常见因果型逻辑漏洞分为四种：1、无因果，强加因果错误;2、时序因果错误;3同时因果错误;4、混淆因果错误。今天小编就着重为GRE考生讲解argument逻辑错误讲解——因果。
我们将四种错误逐一拆开来看。
第一种，无因果，强加因果错误，也就是说，作者一般指出A发生导致B发生，即A是B的原因，B是A的结果;我们要指出A跟B之间不存在因果关系，反驳的时候可以说B这一结果的发生是因为A，而是由于其他原因导致的。常见的标志词有because, so, therefore, as a consequence, consequently, hence等。也就是说，同学们在看到题目中出现表示因果关系的逻辑连词的时候，就要有意识，这里的因果关系可能就是题目的逻辑漏洞之一。下面我们通过例题来看一下：
例：新G14
A recently issued twenty-year study on headaches suffered by the residents of Mentia investigated the possible therapeutic effect of consuming salicylates. Salicylates are members of the same chemical family as aspirin, a medicine used to treat headaches. Although many foods are naturally rich in salicylates, food-processing companies also add salicylates to foods as preservatives. The twenty-year study found a correlation between the rise in the commercial use of salicylates and a steady decline in the average number of headaches reported by study participants. At the time when the study concluded, food-processing companies had just discovered that salicylates can also be used as flavor additives for foods, and, as a result, many companies plan to do so. Based on these study results, some health experts predict that residents of Mentia will suffer even fewer headaches in the future.
Write a response in which you discuss what questions would need to be answered in order to decide whether the prediction and the argument on which it is based are reasonable. Be sure to explain how the answers to these questions would help to evaluate the prediction.
将题目一分析，作者将20年间头疼减少作为了结论之一，支持结论的条件是Salicylates作为食品添加剂被生产商使用，也就是说因为Salicylates的商用这个条件推出了结果：人们头疼的数量减少了。在这里作者就是把头疼人数减少跟Salicylates的商业用途之间强加了因果关系，我们要反驳的时候就可以对原因找他因：可能是其他因素导致了头疼的人数下降，比如现代药物的发展，治疗了头疼;或者人们生活习惯更健康了，经常锻炼身体，身体素质好了，头疼少了等因素，都可以作为反驳的论据。这就是对强加因果的逻辑漏洞的反驳思路：找到条件和结论，对条件找他因，让条件和结论之间的因果关系不成立。
接下来，我们来看第二种常见因果逻辑漏洞：顺序因果错误。
作者通常会说出几年前发生的事情A，接着发生事情B。然后认为B事件的发生是因为A。这样就在本来只存在时序先后关系的事件之间建立了因果联系。我们反驳的思路也是认为因果关系不成立，事件B的发生不是由于A导致的，可能有其他的影响因素。时序因果错误的标志词有：after this, since then, because of this, therefore等表示时间关系的词，同学们在看到这样的连词的时候，就需要引起注意哦。下面我们来看例题：
例：新G12
Fifteen years ago, Omega University implemented a new procedure that encouraged students to evaluate the teaching effectiveness of all their professors. Since that time, Omega professors have begun to assign higher grades in their classes, and overall student grade averages at Omega have risen by 30 percent. Potential employers, looking at this dramatic rise in grades, believe that grades at Omega are inflated and do not accurately reflect student achievement; as a result, Omega graduates have not been as successful at getting jobs as have graduates from nearby Alpha University. To enable its graduates to secure better jobs, Omega University should terminate student evaluation of professors.
Write a response in which you discuss what specific evidence is needed to evaluate the argument and explain how the evidence would weaken or strengthen the argument.
