairperson is permitted to vote. The argument is sound. And “the conclusion don’t follow from the premises.” is not what validity means.
– rus9384
5 hours ago

I’m sorry, to avoid gamesmanship here on the forum… are you asking about the argument ending in “Then the philosophy chairperson…” ? or the one ending in “My answer was it is not…”?
– elliot svensson
5 hours ago

I’m sorry, to avoid gamesmanship here on the forum… are you asking about the argument ending in “Then the philosophy chairperson…” ? or the one ending in “My answer was it is not…”?
– elliot svensson
5 hours ago

I’m asking if my answer was correct or not
– Abdullah O. Alfaqir
5 hours ago

I’m asking if my answer was correct or not
– Abdullah O. Alfaqir
5 hours ago

What you might need to add is why the conclusion does not follow from the premises, not just assert that it doesn’t follow from the premises. What were your reasons? Welcome to this SE!
– Frank Hubeny
1 hour ago

What you might need to add is why the conclusion does not follow from the premises, not just assert that it doesn’t follow from the premises. What were your reasons? Welcome to this SE!
– Frank Hubeny
1 hour ago

2 Answers
2

active

oldest

votes

up vote
3
down vote

accepted

The argument is invalid. In fact, it’s an instance of the fallacy of denying the antecedent.

To see this, we can formalize the argument as follows:

  1. Under-18 → not Permitted
  2. Faculty → not Under-18
  3. Chair is Faculty

From 2 and 3 we can deduce that Chair is not under 18. But we cannot then deduce from this and 1 that Chair is permitted to vote: that would commit the fallacy of denying the antecedent.

Another way to see that the argument is invalid is to imagine a scenario where the premises are true and the conclusion is false. For example, the chairperson might not be permitted to vote because they are not a citizen (which isn’t ruled out by the premises). If it’s possible for the premises to be true and the conclusion false, then the argument is invalid.

share|improve this answer

  • I used the star test by Harry j. Gensler and that’s why my answer was invalid.
    – Abdullah O. Alfaqir
    5 hours ago

up vote
1
down vote

I arrived at the same conclusion (invalidity) as Eliran H, but for a different reason. The premises are insufficient to show, affirmatively, that persons 18 years old and older are permitted to vote. Missing that information, the reasoning fails.

Here are my notes on my attempt to reason it through:

  1. If Person is Underage, then they are not permitted to Vote.

1.1 If Person is permitted to Vote, then they are not Underage. Contrapositive of #1 (looking for an affirmative statement about voting).

  1. If Person is Faculty, then they are not Underage.

  2. If Person is Chairperson, then they are Faculty.

Partial (valid) Conclusion: If Person is Chairperson, then they are not Underage. (#2 + #3)

  1. Final (failed) Conclusion: If Person is Chairperson, then they are permitted to Vote.
share|improve this answer

    Your Answer

    StackExchange.ready(function() {
    var channelOptions = {
    tags: “”.split(” “),
    id: “265”
    };
    initTagRenderer(“”.split(” “), “”.split(” “), channelOptions);

    StackExchange.using(“externalEditor”, function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using(“snippets”, function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: ‘answer’,
    convertImagesToLinks: false,
    noModals: false,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: null,
    bindNavPrevention: true,
    postfix: “”,
    noCode: true, onDemand: true,
    discardSelector: “.discard-answer”
    ,immediatelyShowMarkdownHelp:true
    });

    }
    });

    Abdullah O. Alfaqir is a new contributor. Be nice, and check out our Code of Conduct.

     
    draft saved
    draft discarded

    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin(‘.new-post-login’, ‘https%3a%2f%2fphilosophy.stackexchange.com%2fquestions%2f56506%2fis-this-argument-valid%23new-answer’, ‘question_page’);
    }
    );

    Post as a guest

    2 Answers
    2

    active

    oldest

    votes

    2 Answers
    2

    active

    oldest

    votes

    active

    oldest

    votes

    active

    oldest

    votes

    up vote
    3
    down vote

    accepted

    The argument is invalid. In fact, it’s an instance of the fallacy of denying the antecedent.

