LSAT Prep: Logical Reasoning Tips

LSAT Prep Logical Reasoning TipsThis LSAT Blog post lists all the Logical Reasoning-related blog posts you should read toward the beginning of your prep.

I've listed them in the specific order in which you should read them, along with a link to the categorization of Logical Reasoning questions you should complete from the Actual, Official LSAT PrepTests.

Here are complete explanations for Logical Reasoning questions in those PrepTests.

This is all meant to accompany the initial Logical Reasoning portion of my LSAT study schedules, in order to give you more specific guidance on when to read each Logical Reasoning blog post.


Get a sense of what sorts of topics are covered in LSAT Logical Reasoning:
15 Common LSAT Logical Reasoning Topics

(And just for fun...25 Future LSAT Logical Reasoning Topics)

Before, or during, your LSAT Logical Reasoning prep:
Real Life Logic Examples

Improve your vocabulary and understanding of words used in the Logical Reasoning section:
LSAT Logical Reasoning Vocabulary Words

LSAT Words: "Except" "unless" "until" and "without" mean...

LSAT Numbers: All, Most, Several, Many, Some, None

Sufficient and Necessary Conditions
Learn the difference between them:
Words Indicating Sufficient / Necessary Conditions, and Time

LSAT Logic | Necessary vs Sufficient Conditions

Logical Reasoning: Necessary and Sufficient Conditions

Formal vs. Informal Logic
Get a sense of the difference between formal and informal logic:
Formal vs. Informal Logic in Logical Reasoning

LR Categorization by PrepTest
Use the following spreadsheet (and/or list at the end of that blog post) to identify questions of various types:
LSAT Logical Reasoning Spreadsheet

LR Question Types
Before completing Must Be True Questions:
Logical Reasoning | Formal Logic Inference Questions

Logical Reasoning: Inference Questions and the Contrapositive

Before completing Most Strongly Supported Questions:
Most Strongly Supported Logical Reasoning Questions

Before completing Necessary Assumption Questions:
Necessary Assumption Questions, Negation Test, and Must Be True Qs

Difference Between Necessary & Sufficient Assumption Questions

Arguments and Contrapositives | Necessary and Sufficient Assumptions

Before completing Sufficient Assumption Questions:
Logical Reasoning | Sufficient Assumption (Justify) Questions

Sufficient Assumption Questions | Tips and Categorization

Sufficient Assumption Questions and the Negation Test

Before completing Strengthen Questions:
5 Steps to Solving Strengthen Logical Reasoning Questions

Before completing Weaken Questions:
5 Steps to Solving Weaken Logical Reasoning Questions

Before completing Parallel Reasoning / Parallel Flaw Questions:
Logical Reasoning: Parallel and Parallel Flaw Questions

After learning about the various question-types:

LSAT Logical Reasoning Question Types: A New Approach

Necessary Assumption Question: The Rattlesnake Folktale

Negating Conditional Statements in Logical Reasoning

Miscellaneous (Simple):

7 Logical Reasoning Tips and Tricks

How I Learned to Stop Worrying and Love LSAT Logical Reasoning

How to Ace LSAT Logical Reasoning | 7 Habits

Conditional Reasoning: Contrapositive, Mistaken Reversal, Mistaken Negation

The Logic of Real Arguments by Alec Fisher | Excerpt

Miscellaneous (Complex):

LSAT Logic: Neither Necessary Nor Sufficient

LSAT Logical Reasoning Flaw Questions with the Same Argument

2 Tough LSAT Logical Reasoning Flaw Questions

5 Hardest LSAT Logical Reasoning Questions, Explained

Sample LSAT Logical Reasoning Questions

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  1. Logical Reason Bible (p.86)

    The credited answer states 'some environmentalists' have this view while the stimulus states that 'most environmentalists' hold this view.

    There are explanations for the credited answer selection however, they do not explain how you can reconcile the difference in the groups being referenced in the stimulus vs the credited answer choice.

    Can someone shed some light please /


  2. Premises stating that "most environmentalists" believe something properly infer that "more than zero environmentalists" have that same belief.

    "Most" is NECESSARILY greater than "some" because it is more difinitive, i.e. "most" encompasses "some". Most: X = 51-100%, whereas Some: "X" > 0.

    Hence, if I know that at least 51% of environmentalists believe something, I know that more than zero environmentalists believe the same thing.

    Although "some" could theoretically be greater than "most" if we were dealing with two different stimuli and two different subjects, it is NOT the case when dealing with one stimulus and one direct subject: a group of environmentalists.

    In logical terms, a proper inference is something that must be true/cannot be false - given the stimulus. Because the stimulus claims that "most" environmentalists hold a certain view, the idea that "some" environmentalists hold a certain view must be true/cannot be false, and is thus properly inferred. If most environmentalists hold a certain view, at least some environmentalists must hold that view, and it is impossible for that to be false.

    What if the reverse had occurred? Had the stimulus stated that "some" environmentalists held a certain belief, one could not properly infer an answer stating that "most" environmentalists held that same belief.

    Knowing that "more than zero" (X > 0) environmentalists believe something does not necessarily lead to "at least 51%" (X = 51-100%) of environmentalists believing something. "Some" could mean 35%. Hence, the latter would not have to be true given the stimulus and would not be properly inferred.

  3. Hi Steve,

    Do you think it's ok if I jump to the LR section, to get into the "swing" of it (plus I feel I'm progressing in this area)...before tackling the LG (LG section scares me to hell at this moment and the lack of confidence steers me away from opening any books).

    What do you think?