逻辑推理

paisleyUID: 64183

LSAT逻辑题型及典型问法

www.totoolaw.com  2003-1-22  土兔法律网


　　△加强题 　　Which one of the following statements, if added as a premise to the argument, would make the conclusion valid / strengthen the argument? 　　Which one of the following, if true, would make the conclusion in the passage a logical conclusion? 　　Which one of the following is an additional piece of inFORMation that would support the conclusion? 　　△削弱题 　　Which one of the following statements, if true, most clearly undermines / seriously weaken the conclusion / argument? 　　Which one of the following assertions, if true, provides the most effective challenge to the author’s conclusion? 　　△假设题 　　Which one of the following is an assumption on which the author’s argument relies? 　　Which one of the following most accurately states a hidden assumption that the author must make in order to advance the argument above? 　　Which one of the following is a presupposition essential to the reasoning in the passage above? 　　△评价题 　　Which one of the following is the most accurate evaluation of the author’s reply? 　　Which one of the following principles, if valid, justifies the author’s argument? 　　Which one of the following would it be most helpful to know in order to evaluate the argument? 　　△解释题 　　The author concludes that ... partly because... 　　Which one of the following, if true, argues most strongly against the explanation reported in the passage? 　　Which one of the following, if true, most helps to explain why ...? 　　Which one of the following principles, if established, would justify the judgments about A’s & B’s actions?) 　　△矛盾解决题（也可归类到解释题里） 　　Which one of the following, if true, most helps to resolve the apparent discrepancy between the two? 　　Which one of the following, if true, most helps explain the difference in...? 　　Which one of the following, if true, most helps to reconcile the author’s decision with the goal stated in the passage? 　　△结论（归纳）题 　　It can be concluded from the statements above that... 　　Which one of the following statements most accurately expresses the author’s main point? 　　Which one of the following statements CANNOT be true? 　　Which one of the following inferences can be most reliably drawn from the passage above? 　　The passage as a whole is structured to lead to which one of the following conclusions? 　　Which one of the following is the best statement of the primary point of the passage? 　　Each of the following can be inferred from his argument EXCEPT... 　　Which one of the following claims is central to the author’s argument? 　　If the statements above are true, then which one of the following must also be true? 　　△句子完成（划线填空）题 　　Which one of the following is the best completion of the argument above? 　　Based on the passage above, which phrase does NOT provide a logical completion to the following sentence? 　　△信息支持（反向加强）题 　　Which one of the following is most strongly supported by the inFORMation above? 　　The statement above, if true, most strongly support which one of the following claim? 　　△推理缺陷题 　　What is the flaw in the reasoning above? 　　The author’s argument is logically flawed in that it... 　　The source of the man’s erroneous reasoning is his... 　　The reasoning in the argument is most vulnerable to the criticism that it... 　　△逻辑相似性题 　　Which one of the following is most similar in logic to the argument above? 　　Which one of the following exhibits the same logical flaw as that exhibited above? 　　Which one of the following could be best supported by the same type of reasoning as that exhibited in the passage? 　　Which one of the following contains the error of reasoning described by the author in the passage? 　　Which one of the following most closely parallels the flawed pattern of reasoning in the author’s reply? 　　△逻辑相悖题 　　In which one of the following situations is the principle expressed most clearly violated? 　　△两人争论内容题 　　The source of A & B’s dispute is their lack of agreement on which one of the following terms? Which one of the following is the point at issue between A & B? 　　△逻辑策略方法题 　　Which one of the following is the best line of causal analysis for A to do? 　　The author establishes his position in the passage by doing which one of the following? 　　The author of the passage argues by...;The argument seeks to do which one of the following? 　　A most seriously weakens B’s argument by doing which one of the following? Which one of the following techniques of argument does the author use in the passage? 　　A’s statement most closely conFORMs to which one of the following principles? 　　The relationship if A’s response to B’s argument is that A’s response... A responds to B’s argument by...How is A’s response related to B’s argument?


