#22 - It is an absurd idea that whatever artistic endeavor

[alee]

I have an another question about Q22 of Preptest 25, Section II- a 'match the pattern of reasoning' question. Is the reason why A is correct that the first sentence of the stimulus talks in negatives- i.e. whatever the government does NOT support it does NOT allow.
So just following the NOT...NOT double negative structure, we can narrow down the answer options to A and B. Furthermore, since the stimulus reasoning is sound, and the reasoning in B is not sound, we therefore conclude that A is correct.

Is that right?

[Steve Stein]

Hi Alee,

Thanks for your question. You've basically got it: in a Parallel Reasoning question, if the reasoning in the stimulus is sound, then the reasoning in the correct answer choice must be sound as well. In that one, Answer choice A, like the stimulus provides a conditional statement and its valid contrapositive. Answer choice B provides a mistaken negation; since it is flawed, it cannot possibly parallel the reasoning from the stimulus.

I hope that's helpful--let me know--thanks!

~Steve

[alee]

Yes, thanks Steve! I missed the contrapositive reasoning 1st time round...

[Heather]

Hi Dave!

Could you kindly explain this question and each answer choice? I'm facing a particular difficulty diagramming the premises and answer choices.
For the premise, "No one is allowed to create art without a government subsidy" I diagrammed as A(negative) GS(negative) (In my mind I read this as, 'If you want to create art, then you need a government subsidy. - Is that correct?)

As for the answer choices..
I diagrammed (a) as: "Any driver who is not arrested does not break the law.." as
(negative)A (negative) BL. The conclusion as BL A which also happens to be the contrapositive of the first statement. I understand that this is the correct answer, however, I had considerable difficulty in isolating this from the rest of the answer choices.

I diagrammed the premise for answer choice (b) in the same way as that for (a) but the conclusion as A BL which is a negation and hence wrong.

Answer choice (c) confused me the most. The premises "Every Scientist who is supported by a government grant will be successful" I interpret in this manner: Every=SC indicator; Scientist (subject); what the subject wants to accomplish: Success. So Successful scientist is the SC. "by a government grant" (aka, the manner in which the subject can accomplish what he wants) is the NC. Therefore, Successful Scientist Government Grant
My first question is - is there an easier way to interpret the above? This is the way I was originally interpreting the premises:
Scientist supported by government grant successful
I realized I was wrong and the above is the only reasoning I could come up with for that. However, it takes me far too long to decipher it so an easier way to do so would be welcome.

The conclusion of answer choice (c) "No scientist who is successful is so without a government grant" and the conclusion of answer choice (d) "No scientist lacking government support will be successful" also thoroughly confused me.
In the logical reasoning bible we are told that 'No' modifies the act which is the NC and not the subject which is the SC, such as in "No robot can think" which is interpreted as "If an entity is a robot, then it cannot think".
Scientist who is successful government grant
Is this how the conclusion to (c) will be diagrammed? or will it be the other way around?

Please explain how both conclusions for answer choices (c) (d) and (e) will diagrammed.

Thank you!

[Robert Carroll]

Heather,

The conditionals in this stimulus require very careful attention, but if you diagram them one step at a time, everything will fall into place.

The stimulus essentially says that one conditional is equivalent to the other; it claims that the conditional after the colon means the same thing as the conditional before it, which is supposed to make explicit the absurdity of the first conditional. Since we are meant to parallel the reasoning in this question, we want to know whether the two are equivalent conditionals, because otherwise there may be a flaw (which, of course, we would want to parallel if it exists!).

So, first:

not(government supports) not(government allows)

This is the first conditional.

The conditional after the colon uses the word "without", which is a necessary condition indicator. Thus, the necessary condition of this conditional is "government subsidy." But because "without" is a word that, like "unless", requires special treatment when identifying the sufficient and necessary conditions of a conditional, we need to employ the Unless Equation to get the sufficient condition.

As I said, "government subsidy" is the necessary condition. The other condition must first be negated before it becomes the sufficient condition. Thus, the sufficient condition here is "allowed to create art," because the "no" is negated, and the double negations cancel out. Thus, the conditional after the colon is as follows:

allowed to create art government subsidy

Since "subsidy" and "support" are synonymous in any relevant way in this stimulus, the second conditional is merely the contrapositive of the first.

This is why answer choice (A) is correct - as you identified, the second part of that answer is the contrapositive of the first, as it should be.

Answer choice (B) is a Mistaken Negation, as you also identified.

