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 Clay Cooper
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#26272
Hi LSATconqueror,

Thanks for your question, and welcome to the forum!

I will diagram the stimulus and the correct answer choice. Stimulus first:

Premise:

Encourage free thought and expression :arrow: Creativity flourishes

Conclusion:

Creativity flourished :arrow: encouraged free thought and expression.

This is mistaken reversal - it is not logically valid just to reverse the two elements; if we want to find the contrapositive, we must both reverse and negate them.

Correct answer (E):

Premise:

democratic :arrow: citizens' opinions meaningful

Conclusion:

~citizens' opinions meaningful :arrow: ~democratic

This reasoning, by contrast, is valid; the conditional elements are both reversed and negated, and thus the conclusion is the contrapositive of the premise. Because the reasoning is valid, the answer choice does NOT parallel the flawed reasoning of the argument in the stimulus, and this is the correct answer.

I hope that helps.
 jgray
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#32236
Understand that CF was necessary in the first sentence.
In the second sentence.... how do we determine if the US Creativity or the 18th is the necessary condition? What indicators am I missing?
 Kristina Moen
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#32263
Hi jgray,

The closest I can come to a Conditional Reasoning Indicator in the 2nd sentence is "In the...". This is similar to the construction "People who..." or "When...", which indicates a sufficient condition. You can think "When this happens, then that happens." So here, it is during the US in the 18th century that creativity flourished. The first part is the sufficient and the second part is necessary. You can diagram this as U.S. in 18th century :arrow: creativity flourished.

I'll give you another example. "In the United States, elections are held in November." This means that IF it's November in the United States, THEN we are having an election. The contrapositive is that if there's no election, it's not November in United States. But we could have multiple elections throughout the year and other course countries have elections, so you can't infer if there's an election, it's November in the US.

Hope that helps!
 co659
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#34307
Hello ! I only selected E because all the other choices failed, not because I understood what was being said. The jumbling of the words confused me. I used Ernst and, reading through the explanations here that (E) was the correct choice because it was the contrapositive:

D = democracy
M.E = meaningful effect on the govt.

D :arrow: M.E.
CP: M/E :arrow: /D

I'm confused how the rest of the statement is the contrapositive - does "because" act like "since" and introduce the sufficient?? That's the only way I've been able to make sense of this
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 Jonathan Evans
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#34376
Hi, co659,

Good question. Let's see whether we can parse this out to make it more coherent.

Start with the stimulus. Identify the conclusion:
  • Freedom of thought was encouraged. (We'll call this F)
Now let's take a look at the premises:
  1. If society encourages freedom of thought and expression, then creativity flourishes. (F & E :arrow: C)
  2. Creativity flourished. (C)
To summarize:
  1. F & E :arrow: C
  2. C
  • Conclusion: F
Notice that we have made a Mistaken Reversal™. We have taken a necessary condition (C) to be sufficient for (F).

We need to find the answer choice that DOES NOT contain this error. Let's parse out Answer Choice (E):
  1. If democratic, then opinions matter. (D :arrow: O)
  2. Opinions don't matter. (O)
  • Conclusion: These societies aren't democratic. (D)
This argument is valid. The negation of the necessary condition O implies that the sufficient condition D cannot occur. In other words, answer choice (E) uses the contrapositive to prove its conclusion.

I hope this helps!
 Blueballoon5%
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#40600
I need help diagramming answer choice B. The answer key states, “We can conclude that the Hillside police department has improved its efficiency, because crime rates are down in Hillside, and it is an established fact that the crime rates go down when police departments increase their efficiency.”

I think the first part of this sentence is diagrammed as: “crimes rates down in Hillside :arrow: police improved its efficiency.” I am guessing this is correct, but I am not sure because the word “conclude” is not listed in the lesson book as a necessary condition indicator and the word “because” is not listed as a sufficient condition indicator. If these are not sufficient/necessary condition indicators, how else could we get to the correct conditional statement?
(Note: for the second part, I was able to diagram correctly because “when” is a sufficient condition indicator”)

Hope you can help! Thanks!! :)
 Claire Horan
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#42189
Hi BlueBalloon,

Here is my diagram for answer choice (B):

Conclusion: The Hillside police department has improved its efficiency.
Premise #1: Crime rates are down in Hillside.
Premise #2: Police departments increase their efficiency :arrow: crime rates go down

Because the premises only lead to the conclusion if you reverse it so say "crime rates go down :arrow: increase efficiency," this answer choice employs a mistake reversal, just as the other incorrect answer choices do. (This is a parallel flaw-EXCEPT question.)

From reading your question, it seems like you may be assuming conditional relationships where they aren't. An assertion that something IS the case is not a conditional. Neither Premise #1 or the Conclusion are conditionals. Premise #2 is a conditional because it describes a relationship between two conditions without telling us on its own whether either condition IS actually satisfied. In other words, a conditional relationship cannot tell us anything by itself about what is actually happening. It can only tell us what will happen if a particular condition is present.

On the LSAT, you may see arguments like the one above with a conditional premise, a factual assertion that a condition is or is not occurring, and a conclusion about what is or is not actually happening.

You will also see arguments that contain a conditional premise, another conditional premise, and a conclusion that connects them into a chain. The conclusion will tell you more about the relationships between the conditions, but it will not tell you another about what is actually happening. Be careful not to get confused between these two types of arguments!

And since much of this is difficult to explain without seeing what questions you have, I would encourage you to call the Homework Hotline if anything in this post is unclear. Good luck!
 marchibold
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#65580
Hello,

Could someone explain to me why question number 13 (error of reasoning) of L2 HW answer is E? I thought that A was more appropriate but E is the correct answer.

Thanks!
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 Stephanie Oswalt
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#65590
LSATconqueror wrote:How would you diagram this question? Any help will be greatly appreciated.
Hi LSATconqueror!

Thanks for the post. I'm assuming you were referencing #13 on page 2-72 in your LSAT Course Book. I have moved your question to the post explaining that topic! Let me know if this helps, or if you were referencing another question!

Thanks!
 mallie
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#73377
Hi there,

I am struggling with this question and was hoping for some help. Parallel flaw questions always seem hard to me, especially parallel flaw X!

For starters, I diagrammed the stimulus a little differently:

freedom of thought
and :arrow: creativity will flourish
freedom of expression

creativity flourishedUS :arrow: freedom of thoughtUS

So right off the bat, is this diagram wrong? Based on other comments in the thread, it looks like it. I was thrown off by the "and" in the stimulus. I think this affected how I looked at each answer choice because none of them had a double sufficient condition. But I suppose if even if I assumed that it was a double sufficient condition, it doesn't matter because the contrapositive would only require that one of the two freedom of thought/freedom of expression would be necessary if creativity flourished. And the flaw with the conditional is ultimately that it is a mistaken reversal.

I ended up picking B), which I diagrammed to be:
Improved efficiencyH :arrow: Crime rate downH

Improved efficiency :arrow: Crime rate down

I diagrammed E) as:

democratic :arrow: meaningful effect

No meaningful effect :arrow: not democratic

I hope this makes sense - I found this question really tricky! Thanks in advance for any help.

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