Objection’s LSAT Tips – “Main Point” Questions (LR)

Question Type: Main Point
Section
: Logical Reasoning
Sample Prompts:

…is the main point of the argument?
…leads to the conclusion that…
…expresses the main conclusion

Introduction

Mastering “main point” questions is extremely valuable because they appear in both the logical reasoning and reading comprehension sections of the LSAT. In addition, they are foundational to other types of questions. If you are asked to support or weaken an argument, for instance, it is necessary to have an understanding of the main point of that argument. Hopefully this article will help you consistently recognize the main points of arguments, thereby helping you with a wide range of question types.

Method

One way to begin attacking “main point” problems is by looking for indicator words. For example, ‘therefore,’ ‘thus,’ and ‘in conclusion’ all indicate that what follows will be the conclusion of the argument. Other words, such as ‘since’ and ‘because,’ indicate premises.

I caution against relying too heavily on indicator words because sometimes none will be present in the argument. It is much better to simply understand the roles each sentence plays. Remember that the premises are intended to support the conclusion. If you find yourself struggling to identify the conclusion, go through each statement of the argument and ask if it is supporting some other statement or being supported by other statements. The statement being propped up by the others is your conclusion.

What you do not want to do is get caught up in the merits of the argument. This is irrelevant. It doesn’t matter if the author says something completely ridiculous; your job in this question is to figure out the point of what he is saying, not whether his point is valid or sound.

But, like most LSAT problems, it is best to learn by practice and example. So let’s do a few.

Examples

Mental strength is a limited resource, and mind-training techniques help to use this resource efficiently. Since top students do not differ greatly from each other in mental strength, it follows that for a top student to become a scholar he or she must develop a superior mastery of mind-training techniques.

Which one of the following most accurately expresses the conclusion of the argument?

A) Only scholars have a superior mastery of mind-training techniques.
B) Superior mental strength is a requirement for a top student to become a scholar.
C) No top student can become a scholar without a superior mastery of mind-training techniques.
D) The differences in mental strength between top-students are not great.
E) Mind-training techniques help students use limited resources efficiently.

Analysis: Remember what I said about ignoring the merits of the argument made in the stimulus? This applies here. “Mental strength”? “Mind-training techniques”? Can you get any more vague? But our job is not to evaluate the claims. Our job is to simply discover and summarize the point being made.

“It follows” is one of those key phrases that indicates the conclusion is coming. Immediately after “it follows,” the stimulus states that “that for a top student to become a scholar he or she must develop a superior mastery of mind-training techniques.” This is our conclusion and you will want to look for an answer that says something similar. 

A – Incorrect. There might be others who have a superior mastery of mind-training techniques but are not scholars. The stimulus is not saying that all people with a superior mastery of mind-training techniques are scholars. The stimulus is saying that all scholars are people with a superior mastery of mind-training techniques. There is a difference.
B – Incorrect. The very first sentence says that top students do not differ greatly from each other in mental strength. This is an attempt to trap those who are not reading carefully.
C – Correct. This simply rephrases what the author says after “it follows” in the stimulus. If superior mastery of mind-training techniques is a requirement for top students to become scholars, then it follows that no student can become a scholar without this superior mastery. The two statements are essentially logically equivalent.
D – Incorrect. While true according to the stimulus, it is a premise. We want the conclusion.
E – Incorrect for the same reason as D.

-----

The explosion that destroyed City Hall happened early this morning, and the last rescue workers did not leave until late this afternoon. No one could have been anywhere in the vicinity of an explosion like that and failed to notice it. John must have seen it, regardless of what he says to the contrary. He admits that he went from his apartment to the school this morning, and there is no way for him to get from his apartment to the school without going past City Hall.

The main conclusion of the argument is that

A) John was in the vicinity of the explosion this morning.
B) John claimed not to have seen the explosion.
C) John saw the explosion this morning.
D) John went directly from his apartment to the school this morning.
E) John went by City Hall this morning.

Analysis: This argument is a good example of why you should not assume the last sentence is the conclusion. Here, the conclusion is smack dab in the middle: “John must have seen [the explosion].” Every other sentence is a premise supporting that conclusion. Rearrange them in your head:

Premise: There was an explosion at City Hall this morning.
Premise: No one could have been in the vicinity and not seen the explosion.
Premise: John admits he went from his apartment to the school this morning.
Premise: John can’t get to the school without going past City Hall.

Conclusion: John must have seen the explosion.

Again, there are plenty of potential holes in this argument. Let’s ignore them and try to find the answer choice that captures the essence of the conclusion.

A – Incorrect. While this is true according to the stimulus, this is just a premise.
B – Incorrect. This could be the case, but the stimulus does not say whether John claimed to see it or not. Even if you take the “regardless of what he says to the contrary” as implying that he lied (and as a good logician, you shouldn’t), it would still only be a premise.
C – Correct.
D – Incorrect. It simply says he went from his apartment to school – it doesn’t mention any stops. Besides, this would also be just a premise.
E – Incorrect. While true according to the stimulus, this is a premise supporting the conclusion.

Be careful. You want to rephrase the conclusion, not one of the premises. -----

Some pets release allergens and dirt into the household air supply. This is not a problem in well-ventilated houses, but it is a problem in houses that are so well-insulated that they trap allergens and dirt as well as heat. Recent tests, however, demonstrate that air purifiers remove some allergens and dirt from the air and thereby eliminate their danger. In one test, three large air purifiers eliminated allergens from a small, well-insulated house.

The passage is structured to lead to which one of the following conclusions?

A) Air purifiers can remove dirt from the air.
B) Only pets release allergens and dirt into the air.
C) Air purifiers are effective means of trapping heat inside a poorly insulated house.
D) Keeping air purifiers can compensate for some of the negative effects of poor ventilation.
E) The air in a well-insulated house with air purifiers will contain fewer allergens and dirt than the air in a well-ventilated house without air purifiers.

Analysis: This is a tricky questions with lots of nitpicky answer choices. Remember to always read carefully.

A – Incorrect. This is a trap answer. The test done shows that air purifiers eliminated allergens. It makes no mention of dirt. Regardless, this is not the point this argument is trying to show.
B – Incorrect. The stimulus does not say this. It does say that pets release allergens and dirt into the air, but not that only pets do. And besides, this wouldn’t be the conclusion.
C – Incorrect. The stimulus does not imply this at all.
D – Correct. It broadly summarizes the conclusion. Air purifiers help with some of the negative effects of poor ventilation. Not all of the effects or most of the effects – just some of the effects. This is exactly what the stimulus is claiming.
E – Incorrect. The stimulus never attempts to demonstrate this.

Final Notes

The key to “main point” questions is to be able to identify the conclusion. Being able to identify the various parts of an argument and the roles they play is crucial to much more than just “main point” questions, though. By mastering “main point” questions, you are on your way to mastering much more of the logical reasoning section.