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【逻辑入门】（六）Weaken

Common Prompts for Weakening questions:
• Which one of the following, if true, most seriously weakens the argument?
• Similar verbs: attack, call into question, cast doubt on, challenge, contradict, counter, damage, rebut, refute, undermine.

Before you look at the answers:
1.Pinpoint the main conclusion in the passage. (Read my previous Main Point post.)
2.Separate the premises from everything else. After you find the main point, don’t assume that all the other statements are premises; they might include opposing viewpoints, background information, and concessions.
3. Ask yourself, “Do the premises (exactly as they are stated in the passage) support the conclusion (exactly as it is stated in the passage)?” In other words, once discard everything else, how well do the premises support the conclusion? The reason you want to focus on exactly what the premises and the conclusion state is that you do not want to subconsciously make the argument better than it actually is. Do not help the author. Look at what he actually said and then decide whether his evidence stacks up:

• Does the author make any unreasonable assumptions? For example, read the following statements: “We should support the proposed law, which requires government officials to disclose their annual incomes, because it will give ordinary citizens a fair chance to keep an eye on and more control over when and how elected officials receive gifts and benefits from lobbyists.” Watch out for should, moral ethical and other loaded conclusions. The test makers like to play off commonly held assumptions about what is right or wrong in our heads. This argument unreasonably assumes that “giving ordinary citizens a fair chance to keep an eye on and more control” is good. If this is the case, the author must clearly point out this premise in his argument.
• Does the author rely on an unrepresentative survey/samples? For example, read the following statement: “Mr Xi will likely become the next President because over two-thirds of students in Fudan University said that they would vote for him.” Do these students represent fairly of the voters in the political process? Do these students even have the right to elect the next President?
• Does the author rely on a questionable analogy or comparison? For example, read the following statement: “A terrorist caught by police in Xinjiang with explosives in his backpack should first be given a warning just like a vendor without license caught by urban management officers in Beijing. First offense is not a big deal.” My God. This cannot be happening!
• Does the author’s conclusion overstate the premises? For example, read the following statements: “Acupuncture has been shown to reduce the risk of stroke. Therefore, anyone who undergoes acupuncture treatment will not experience a stroke when they are older.” Do these words sound like a TV commercial? If you are good at CR, you can have a lot of funs to pick apart commercials in Chinese or English.

Then look for the answer that exploits one of those weaknesses:
• The correct answer usually offers new evidence that makes you doubt the conclusion without directly contradicting the original evidence in the passage. “Mr. Zhang will be a good addition to our finance department because he has worked in banks in Wall Street.” New evidence: “Mr. Zhang worked as a computer programmer in Wall Street.” This new evidence does not contradict the original premise, but it does cast doubt on the original conclusion. Another possible answer: “Mr. Zhang worked in Wall Street for a total of two weeks before being let go.” Still another: “Mr. Zhang recently had a big fight with our current finance VP during a M&A discussion.” Notice, this evidence is unrelated to the original premises; it has nothing to do with Wall Street. So do not skip an answer choice because it does not address the points raised in the original argument. Focus on the new unfavorable light shining on the conclusion.
• Some arguments will tell you that two events are correlated (happened together) and then conclude that one event causes the other. The problem with this kind of causal argument is that it relies on many questionable assumptions. If the conclusion states that A causes B (If reading my posts,a reader’s understanding of CR is increased), look for evidence that says
- B causes A (A reader with good understanding of CR tends to read my posts).
- C causes B or A or both (CDer whose English is superb are more likely to read my posts and have better understanding of CR).
-A and B are not actually correlated (The survey overestimated the increased understanding of CR for most readers after reading my posts).
Any evidence that supports one of these three possibilities will weaken the conclusion that A causes B. However, I do hope by reading my posts, you can improve your understanding of CR eventually.