For answer choice (C), the sufficient condition is "supported by a government grant." Remember that when a statement says "Every member of group A has quality B," the conditional is A B. Here, it says that being a scientist supported by a grant is sufficient to make success necessary. So:

supported by grant successful

For the second part of answer choice (C), "without" again requires the use of the Unless Equation. So, "No A without B" = A B. (B is necessary, "No A" must be negated to become sufficient, so "No-no-A = A by double negation) Thus:

successful grant

which you can see is not the contrapositive.

In answer choice (D), the first conditional is as in answer choice (C), while the second says that no scientist lacking something (thus, no scientist who does not have support) will be successful. Thus:

not(support) not(successful)

This is also not the contrapositive of the first conditional.

In answer choice (E), the second conditional mentions being "allowed" to do research, while the first conditional mentions success and support. Thus, the second conditional brings up a third condition that was not in the sufficient or necessary condition of the first conditional. This does not parallel the reasoning in the stimulus, so answer choice (E) is wrong.

If anything continues to be unclear, please let me know!

Robert Carroll

[Heather]

I still don't understand how you've interpreted the second part of answer choice (d).

You said: "No scientist lacking something (thus, no scientist who does not have support) will be successful. Thus:

not(support) not(successful)

As I mentioned earlier, in the logical reasoning bible we are told that 'No' modifies the act which is the NC and not the subject (which is the SC), such as in "No robot can think" which is interpreted as "If an entity is a robot, then it cannot think". If we apply this concept to the above statement in answer choice (d) should it not equal to:
Scientist who is successful government grant ?

[Adam Tyson]

I wonder if the double negative in that second sentence in answer D (NO scientist LACKING support) might be contributing to the confusion here? Heather, your approach here (gleaned from the LR Bible) works just fine, but it results in the diagram that Robert gave.

No X lacking support succeeds - take the "no" at the beginning and attach it to the necessary condition, success, making it into "not succeed" or succeed. What you are left with is the sufficient condition of "X lacking support" or support. Thus, the original statement in D is:

Support -> Succeed

and the second sentence is:

Support -> Succeed

Since that is a Mistaken Negation, rather than the contrapositive we were looking for, it's out. See it now? If not, try using your robot example as a template and substitute terms - plug in "X lacking support" in place of "robot" and "succeed" in place of "think", and all should be clear.

Hope that helps!

[Heather]

Makes sense now! Thank you very much!!

[Johnclem]

Hello ,

Just a quick question about this that has been bothering me! If I am correct , the argument is valid as it's a conditional statement with its contrapositive . And I also believe it's a valid argument as the question stem most likely would have told me to look for a flawed match. but isn't it also a circular reasoning and therefore flawed ?


Thanks
John

[Adam Tyson]

Thanks for the question, John, as it gives me the chance to address what may be a common misconception among test takers. Certainly, when the question stem tells that we are to seek an answer with the same flaw as the one in the stimulus (a Parallel Flaw question), we then know for certain that the argument is indeed flawed. However, when they do not tell us that the argument is flawed there is no guarantee that it is valid. In fact, it's pretty common for them to ask us an ordinary Parallel Reasoning question (which of the following is most similar,etc.) when there is a flaw in the stimulus! For a while there, the test authors mostly avoided that, and they were kind enough to almost always point out the existence of flaw, but in the last few years they have stopped being all that friendly (and there was never any guarantee about it).

You have a point about conditional reasoning, in that contrapositives are, in a sense, an example of circular reasoning. We typically don't treat them that way, though, because we are typically told to accept the premises as true, and a conditional premise, if true, does indeed prove its contrapositive. Circular reasoning usually appears as something more obviously lacking in support, like "this team is the best because it is better than the other teams".

That said, we don't actually have circular reasoning in this case, because our author is not trying to convince us that a claim is true because its contrapositive is true. Rather, the author uses the contrapositive to help illustrate the absurdity of the original claim. In other words, he paraphrases the argument to make it clearer to the reader how silly the claim is. He isn't trying to prove the original claim, or the contrapositive - he is trying to show that they are absurd. He's just shining a light on the argument (in the form of easier to grasp language) to help us see its flaws better.

Real circular reasoning flaws on the LSAT are pretty rare, while contrapositives are very common. Like I said, you do have a point about them - you can't really use one conditional claim as the sole evidence to prove the contrapositive to be true, unless you take for granted from the beginning that one of them is true. However, in our attack on the LSAT, we pretty much give those claims a pass and say that they aren't truly flawed, and we instead point out problems like mistaken negations and reversals. Good thinking, and good question! Don't go too far down that rabbit hole, but do remain vigilant about the possible flaws even in contrapositives.