Logical Reasoning—Understanding Argument Structure on the LSAT

Conclusion

The statement an author most wants you to accept, supported by premises.

Premise

A claim offered as support for another claim, which can include evidence, rules, statistics, observations, or analogies.

Main Point

The top-level conclusion that the entire argument ultimately attempts to establish.

Intermediate Conclusion

A claim supported by earlier premises but that also serves to support the main conclusion.

Sub-conclusions

Conclusions that function as premises for a larger conclusion.

Conclusion Indicators

Words or phrases that signal a conclusion, such as 'therefore,' 'thus,' and 'hence.'

Premise Indicators

Words that indicate premises, such as 'because,' 'since,' and 'for.'

Support Question

An inquiry asking whether a claim is presented as a reason or conclusion.

Therefore Ladders

A hierarchy of claims where one claim supports another.

Point at Issue

The claim that two speakers disagree about in a dialogue.

Factual Claim

A claim that is about a factual statement, e.g., 'The policy reduced crime.'

Causal Claim

A claim that describes a cause-and-effect relationship, e.g., 'The policy reduced crime because…'

Value Judgment

An assessment of worth or importance, e.g., 'The policy is unfair.'

Recommendation

A suggested action, e.g., 'We should repeal it.'

Core Claims

The main assertions each speaker makes, stripped of rhetoric.

Yes/No Table

A mental table used to compare each speaker's commitments to answer choices.

Point of Agreement

A statement that both speakers can agree upon based on their dialogue.

Principle in Logical Reasoning

A general rule that justifies a conclusion or is illustrated by a specific scenario.

Principle Strengthen/Justify

A type of principle question where the principle supports the reasoning of the argument.

Principle Match/Conform

A type of principle question where the scenario matches or illustrates the given principle.

Gap in Reasoning

The disconnect between premises and conclusion that the principle must bridge.

Scope Shift

When wrong answers use stronger language or introduce new concepts that go beyond the argument.

Conditional Agreement

Agreement that relies on meeting a specific condition, e.g., 'If A then B.'

Common Mistake: Indicator Words

Treating words like 'thus' as guarantees of conclusions, rather than checking the context.

Common Mistake: Premises and Conclusions

Mistaking a premise for a conclusion due to its prominence or emphasis in the text.

Common Mistake: Concessions

Mistaking a concession for agreement with an opponent's conclusion.

Typical Question Patterns

Common phrasing found in LSAT questions, such as 'Which of the following…' for various types of reasoning.

Common Errors in Principle Questions

Mistakes like choosing answers that merely restate conclusions or overlook necessary conditions.