The LSAT Logical Reasoning section tests your ability to analyze, evaluate, and complete arguments. With two sections, each containing approximately 24-26 questions, this section forms a significant part of the LSAT exam.
Importance in LSAT
Logical Reasoning is crucial as it assesses critical skills required in law school and legal practice, including argument analysis, flaw identification, and logical consistency.
Must Be True Questions
Identifying Must Be True Questions
Must Be True questions require you to find a statement that logically follows from the information provided in the Stimulus. Typical question stems include:
- “If the statements above are true…”
- “Which one of the following can be properly inferred…”
Common Traps and Pitfalls
- Misinterpreting the Stimulus: Incorrectly understanding the given information.
- Introducing New Information: Choosing answers that seem plausible but introduce new, unsupported facts.
Strategies to Answer
- Stick to the Stimulus: Ensure your answer is directly supported by the information provided.
- Avoid Over-Interpretation: Do not infer beyond what is explicitly or logically implied.
- Eliminate New Information: Correct answers will not introduce new details.
Example and Analysis
Stimulus: “All dogs bark. Rex is a dog.”
Question: “If the statements above are true, which one of the following must be true?”
Answer Choices:
A. Rex is brown.
B. Rex barks.
C. All dogs are brown.
D. Some dogs do not bark.
E. Rex likes bones.
Analysis: The correct answer is B. Rex barks, as it directly follows from the premises provided.
Main Point Questions
Identifying Main Point Questions
Main Point questions ask you to identify the primary conclusion of the argument. Common question stems include:
- “The main point of the argument is…”
- “Which of the following best expresses the main conclusion…”
Common Traps and Pitfalls
- Confusing Supporting Evidence with Conclusion: Mistaking evidence or premises for the main point.
- Restating Parts of the Argument: Choosing answers that capture parts but not the entirety of the conclusion.
Strategies to Answer
- Identify the Conclusion: Determine the statement the rest of the argument is supporting.
- Check for Consistency: Ensure the answer choice reflects the overall argument.
Example and Analysis
Stimulus: “Reducing pollution requires strong regulations. Therefore, governments should impose stricter laws on emissions.”
Question: “The main point of the argument is that…”
Answer Choices:
A. Pollution is harmful.
B. Reducing pollution requires strong regulations.
C. Governments should impose stricter laws on emissions.
D. Emissions are the primary cause of pollution.
E. Stricter laws on emissions will reduce pollution.
Analysis: The correct answer is C. Governments should impose stricter laws on emissions, as it represents the main conclusion.
Assumption Questions
Identifying Assumption Questions
Assumption questions ask you to identify an unstated premise that the argument relies on. Look for phrases like:
- “The argument assumes which of the following…”
- “Which of the following is an assumption required by the argument…”
Common Traps and Pitfalls
- Confusing Necessary and Sufficient Assumptions: Misunderstanding what the argument needs versus what would guarantee the conclusion.
- Selecting Irrelevant Assumptions: Choosing assumptions that do not directly support the argument.
Strategies to Answer
- Negation Test: Negate the assumption; if the argument falls apart, the assumption is necessary.
- Identify Gaps: Find where the argument has logical gaps and what assumptions would fill them.
Example and Analysis
Stimulus: “To improve public health, the city must increase funding for hospitals. Therefore, the city council should allocate more resources to healthcare.”
Question: “The argument assumes which of the following?”
Answer Choices:
A. The city has sufficient funds.
B. Increased funding will lead to better healthcare.
C. Public health is currently poor.
D. The city council supports healthcare improvements.
E. Hospital funding is the only way to improve public health.
Analysis: The correct answer is B. Increased funding will lead to better healthcare, as it is a necessary assumption for the argument to hold.
Strengthen/Weaken Questions
Identifying Strengthen/Weaken Questions
Strengthen questions ask for information that makes the argument more convincing, while weaken questions look for information that undermines the argument. Look for phrases like:
- “Which of the following, if true, strengthens/weakens the argument…”
Common Traps and Pitfalls
- Choosing Irrelevant Information: Selecting answers that do not directly impact the argument’s strength.
