Is the argument below valid?












2
















If interest rates go down, then I will buy a house. If I buy a house, I will need
a loan. Therefore, I will not need a loan if I do not buy a house.




Is this argument valid?










share|improve this question









New contributor




Bruce Grayton Toodeep Muzawazi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





















  • I made an edit. You may roll this back if it does not represent your view by clicking on the "edited" link above my image and then on a rollback link. Welcome!

    – Frank Hubeny
    12 hours ago
















2
















If interest rates go down, then I will buy a house. If I buy a house, I will need
a loan. Therefore, I will not need a loan if I do not buy a house.




Is this argument valid?










share|improve this question









New contributor




Bruce Grayton Toodeep Muzawazi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





















  • I made an edit. You may roll this back if it does not represent your view by clicking on the "edited" link above my image and then on a rollback link. Welcome!

    – Frank Hubeny
    12 hours ago














2












2








2









If interest rates go down, then I will buy a house. If I buy a house, I will need
a loan. Therefore, I will not need a loan if I do not buy a house.




Is this argument valid?










share|improve this question









New contributor




Bruce Grayton Toodeep Muzawazi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.













If interest rates go down, then I will buy a house. If I buy a house, I will need
a loan. Therefore, I will not need a loan if I do not buy a house.




Is this argument valid?







logic






share|improve this question









New contributor




Bruce Grayton Toodeep Muzawazi 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




Bruce Grayton Toodeep Muzawazi 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 12 hours ago









Frank Hubeny

10.5k51558




10.5k51558






New contributor




Bruce Grayton Toodeep Muzawazi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 12 hours ago









Bruce Grayton Toodeep MuzawaziBruce Grayton Toodeep Muzawazi

111




111




New contributor




Bruce Grayton Toodeep Muzawazi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





Bruce Grayton Toodeep Muzawazi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






Bruce Grayton Toodeep Muzawazi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.













  • I made an edit. You may roll this back if it does not represent your view by clicking on the "edited" link above my image and then on a rollback link. Welcome!

    – Frank Hubeny
    12 hours ago



















  • I made an edit. You may roll this back if it does not represent your view by clicking on the "edited" link above my image and then on a rollback link. Welcome!

    – Frank Hubeny
    12 hours ago

















I made an edit. You may roll this back if it does not represent your view by clicking on the "edited" link above my image and then on a rollback link. Welcome!

– Frank Hubeny
12 hours ago





I made an edit. You may roll this back if it does not represent your view by clicking on the "edited" link above my image and then on a rollback link. Welcome!

– Frank Hubeny
12 hours ago










3 Answers
3






active

oldest

votes


















5















Is the argument valid?




No.



"I will not need a loan if I do not buy a house" is the same as "If I do not buy a house, then I will not need a loan".



This is not implied by "If I buy a house, I will need a loan".



See Denying the antecedent.






share|improve this answer































    4














    Wikipedia describes validity as follows:




    In logic, an argument is valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false.




    The argument we want to test for validity is the following:




    If interest rates go down, then I will buy a house. If I buy a house, I will need a loan. Therefore, I will not need a loan if I do not buy a house.




    This can be broken up into propositions with this symbolization key:




    • R: "Interest rates go down."

    • B: "I will buy a house."

    • L: "I will need a loan."


    If R then B. If B then L. Therefore, if not B then not L.



    We could place the following into a truth table generator. For the truth table generator I am using I would enter the following string:




    ((R=>B)&&(B=>L))=>(~B=>~L)




    This is the result I get:



    enter image description here



    Note the "F" in the third line of the table. This is a line where the premises are true but the conclusion false. Therefore the argument is invalid.





    Stanford Truth Table Tool http://web.stanford.edu/class/cs103/tools/truth-table-tool/



    Wikipedia contributors. (2019, March 28). Validity (logic). In Wikipedia, The Free Encyclopedia. Retrieved 18:05, April 15, 2019, from https://en.wikipedia.org/w/index.php?title=Validity_(logic)&oldid=889899195






    share|improve this answer































      0














      The last statement suggests that buying a house is the only reason you would need a loan. Not buying a house does not rule out other reasons for needing a loan. Therefore it's logically false.



      If it were explicitly stated that you would only ever need a loan when buying a house, it would be logically correct, even though it would be potentially false in reality.






      share|improve this answer








      New contributor




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





















        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',
        autoActivateHeartbeat: false,
        convertImagesToLinks: false,
        noModals: true,
        showLowRepImageUploadWarning: true,
        reputationToPostImages: null,
        bindNavPrevention: true,
        postfix: "",
        imageUploader: {
        brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
        contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
        allowUrls: true
        },
        noCode: true, onDemand: true,
        discardSelector: ".discard-answer"
        ,immediatelyShowMarkdownHelp:true
        });


        }
        });






        Bruce Grayton Toodeep Muzawazi 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%2f61847%2fis-the-argument-below-valid%23new-answer', 'question_page');
        }
        );

        Post as a guest















        Required, but never shown

























        3 Answers
        3






        active

        oldest

        votes








        3 Answers
        3






        active

        oldest

        votes









        active

        oldest

        votes






        active

        oldest

        votes









        5















        Is the argument valid?




