PT21.S3.Q06 - Books about architectural works

Stimmy Turner

Hey guys I'm really struggling with the logic on this one when diagramming. https://7sage.com/lsat_explanations/lsat-21-section-3-question-06/

I think the majority of the confusion is coming from issues with my initial conditional chain and never having encountered wording like this before/how to make sense of it. I think I have an idea of what is going on but just wanted to see if I might be off since no one else in the comments seemed to be having the issue I'm having.

What I initially had up to the referential phrase of "if they do not" was:

IGA→ U or A

When I read the "if they do not" I thought it translated to /U or A and then became
/(U or A) → F

But since I already had U or A as a conditional I thought this would create two conditionals stemming from /(U or A):
/(U or A) → F
/(U or A)→ /IGA

What JY, and seems like everyone else did, was during the very beginning go like:
1. IGA → (U or A)
OR
2. IGA→ /(U or A)→ F

1 being the should be scenario and #2 being the less than ideal situation.

Since the stim goes on to give us Morton's book, and you can assume that Morton's book falls into the less than ideal situation, you don't even worry about using option #1. So what I'm wondering is when I see a stimulus like this where it uses prescriptive words like "should" "ought" etc. with a conditional then I need to think of it more like this problem where its scenario based over the usual "If, then" construction and then trying to link that statement with potentially more.

yang9999

I don't think this is a question you should diagram (it should not be a knee-jerk reaction to diagram every question that has a conditional). We know that a book, unless it is not made for a general audience, must include both a discussion on utility (function) and aesthetics, and that if not, it is flawed. We also know that Morton's book talks about the function, but lacks a discussion of the ceiling (aesthetics). Since the conclusion says that his book is flawed, it is necessary to assume that he is writing for a general audience -- this is the gap that is critically missing in the argument

itanajbt

The "unless" and the "not" cancel each other out, so this should be diagrammed as IGR → (U and A). But it looks like your main issue was when it came to the next part (diagramming "Morton's book is flawed.")

By the logic of the stimulus, anything that makes the entire statement (IGR → U and A) false is sufficient for Morton's book to be flawed. The statement IGR → U and A is false when you have IGR but /U or /A, or /U and /A. So /(U or A) → F is incomplete, it should be IGR + /(U and A) → F. This is because the statement IGR → U and A is not false unless you don't have one of U or A (or neither) AND you have IGR. The stimulus already told you that you don't have U, hence having IGR without U is sufficient to conclude that Morton's book is flawed. However the stimulus did not establish whether Morton's book was IGR, which is what makes IGR necessary to conclude that Morton's book is flawed.