Guide to Logical Reasoning on the LSAT

The logical reasoning section of the Law School Admissions Test (LSAT) is one of the most important on the entire exam. This is because the exam’s structure features sections that are weighted, with logical reasoning taking the lion’s share of weight when determining your final score on the LSAT. The logic games section and the reading comprehension section are each weighted at 25%, while the LSAT logical reasoning section takes a whopping 50% of your entire LSAT exam grade.

Why is this? There are actually two logical reasoning sections on the exam, while there is only one reading comprehension section and one analytical reasoning section.

If you do poorly on logic games or reading comprehension, your score will suffer. However, if you bomb the logical reasoning section, it will severely impact your score. 

With that in mind, it’s important to fully understand what to expect on the logical reasoning portion, and create a study strategy that will help you crush the LSAT exam!

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What is the purpose of the LSAT logical reasoning section?

It probably comes as no surprise that being able to reason with logic is integral to success in law school and in life as an attorney. In both areas, you’ll come across a lot of arguments; in fact, arguments are fundamental to law. Therefore, you’ll need to be able to analyze these effectively and understand the logic behind them.

Consequently, critical thinking is a skill expected and built upon in law school. One measure of your ability to display critical thinking is the logical reasoning section of the LSAT.

Specifically, the logical reasoning section measures your ability to analyze and evaluate arguments. The arguments presented are not lengthy legal arguments – instead, they’re written in everyday language and pulled from newspapers, school papers and magazines. Each passage mirrors legal reasoning, but isn’t presented in legal terms. 

Because of this, you aren’t expected to know legal vocabulary or lengthy Latin phrases (thank goodness!) However, in order to succeed, you will have to have a basic understanding of arguments and their terms (like debate, refute, premise, assumption and conclusion) to perform well on this portion of the test.

If you don’t know these terms and understand how to pick them out in an argument, you should brush up before the test to maximize your understanding of the passages and questions.

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Understanding LSAT Logical Reasoning

The logical reasoning section can be boiled down to understanding an argument presented in a passage and then answering a question associated with it.

Easy, right? Not so fast!

A key part of many of the logical reasoning questions is identifying a flaw in the argument presented. Word choice plays a heavy role in this, so looking at the words that connect statements and provide structure to the piece are important.

In order to succeed in the LSAT logic reasoning section, you should build your skills in quickly identifying an arguments premises and conclusion.

A premise is a statement or proposition that leads to a conclusion. A conclusion is a judgement or decision. So basically, a premise is the statement or argument made that directly leads to a conclusion.

Both of these can be identified by identifying key words in the text. Be on the lookout for:

• Words that indicate premises (“Because”, “since”, and “for”)
• Words that indicate conclusion (“Therefore”, “thus” , “as a result”) and,
• Words that indicate conflict (“Although”, “While”, “However”)

It may even help you to quickly circle these keywords to help you understand the argument, the conclusion, and the counter-argument presented in a logic game question. 

Now, we mentioned identifying a flaw in the argument. This is the next piece of the recipe for the LSAT logical reasoning section: identifying whether an argument is valid or invalid. 

An argument is valid if the conclusion logically follows a premise. In contrast, it’s not valid if it does not logically follow a premise. 

This probably sounds pretty easy right about now, but this is where most people get tripped up when it comes to “flaw in reasoning” questions on the LSAT. To perform well, you have to understand one very important thing:

The absolute truth does not matter in the logical reasoning section. 

The question you answer could come to a conclusion that you know is not true, but that’s not what you’re looking for. You’re looking at the argument, and the reasoning. More specifically, you’re looking for a flaw in the reasoning, not in the actual facts.

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Types of Arguments

On the test and in your study materials, you’ll come across two main types of arguments pretty frequently. These are arguments using inductive reasoning and deductive reasoning. 

Inductive reasoning means that the argument only gives some support for the conclusion- i.e. the conclusion states that something is highly likely. Basically, the premises support the conclusion. 

In deductive reasoning, the premise gives complete support for the conclusion, which is stated without a doubt.

In both types of arguments, you must look for any flaws in the reasoning that led to the conclusion to decide if it is valid. 

Now that you know the two main types of arguments on the LSAT, let’s look at the types of flaws you’ll be identifying in those arguments.

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Flaws in the LSAT Logical Reasoning Section

There are many types of flaws to identify in the logical reasoning section, but don’t be overwhelmed.

When you train yourself to identify a flaw, it becomes much easier to recognize why the flaw is a flaw.

