Getting to Know the Implication Family

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With classes starting up for the June LSAT, we thought it would be a good idea to do a post covering one of the foundational groups of questions you’ll encounter on the LSAT. At Blueprint, we subdivide one of the big sections of the LSAT — the biggest section, in fact, Logical Reasoning — into three “families.” We’re going to zoom in on one of those families today: the Implication family.

There are a few specific types of questions that fall within this family. The most prevalent ones are “Must Be True,” “Must Be False,” and “Soft Must Be True” questions. These questions fall into the Implication family because they require you to make supported deductions from the stimulus. As you might guess, they’ll ask you to infer which of the answer choices must be (i.e., absolutely has to be, 100% of the time) true or false, or which answer choice gets the most support from the information in the stimulus — that’s the “Soft Must Be True” one.

So, what type of inferential leaps should you look to make? First off, you’ll have to familiarize yourself with transitive deductions. Transitive deductions are derived from diagramming conditional language. You’ll learn a lot more about this topic, but the basic logical structure will look something like this: if A, then B; if B, then C; therefore, if A, then C.

For example, a question might say, “If I listen to N*SYNC, I dance. And if I dance, then I look like a fool.” Based on those statements, we could conclude that, therefore, if I listen to N*SYNC, I look like a fool. Naturally, it isn’t always that simple on the real test, but you’ll be looking for an answer choice that matches the supported deduction that you’ve drawn from the logical relationships in the stimulus. You should also look for reasonable explanations for the logical relationships in the stimulus.

You also might be tasked with finding which deduction can most reasonably be inferred from the stimulus. In my silly hypothetical, that might be that this person enjoys N*SYNC and doesn’t let looking like a fool get in the way of dancing.

On the flip side, there are a couple common, unsupported deductions you should avoid in the answer choices. For example, a deduction that exceeds the logical force of the stimulus. If you’re doing a “Must Be True” or “Soft Must Be True” question, and you see an answer choice using super strong words like “always” or “never,” then odds are that the answer choice is wrong. Usually, the stimulus will only allow you to draw a supported deduction relating to “some” or, maybe, “most” situations, but not “all” situations. Similarly, if you see an answer choice that comes out of left field — that brings in new information that isn’t contained in the stimulus — it is probably wrong. You can only derive logical deductions from the closed universe of information contained in the stimulus; once you step outside of that universe, it is impossible to know whether something “must be true” or “must be false” or even “most reasonably supported.”

It is worth noting that the Implication family isn’t very popular on the LSAT — there aren’t a lot of questions from the family on the exam. So, why is this the family we start out by emphasizing? As you’ll learn throughout your studying process, the concepts in the LSAT build on one another. Learning to recognize supported deductions in this family is an important step toward answering other questions. For example, questions will ask you to identify flaws in the stimulus. In order to understand where the flaw is, you have to understand the logical relationship between propositions and whether they support or don’t support the provided answer choices. The better you understand the Implication family, the easier your job will be as you work your way through the other question groups.

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