Self-study
Essayist: Every contract negotiator has been lied to by someone or other, and whoever lies to anyone is practicing deception. ████ ██ ███████ ██████ ███ ███ ████ ████ ██ ███ ████ ████ ██ ███████ ██ ██████
Summary
The stimulus can be diagrammed as follows:
Notable Valid Inferences
Every contract negotiator has lied to someone, and therefore practiced deception. If a person has not practiced deception, they are not a contract negotiator.
25.
If the essayist's statements are █████ █████ ███ ██ ███ █████████ ████ ████ ██ █████
a
Every contract negotiator ███ █████████ ██████████
This must be true. As shown below, by chaining the conditional claims, we see that all contract negotiators must have lied to someone and, in extension, have practiced deception.
b
Not everyone who █████████ █████████ ██ █████ ██ ████████
This could be false. Practicing deception is not a sufficient condition for anything in our stimulus, which means there are no implications from knowing someone practices deception.
c
Not everyone who ████ ██ ███████ ██ ██████████ ██████████
This must be false. Whoever lies to anyone is practicing deception.
d
Whoever lies to █ ████████ ██████████ ███ ████ ████ ██ ██ █ ████████ ███████████
This could be false. No information in the stimulus suggests that if someone lies to a contract negotiator they have been lied to by one in the past.
e
Whoever lies to ██████ ██ ████ ██ ██ ████████
This could be false. We know that anyone who has been lied to has lied to someone, but we don’t know if this conditional relationship goes both ways, as (E) suggests.