Testprep数学精解
N. TO IMPLY THAT A POSITION IS TRUE MERELY BECAUSE NO ONE HAS DISPROVED IT I
S TO SHIFT THE BURDEN OF PROOF TO OTHERS.
EXAMPLE:
SINCE NO ONE HAS BEEN ABLE TO PROVE GOD’S EXISTENCE, THERE MUST NOT BE A GOD
..
THERE ARE TWO MAJOR WEAKNESSES IN THIS ARGUMENT. FIRST, THE FACT THAT GOD’S
EXISTENCE HAS YET TO BE PROVEN DOES NOT PRECLUDE ANY FUTURE PROOF OF EXISTEN
CE. SECOND, IF THERE IS A GOD, ONE WOULD EXPECT THAT HIS EXISTENCE IS INDEPE
NDENT OF ANY PROOF BY MAN.
UNWARRANTED ASSUMPTIONS
THE FALLACY OF UNWARRANTED ASSUMPTION IS COMMITTED WHEN THE CONCLUSION OF AN
ARGUMENT IS BASED ON A PREMISE (IMPLICIT OR EXPLICIT) THAT IS FALSE OR UNWA
RRANTED. AN ASSUMPTION IS UNWARRANTED WHEN IT IS FALSE--THESE PREMISES ARE U
SUALLY SUPPRESSED OR VAGUELY WRITTEN. AN ASSUMPTION IS ALSO UNWARRANTED WHEN
IT IS TRUE BUT DOES NOT APPLY IN THE GIVEN CONTEXT--THESE PREMISES ARE USUA
LLY EXPLICIT.
EXAMPLE: (FALSE DICHOTOMY)
EITHER RESTRICTIONS MUST BE PLACED ON FREEDOM OF SPEECH OR CERTAIN SUBVERSIV
E ELEMENTS IN SOCIETY WILL USE IT TO DESTROY THIS COUNTRY. SINCE TO ALLOW TH
E LATTER TO OCCUR IS UNCONSCIONABLE, WE MUST RESTRICT FREEDOM OF SPEECH.
THE CONCLUSION ABOVE IS UNSOUND BECAUSE
(A) SUBVERSIVES DO NOT IN FACT WANT TO DESTROY THE COUNTRY
(B) THE AUTHOR PLACES TOO MUCH IMPORTANCE ON THE FREEDOM OF SPEECH
(C) THE AUTHOR FAILS TO CONSIDER AN ACCOMMODATION BETWEEN THE TWO ALTERNATIV
ES
(D) THE MEANING OF "FREEDOM OF SPEECH" HAS NOT BEEN DEFINED
(E) SUBVERSIVES ARE A TRUE THREAT TO OUR WAY OF LIFE
THE ARGUER OFFERS TWO OPTIONS: EITHER RESTRICT FREEDOM OF SPEECH, OR LOSE TH
E COUNTRY. HE HOPES THE READER WILL ASSUME THAT THESE ARE THE ONLY OPTIONS A
VAILABLE. THIS IS UNWARRANTED. HE DOES NOT STATE HOW THE SO-CALLED "SUBVERSI
VE ELEMENTS" WOULD DESTROY THE COUNTRY, NOR FOR THAT MATTER, WHY THEY WOULD
WANT TO DESTROY IT. THERE MAY BE A THIRD OPTION THAT THE AUTHOR DID NOT MENT
ION; NAMELY, THAT SOCIETY MAY BE ABLE TO TOLERATE THE "SUBVERSIVES" AND IT M
AY EVEN BE IMPROVED BY THE DIVERSITY OF OPINION THEY OFFER. THE ANSWER IS (C
).
APPEAL TO AUTHORITY
TO APPEAL TO AUTHORITY IS TO CITE AN EXPERT’S OPINION AS SUPPORT FOR ONE’S O
WN OPINION. THIS METHOD OF THOUGHT IS NOT NECESSARILY FALLACIOUS. CLEARLY, T
HE REASONABLENESS OF THE ARGUMENT DEPENDS ON THE "EXPERTISE" OF THE PERSON B
EING CITED AND WHETHER SHE IS AN EXPERT IN A FIELD RELEVANT TO THE ARGUMENT.
APPEALING TO A DOCTOR’S AUTHORITY ON A MEDICAL ISSUE, FOR EXAMPLE, WOULD BE
REASONABLE; BUT IF THE ISSUE IS ABOUT DERMATOLOGY AND THE DOCTOR IS AN ORTH
OPEDIST, THEN THE ARGUMENT WOULD BE QUESTIONABLE.
PERSONAL ATTACK
IN A PERSONAL ATTACK (AD HOMINEM), A PERSON’S CHARACTER IS CHALLENGED INSTEA
D OF HER OPINIONS.
EXAMPLE:
POLITICIAN: HOW CAN WE TRUST MY OPPONENT TO BE TRUE TO THE VOTERS? HE ISN’T
TRUE TO HIS WIFE!
THIS ARGUMENT IS WEAK BECAUSE IT ATTACKS THE OPPONENT’S CHARACTER, NOT HIS P
OSITIONS. SOME PEOPLE MAY CONSIDER FIDELITY A PREREQUISITE FOR PUBLIC OFFICE
.. HISTORY, HOWEVER, SHOWS NO CORRELATION BETWEEN FIDELITY AND GREAT POLITICA
L LEADERSHIP.
--
I WOULD FLY YOU TO THE MOON AND BACK
IF YOU’LL BE IF YOU’LL BE MY BABY
GOT A TICKET FOR A WORLDSWHERESWE BELONG
SO WOULD YOU BE MY BABY
TESTPREP充分性精解转载SMTH 2001-10-14 10:51:58发信人: YKK (我不说话并不代表我不在乎),信区: ENGLISHTEST
标题: (GMAT)TESTPREP充分性精解
发信站: BBS水木清华站(FRI OCT 12 16:07:05 2001)
DATA SUFFICIENCY
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INTRODUCTION DATA SUFFICIENCY
MOST PEOPLE HAVE MUCH MORE DIFFICULTY WITH THE DATA SUFFICIENCY PROBLEMS THA
N WITH THE STANDARD MATH PROBLEMS. HOWEVER, THE MATHEMATICAL KNOWLEDGE AND S
KILL REQUIRED TO SOLVE DATA SUFFICIENCY PROBLEMS IS NO GREATER THAN THAT REQ
UIRED TO SOLVE STANDARD MATH PROBLEMS. WHAT MAKES DATA SUFFICIENCY PROBLEMS
APPEAR HARDER AT FIRST IS THE COMPLICATED DIRECTIONS. BUT ONCE YOU BECOME FA
MILIAR WITH THE DIRECTIONS, YOU’LL FIND THESE PROBLEMS NO HARDER THAN STANDA
RD MATH PROBLEMS. IN FACT, PEOPLE USUALLY BECOME PROFICIENT MORE QUICKLY ON
DATA SUFFICIENCY PROBLEMS.
THE DIRECTIONS
THE DIRECTIONS FOR DATA SUFFICIENCY QUESTIONS ARE RATHER COMPLICATED. BEFORE
READING ANY FURTHER, TAKE SOME TIME TO LEARN THE DIRECTIONS COLD. SOME OF T
HE WORDING IN THE DIRECTIONS BELOW HAS BEEN CHANGED FROM THE GMAT TO MAKE IT
CLEARER. YOU SHOULD NEVER HAVE TO LOOK