Assessing Arguments for Validity Using the Intuitive Method

Directions: Determine the validity and soundness of the arguments below.


(1) Start by just assuming that the premises are true.

(2) Then, ask yourself “Would the truth of these premises guarantee the truth of this conclusion?” If they do, the argument is valid -- if they don’t, the argument is invalid.


Indicate whether the following arguments are valid or invalid. Use the Intuitive Method.

  1. My math teacher told me she’d give me two dollars for every test for which I earned an A. I earned an A in three of her math tests. Therefore, she owes me 6 dollars.

  2. All students are drivers. All parents are drivers. Some students are parents.

  3. Oprah knows that all is one. Therefore, all is one.

  4. Oprah believes that pie is good. Therefore, pie is good.

  5. Sarah told Amanda that perpetual motion begets perpetual nausea. Therefore, someone told somebody something.

  6. The NSA is out to get everyone. Therefore, the NSA is out to get me.

  7. The NSA must be out to get everyone, because they’re out to get me.

  8. Every member of the Progressive Labor Party has read the writings of Chairman Mao. Bob studied the writings of the Chairman Mao. So, Bob must be in the Progressive Labor Party.

  9. Only Hell’s Angels live in Coastline Apartments. Harry is a member of the Hell’s Angels. So, Harry must live at Coastline Apartments.

  10. The document is in my folder. My folder is in my office. Therefore, the document is in my office.


Make the arguments below valid by adding the necessary conclusion.

P1: If you take the red pill, you will free your mind.

P2: Neo took the red pill.



P1: Either Neo is The One or he is a ham sandwich.

P2: Neo is not The One.



P1: You are in The Matrix only if Professor García came to class.

P2: Professor García came to class.