The BriefA Blog about the LSAT, Law School and Beyond
When we say an argument is "good," what do we really mean? Well, recall that an argument is just premise(s) plus conclusion. Premises supports the conclusion and the conclusion is supported by the premises. So, “good” really just describes how well the premises support the conclusion. In other words, “good” describes the strength of the support relationship between the premises and the conclusion. Just how “good” can the relationship be? Until it becomes perfect, of course. When that happens, it is said that the argument is valid. Turn your attention to the chart below:
To weaken any argument on the LSAT's Logical Reasoning section, you have to understand one thing.
This thing is not tangible nor obvious. It’s instead abstract and subtle – which means it’s hard to understand. Here it is: You have to take away the support. What support? The support that the premises give to the conclusion. Please read that again. It may sound very obvious, but you’d be surprised at how often you will fall prey because you didn’t heed this warning. It’s only nature since our instinct when arguing is to deny our opponents’ premises. He asserts that there are bugs in the kitchen and therefore an exterminator visit is in order. You deny his premise by asserting that there are no bugs in the kitchen. But what would be the point of asking a question like this? All you did was to say “no.” Much more interesting is it to concede to your opponent her premises and then try to argue that despite your concession, her conclusion still doesn’t follow from her premises. That’s what Weaken (weakening) questions test you on. It most certainly does not say that you are to contradict, attack or weaken a premise nor does it ask you to contradict, attack or weaken the conclusion. It says you are to deprive the support that the premises give to the conclusion, as if with magic. Let me illustrate. Did you watch Dragon Ball Z growing up? Remember Goku’s Kamehameha?
Necessary assumptions can wreck an argument.
First, let’s understand what a necessary assumption is. It’s an assumption (definition: unstated premise) that is necessary for the argument. “Necessary” here means the same thing it does when we talk about a “necessary condition” (as opposed to a “sufficient condition”). Let’s put the relationship between argument and necessary assumption in Lawgic and then run the contrapositive.
Argument (valid) –> Necessary Assumption (true)
/Necessary Assumption –> /Argument
In English, this means that when we negate the necessary assumption, the argument falls apart. No necessary assumption, no argument.
Necessary Assumption questions present you with an argument (premises + conclusion) where in order for the conclusion to be valid, there is a necessary (critical) assumption not stated in the argument. Without this particular assumption, the argument falls apart. Your job is to find this sucker, a necessary assumption, in the answer choice.
There are two types of Necessary Assumptions (NA).
I cannot over-stress the importance of being able to identify premises and conclusions on the LSAT. Not only that, but to do it fast. But, we gotta start somewhere so slow is better than not being able to do it at all. Here are three distinctive slow ways that students have found very effective.
As a learning device, this is good. You can rely on these. But, take this caveat to heart. You can’t consciously rely on these three devices. At the end of the day, you have to internalize all of it. It has to be very, very quick. Intuitive. You read the passage and you just know that this is the premise and this is the conclusion. Somewhere in the back of your mind, one of these three devices is operating subconsciously and telling you what the premise is and what the conclusion is.
LSAT Conditional Logic GROUP 2 is made up of the following terms:
- Only if
- Only when
- Only where
All the words in this group follow this translation rule:
The ideas introduced by (i.e., immediately following) these words are the necessary conditions.
Let’s try it:
LSAT Conditional Logic Group 1 is made up of the following terms:
- The only
All the words in this group follow this translation rule:
The ideas introduced by (i.e., immediately following) these words are the sufficient conditions.
Let’s try it
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Thomas Edison said that genius is "1 percent inspiration and 99 percent perspiration." Rene Descartes said "You just keep pushing. You just keep pushing. I made every mistake that could be made. But I just kept pushing." Lucretius, the Roman philosopher, said "Constant dripping hollows out a stone." The point is that hard work counts a lot. Especially when it comes to the LSAT. Yes, how well you do on the LSAT does depend on your raw intellect too, but do not discount how large a role your work ethics will play.
Here is a list of all of the LSAT questions for which there are two correct answer choices:
When it comes to LSAT correct answer choices: There can be only one!
I tend to always hear from typically new students, disgruntled at having gotten a question wrong, “Hey, I totally understand why C is right, but I’m sure B is also right. Here, look at my proof.”
Since, you’re just starting down this long road, I want unburden you from this misconception. It makes for lighter travel. Plus, I don’t want to yell at you later.
So, drop this misconception on the ground, dig a fire pit, burn it, and bury the ashes. There is never another answer choice that is even arguably right for any LSAT question. Don’t even think about it.
I’ll say it again. There is only ever one right answer choice and four massively, horrendously, embarrassingly, wrong answer choices.
This is not to say that it’s easy to identify the right answer choice. Quite the opposite, it’s very difficult. Often, I have a difficult time figuring out why an answer is right or wrong. But, I never think it’s because the LSAC messed up. Rather, it is invariably true that I just haven’t figured it out yet.
Why am I so certain of this? For a couple of reasons. First, I’ve done or taught every LSAT question in existence (over 7,000) and I have never run across a wrong answer choice that I thought was even arguably right. Second, I’ve discussed this issue at length with other LSAT instructors and high scoring students and we’ve always independently come to the same conclusion. Third, and this is the important one, LSAC’s policy in dealing with possible mistakes in their questions guarantees this result.
Of the four LSATs administered each year, the June, October, and December LSATs are disclosed to the test takers. You receive a PDF of the test and you have 90 days to challenge any question you want.
Just think about that for a second. Think about the importance of your LSAT score. The difference even a few points make. Think about the level of neuroses that pervades LSAT takers. When you get your score back and you see that you got some questions wrong and the LSAC is telling you that you have the option to challenge every one of those questions and that’s your only chance of getting a higher score, what do you think you’re going to do? Of course you’re going to scrutinize the shit out of every single question.
Except it’s not just you doing this. It’s everyone who took that LSAT. That’s the insane level of scrutiny that every LSAT question is subject to.
It doesn’t even end there. Say you sincerely believe that the LSAT has made a mistake. You write in your challenge. The LSAC will answer every challenge in writing showing you why the right answer is right and the wrong ones wrong and why your argument fails miserably.
But, say you get their response back and you’re still not satisfied. Then, you get to appeal this issue to a panel of independent outside experts. This means that the LSAC writers must ultimately write their questions with reasoning solid enough to persuade a entire fucking panel of independent outside experts that there is only one right answer choice and four wrong answer choices. If a wrong answer choice was even arguably right, they would be unable to meet this standard.
Now, of course, this doesn’t mean the LSAC never makes mistakes. Even the LSAT writers are human after all and even though the system they designed is solid, any human system is subject to error. Every once in a while a written challenge does reveal an error. When that happens, the question is removed from scoring and removed from the published Prep Test. By the time you are taking that Prep Test, it’s already been through hellish scrutiny. You’re not going to find anything new that tens of thousands of people just like you only with way more riding on the line haven’t found before.
So remember. There is only one right answer choice.