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 Administrator
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#36961
Complete Question Explanation

Parallel Flaw—SN. The correct answer choice is (B)

In this stimulus, the political scientist provides the following conditional premises:
  • Premise: All governments worthy of respect allow dissent from policies:
    GWR :arrow: AD

    Premise: No government worthy of respect leaves minorities unprotected (so, if
    one does not protect minorities, one is not a government worthy of respect, and on
    the other side of the coin, if a government is worthy of respect, it will protect its
    minorities):
    GWR :arrow: PM

The political scientist then jumps to the following unwarranted conclusion:
  • Conclusion: Any government that protects minorities permits criticism of its policies (that is, any
    government that protects minorities allows some dissent)
    PM :arrow: AD
If we revisit the three statements as diagrammed, the political scientist’s misstep in logic becomes clear:
  • GWR :arrow: AD
    GWR :arrow: PM
The scientist’s conclusion is that PM :arrow: AD, but the flaw is clear. What we really know based
on the above premises is that any government worthy of respect (GWR) exhibits both of the other
discussed attributes: that is, they allow dissent (AD), and they protect minorities (PM). The speaker
cannot logically conclude that any government that protects minorities will also allow dissent from
government policies, so the argument is flawed.

We are asked to find the answer that most closely parallels the argument in the stimulus, so we should
look for the choice that employs a similar brand of flawed reasoning.

Answer choice (A): Although the reasoning in this answer is flawed, the mistake is of a different sort;
here, the stimulus defines politicians as admirable if they put the interests of those they serve above their
own. The author attempts to draw from this the conclusion that politicians are admirable for putting the
nation’s interests above those of their constituents. This leap is unjustified, but not in the same way as
the conditional reasoning in the stimulus, so this answer is incorrect.

Answer choice (B): This is the correct answer choice, as it employs the same type of flawed reasoning:
  • All jazz musicians are capable of improvising: JM :arrow: I
    No jazz musician is incapable of reading music
    (which means every one is capable of reading music): :arrow: JM RM

    Conclusion: All who can read music can improvise: RM :arrow: I
In this example we can see the exact same pattern of flawed reasoning. The author has taken the two
necessary variables from the premises and has attempted to tie them together in a sufficient/necessary
relationship.

Answer choice (C): This answer choice also represents a mistake in logic, but the reasoning here does
not parallel that found in the stimulus. Rather, this choice represents a mistaken negation, as follows:

Cool, dry ecosystems are populated by large mammals: ..... CDE :arrow: LM
No such systems have abundant and varied plant life: ..... LM :arrow: AVPL
If we link these two premises, we get the following: ..... CDE :arrow: LM :arrow: AVPL
From the above statement this inference can be drawn: ..... CDE :arrow: AVPL
But the mistaken negation is drawn instead: ..... CDE :arrow: AVPL

Answer choice (D): The fact that the conditional variable in this case introduces “some” into the
equation tells us that it will not logically parallel the method of argumentation used in the stimulus.

Answer choice (E): This answer also contains a “some,” so we can safely conclude that it will not follow
the same overall logical flow, and is incorrect.
 wayouteast
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#38626
I'm having trouble deciphering the second premise of this conditional chain.
For the first one I correctly saw A-->B
BUT... How does No govt worthy of respect leaves minorities unprotected equate to A-->C? I am reading it as
~A-->C and via contrapositive ~C-->A.

I feel like I'm forgetting some simple thing that would allow you translate this conditional statement to the correct form- any help would be much appreciated!
 AthenaDalton
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#38684
Great question!

Since the second sentence uses a double negative, you may find it helpful to 'translate' the sentence into plain English before diagramming it.

Original sentence: No government worthy of respect leaves minorities unprotected.

This could be diagrammed as: -PM :arrow: -GWR

Translation without double negatives: Every government worthy of respect protects minorities.

From here, we can get GWP :arrow: PM

It's not essential to remove the double negatives, but I find this 'translation' to be a helpful step in setting up diagrams. I hope this helps clear things up. :) Good luck studying!
 wayouteast
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#38706
I'm still confused by the second conditional. Even with the negatives- doesn't No govt worth of respect leaves minorities unprotected translate into ~A-->~C and therefore C-->A. Am I missing some simple word that's causing me to mix up the sufficient and necessary condition on this?

Sorry for the pedantic questioning- just very confused as to how I'm not grasping this seemingly simple conditional chain correctly!
 Francis O'Rourke
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#38736
Hi wayout,

If I am interpreting your A's and C's correctly, your diagram tells us the following:
If a government is not worthy of respect, it will not leave minorities unprotected.
GWR :arrow: LMU
If that is correct, then you are inserting an extra negation into the relationship. The correct translation of this statement is instead: If a government is worthy of respect, then it does not leave it's minorities unprotected.

No X does Y should be interpreted as the following: X :arrow: Y. Or in other words: if X, then no Y; and if Y, then no X

Let us know if this helps!
 alexmcc
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#55765
It took me a while to answer this question because B seemed to have a generalization flaw which the passage didn't show. Going from characteristics of jazz musicians to a characteristic of all musicians seemed like a generalization error to me. I am wondering why this is OK.

Edit: Ah OK it looks like the passage goes from "governments worthy of respect" to "any government" in the conclusion, so this makes more sense now. Leaving this here in case it might help someone else.

Alex
 Claire Horan
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#60790
Thanks, Alex! Good job spotting the slippage in language!

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