September 2017 LSAT Logical Reasoning Recap

LSAT Logical Reasoning | LSAT Prep | LSAT Forum



Y'all ready to make some illicit inferences? It's that time again, post-Grey Day; September LSAT scores are out. Congratulations to all who wrote the exam! At PowerScore, we strive to give students the most up-to-the-minute information possible about past and upcoming LSATs, and in keeping with this goal, we are proud to share our recap of the September 2017 Logical Reasoning sections. Recaps of both Logic Games and Reading Comprehension will follow shortly, so please subscribe to the blog to get notified of these and other upcoming posts, including weekly discussions of interest to all preparing for an upcoming LSAT or law school admissions.

Let's get down to business! Here are the highlights from the September 2017 LR sections:

  • A rare circular reasoning fallacy (!) on a flaw question.
  • Continued importance of ability to prephrase accurate, abstract descriptions of scenarios presented in Flaw and Method of Reasoning questions.
  • Fill-in-the-blank question used for a hybrid Main Point/Must Be True task.
  • Slightly above-average number of difficult questions among the first ten.
  • Continued high frequency of questions involving conditional reasoning.

Read below for further discussion and statistics about the questions.







Must Be True 3 2   2 req logical validity 
Main Point 1 1   1 "fill in the blank" 
Point at Issue/Agree 1 3   Double June
Assumption 4 2   More than June
Justify  0 2   Half June
Strengthen 3 3 3 principle, 1 EXCEPT  
Resolve the Paradox 3 2    
Weaken 2 4 1 EXCEPT Increase from June
Method of Reasoning 1 2    
Flaw 4 3   Circular reasoning!
Parallel  1 2 2 Reasoning, 1 Flaw  
Evaluate 0 0    
Cannot Be True 1 0    

Overall there were twenty-five questions in the first LR section and twenty-six in the second. There was a slight uptick this time in Weaken questions.

Causal reasoning made a strong showing, as usual, but based on recent trends, conditional reasoning, the old bastion of the LSAT, might be making a comeback with frequent appearances across question types and especially on more difficult questions. For instance, the LSAT writers opened the conditional reasoning Pandora's Box more than once to ramp up the difficulty, as on a lengthy Must Be True question in the first Logical Reasoning section.

The flaw questions were a veritable rainbow coalition of fallacies, featuring a highly unusual appearance of circular reasoning. 

One early question that looked markedly like a Justify the Conclusion question was actually a Strengthen Question in disguise. Sneaky!

Process of elimination was, as always, a crucial test-taking skill. One Resolve the Paradox question might have prompted students to start drawing maps to determine conclusively the right answer. Far more effective here to rule out the wrong choices than to belabor verifying the correct answer.

The following table is an overview of some of the principles of argumentation and fallacies that appeared on this test.

Reasoning Principle/Flaw

Number of Occurrences


Causal 12  
Argument from Analogy 3  
Conditional Reasoning 10  
No True Scotsman 1  
Ad Hominem 1  
Error in the Use of Evidence 5 Several absence of evidence flaws
Tu quoque/appeal to hypocrisy 1  
Percent/Rate 1  
Circular Reasoning 1 Don't you forget about me! 

This LSAT got slightly more esoteric to create the pandemonium of fallacies listed above. Since LSAT students get relatively little practice with circular reasoning, an appearance of just such a flaw question late on the first question may have come as a surprise.

There were no Evaluate questions this time, but there was a Cannot Be True question. Among the minor question types, Resolve the Paradox punched above its weight and was occasionally more challenging than usual.

As usual, there were a couple stumpers lumped into the beginning of each section, serving as a reminder of the importance of pacing and multiple passes. Personally, I'm still wondering exactly what Jones's theory is!


If you are preparing for the February LSAT, what's the takeaway from the September 2017 Logical Reasoning sections?

  • By all accounts, this -11 curve test has been polarizing among students. One reason might be the variety of minor fallacies tested. For some, such esoterica might have been exhilarating and fun. For others, these fallacies might have thrown a wrench in the operation.
  • The difficult conditional reasoning was a back-to-basics moment that might have slowed students down considerably midway through each LR section. Mastery of this LSAT fundamental continues to be essential.
  • Just as in June's test, the September exam served as a reminder not to overlook minor flaws and informal fallacies. As we remarked then, your ability quickly to describe some of these less-common situations will strengthen your ability to prephrase/predict the answer and maintain your momentum throughout the test.
  • Continue to practice strong test-taking strategy such as making strong prephrasing from your own analysis and then moving aggressively through the answer choices. Remember that you need not completely grasp why the right answer is correct as long as you can eliminate the four other choices!

We encourage you to join us in our LSAT Forum to share your comments and insights about the September exam. The discussion in our forum is ongoing, and our expert instructors are ready to respond to your questions. Subscribe to the blog and stay tuned for the next installment in our September 2017 recap! 

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