例题中说给教授评价的措施是15年之前实行的，从那以后，教授开始给学生打高分了。是在教授给学生打高分和教授评教制度之间建立了因果关系。我们可以进行如下反驳：文中并没有给出确切的信息从什么时候开始学生得分高的，缺乏这些信息我们就不能够得出学生的高分由于评价体系实施以后造成的。然后可以补充说明一下，学生得高分如果不是因为教授的评教制度，可能有哪些因素造成的呢?可以说是由于学生自身素质提高了，或者由于教育或考试改革而使得题目变简单等，不排除这些因素我们同样不能得出学生的高分是由于评价体系造成的结论。这样将思路一总结，还是找到题目中存在时序因果错误的条件和结论，反驳其因果关系不成立，然后对条件找他因进行反驳。这个思路是个万能的通用思路哦。
紧接着，我们就来看第三种常见因果错误：同时因果错误。同时因果错误是指：时间轴上的某一个段内或某个时刻上，同时发生的两件事情A跟B，但作者在两个事件中强行加入了逻辑联系或者因果联系。也就是说AB同时发生，AB之间存在因果关系;或者AB之间存在逻辑相关，共同导致了一个结果。反驳的思路就是找到同时发生的两件事，反驳他们之间的关系不成立，对原因找他因。我们还是通过例题来看：
例题：新G75.
The following appeared in a letter to the editor of a Batavia newspaper.
"The department of agriculture in Batavia reports that the number of dairy farms throughout the country is now 25 percent greater than it was 10 years ago. During this same time period, however, the price of milk at the local Excello Food Market has increased from $1.50 to over $3.00 per gallon. To prevent farmers from continuing to receive excessive profits on an apparently increased supply of milk, the Batavia government should begin to regulate retail milk prices. Such regulation is necessary to ensure fair prices for consumers."
Write a response in which you discuss what questions would need to be answered in order to decide whether the recommendation is likely to have the predicted result. Be sure to explain how the answers to these questions would help to evaluate the recommendation.
题目中说农场数量的增加和一家超市牛奶价格的上涨两件事情同时发生了，将他们两个联系起来，导致的结果是牛奶供应的增长会让农民获得暴利。这是对同时发生的两件事联系到一起，向外推出了一个结果，我们就要反驳这个因果不成立。比如说，可以先从条件入手，奶牛场数目变多并不等于产奶量多，一是奶牛场增加25%并不一定代表奶牛场数目显著增加，因为不知道基数，二是由于不知道每个奶牛场奶牛的数量，以及日产量，所以数量的增加并不意味着产奶量的增加。反驳了产量以后，可以反驳价格：一个超市牛奶价格的上涨不代表所有的牛奶价格都上涨了，即使价格是上涨了，那么也由于不知道目前生产牛奶的成本是否上涨，如果成本也上涨了，那么利润空间没有多大变化，那么农民也不会获得暴利的。因此，结论不成立。这个呢就是同时因果错误的反驳方法。
下面，我们来看最后一种：混淆因果错误。混淆因果错误的发生是作者将原因与结果颠倒了。题目中说A导致B的发生，正常的因果关系应该是B导致A。反驳的思路就是：首先攻击二者之间可能不存在因果关系;进而让步，即使真的存在因果关系，但似乎我们通过常理可以看出，更多的可能性是由于B的发生导致A的发生。
下面我们来看例题：
例：新G77
The following recommendation appeared in a memo from the mayor of the town of Hopewell.
"Two years ago, the nearby town of Ocean View built a new municipal golf course and resort hotel. During the past two years, tourism in Ocean View has increased, new businesses have opened there, and Ocean View's tax revenues have risen by 30 percent. Therefore, the best way to improve Hopewell's economy—and generate additional tax revenues—is to build a golf course and resort hotel similar to those in Ocean View."
Write a response in which you examine the stated and/or unstated assumptions of the argument. Be sure to explain how the argument depends on these assumptions and what the implications are for the argument if the assumptions prove unwarranted.
例题中是将旅游业的发展，新兴产业的发展等归因于高尔夫球场和酒店的建立了。这个因果关系是错误的，我们可以先反驳二者之间不存在因果关系，认为旅游业的发展更多的原因是当地旅欧资源丰富导致的;进而再让步，即使存在逻辑关系，也应该是旅游业的发展带动了高尔夫球场和酒店的建立。这样就是混淆型因果错误的反驳思路啦。
分析完四种常见因果型逻辑漏洞之后，下面我们来总结一下，反驳argument逻辑错误讲解——因果的通用思路：找到题目中建立因果关系的条件和结论，通过找他因来反驳其因果关系不成立。同学们还是需要多加练习，才能练就火眼金睛!更多GRE备考信息请登录前程百利GRE考试网站或拨打前程百利GRE考试热线400-890-6000咨询。
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