56.2.9 Rifka: We do not

Accounts Playable

This might be one of the more frustrating questions I have come across! Can someone breakdown the answer choices (specifically why A is better than ?

R (is Rifka a common name? I looked it up; it's apparently a variant of Rebecca: https://en.wikipedia.org/wiki/Rebecca): Anyway, Stop or Ask for directions--->Lost. Therefore, Not stop.

C: We are lost. Therefore, we must stop.

What I am looking for: Craig is denying R's conclusion by contradicting R's conditional statement. In other words, Craig thinks being lost is sufficient for stopping while R thinks it is necessary.

Answer A: I confidently chose this one during the exam, and I can't figure out what's wrong with it. Doesn't C contradict R's conclusion (he says we should stop while R disagrees) and doesn't he give no reason to reject R's implicit premise. The implicit premise referred to is R's assumption that they are Not lost. C simply flat out denies that, but he doesn't give any evidence/ reason why R's assumption is wrong. I don't really see how this doesn't perfectly capture C's rebuttal.

Answer B: This is really good as well, but what makes this better than A? C does deny the implicit premise that they are not lost and he does arrive at a different conclusion (that they should stop). I chose A over this since A captured the idea that C didn't give any evidence/reason why R's implicit premise was incorrect. Thus, I though A better captured the essence of the argument.

Answer C: This is a pretty popular choice according to the statistics, but it is way wrong. C doesn't call R's argument invalid and C doesn't accept the truth of the premise.

Answer What counterexample?

Answer E: Noncommittal? Way wrong. C contradicts R's conclusion explicitly.

iiiSpoon

Hey Accounts Playable,

R states that if we need to stop and ask for directions (N) then we are lost (L): N -> L. Therefore, we do not need to stop and ask for directions (/N).

So the argument R provides is:

N -> L
_______
/N

R makes the implicit assumption that they are not lost (/L) because that is the only way we can conclude, given the premises, that they do not need to stop and ask for directions (/N).

C does not contradict R's conclusion without offering any reasons to reject any of R's implicit premises (which is what (A) says). An answer choice like that would be, "We need to stop and ask for direction." Instead, C denies the implicit assumption R makes, that being /L, with his premise "the fact we are lost," thereby allowing him to come to a different conclusion of R.

Hope this answers your question.