Logical Reasoning Basics

Page 1

Premises and Conclusions

Premises and Conclusions:

What is a premise?

A premise is a fact, proposition, or statement from which a conclusion is made

What is a conclusion?

A statement or judgment that follows from one or more reasons

Episode 1.4: Premises and Conclusions (Embed)

How to Identify Premises and Conclusions

Indicator words

words such as because, since, for example, for, due to, etc indicate a premise

Words such as thus, therefore, hence, consequently, as a result, etc indicate a conclusion

How to Approach

When reading a stimulus lookout for indicator words

Try to identify "claims", if a claim is identified, look for the conclusion to follow

Ex: Fraud has cost the insurance industry millions of dollars in lost revenue. Thus, Congress will pass a stricter fraud control bill since the insurance industry has one of the most powerful lobbies

Premise- Fraud has cost the insurance industry millions; since the insurance industry has one of the most powerful lobbies

Conclusion- Thus, congress will pass a Stricter fraud control bill

In this example there are two premises that are connected by the conclusion (thus). "Since" os also a premise word

Identify the conclusion | Example | Logical reasoning | LSAT | Khan Academy (Embed)

Counter-Premises:

A counter-premise is a premise that actually contains an idea that is counter to the argument and would generally weaken it

Can also be ideas that compare and contrast with the argument, or work against a previously raise a point

Indicated by words such as furthermore, moreover, besides, in addition, what's more, and after all

Further Practice:

Complete Premise-conclusion worksheet

Make Indicator word chart for study materials

Complete Practice Drill

Page 2

Complex Arguments

Complex Arguments:

Complex arguments are arguments that have more than one conclusion

One is the main conclusion, and one is subsidiary

The argument uses one conclusion as fuel for the main conclusion

One of the most commonly used complex argument forms is to place the main conclusion in the first sentence of the argument, and then to place the sub conclusion in the last sentence of the argument, preseeded by a conclusion indicator

LSAT Logical Reasoning 1b - Complex Arguments (Embed)

Further Practice:

Complex argument worksheet

Page 3

Decoding Text

Killer Sentences:

sentences that contain large amounts of information, while also being hard to read and understand

How to address Killer Sentences:

break down the sentence into smaller parts

do this by separating the sentence at things like commas, colons, semi-colons, dashes

rephrase the sentences so they make sense to you

Use context clues and simplification to understand the main points of these sentences

Breaking down sentences in Reading Comprehension (Embed)

Reference Words:

words used to refer back and forth to ideas in the stimulus without explicitly naming that idea

This/that/these/those

It

They/Them/Their

Further Reference:

PowerScore reference pages 47-49 (resources)

Page 4

Understanding the Stimulus

Truth vs. Validity

when evaluating LSAT arguments, primarily be concerned with the validity

look at the pieces of the argument and how well the premises prove the conclusion

Do not look into the reality of the argument, the argument can be unrealistic

Identifying Strong and Weak Arguments

Do the premises strongly or weakly impact the conclusion of the argument?

How persuasive does the argument seem?

Are there any questions left after the conclusion or is the argument air-tight?

Inference v. Assumption

Inference is something that must be true

what follows from an argument

An assumption is an unstated premise

Do not use these words interchangeably

Quantity and Probability Indicators

quantity indicators refer to the amount or quantity in the relationship

probability indicators refer to the likelihood of an occurrence

Scope:

the scope of an argument is the range which premises and conclusions encompass certain ideas

Narrow vs. Broad arguments

Test Strategies:

summarize arguments so that you understand them in your own words

Further Practice:

PowerScore Premise and Conclusion Anaysis Drill pp. 65-70

Identify the Conclusion Examples, Khan Academy (logical reasoning lessons)

Page 5

Chapter Summary

This chapter went over:

premises and conclusions

Complex Arguments

Killer Text and Decoding them

Understanding Stimuli

Important Terminology

Premise

Conclusion

Complex Argument

Comma

Colon

Dash

Indicator Word

Further Reference:

How To Master LR | LSAT Logical Reasoning (Embed)

LSAT Logical Reasoning | Logical Reasoning Basics (Embed)

Fill In The Blank Worksheet (application/pdf)

Further Practice:

fill in the blank worksheet, attached

Khan Academy Logical Reasoning practice section