Free LSAT Course > Logical Reasoning > LSAT Reasoning Intro

 (00:1) Intro |(3:48) Demo Question | (11:41) Trap Answers | (13:41) Difficulty | (19:03) Summary
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The three parts of most Logical Reasoning arguments: Premise(s) + Assumption(s) = Conclusion

Premises

These are statements that support a conclusion. They are like evidence.

Indicator words:

  • Since…
  • Because…
  • Due to…
  • Studies have shown…
  • As indicated…
  • Given that…
  • This can be seen from…

Assumptions

While the conclusion and the premises are stated in the argument, assumptions are not. On the LSAT, it’s a crucial skill to be able to identify any assumptions, or gaps, between the evidence and the conclusion.

Indicator words:

Assumptions have no indicator words because they are unstated.

Conclusions

You may be asked to identify the conclusion, strengthen it, weaken it, identify why the reasoning in the argument is flawed, or find an answer choice with parallel reasoning to the argument to reach the conclusion.

Indicator words:

  • Therefore,…
  • Thus,…
  • Hence,…
  • So,…
  • Accordingly,…
  • For this reason,…

No one ever said the LSAT was an easy test; don’t expect the test writers to make it as simple as described above. Expect patterns such as Premise + Premise = Sub-Conclusion + Premise = Conclusion. We’ll be reviewing these complex structures later in the course.

Next LSAT: April 25th

Parts of a Logical Reasoning Question

The Passage

The first segment of the question contains an argument or just a series of facts. The premises in the Passage on the LSAT are true. Don’t argue with them. So, in this example, you should assume that the price did increase sevenfold for the purposes of the question.

The postal service of Fairfield is badly mismanaged. Thirty years ago, a first-class letter delivery cost only three cents. The price has increased sevenfold since then while the reliability and speed of the delivery have declined.

The Stem

The Stem (aka “the stimulus”) is sometimes in the form of a question and sometimes written as a statement. Be on the lookout for words like “EXCEPT.” The importance of the Stem is that it will give you a clue about the question category (giving you a huge insight into the question). We’ll spend most of the Logical Reasoning course reviewing these 20+ question categories.

Each of the following weakens the above conclusion EXCEPT:

The Answer Choices

There are always five possible choices. Your job is to figure out the one answer that satisfies the requirement in the “best” way. Often this is most efficiently done by finding something “wrong” with 4 out of the 5 answer choices. Other times, one answer will jump out as definitely “right.”

A. The volume of mail handled by the postal service has increased dramatically over the last thirty years.

B. Unprecedented increases in the cost of fuel for trucks and planes have put severe upward pressures on postal delivery costs.

C. Private delivery services usually charge more than the postal service does for comparable delivery services.

D. The average delivery time for a first-class letter three decades ago was slightly longer than it is today.

E. The average level of consumer prices overall has increased fourfold over the last thirty years.

Four-Step Method to Solving Logical Reasoning Questions

Step 1:
Understand the Stem

The LSAT commonly uses only about 20 or so question stem types. In this course, we go through these question stem types so you can get a jump start on the question just by reading the stem.

Step 2:
Read the Question

Read carefully and efficiently! You can’t skim much. You’ll need to look carefully for important keywords to identify conclusions and premises.

Step 3:
Predict the Answer

Before you read the answer choices, it can be helpful to come up with your own answer to the question. Don’t try to predict the exact answer, but just get a general idea so you don’t blunder blindly into the answer choices.

Quit?

If the question is far over your head, it’s time to consider flagging the question and skipping it for now.

Step 4:
Evaluate the Choices

One or two of the answer choices will be absolute junk, so you can make it easier on yourself by eliminating a few from the start. Work as systematically as you can. Time is a factor, so don’t get into the habit of spending minutes debating your choices.

Double Check?

If you are prone to careless errors and have extra time, take a moment to double check your answer. You can also note the question to return to it later.

Read Like a Lawyer

The LSAT requires you to read things using a magnifying glass. Every word counts. Every qualifier has meaning. Try this exercise to see how words can be manipulated to change their meaning.

The following are famous denials. Are they good or poor denials? Pretend that you are a criminal prosecutor evaluating these statements. Read each carefully, paying attention to logical keywords. The honest person will try to make sure everyone understands. The deceptive will encourage misunderstanding.

1. “I am absolutely, 100 percent not guilty.” O.J. Simpson, at his 1994 arraignment on criminal charges of murder.

Explanation

Analysis: This denial is technically true: He’s 100 percent not guilty at this point in the criminal justice system. All accused aren’t guilty until proven guilty beyond a reasonable doubt.

2. “I have never doped. I can say it again … but I’ve said it for seven years.” Lance Armstrong, 2005

Explanation

Analysis: In looking at many of Armstrong’s denials over the years, there’s evidence that he defines “doped” in the legal sense: the failing of a dope test not the mere use of performance-enhancing drugs. “I can say it again … but I’ve said it for seven years.” The retroactive introduction again makes this a poor denial. Further,  That gives a new interpretation of, “I have never doped.” Because he was ahead of the testing process, he enjoyed many years of never failing a drug test. Deceptive people will seize on poorly defined words to make you believe they’re saying one thing, when in fact, they’re saying something else.

3. “I’m not a murderer.” Amanda Knox, 2013

Explanation

Background: Amanda Knox, then a 20-year-old American in 2007, was accused of murder in Italy, convicted, spent almost four years in an Italian prison and then — after a lengthy and convoluted trial process — was acquitted after the Supreme Court of Italy dismissed the case in 2015.

Analysis: The word “murderer” is subject to many interpretations. Therefore, it’s not “mutually understood.” Does “murderer” mean someone convicted by what she feels was an improper forum? I think not. While this might well be a truthful denial because of the possibly misunderstood word, we can’t rely on it.

4. “I’m very comfortable saying nobody did it as far as I know.” Tom Brady, New England Patriots’ quarterback, 2015

Explanation

Background: Tom Brady was the center of an alleged underinflation scheme of American football.

Analysis: Again, “saying” is a giveaway. He could’ve said, “Nobody did it” without any qualifiers. The fact he didn’t makes this a poor denial. An additional qualifier is the, “as far as I know.”

5. “I barely knew the man, and why would I kill him?” John McAfee, 2012

Explanation

Background: John McAfee, founder of the software company McAfee Associates, was named a person of interest in 2012 in connection with the murder of Gregory Viant Faull in Belize. McAffee was never charged.

Analysis: He never denies killing the man. He could have said, “I didn’t kill him.”

6. “As far as the allegations of CIA hacking into Senate computers — nothing could be further from the truth.” CIA Director John Brennan, 2014

Explanation

Background: Former CIA Director John Brennan was accused in 2013 by the U.S. Senate Intelligence Committee (SSCI) of illegally searching the computers.

Analysis: Brennan never denied the allegation of hacking into Senate computers. About a month later, he issued an apology: “The Director subsequently informed the SSCI Chairman and Vice Chairman of the findings and apologized to them for such actions by CIA officers as described in the OIG report.”

LSAT Prep Mindset Video Summary

  • 00:01 – The LSAT requires a critical and skeptical mindset. You must evaluate arguments actively.
  • 00:14 – It also requires curiosity about unfamiliar topics.

Question Types

Our Logical Reasoning course is organized by the major Logical Reasoning question types. We’ve broken them down into five chapters:

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Logical Reasoning Seminars

The Logical Reasoning chapter begins with a short course in Formal Logic.

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Next LSAT: April 25th