- Misinterpreting Evidence and Conclusion: Misunderstanding how new information affects the relationship between evidence and conclusion.
Strategies to Answer
- Identify Conclusion and Evidence: Understand what the argument is concluding and the evidence it relies on.
- Evaluate Impact: Determine how each answer choice affects the relationship between the evidence and the conclusion.
Example and Analysis
Stimulus: “The new park will increase property values in the neighborhood. Therefore, the city should proceed with its construction.”
Question: “Which of the following, if true, most strengthens the argument?”
Answer Choices:
A. The park will be expensive to maintain.
B. Residents oppose the park.
C. Increased property values will lead to higher tax revenue.
D. The park will be the largest in the city.
E. The construction of the park will create jobs.
Analysis: The correct answer is C. Increased property values will lead to higher tax revenue, as it provides a strong reason for the city to proceed with the park’s construction.
Parallel Reasoning Questions
Identifying Parallel Reasoning Questions
Parallel Reasoning questions ask you to find an argument that is logically similar to the one presented. Look for phrases like:
- “Which of the following is most similar in reasoning to the argument above…”
Common Traps and Pitfalls
- Focusing on Content Instead of Structure: Choosing answers with similar content but different logical structures.
- Misidentifying Logical Structure: Misunderstanding the argument’s logical components.
Strategies to Answer
- Break Down the Argument: Identify the premises and conclusion.
- Compare Structures: Ensure the logical structure of the answer matches the original argument.
Example and Analysis
Stimulus: “All students who study diligently pass the exam. Maria studied diligently. Therefore, Maria passed the exam.”
Question: “Which of the following is most similar in reasoning to the argument above?”
Answer Choices:
A. All employees who work hard receive promotions. John received a promotion. Therefore, John worked hard.
B. All citizens who vote contribute to democracy. Sam is a citizen who votes. Therefore, Sam contributes to democracy.
C. All plants need water to survive. This plant has water. Therefore, this plant will survive.
D. All teachers who are dedicated inspire students. Ms. Smith inspires students. Therefore, Ms. Smith is a dedicated teacher.
E. All athletes who train consistently improve their performance. Sarah improved her performance. Therefore, Sarah trained consistently.
Analysis: The correct answer is B. All citizens who vote contribute to democracy. Sam is a citizen who votes. Therefore, Sam contributes to democracy, as it follows the same logical structure.
Method of Reasoning Questions
Identifying Method of Reasoning Questions
Method of Reasoning questions ask you to describe the technique or approach used in the argument. Look for phrases like:
- “The argument proceeds by…”
- “Which of the following best describes the method of reasoning…”
Common Traps and Pitfalls
- Misinterpreting the Argument’s Structure: Misunderstanding how the argument is constructed.
- Overlooking Logical Moves: Ignoring key logical steps in the argument.
Strategies to Answer
- Analyze Step-by-Step: Break down the argument into logical steps.
- Identify Techniques: Recognize common reasoning methods such as analogy, causation, or comparison.
Example and Analysis
Stimulus: “To justify its budget cuts, the administration argues that the current budget is unsustainable. However, this conclusion overlooks the possibility of increasing revenue through alternative sources.”
Question: “The argument proceeds by…”
Answer Choices:
A. Attacking the administration’s credibility.
B. Pointing out an overlooked alternative.
C. Presenting an analogy.
D. Drawing a distinction between two scenarios.
E. Providing evidence to support a different conclusion.
Analysis: The correct answer is B. Pointing out an overlooked alternative, as the argument highlights an ignored possibility in the administration’s reasoning.
Flaw in Reasoning Questions
Identifying Flaw in Reasoning Questions
These questions require you to identify a logical flaw in the argument. Look for phrases like:
- “The argument is most vulnerable to criticism on the grounds that it…”
- “Which of the following indicates a flaw in the reasoning…”
Common Traps and Pitfalls
- Overlooking Subtle Logical Errors: Missing less obvious flaws.
- Misidentifying the Nature of the Flaw: Confusing different types of logical fallacies.
Strategies to Answer
- Familiarize with Fallacies: Know common logical fallacies such as ad hominem, straw man, and false dilemma.
