Just to clarify, just the diagrams of the pure logic would be great, don't need anything else. Thanks again!
MehranNovember 27, 2017
Hi @RJeh, thanks for your posts. Happy to help.
Let's start with the stimulus.
Not all tenured faculty are full professors. TF-some-not FP
Therefore, although every faculty member in the linguistics department has tenure . . . LD ==> TF (if linguistics department, then tenured faculty)
. . . it must be the case that not all of the faculty members in the linguistics department are full professors. LD-some-not FP.
This question gives us a chance to review the key rules that apply when one tries to create a transitive statement by combining a "some" and an "all/none" statement. These rules are critically important for LSAT success.
A proper transitive statement may only be created as follows: A-some-B==>C A-some-C
The "some" statement must be to the left of the "all/none" statement.
This is not what is happening here. If you try to put the statements onto a single line, you get: LD ==> TF-some-not FP
Do you see how, here, the "some" statement is to the right of the "all/none" statement? There is no valid transitive in cases like this.
All right. Now let's examine the answer choices. This is a flawed parallel reasoning question, so we need to select the answer choice that exhibits the same logical flaw as the stimulus.
Answer (A): Although all modern office towers are climate-controlled buildings . . . MOT ==> CC . . . not all office buildings are climate-controlled OB-some-not CC Therefore, it must be the case that not all office buildings are modern office towers. OB-some-not MOT This is a valid transitive argument that combines the contrapositive of premise 1 and premise 2, as follows: OB-some-not CC==> not MOT Because this is a valid argument, it can be eliminated.
Answer (B): All municipal hospital buildings are massive . . . MHB ==> M . . . but not all municipal hospital buildings are forbidding in appearance. MHB-some-not FA Therefore, massive buildings need not present a forbidding appearance.
Put differently, one could say some massive buildings are not forbidding in appearance. This is a valid transitive conclusion, linking the given premises as follows: not FA-some-MHB==>M not FA-some-M Because this is a valid argument, it can be eliminated.
Answer (C): Although some buildings designed by famous architects are not well proportioned . . . DFA-some-not WP . . . all government buildings are designed by famous architects. GB ==> DFA Therefore, some government buildings are not well proportioned. GB-some-not WP
You can see that this answer choice mimics the same flaw as that found in the stimulus. If you try to construct a transitive sentence with these statements, you get the following: GB ==> DFA-some-not WP
See how, here, the "some" statement is again to the right of the "all/none" statement? No valid transitive is available.
I hope this helps! Please let us know if you have additional questions (or need help diagramming (D) or (E)). Best of luck.
RJEhNovember 27, 2017
Thanks so much for the quick response @ Mehran, I really appreciate that.
Let's see if I've got this now...
Answer (D): This one throws me off because of the switch from "not well designed" to "poorly designed" while also combining "poorly designed" with "public buildings" halfway through. Is one of the flaws here that the author makes that combination?
Not all public buildings are well designed...
PB - some - not WD or should I diagram as PB - some - PD?
... but some poorly designed public buildings were originally intended for private use.
PDPB - some - OIPU
Therefore, the poorly designed public buildings were all originally designed for private use.
PDPB ==> OIPU
Answer (E):
Although some cathedrals are not built of stone...
C - some - not BoS
...every cathedral is impressive.
C ==> I
Therefore, buildings can be impressive even though they are not built of stone.
not BoS - some - I