    To see this, we can formalize the argument as follows:

    1. Under-18 → not Permitted
    2. Faculty → not Under-18
    3. Chair is Faculty

    From 2 and 3 we can deduce that Chair is not under 18. But we cannot then deduce from this and 1 that Chair is permitted to vote: that would commit the fallacy of denying the antecedent.

    Another way to see that the argument is invalid is to imagine a scenario where the premises are true and the conclusion is false. For example, the chairperson might not be permitted to vote because they are not a citizen (which isn’t ruled out by the premises). If it’s possible for the premises to be true and the conclusion false, then the argument is invalid.

    share|improve this answer

    • I used the star test by Harry j. Gensler and that’s why my answer was invalid.
      – Abdullah O. Alfaqir
      5 hours ago

    up vote
    3
    down vote

    accepted

    The argument is invalid. In fact, it’s an instance of the fallacy of denying the antecedent.

    To see this, we can formalize the argument as follows:

    1. Under-18 → not Permitted
    2. Faculty → not Under-18
    3. Chair is Faculty

    From 2 and 3 we can deduce that Chair is not under 18. But we cannot then deduce from this and 1 that Chair is permitted to vote: that would commit the fallacy of denying the antecedent.

    Another way to see that the argument is invalid is to imagine a scenario where the premises are true and the conclusion is false. For example, the chairperson might not be permitted to vote because they are not a citizen (which isn’t ruled out by the premises). If it’s possible for the premises to be true and the conclusion false, then the argument is invalid.

    share|improve this answer

    • I used the star test by Harry j. Gensler and that’s why my answer was invalid.
      – Abdullah O. Alfaqir
      5 hours ago

    up vote
    3
    down vote

    accepted

    up vote
    3
    down vote

    accepted

    The argument is invalid. In fact, it’s an instance of the fallacy of denying the antecedent.

    To see this, we can formalize the argument as follows:

    1. Under-18 → not Permitted
    2. Faculty → not Under-18
    3. Chair is Faculty

    From 2 and 3 we can deduce that Chair is not under 18. But we cannot then deduce from this and 1 that Chair is permitted to vote: that would commit the fallacy of denying the antecedent.

    Another way to see that the argument is invalid is to imagine a scenario where the premises are true and the conclusion is false. For example, the chairperson might not be permitted to vote because they are not a citizen (which isn’t ruled out by the premises). If it’s possible for the premises to be true and the conclusion false, then the argument is invalid.

    share|improve this answer

    The argument is invalid. In fact, it’s an instance of the fallacy of denying the antecedent.

    To see this, we can formalize the argument as follows:

    1. Under-18 → not Permitted
    2. Faculty → not Under-18
    3. Chair is Faculty

    From 2 and 3 we can deduce that Chair is not under 18. But we cannot then deduce from this and 1 that Chair is permitted to vote: that would commit the fallacy of denying the antecedent.

    Another way to see that the argument is invalid is to imagine a scenario where the premises are true and the conclusion is false. For example, the chairperson might not be permitted to vote because they are not a citizen (which isn’t ruled out by the premises). If it’s possible for the premises to be true and the conclusion false, then the argument is invalid.

    share|improve this answer

    share|improve this answer

    share|improve this answer

    answered 5 hours ago

    Eliran H

    4,02521133

    4,02521133

    • I used the star test by Harry j. Gensler and that’s why my answer was invalid.
      – Abdullah O. Alfaqir
      5 hours ago

    • I used the star test by Harry j. Gensler and that’s why my answer was invalid.
      – Abdullah O. Alfaqir
      5 hours ago

    I used the star test by Harry j. Gensler and that’s why my answer was invalid.
    – Abdullah O. Alfaqir
    5 hours ago

    I used the star test by Harry j. Gensler and that’s why my answer was invalid.
    – Abdullah O. Alfaqir
    5 hours ago

    up vote
    1
    down vote

    I arrived at the same conclusion (invalidity) as Eliran H, but for a different reason. The premises are insufficient to show, affirmatively, that persons 18 years old and older are permitted to vote. Missing that information, the reasoning fails.

