Category Archive: Advice on Logical Reasoning

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LSAT Logic: If You Read This, Then You’ll Be Awesome At Conditional Statments

No discussion of conditional statements would be complete without a thorough review of sufficient conditions. Luckily, and entirely coincidentally, that’s the topic of today’s post in our ongoing review of diagramming LR questions.

Simply put, the sufficient guarantees the necessary. As long as the sufficient condition is satisfied, the necessary must follow. For example:

“If you study hard, then you’ll do well on the LSAT.”

To illustrate this relationship, we’ll want to diagram the above with the sufficient condition leading to the necessary condition, in the form of:

Suff. —> Necc.

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A Necessary Skill for Acing the LSAT

In case you hadn’t already noticed, understanding and manipulating conditional statements is key to success on Logical Reasoning questions. If you don’t master this skill, then your target score will elude you (ya see what I did there?). 

In our ongoing series we’ve covered many of the trickier types of conditional statements, but today we’re going to bring it back to basics with identifying the necessary condition through what we at Blueprint call “indicator words.” 

This skill is fundamental in the sense that it’s necessary (dry puns abound) in order to get your diagramming off the ground. If the necessary and sufficient conditions are misinterpreted and thus diagrammed incorrectly, transitive chains will be missed, sufficient stacks will go unnoticed, etc., etc. Most common, perhaps, is confusing which of two statements in a sentence is the sufficient and which is the necessary.

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Oh, Yes: How to Diagram “No” Statements on the LSAT

With a scurry and dash, a dodge and a slash, the No Ninja appears on the scene. Or: There She Blows, No Torpedoes the Necessary. Maybe, I don’t know…Calamatizes the Consequent, Foils the Following, what have you. 


All of these mnemonics illustrate a very simple but highly effective tool for diagramming “No” statements on the LSAT. These are common conditionals, and they can come in many forms:


· No mathletes have girlfriends.
· None of the above are correct.
· Neither of them are getting her number.
· No one who dislikes Star Wars can be my friend.

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How to Diagram “Unless” LSAT Logical Reasoning Questions

Welcome to our ongoing series on the more nefarious elements of diagramming.

Topping the agenda today are “unless” questions. These are much more straightforward than the “only” conditionals we reviewed last week. Unlike “only” questions, which require one to search for the referent, “unless” questions have a more standardized approach. Consider the following:

“Unless I just brushed my teeth, you’ll find me sipping a cold glass of orange juice”

What does this mean? It tells us that, in all cases where I haven’t just finished brushing my teeth, I’ve got a tall glass of nature’s goodness by my side. To simplify: if I have not just brushed, then I’ve got OJ. Look diagrammable?

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How to Diagram Ornery “Only” Logical Reasoning Questions

If only the LSAT would stick with easy-to-diagram conditional statements like “if it’s a carrot, then it’s a vegetable”, or “if I get Mike Tyson’s tattoo, I’ll forever regret it.”

Alas, your Logical Reasoning section will rarely be quite so friendly. You’ll be nailed with parallel flaws, double negatives, “EXCEPT” questions and, most of all, lots of diagramming. So, to perfect your diagramming skills, we’re launching a series of articles that will cover some of the trickier elements of conditional statements.

Up first: “Only” Questions.

If memorization is your forte, then remember simply that “only” always introduces a necessary condition. As in “the only time you’ll see ‘only’ on LR is when it is introducing the proposition that is guaranteed by the sufficient condition.”

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The Keys to Becoming an LSAT Diagramming Master

Diagramming is an essential skill on the LSAT, but it’s also a bit like speaking a foreign language. At first you will feel awkward and clumsy and slow; then suddenly you’re spitting out full sentences and fully understanding the answers and you wonder why you ever had such a problem with it.

What is diagramming and why is it important on the LSAT?

Diagramming is a shorthand way of representing conditional statements (otherwise known as if-then statements). I don’t have enough space to fully get into the basics here, but if you’re studying for the LSAT and you’re not comfortable or familiar with conditional logic, you should do yourself a solid and look it up.

Diagramming crops up mainly on the Logical Reasoning sections and on Logic Games (for instance, Tanika is in every photo that Morlanda is in).

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Permissible Assumptions on the LSAT: Part II of II

Last week, we took a look at non-permissible assumptions on the LSAT. For Part II, here’s a breakdown of what you CAN assume…

Permissible Assumptions Part II: What you CAN assume on the LSAT

Let’s contrast Part I’s ulcer question with Question 6, Section 4, from the February 1995 LSAT.

Outside knowledge is verboten on the LSAT, but you are allowed to use common sense. For instance, no person in the world would disagree that grass is green or that people would tend to seek pleasure and avoid pain. These sorts of common-sense assumptions can come into play on LSAT questions.

The question from PT 57 hinges on whether someone with an ulcer is going to get a prescription for it.

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Make Quantified Logic on the LSAT Easier By Simplifying It

During Blueprint LSAT Prep courses, few subjects are more vexing for students than quantified logic. Shoot, it even sounds scary.

But it doesn’t have to be.

On every LSAT, there are a handful of Logical Reasoning questions that test a student’s ability to combine all, most, some, and no statements. The problem is that there are a number of combinations that the LSAT can throw in your direction, and memorizing all of these combinations is reminiscent of calculus class (also know as the reason you are going to law school in the first place).

Good news: When broken down, there are really only two principles that define the valid and invalid conclusions that can be drawn from quantified statements.

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Add Points to Your LSAT Score by Chewing Gum: Study

A recent study found a correlation between chewing gum consumption and test performance, and concluded that mastication-induced arousal causes improved performance — especially in the latter stages of a sustained task along the lines of, oh, say, an LSAT section.

Before any LSAT students shout that there’s a causal flaw, note that the study eliminated some alternate causes. The researchers split the subjects into a masticating group and a control group, which argues against any potential reversal of cause and effect. In other words, it seems unlikely that this is all because people who are better at tests like to chew gum. In a previous study, the subjects achieved the same benefits from sugar-free gum, so it doesn’t appear to be a case of a simple sugar high.

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Tackle These 8 Manti Te’o Hoax LSAT Flaws

There are two main interpretations of the Manti Te’o hoax. The first is that he was involved in it all along, creating a sob story to drive national attention and a Heisman Trophy bid. The second is that he fell for one of the longest cons of all time.

I’ve long been in the latter camp, mainly because, as a Boston College alum, I prefer to think of Notre Dame students as idiots rather than fraudsters. After all, you can wake up one morning and stop committing fraud, but…

So here is a long list of LSAT flaws committed by Manti Te’o during his multi-year relationship with a figment. Some are apt, some are a stretch, but the important thing is they all belittle Notre Dame.

Manti Te’o Hoax LSAT Flaw I: Equivocation