You’ve seen them on social media. You’ve heard them in movie dialogue. You’ve probably even used them yourself. They’re logical fallacies, those not-quite logically sound statements that might seem solid at first glance, but crumble the moment you give them a second thought. 

Logical fallacies are everywhere. Being able to identify logical fallacies in others’ writing as well as in your own will make you a more critical thinker, which in turn will make you a stronger writer and reader. As you’ll see below, there are a lot of ways an argument can be flawed. Take a look at some of the most commonly used logical fallacies.

Red herring 

A red herring is an attempt to shift focus from the debate at hand by introducing an irrelevant point. Example: Losing a tooth can be scary, but have you heard about the Tooth Fairy? 

Straw man 

A straw man argument is one that argues against an inaccurate version of the opposition rather than their actual argument. Example: Erin thinks we need to stop using all plastics, right now, to save the planet from climate change. 

Ad hominem 

An ad hominem fallacy is one that directed against a person, rather than against what that person says. Example: You have no idea what you’re talking about; you’ve only lived here for six months.

False dilemma 

A false dilemma claims there are only two options in a given situation. Often, these two options are extreme opposites of each other, failing to acknowledge that other, more reasonable, options exist. Example: If you don’t support my decision, you were never really my friend. 

Causal fallacy

A causal fallacy is one that implies a relationship between two things where one can’t actually be proven. Example: When ice cream sales are up, so are shark attacks. Therefore, buying ice cream increases your risk of being bitten by a shark. 

1.What does the underlined word “crumble” mean?

A Get stronger.

B Fade away.

C Become different.

D Break off.

解析：选D。D词义猜测题。根据划线部分前的“but”可知前后文意思表转折，结合“might seem solid at first glance”“crumble the moment you give them a second thought”可知那些陈述乍一看合乎逻辑，再一想就站不住脚“崩溃”了。故选D。

2.What’s mentioned about learning about logical fallacies in Para. 2?

A The function.

B The methods.

C The definition.

D The history.

解析：选A。A细节理解题。根据第二段的“make you a more critical thinker”“make you a stronger writer and reader”可知第二段讲到了学习逻辑谬误的作用/好处。故选A。

3.What do Red herring and Straw man share?

A They offer irrelevant reasons.

B They both changed the topic.

C Their statement lack evidence.

D They support others emotionally.

解析：选B。B推理判断题。根据Red herring部分的“introducing an irrelevant point”和Straw man部分的“argues against an inaccurate version of the opposition”可知红鲱鱼谬误和稻草人谬误都改变了论题，红鲱鱼谬误是提出一个不相关的论题，稻草人谬误是歪曲论题。故选B。

4.Which of the following sentences belongs to “Ad hominem”?

A You are for us, or you are against us.

B Only a stupid person would offer such an argument.

C Every time they see a rainbow in the sky, something good happens.

D I pay my taxes every month; you shouldn’t arrest me just because I drove a little drunk!

解析：选B。B推理判断题。根据全文内容可知，文章介绍了五种常见逻辑谬论，分别为Red herring红鲱鱼谬论；Straw man稻草人谬论；Ad hominem人身攻击；False dilemma非黑即白；Causal fallacy因果谬论。选项A为False dilemma；B为Ad hominem；C为Causal fallacy；D为Red herring。故选B。