    Here are my notes on my attempt to reason it through:

    1. If Person is Underage, then they are not permitted to Vote.

    1.1 If Person is permitted to Vote, then they are not Underage. Contrapositive of #1 (looking for an affirmative statement about voting).

    1. If Person is Faculty, then they are not Underage.

    2. If Person is Chairperson, then they are Faculty.

    Partial (valid) Conclusion: If Person is Chairperson, then they are not Underage. (#2 + #3)

    1. Final (failed) Conclusion: If Person is Chairperson, then they are permitted to Vote.
    share|improve this answer

      up vote
      1
      down vote

      I arrived at the same conclusion (invalidity) as Eliran H, but for a different reason. The premises are insufficient to show, affirmatively, that persons 18 years old and older are permitted to vote. Missing that information, the reasoning fails.

      Here are my notes on my attempt to reason it through:

      1. If Person is Underage, then they are not permitted to Vote.

      1.1 If Person is permitted to Vote, then they are not Underage. Contrapositive of #1 (looking for an affirmative statement about voting).

      1. If Person is Faculty, then they are not Underage.

      2. If Person is Chairperson, then they are Faculty.

      Partial (valid) Conclusion: If Person is Chairperson, then they are not Underage. (#2 + #3)

      1. Final (failed) Conclusion: If Person is Chairperson, then they are permitted to Vote.
      share|improve this answer

        up vote
        1
        down vote

        up vote
        1
        down vote

        I arrived at the same conclusion (invalidity) as Eliran H, but for a different reason. The premises are insufficient to show, affirmatively, that persons 18 years old and older are permitted to vote. Missing that information, the reasoning fails.

        Here are my notes on my attempt to reason it through:

        1. If Person is Underage, then they are not permitted to Vote.

        1.1 If Person is permitted to Vote, then they are not Underage. Contrapositive of #1 (looking for an affirmative statement about voting).

        1. If Person is Faculty, then they are not Underage.

        2. If Person is Chairperson, then they are Faculty.

        Partial (valid) Conclusion: If Person is Chairperson, then they are not Underage. (#2 + #3)

        1. Final (failed) Conclusion: If Person is Chairperson, then they are permitted to Vote.
        share|improve this answer

        I arrived at the same conclusion (invalidity) as Eliran H, but for a different reason. The premises are insufficient to show, affirmatively, that persons 18 years old and older are permitted to vote. Missing that information, the reasoning fails.

        Here are my notes on my attempt to reason it through:

        1. If Person is Underage, then they are not permitted to Vote.

        1.1 If Person is permitted to Vote, then they are not Underage. Contrapositive of #1 (looking for an affirmative statement about voting).

        1. If Person is Faculty, then they are not Underage.

        2. If Person is Chairperson, then they are Faculty.

        Partial (valid) Conclusion: If Person is Chairperson, then they are not Underage. (#2 + #3)

        1. Final (failed) Conclusion: If Person is Chairperson, then they are permitted to Vote.
        share|improve this answer

        share|improve this answer

        share|improve this answer

        answered 43 mins ago

        Mark Andrews

        2,170621

        2,170621

            Abdullah O. Alfaqir is a new contributor. Be nice, and check out our Code of Conduct.

             
            draft saved
            draft discarded
            Abdullah O. Alfaqir is a new contributor. Be nice, and check out our Code of Conduct.

            Abdullah O. Alfaqir is a new contributor. Be nice, and check out our Code of Conduct.

            Abdullah O. Alfaqir is a new contributor. Be nice, and check out our Code of Conduct.

             

            draft saved

            draft discarded

            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin(‘.new-post-login’, ‘https%3a%2f%2fphilosophy.stackexchange.com%2fquestions%2f56506%2fis-this-argument-valid%23new-answer’, ‘question_page’);
            }
            );

            Post as a guest

            Related Post

            Leave a Reply

            Your email address will not be published. Required fields are marked *