A community for students.
Here's the question you clicked on:
 0 viewing
Bee_see
 one year ago
The following argument is valid: If Superman were willing and able to prevent evil, he would do so. If Superman were unable to prevent evil, he would be impotent; if he were unwilling to prevent evil, he would be malevolent. Superman does not prevent evil. If Superman exists, he is neither impotent nor malevolent. Therefore, Superman does not exist.
Bee_see
 one year ago
The following argument is valid: If Superman were willing and able to prevent evil, he would do so. If Superman were unable to prevent evil, he would be impotent; if he were unwilling to prevent evil, he would be malevolent. Superman does not prevent evil. If Superman exists, he is neither impotent nor malevolent. Therefore, Superman does not exist.

This Question is Closed

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0Ok, I'd do a truth table

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0P is the if part of each statement Q is the then. Write each sentence as a P implies Q. Then negate each. And use the final statement to say well since there is evil, superman can't exist

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0dw:1444012942048:dw?

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0more like P>~Q uh contrapositive I think? Sorry it has been like 4 years since logic. But let me work on this. It will help me with the test I'm studying for

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0SO my first thought, If sup exist then he's not imp. and he's not malev.

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0Hmm, I used the (p imples q) implies (not p or q) table and I got all truth...I want to use the rules of inference though instead of the truth tables. And I'm not sure how.

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0So, since sup can't prevent evil there exists evil> sup would prevent it but he doesn't>imp. and malev. BUT that is a contradiction

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0(p implies q) bi conditional statement (not p or q) *

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0and or malev**

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0how would you show that though using the rules of inference. I'm supposed to do a table.I have the premises like this: Superman is willing to prevent evil(W), superman is able to prevent evil (A), superman prevents evil(P), superman is impotent I, superman is malevolent (M), and superman exists(X).

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0I haven't seen that style before, but my basic argument is, there is evil, it isn't prevented sup isn't I or M > no sup

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0So let's put it into words, it's essentially a contradiction proof

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0SO I'm looking at these inference rules(Gosh they would have been helpful to see before....Thanks BANOT)

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0so this argument is case analysis I think

FibonacciChick666
 one year ago
Best ResponseYou've already chosen the best response.0ugh, let me get someone smart here. @dan815 can you fix my mess please?

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0This is how the professors wants it to look if anyone can help:

dan815
 one year ago
Best ResponseYou've already chosen the best response.1are you still working on this The following argument is valid: If Superman were willing and able to prevent evil, he would do so. If Superman were unable to prevent evil, he would be impotent; if he were unwilling to prevent evil, he would be malevolent. Superman does not prevent evil. If Superman exists, he is neither impotent nor malevolent. Therefore, Superman does not exist.

dan815
 one year ago
Best ResponseYou've already chosen the best response.1super man is neither impotent nor malevolent

dan815
 one year ago
Best ResponseYou've already chosen the best response.1superman does not prevent evil, so superman is malevolent, so superman cannot exist

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0I have some solutions, but I don't understand then. So for example, after writing all the premises, the person used modus tollens 5 and 4. (5 being not p and 4 being W and A implies p)...I'm not sure how the person knew that modus tollens had to be used.

dan815
 one year ago
Best ResponseYou've already chosen the best response.1just 1 little thing that might come up

dan815
 one year ago
Best ResponseYou've already chosen the best response.1superman does not prevent evil means, either there was no evil to prevent, or he was unable to prevent evil

dan815
 one year ago
Best ResponseYou've already chosen the best response.1but if they say does not prevent evil, that means evil must have took place for him to not prevent it

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0then the person said not W or not A (I'm not sure what rules was used), then M or I (modus ponen....not sure which options). Then not (not M and not I). Came the conclusion that not X. Superman doesn't exist.

dan815
 one year ago
Best ResponseYou've already chosen the best response.1not willing and not able right

dan815
 one year ago
Best ResponseYou've already chosen the best response.1um wait is upside down V or or and

dan815
 one year ago
Best ResponseYou've already chosen the best response.1because not P should be not (W or A) and W and A > P but they are using the same operators

dan815
 one year ago
Best ResponseYou've already chosen the best response.1okay then isnt there a mistake in there

dan815
 one year ago
Best ResponseYou've already chosen the best response.1because not (W or A ) = W and A so it ha to be W and A =>P there

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0can you explain the solution? what rules of inference were used and how?

dan815
 one year ago
Best ResponseYou've already chosen the best response.1what do u mean what step is confusing u

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0the last 6 steps...why use modus tollens for 5 and 4?

dan815
 one year ago
Best ResponseYou've already chosen the best response.1okay there are 2 main ones u need to know

dan815
 one year ago
Best ResponseYou've already chosen the best response.1u can see from truth tables

dan815
 one year ago
Best ResponseYou've already chosen the best response.1this proves not (A and B) = not a or not b

dan815
 one year ago
Best ResponseYou've already chosen the best response.1similiary u can show that not (A or B) = not A and not B

dan815
 one year ago
Best ResponseYou've already chosen the best response.1so these 2 transformations are justified, does that clear it up?

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0what rules were used to do the last 4 steps?

dan815
 one year ago
Best ResponseYou've already chosen the best response.1well we showed how they are equivalent with the truth table

dan815
 one year ago
Best ResponseYou've already chosen the best response.1its just an identity we just showed so its justified

Bee_see
 one year ago
Best ResponseYou've already chosen the best response.0My professors wants something like this: