Argumentation: Premises

Introduction

The LSAT tests your ability to understand and analyze arguments. A key part of this is identifying premises—the facts or statements that support a conclusion. Mastering how to spot premises will significantly improve your performance on the LSAT’s Logical Reasoning section. In this guide, we’ll break down what premises are, how to recognize them, and how they fit into the structure of an argument.

What is a Premise?

A premise is a foundational statement or evidence that supports the conclusion of an argument. Think of it as the building block on which the argument rests. In LSAT questions, premises are used to lay out the reasoning behind a conclusion, and your job is to determine whether the conclusion is logically valid based on those premises.

Definition of a Premise on the LSAT:
A premise is any piece of information in an argument that provides evidence or reasons supporting the conclusion.

For example, in the statement, “All dogs are mammals. Fido is a dog, so Fido is a mammal,” the two premises are “All dogs are mammals” and “Fido is a dog.” These statements directly support the conclusion that “Fido is a mammal.”

Premises vs. Conclusions: Key Differences

To excel in LSAT Logical Reasoning, it’s critical to distinguish between premises and conclusions. Here’s how they differ:

• Premises: Statements that provide evidence or reasons. They are given facts that support the argument.
• Conclusions: The main point or claim of the argument, which the premises are intended to support.

Understanding this distinction is vital because LSAT questions will often ask you to evaluate whether the premises logically lead to the conclusion.

Bolded Example: If the argument is “Since all men are mortal, and Socrates is a man, Socrates must be mortal,” the premises are “all men are mortal” and “Socrates is a man,” while the conclusion is “Socrates must be mortal.”

Common Premise Indicators

When dissecting LSAT arguments, certain words or phrases often signal that a premise is being introduced. Memorizing these premise indicators will make it easier to identify the supporting evidence in any argument.

Key Premise Indicators:

• Since
• Because
• Given that
• For the reason that
• As indicated by
• Owing to
• Due to
• After all
• Proven by the fact that

For instance, in a statement like “Given that all birds have wings, and this creature has wings, it must be a bird,” the phrase “Given that” signals the start of a premise.

How Premises Function in LSAT Questions

In LSAT Logical Reasoning questions, premises serve as the backbone of the argument. Most of the time, your task is to determine whether the premises adequately support the conclusion, or whether there is a gap in reasoning.

• Strengthen/Weaken Questions: These questions ask you to identify information that either strengthens or weakens the relationship between the premises and conclusion.
• Assumption Questions: Here, you’ll need to identify what unstated assumptions link the premises to the conclusion.

In these cases, recognizing the premises is essential for analyzing whether the conclusion is logically valid.

Strategies for Identifying Premises in Logical Reasoning

Here are some effective strategies to help you quickly and accurately identify premises in LSAT Logical Reasoning questions:

• Focus on the Indicators: Use premise indicators (like “since,” “because,” etc.) to quickly identify the supporting evidence in the argument. These clues are particularly helpful when breaking down long or complex arguments.
• Differentiate Between Fact and Opinion: Premises are typically objective facts, while conclusions are often opinions or interpretations of those facts. Pay attention to the language used in the argument to distinguish the two.
• Use Process of Elimination: If the question asks for the premise, eliminate any statements that seem opinion-based or speculative. Premises should be concrete and fact-based.
• Paraphrase the Argument: Break down the argument by restating the premises in your own words. This helps clarify what is being used as support for the conclusion.

Example Strategy in Action:
In the argument “Due to the fact that all employees were given raises, and company profits increased, the company must be doing well,” the premise is “All employees were given raises,” as it directly supports the conclusion that “the company must be doing well.”

Practice Examples of Premises

To solidify your understanding of premises, let’s analyze some practice LSAT examples.

Example 1:
“Since all professional athletes must maintain a strict diet, and Mark is a professional athlete, Mark must maintain a strict diet.”

• Premises: All professional athletes must maintain a strict diet; Mark is a professional athlete.
• Conclusion: Mark must maintain a strict diet.

Example 2:
“Because this legislation was passed unanimously, it must reflect the views of all the lawmakers.”

• Premise: This legislation was passed unanimously.
• Conclusion: It must reflect the views of all the lawmakers.

Tip: When reviewing LSAT arguments, practice spotting these premises and using them to evaluate whether the conclusion follows logically.

Conclusion: Mastering Premises for LSAT Success

Understanding how premises work in LSAT Logical Reasoning questions is essential to scoring well. A premise serves as the foundation of any argument, providing the necessary support for the conclusion. By learning to identify key premise indicators and practicing with real LSAT questions, you can significantly improve your argument analysis skills.

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