原作者：coolaw

paisleyUID: 64183

LSAT逻辑推理讲义


(陈向东的讲义，Qianyi注）

PART I 两大推理模式如果我们把先发生的记作A，后发生的记作B，那么逻辑推理题的两大推理模式为：
一、“B，A”模式逻辑推理题中有很大一部分题目是由一个Survey,record,data,study,experiment或phenomena等而得出一个结论，而这个结论往往是对Survey,record,data,study,experiment，phenomena等的内容做出了一个解释。按照先发生的记作A，后发生的记作B的原则，我们把Survey,record,data,study,experiment,phenomena等记作B，而把由此得出的解释性的结论记作A。当由B得到解释性的结论A时，推理所做的hidden premise多为A是唯一的原因。换句话说，当一个推理是从一个已知的、已经发生的事实，已经存在的现象或一个研究的发现中得出一个解释性的结论时，一把暗含除了这个解释性的结论以外没有别的因素可以解释B。
此类推理模式典型的引导词有：demonstrate,show,result,due to,attribute to,reason,hypothesize,the explaination is, be responsible for等。这里的A为conclusion。另外，当推理是为达到一个目的而提出一个方法或建议的时候，推理成立暗含的假设是这个方法或建议是唯一或最具有关键性的能够实现目的的方法或建议。
由于只有先实施了某一方法之后才能达到一目的，因此，按照“先发生的为A，后发生的为B”的原则，我们把目的记作B，把方法或建议记作A，这里的A为conclusion。

二、“A，B”模式（一）当推理是由某个原因而试图得到一个结果时，推理成立的hidden premise是这个原因能够得到这个结果。由于原因一般发生在前，结果一般发生在后，因此我们把原因记作A，结果叫做B，这里的B为conclusion。（注意Because，since，for等原因引导词）。（二）当推理时由某一条件而试图得到一个结论时，推理成立的hidden premise时该条件却能得到此结论。我们把条件叫做A，结论叫做B。（注意if，when，as long as引导条件）。（三）当推理是由某一方法而试图达到某一目的时，推理成立的hidden premise是该方法确实能实现此目的。我们把方法叫做A，目的叫做B。注意这时并不表明A是唯一的，只是表明A是可行的。（注意By引导方法，to的不定式，in this way等引导目的）。（四）当推理由某一个事实现象、研究的结论而试图类推（由此及彼）或外推（由过去及将来）或不完全归纳推理（由某类的部分对象推至该类的全部对象）时，推理成立的hidden premise是此与彼、过去与将来、某类的部分对象与该类的全部对象在所有属性上没有差异。我们按照“先发生的记作A，后发生的记作B”的原则，把事实、现象、研究的结论记作A，而把类推，外推或不完全归纳推理记作B。请注意此类推理与“B，A”模式的根本差异：尽管两个推理都是由一个事实、现象、研究出发，但“B，A”模式的A是对B的一个解释，说明A是导致B的原因，且暗含A是唯一的，所以A为结论：而“A，B”的B是类推、外推或进行的不完全归纳推理，且这里B是结论。就假设（assumption）、支持（support）、反对（weaken）、评价（evaluate）这四类题型来说，把握上面两大推理模式尤为重要。因为无论是“A，B”还是“B ，A”模式，绝大多数论证都依据于hidden premise。

PART II 三大解题步骤（一）读问题，明晰问题目的，从而迅速确定解题方向。先读问题而不是段落似乎有为常理，但是可以实现了解题目类型。只有知道了问题目的类型，阅读段落才能更具有针对性。另外，问题目的本身的变化不多，往往一眼就能看出题型。注意：警惕选项中出现的not,unless,except,least等词，许多人由于漏看了这些小词而与正确答案无缘。（二）读段落，根据不同的问题目的确定不同的解题重点。如问题属于“假设、支持、反对、评价”类，读段落时重点在找出论点的前提与结论。边读边思考：从前题中能否推出结论？结论成立还需要哪些假设？如问题属于“归纳”类，读段落时要注意其逻辑层次结构及去向。边读边琢磨：作者想要说明什么？如问题属于“逻辑应用与技法”类，读段落时分清前提与结论。边读边考虑：段落推理犯了那种推理错误？结论的成立还需要哪些假设，假设的合理性如何等？如问题属于“解释”类，读段落时要格外关注要解释的对象以及解释对象的特点，边读边斟酌：怎样才能找到一个与要解释的内容直接相关的答案？（三）找答案，注意有些题型可调整看选项的顺序。读完问题与段落之后，寻读五个选项，选出正确答案。有时阅读选项时要放慢速度，有时应该反复掂量。当然若费时过多，猜测并非下策。


原作者：陈向东
来 源：新东方