Plus, you’ll begin to notice that once you’ve seen a flaw, you’ll begin seeing the same ones frequently, just framed in a different context. 

Here are some of the flaws in reasoning that appear on the LSAT logical reasoning section:

• Correlation equals causation
• Unrepresentative Sample
• Error of equivocation
• Ad Hominem attacks (we know we said you wouldn’t have to learn Latin – this means an argument against a person, not the position they’ve chosen)
• Circular reasoning
• Error of conditional reasoning
• Appeal to opinion
• Overgeneralization

Correlation equals causation and unrepresentative sample make it to the top of the list because they’re the most common flawed reasoning examples to appear on the LSAT.  We recommend you brush up on all of these; however, you should take great care to know how to identify a correlation equals causation argument and when an unrepresentative sample is being used.

Correlation equals causation means that the speaker or author concludes that because two events or characteristics happened at the same time, or in quick succession, they must be related. I.e, one of the two caused the other.

In unrepresentative samples, the author draws a conclusion about a larger group of people or things based on a smaller sample of that group that we have no reason to believe is representative of the group as a whole. 

When planning your study strategy for this portion of the LSAT, make sure that you familiarize yourself with all of these different types of flawed reasoning examples. After all, logical reasoning questions make up about 50% of your LSAT score- so having a solid study strategy in this area is key for your success!

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The Different Types of LSAT Logical Reasoning Questions You’ll See

The types of questions you’ll see in the LSAT logical reasoning section can be broken down into seven types. We’ve talked a lot about the flaw questions; these are often the most tricky. However, there are six others, including:

• Assumption Questions
• Inference Questions
• Paradox Questions
• Principle Questions
• Strengthen Questions
• Weaken Questions

Assumption questions ask you to find a gap between evidence and conclusion – i.e., identifying an assumption that was made. 

Inference questions ask you to find the statement that is most supported by the argument.

Paradox questions have you identifying the answer choice that holds the most similar argument structure to the one in the passage. 

Principle asks you to identify the answer that is the best example of the idea, or principle, in the argument. 

Strengthen asks you to find the statement that best supports the author’s stance and the conclusion, while Weaken questions ask you to find the opposite. 

Now that you know the types of questions you’ll be answering, let’s quickly go over some LSAT logical reasoning tips:

The logical reasoning sections each carry approximately 24-26 questions and you’ll have 35 minutes to work through each section. This means you’ve got to use your time efficiently when reading the passages and answering the prompts. Here are our favorite tips to navigating this challenging portion of the LSAT.

Read Carefully, and Underline Key Words and Phrases

Above, we talked about some key words and phrases that indicated the structure of the argument, premises and conclusion. While reading the prompt on the logical reasoning test, look for these words and note them with underlines or circles. This will help you mentally check in with structure you’re looking for, and help you understand the elements of the argument.

Figure Out the Question Type

We listed out some question types for you that frequently appear on the LSAT. A quick scan of the question will tell you what type of question it is – in other words, what you’re looking for. Always make sure you revisit the question before wading into the answer choices to ensure you’ve found the right elements in the argument above.

Check In With Yourself On Premises and Conclusions

Before answering the question, review in your mind what the premises you identified were, as well as the conclusion. The LSAT is long and test-takers tend to have mental fatigue around this portion of the test. Hence, it helps to ask yourself exactly what you understood from the text before you answer.

Eliminate Wrong Answers First

Eliminating answer choices that obviously can’t be right is a strategy that works on every test, but especially on the LSAT. Oftentimes, the differences between the right answer and the closest answer are subtle and designed to test your keen understanding and reasoning. Eliminating choices helps you zero in on the correct answer without using valuable brainspace to evaluate answers that simply can’t be true.

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Main Takeaways

There’s no doubt about it; the logical reasoning section on the LSAT is profoundly challenging. However, it’s doable as long as you set your study strategy early and continually test yourself with LSAT logical reasoning practice questions. The more you study on the real types of questions used on the LSAT, the more you’ll begin to see the same flawed reasoning over and over in different contexts.

In addition to some solid LSAT practice question materials, you’ll want to invest in a quality study program that helps explain the concepts and methods that the LSAT is looking for when it comes to dissecting arguments.

There are several amazing programs online, and we’ve taken the guesswork out of choosing the right one for you. Check out our quick comparison table to look at the features of the top five LSAT prep review courses, or read our in-depth reviews on each to find the right review for you.

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