GMAT 逻辑分析题 (21)

sdcar2010

GMAT tutor: If a student always compares himself to the NiuNiu at www.chasedream.com, he is most likely belittling himself. On the other side of the coin, if a student always compares himself to the BenBen at www.chasedream.com, he is most likely belittling others. So, those students who normally refrain from comparing themselves to others at www.chasedream.com will most likely to have self-respect and respect others.

The tutor’s reasoning is most vulnerable to which of the following criticisms?

A) It overlooks the possibility that a student can compare himself both to the NiuNiu and the BenBen at www.chasedream.com.
B) It overlooks the possibility that always comparing oneself to others might have other beneficial effects that outweigh its detrimental effects.
C) It takes for granted that if a student is both self-belittling and belittling others, he will not have self-respect and respect others.
D) It overlooks the possibility that self-belittling and belittling others can result from something other than comparing oneself to others
E) It takes for granted that whenever a student compares himself to others in www.chasedream.com he sees others as NiuNiu or BenBen.

elena152

我想选e

lmf0801

A 对不？

sdcar2010

Neither A nor E is the correct answer.

eliasfan

Neither A nor E is the correct answer.

-- by 会员 sdcar2010 (2010/12/3 22:07:14)

So what's the answer to this question? how about B?

sdcar2010

B is very tempting, but is not the right answer, either.

The correct answer is D

Premises:
1) Comparing oneself to NiuNiu --> belittling oneself
2) Comparing oneself to BenBen --> belittling others

Conclusion:
Not comparing oneself to NiuNiu and not comparing oneself to BenBen --> not belittling oneself and not belittling others

Basically the conclusion negates both premises in the argument.  This type of negation is what we called mistaken negation or inversion. From the principle of logic, if a statement is true, then the contrapositive is also logically true, but not the mistaken negation - negation without reversing the condition and conclusion in the original statement.

Look at premise 1) Comparing oneself to NiuNiu --> belittling oneself
Comparing oneself to NiuNiu will lead to belittling oneself.  So comparing oneself to NiuNiu is ONE sufficient condition leading to belittling oneself.  There might be other reasons for one to belittling oneself besides comparing oneself to NiuNiu. Simply removing the possibility of comparing oneself to NiuNiu will not ensure that one will not belittle oneself. Likewise, simply removing the possibility of comparing oneself to BenBen will not ensure that one will not belittle others.

Answer D points out this flaw of the argument.

clumsy123

sd大侠，看了你的解释还是有点不明白~if a statement is true, then the contrapositive is also logically true, but not the mistaken negation，这句话是什么意思？是说原命题是真命题，那么他的逆否命题（contrapositive）是真的，否命题（negation）不一定是真的~（是这个意思么？）
所以D只是为了支持Comparing oneself to NiuNiu or BenBen只是一个充分条件。所以如果Comparing oneself to NiuNiu or BenBen是充分必要条件的话，那么他的否命题也是成立的，对么？

sdcar2010

sd大侠，看了你的解释还是有点不明白~if a statement is true, then the contrapositive is also logically true, but not the mistaken negation，这句话是什么意思？是说原命题是真命题，那么他的逆否命题（contrapositive）是真的，否命题（negation）不一定是真的~（是这个意思么？）(YES)
所以D只是为了支持Comparing oneself to NiuNiu or BenBen只是一个充分条件。(YES)
所以如果Comparing oneself to NiuNiu or BenBen是充分必要条件的话，那么他的否命题也是成立的，对么？(No. What I meant is that as long as the statement "if comparing to Niuniu, then you are depessed" is correct, its contrapositive statement "if you are not depressed, then you did not compared yourself to NiuNiu" is also correct.)

-- by 会员 clumsy123 (2011/8/8 16:58:21)

clumsy123

en, what i mean is that if the statement is true that comparing oneself to others is the ONLY way leading to self-belittling and belittling others, will the argument be logical and sound?

sdcar2010

en, what i mean is that if the statement is true that comparing oneself to others is the ONLY way leading to self-belittling and belittling others, will the argument be logical and sound?

-- by 会员 clumsy123 (2011/8/8 23:04:15)

Yes, then the flaw is gone.