PrepTest 10 (Dec 1994), Section A, Question 10--Please help! Forum

[LSAT_Padawan]

The MUST BE TRUE question reads, "Every political philosopher of the early twentieth century who was either a socialist or a communist was influenced by Rosa Luxemburg. No one who was influenced by Rosa Luxemburg advocated a totalitarian state.

If the statements above are true, which one of the following must on the basis of them also be true?

(A) No early twentieth century socialist political philosopher advocated a totalitarian state.
(D) Every early twentieth century political philosopher who was influenced by Rosa Luxemburg and was not a socialist was a communist.

I incorrectly picked (D). How I interpret the stimulus is that Rosa Luxemburg influenced ALL political philosophers so they were either socialist or communist. Where did my reasoning go awry? If Rosa's influence was not in fact inclusive of this group (early twentieth century philosophers) than how can (A) be the correct answer?


Thank you for your enlightenment.

[beidoun]

The MUST BE TRUE question reads, "Every political philosopher of the early twentieth century who was either a socialist or a communist was influenced by Rosa Luxemburg. No one who was influenced by Rosa Luxemburg advocated a totalitarian state.

If the statements above are true, which one of the following must on the basis of them also be true?

(A) No early twentieth century socialist political philosopher advocated a totalitarian state.
(D) Every early twentieth century political philosopher who was influenced by Rosa Luxemburg and was not a socialist was a communist.

I incorrectly picked (D). How I interpret the stimulus is that Rosa Luxemburg influenced ALL political philosophers so they were either socialist or communist. Where did my reasoning go awry? If Rosa's influence was not in fact inclusive of this group (early twentieth century philosophers) than how can (A) be the correct answer?


Thank you for your enlightenment.

Just took this PT. Might not be the best at explaining but I will try.

D is incorrect because while it could be true, it does not say that political philosophers that were influenced by RL were either socialist or communist. It just says that if they are socialist or communist then they were influenced by RL.

A is correct because all socialist of the 20th century were influence by RL. No one who was influenced by RL advocated a TS. Making A correct.

Hope that helps.

[skip james]

The MUST BE TRUE question reads, "Every political philosopher of the early twentieth century who was either a socialist or a communist was influenced by Rosa Luxemburg. No one who was influenced by Rosa Luxemburg advocated a totalitarian state.

If the statements above are true, which one of the following must on the basis of them also be true?

(A) No early twentieth century socialist political philosopher advocated a totalitarian state.
(D) Every early twentieth century political philosopher who was influenced by Rosa Luxemburg and was not a socialist was a communist.

I incorrectly picked (D). How I interpret the stimulus is that Rosa Luxemburg influenced ALL political philosophers so they were either socialist or communist. Where did my reasoning go awry? If Rosa's influence was not in fact inclusive of this group (early twentieth century philosophers) than how can (A) be the correct answer?


Thank you for your enlightenment.

You should work on your conditional diagramming, it would probably help a lot.

So Premise 1, "Every political philosopher of the early twentieth century who was either a socialist or a communist was influenced by Rosa Luxemburg"

can be diagrammed like this:

IF early 20th century socialist philpsopher (let's just call this 'S') OR early 20th century communist philosopher (and this one 'C') THEN influenced by RL

But look, if you have a conditional statement with an 'OR' in the sufficient condition, then what you actually have is TWO distinct conditional statements. So..

IF S THEN RL

IF C THEN RL

Our other premise is this: "No one who was influenced by Rosa Luxemburg advocated a totalitarian state."

IF RL THEN NOT TS

____________________

Combinations! That's the crux of conditional must be trues (at least the harder ones, and not the ones that merely restate the stimulus). By combining our conditional statements, we can see we have TWO derivations which could possibly be answers.

S --> RL --> NOT TS

or

C --> RL --> NOT TS

Basically this reads in plain english as, "If you are an early century socialist political philosopher THEN you do not advocate a totalitarian state' or "If you are an early century communist political philosopher THEN you do not advocate a totalitarian state'

And you can see that answer choice A is the former of the two. It's a bit tricky though since they hide the conditional statement by starting the answer with 'NO...' which forces you to have to translate it into a simpler conditional form.

[EdmundBurke23]

I nearly tainted my untouched PT 10 by reading into the question/// bad me

[bgdddymtty]

I incorrectly picked (D). How I interpret the stimulus is that Rosa Luxemburg influenced ALL political philosophers so they were either socialist or communist. Where did my reasoning go awry?

The stimulus doesn't say that Luxemberg's influence caused all early 20th century political philosophers to become socialists or communists. It simply says that all of the ones who were socialists or communists were influenced by her. Many others who were, for example, capitalists may or may not have been influenced by her.

If Rosa's influence was not in fact inclusive of this group (early twentieth century philosophers) than how can (A) be the correct answer?

Because (A) only talks about socialist philosophers, not all philosophers.