- Analyze for Consistency: Check if the argument follows logical principles without contradiction.
Example and Analysis
Stimulus: “Because it rained today, the soccer game was canceled. Therefore, if it rains tomorrow, the soccer game will be canceled.”
Question: “The argument is most vulnerable to criticism on the grounds that it…”
Answer Choices:
A. Assumes what it seeks to prove.
B. Fails to consider other reasons for canceling the game.
C. Makes an unwarranted assumption about future events.
D. Ignores the possibility of rescheduling.
E. Relies on a faulty analogy.
Analysis: The correct answer is C. Makes an unwarranted assumption about future events, as it incorrectly assumes that future events will mirror past events without justification.
Evaluate the Argument Questions
Identifying Evaluate the Argument Questions
These questions ask you to identify information that would help determine the argument’s validity. Look for phrases like:
- “Which of the following would be most useful to know in order to evaluate the argument…”
Common Traps and Pitfalls
- Choosing Relevant but Non-Critical Information: Selecting answers that do not directly impact the argument’s validity.
- Misunderstanding Impact: Failing to see how certain information would affect the argument.
Strategies to Answer
- Identify Conclusion and Evidence: Understand the core of the argument.
- Determine Impact: Assess how new information could influence the argument’s validity.
Example and Analysis
Stimulus: “The company’s profits increased significantly last quarter. Therefore, the new marketing strategy must be effective.”
Question: “Which of the following would be most useful to know in order to evaluate the argument?”
Answer Choices:
A. How long the new marketing strategy has been in place.
B. The company’s profits in previous quarters.
C. Changes in the company’s expenses.
D. Competitors’ performance last quarter.
E. Customer satisfaction with the new marketing strategy.
Analysis: The correct answer is A. How long the new marketing strategy has been in place, as it directly affects whether the strategy could be responsible for the profit increase.
Point at Issue Questions
Identifying Point at Issue Questions
Point at Issue questions require you to identify the specific point of disagreement between two speakers. Look for phrases like:
- “X and Y disagree over whether…”
- “Which of the following is a point of contention between…”
Common Traps and Pitfalls
- Misunderstanding Positions: Misinterpreting one or both speakers’ views.
- Choosing Irrelevant Disagreements: Selecting answers that are not relevant to the core disagreement.
Strategies to Answer
- Compare Positions: Carefully analyze each speaker’s stance.
- Find the Divergence: Identify the exact point where their opinions differ.
Example and Analysis
Stimulus: Speaker A: “Mandatory recycling programs are essential for reducing waste.” Speaker B: “Mandatory recycling programs infringe on personal freedom.”
Question: “Speaker A and Speaker B disagree over whether…”
Answer Choices:
A. Recycling is important.
B. Waste reduction is necessary.
C. Personal freedom is important.
D. Mandatory recycling programs are justified.
E. Voluntary recycling programs are effective.
Analysis: The correct answer is D. Mandatory recycling programs are justified, as it directly captures the point of disagreement.
Principle Questions
Identifying Principle Questions
Principle questions ask you to identify a general principle that underlies the argument. Look for phrases like:
- “Which of the following principles, if valid, most helps to justify the reasoning…”
Common Traps and Pitfalls
- Confusing Principles with Facts: Mistaking specific details for underlying principles.
- Choosing Tangential Principles: Selecting principles that are not fundamental to the argument.
Strategies to Answer
- Identify the Core Principle: Determine the underlying rule that supports the argument.
- Ensure Applicability: Ensure the principle applies broadly but specifically supports the argument.
Example and Analysis
Stimulus: “To ensure public safety, the government must regulate the production of harmful chemicals.”
Question: “Which of the following principles, if valid, most helps to justify the reasoning?”
Answer Choices:
A. Public safety is the government’s primary responsibility.
B. The production of chemicals is inherently dangerous.
C. Harmful chemicals should be banned.
D. Government regulations are effective in ensuring safety.
E. Public awareness of chemical dangers should be increased.
Analysis: The correct answer is A. Public safety is the government’s primary responsibility, as it provides a strong justification for the argument.
