LSAT Explanation PT 22, S4, Q25: Essayist: Every contract negotiator has been

LSAT Question Stem

If the essayist's statements are true, which one of the following must also be true? 

Logical Reasoning Question Type

This is a Must Be True question. 

Correct Answer

The correct answer to this question is A. 

LSAT Question Complete Explanation

Let's first analyze the passage and simplify any complex parts to make it more understandable. The essayist presents several conditional statements:

1. If you're a contract negotiator, then you've been lied to by someone (CN -> BLT).

2. If you lie to someone, then you're practicing deception (LT -> PD).

3. If you've been lied to, then you have also lied to someone (BLT -> LT).

Imagine a simple example: If you're a teacher (CN), then you've eaten an apple (BLT). If you eat an apple, then you like fruits (LT -> PD). If you've eaten an apple, then you've also eaten a banana (BLT -> LT). This helps us understand the structure of the passage better.

Now let's look at the question type: Must Be True (MBT). We need to find an answer choice that must be true based on the essayist's statements.

a) Every contract negotiator has practiced deception.

This is the correct answer choice. It links the two ends of our master diagram together, starting at the leftmost sufficient condition (CN), and ending with the rightmost necessary condition (PD). In other words, CN -> PD: If you're a contract negotiator, then you've practiced deception.

b) Not everyone who practices deception is lying to someone.

This statement contradicts our second diagram (LT -> PD), where if you lie to someone, then you're practicing deception. We cannot start any SN relationship with PD, as it would be a mistaken reversal. This answer choice is incorrect.

c) Not everyone who lies to someone is practicing deception.

This statement is invalid because of our second diagram (LT -> PD), which states that whoever lies to anyone is practicing deception. There's no room for someone to lie to someone but not practice deception. This answer choice is incorrect.

d) Whoever lies to a contract negotiator has been lied to by a contract negotiator.

This answer choice is too specific and not mentioned in the passage. Our master diagram starts with "If you're a contract negotiator…", not "if you've lied to a contract negotiator". This answer choice is incorrect.

e) Whoever lies to anyone is lied to by someone.

This answer choice is a mistaken reversal of the third diagram (BLT -> LT). We can say that if you've been lied to, you've also lied, but we can't reverse that and say that if you've lied, you've also been lied to. This answer choice is incorrect.

In conclusion, the correct answer choice is (a): Every contract negotiator has practiced deception.