        No.



        "I will not need a loan if I do not buy a house" is the same as "If I do not buy a house, then I will not need a loan".



        This is not implied by "If I buy a house, I will need a loan".



        See Denying the antecedent.






        share|improve this answer




























          5















          Is the argument valid?




          No.



          "I will not need a loan if I do not buy a house" is the same as "If I do not buy a house, then I will not need a loan".



          This is not implied by "If I buy a house, I will need a loan".



          See Denying the antecedent.






          share|improve this answer


























            5












            5








            5








            Is the argument valid?




            No.



            "I will not need a loan if I do not buy a house" is the same as "If I do not buy a house, then I will not need a loan".



            This is not implied by "If I buy a house, I will need a loan".



            See Denying the antecedent.






            share|improve this answer














            Is the argument valid?




            No.



            "I will not need a loan if I do not buy a house" is the same as "If I do not buy a house, then I will not need a loan".



            This is not implied by "If I buy a house, I will need a loan".



            See Denying the antecedent.







            share|improve this answer












            share|improve this answer



            share|improve this answer










            answered 12 hours ago









            Mauro ALLEGRANZAMauro ALLEGRANZA

            29.7k22065




            29.7k22065























                4














                Wikipedia describes validity as follows:




                In logic, an argument is valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false.




                The argument we want to test for validity is the following:




                If interest rates go down, then I will buy a house. If I buy a house, I will need a loan. Therefore, I will not need a loan if I do not buy a house.




                This can be broken up into propositions with this symbolization key:




                • R: "Interest rates go down."

                • B: "I will buy a house."

                • L: "I will need a loan."


                If R then B. If B then L. Therefore, if not B then not L.



                We could place the following into a truth table generator. For the truth table generator I am using I would enter the following string:




                ((R=>B)&&(B=>L))=>(~B=>~L)




                This is the result I get:



                enter image description here



                Note the "F" in the third line of the table. This is a line where the premises are true but the conclusion false. Therefore the argument is invalid.





                Stanford Truth Table Tool http://web.stanford.edu/class/cs103/tools/truth-table-tool/



                Wikipedia contributors. (2019, March 28). Validity (logic). In Wikipedia, The Free Encyclopedia. Retrieved 18:05, April 15, 2019, from https://en.wikipedia.org/w/index.php?title=Validity_(logic)&oldid=889899195






                share|improve this answer




























                  4














                  Wikipedia describes validity as follows:




                  In logic, an argument is valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false.




                  The argument we want to test for validity is the following:




                  If interest rates go down, then I will buy a house. If I buy a house, I will need a loan. Therefore, I will not need a loan if I do not buy a house.




                  This can be broken up into propositions with this symbolization key:




                  • R: "Interest rates go down."

                  • B: "I will buy a house."

                  • L: "I will need a loan."


                  If R then B. If B then L. Therefore, if not B then not L.



                  We could place the following into a truth table generator. For the truth table generator I am using I would enter the following string:




                  ((R=>B)&&(B=>L))=>(~B=>~L)




                  This is the result I get:



                  enter image description here



                  Note the "F" in the third line of the table. This is a line where the premises are true but the conclusion false. Therefore the argument is invalid.





                  Stanford Truth Table Tool http://web.stanford.edu/class/cs103/tools/truth-table-tool/



                  Wikipedia contributors. (2019, March 28). Validity (logic). In Wikipedia, The Free Encyclopedia. Retrieved 18:05, April 15, 2019, from https://en.wikipedia.org/w/index.php?title=Validity_(logic)&oldid=889899195






                  share|improve this answer


























                    4












                    4








                    4







                    Wikipedia describes validity as follows:




                    In logic, an argument is valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false.




                    The argument we want to test for validity is the following:




                    If interest rates go down, then I will buy a house. If I buy a house, I will need a loan. Therefore, I will not need a loan if I do not buy a house.




                    This can be broken up into propositions with this symbolization key:




                    • R: "Interest rates go down."

                    • B: "I will buy a house."

                    • L: "I will need a loan."


                    If R then B. If B then L. Therefore, if not B then not L.



                    We could place the following into a truth table generator. For the truth table generator I am using I would enter the following string:




                    ((R=>B)&&(B=>L))=>(~B=>~L)




                    This is the result I get:



                    enter image description here



                    Note the "F" in the third line of the table. This is a line where the premises are true but the conclusion false. Therefore the argument is invalid.





