PHL111 Valid Reasoning, current assignments




Current Assignments
NOTE: please do me the favor of
  1. logging into Angel and
  2. Going to the Learning Modules
  3. Clicking on "Repository - Philosophy Department Respository"
  4. Completing the online evaluations.
They are anonymous. I'm trying to save paper for the class and so am using the online evals. However, that means I depend on you to take the time to do them. It's only two minutes! I appreciate it greatly if you can do them.

November 21, 23
Here is part 1 of quiz four.

A note about the quiz. You can tell me who you ruled out, and that's OK, but also if you like to be thorough you can use MTP to rule out some of the suspects. A special note. I'll let you do MTP on any disjunct in a big disjunction. This is kind of leaping ahead, but it is OK. So, you can do MTP with ¬P and ((P v Q) v (R v S)) and get (Q v (R v S)); or do MTP with ¬R and ((P v Q) v (R v S)) and get ((P v Q) v S); and so on. That stretches our rule a bit, but works out OK.

Here is the list of teams.

Work on the quiz on your own over the weekend. Then, on Monday, teams can work together for part of our class. Your team will be the same team as we had for quiz 3. On Monday, let's sit in our assigned rows, just to make things easier.

If you're not here Monday, and what is here from your team finishes the quiz on Monday, you'll have to finish the quiz part 1 on your own.
December 3
Part 2 of the quiz will be posted; thus, anyone who hasn't already completed part 1 will at this time get part 2.

Homework 10 due. This homework has 10 problems.
    For the first three problems, complete the proof. You will need to use universal derivation in these proofs.

  1. Premises: ∀x(Fx ↔ Hx), ∀y(Hy ↔ Gy). Conclusion: ∀z(Fz ↔ Gz).
  2. Conclusion: (∀x(¬Fx v Gx) → ∀x(Fx → Gx))
  3. Conclusion: (∀xFx ↔ ¬∃x¬Fx)

    For these three problems, create an informal model that shows the argument is obviously invalid.

  4. Premises: ∀x(Fx → Gx), ¬Ga. Conclusion: ¬Fb.
  5. Premises: ∀x(Fx v Gx), ¬Fa. Conclusion: Gb.
  6. Premises: ∀x(Fx → Gx), ∃xFx. Conclusion: Gc.

    For these last four problems, let's try something new. You've learned to test arguments for validity. But can you create your own valid arguments? Use your logic skills to write arguments. Try to write about your field of study: if you are a management major, illustrate some important argument in management; and so on.

  7. Write a valid argument in everday English that has at least two premises. One of the premises must be a conditional.
  8. Write a valid argument in everday English that has at least two premises. One of the premises must be a disjunction.
  9. Write a valid argument in everday English that has at least two premises. One of the premises must be a universal claim (such as, "all F are G").
  10. Write a valid argument in everday English that has at least two premises. One of the premises must be an existential claim (such as, "something is an F").
December 5
Also, all outstanding parts of quiz 4 will be due at the beginning of class.
December 10
Final exam, 8:00 a.m. -- 10:00 a.m.

Watch all five of these videos before you start studying for the final. They are short and they will do you a ton of good.




Tentative/expected Assignments (subject to revision)