Mr. Nance,
It is said that the key exercise of the Poll-parrot (grammar) stage is Latin Grammar, and of the Pert (dialectic) stage is Formal Logic. What is the key exercise of the Poetic (rhetoric) stage?
Thank you. Continue reading Extrapolating Sayers
Hello, Mr Nance!
Could you please explain to me why the tests and quizzes pack for the Introductory Logic has a test form A and a test form B for the same chapters? I am sure it is logical (pun intended) but I am not getting it and just want to be sure I am administering them correctly.
Thanks in advance! Continue reading Why Logic Test A and B?
Mr. Nance,
I have a question on Intermediate Logic, Test 2, Form B, Problem 4. The question says: “An invalid argument can have true premises and a true conclusion, is this true or false?” The answer book says it’s true but the definition of an invalid argument would prove that statement to be false. Is there a typo or is that correct? Continue reading Invalidity and truth
Mr. Nance,
Question 6 of Intermediate Logic Quiz 2 asks to symbolize this proposition: “The knight attacks the dragon only if the dragon devours the damsel.” The answer key says K ⊃ D (“If K then D”). I would have thought the answer was D ⊃ K (“If D then K”). Am I wrong? Continue reading Translating “only if”
Mr. Nance,
I have a student asking me if this would be a valid way of completing this truth tree for consistency. She thinks since she already found inconsistency in the branches, that she doesn’t have to do line 3 (per lesson 24). I’m thinking that this thought process only applies if she finds it consistent, not inconsistent. She’s also asking if it matters the order they are done in (I told her non-branching first, then branching, but that I didn’t think the order mattered if it was all branching that was left). Please help me give her direction! Continue reading Do these truth tree branches close?
Mr. Nance,
I’m stumped on Logic lesson 18 #5. We got same answers as answer key until line 7…I can see from line 8 why line 7 is important, but how did we deduce a consequent that was not the original consequent of line 1 (from which we assumed the antecedent in line 3)?
Hope that makes sense! Continue reading Where does the CPA come from?
Mr. Nance,
I have a question on Intermediate Logic, Exercise 17a, problem 5. To justify the conclusion (L • M) ⊃ N, the answer key says to use the rule of commutation from (M • L) ⊃ N. But the rule of commutation says (p • q) ≡ (q • p). How can I use that rule without switching the propositions, but switching the letters inside of a proposition? For example, in step 3, they are switching the propositions and not the letters inside the parentheses. Continue reading Rule of Commutation
Mr. Nance,
I am contemplating conducting a summer camp on digital logic using unit 5 of the Intermediate Logic text. Any suggestions for making this fun, interactive and hands-on? Continue reading Hands-on Digital Logic
Mr. Nance,
In our logic studies, my son and I wrestle to work through the proofs, generally together. When we get stuck, really stuck, we go to the answer key, cover the answer, and move through the proof step-by-step until we find where we veered off-track. Then we use that one step to get us back where we need to be; and then, hopefully, we finish the proof. My question is, is this a reasonable approach? Continue reading Tackling More Difficult Proofs
Mr. Nance,
I have a question Lesson 11 of Intermediate Logic. I have all of the right answers to the exercises, but I noticed that on a few of the questions, I wrote more lines in my answers because I thought I had to be exhaustive in my efforts to find no contradiction. A specific example would be #5. I agree that there is only one way for the conditional to be false. But, there are multiple ways the conditional can be true. Why didn’t you try lines with I as true and C false, or C false and I true? Am I misinterpreting the fourth instruction from p.70 to “switch the assigned truth values and try again”? Is this directive leveled at each whole proposition, or at each constant? (I hope this is making sense). Continue reading Shorter Truth Tables for Equivalence