                    Stanford Truth Table Tool http://web.stanford.edu/class/cs103/tools/truth-table-tool/



                    Wikipedia contributors. (2019, March 28). Validity (logic). In Wikipedia, The Free Encyclopedia. Retrieved 18:05, April 15, 2019, from https://en.wikipedia.org/w/index.php?title=Validity_(logic)&oldid=889899195






                    share|improve this answer













                    Wikipedia describes validity as follows:




                    In logic, an argument is valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false.




                    The argument we want to test for validity is the following:




                    If interest rates go down, then I will buy a house. If I buy a house, I will need a loan. Therefore, I will not need a loan if I do not buy a house.




                    This can be broken up into propositions with this symbolization key:




                    • R: "Interest rates go down."

                    • B: "I will buy a house."

                    • L: "I will need a loan."


                    If R then B. If B then L. Therefore, if not B then not L.



                    We could place the following into a truth table generator. For the truth table generator I am using I would enter the following string:




                    ((R=>B)&&(B=>L))=>(~B=>~L)




                    This is the result I get:



                    enter image description here



                    Note the "F" in the third line of the table. This is a line where the premises are true but the conclusion false. Therefore the argument is invalid.





                    Stanford Truth Table Tool http://web.stanford.edu/class/cs103/tools/truth-table-tool/



                    Wikipedia contributors. (2019, March 28). Validity (logic). In Wikipedia, The Free Encyclopedia. Retrieved 18:05, April 15, 2019, from https://en.wikipedia.org/w/index.php?title=Validity_(logic)&oldid=889899195







                    share|improve this answer












                    share|improve this answer



                    share|improve this answer










                    answered 12 hours ago









                    Frank HubenyFrank Hubeny

                    10.5k51558




                    10.5k51558























                        0














                        The last statement suggests that buying a house is the only reason you would need a loan. Not buying a house does not rule out other reasons for needing a loan. Therefore it's logically false.



                        If it were explicitly stated that you would only ever need a loan when buying a house, it would be logically correct, even though it would be potentially false in reality.






                        share|improve this answer








                        New contributor




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

























                          0














                          The last statement suggests that buying a house is the only reason you would need a loan. Not buying a house does not rule out other reasons for needing a loan. Therefore it's logically false.



                          If it were explicitly stated that you would only ever need a loan when buying a house, it would be logically correct, even though it would be potentially false in reality.






                          share|improve this answer








                          New contributor




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























                            0












                            0








                            0







                            The last statement suggests that buying a house is the only reason you would need a loan. Not buying a house does not rule out other reasons for needing a loan. Therefore it's logically false.



                            If it were explicitly stated that you would only ever need a loan when buying a house, it would be logically correct, even though it would be potentially false in reality.






                            share|improve this answer








                            New contributor




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










                            The last statement suggests that buying a house is the only reason you would need a loan. Not buying a house does not rule out other reasons for needing a loan. Therefore it's logically false.



                            If it were explicitly stated that you would only ever need a loan when buying a house, it would be logically correct, even though it would be potentially false in reality.







                            share|improve this answer








                            New contributor




                            YoupT 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 answer



                            share|improve this answer






                            New contributor




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









                            answered 42 mins ago









                            YoupTYoupT

                            235




                            235




                            New contributor




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





                            New contributor





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






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






















                                Bruce Grayton Toodeep Muzawazi is a new contributor. Be nice, and check out our Code of Conduct.










                                draft saved

                                draft discarded


















                                Bruce Grayton Toodeep Muzawazi is a new contributor. Be nice, and check out our Code of Conduct.













                                Bruce Grayton Toodeep Muzawazi is a new contributor. Be nice, and check out our Code of Conduct.












                                Bruce Grayton Toodeep Muzawazi is a new contributor. Be nice, and check out our Code of Conduct.
















                                Thanks for contributing an answer to Philosophy Stack Exchange!


                                • Please be sure to answer the question. Provide details and share your research!

                                But avoid



                                • Asking for help, clarification, or responding to other answers.

                                • Making statements based on opinion; back them up with references or personal experience.


                                To learn more, see our tips on writing great answers.




                                draft saved


                                draft discarded














                                StackExchange.ready(
                                function () {
                                StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fphilosophy.stackexchange.com%2fquestions%2f61847%2fis-the-argument-below-valid%23new-answer', 'question_page');
                                }
                                );

                                Post as a guest















                                Required, but never shown





















































                                Required, but never shown














                                Required, but never shown












                                Required, but never shown







                                Required, but never shown

































                                Required, but never shown














                                Required, but never shown












                                Required, but never shown







                                Required, but never shown







                                Popular posts from this blog

                                Liste der Baudenkmale in Friedland (Mecklenburg)

                                Single-Malt-Whisky

                                Czorneboh