#25 - Essayist: Every contract negotiator has been lied to

[jennyli0804]

Hi,

While I got this question correct, I couldn't really wrap my head around the conditional reasonings within answer choices B and C. How would one would diagram a conditional reasoning that starts with "Not everyone who..." ?

Thank you.

[Adam Tyson]

The short answer, jennyli0804, is that you wouldn't! "Not everyone" is NOT a conditional indicator. Instead, it indicates Formal Logic, which is different from Conditional Reasoning in some important respects but which can also be diagrammed in a very similar way. If not everyone who practices deception is lying to someone, then it must be true that some people practicing deception are NOT lying to someone. We could diagram that like this:

Practice Deception Lying

If you have the LR Bible, there is a chapter on Formal Logic that might be worth your time. If you took our full length course, you could find a module on it in the Online Student Center. If neither, there are plenty of discussions about it in relation to specific LR questions in this Forum. The basic idea is that "some" is a two-way street - if some As are Bs, then some Bs are As. "Most" is a one-way street - if most As are Bs, we cannot say anything about "most Bs." The best we could do is go backwards with a "some" statement - some Bs are As.

Watch out for those "some" and "most" statements (and their strange, subjective cousins, "few" and "many"), and don't fall into the trap of treating them as purely conditional. Conditional statements are about "all" and "every" and "whenever" - they are absolute.

[kmaragh]

This is not in reference to this question in particular, but I am having a hard time prephasing questions. For some I have an inkling on how to prephase and for some I'm stuck and don't know how to prephase. Are there any tips on prephasing?

[kmaragh]

Also, Can someone please explain why E is wrong? Can you use the conditional statements to explain like you did with explaining why A is right with the branching of the conditional statements? I can see why A is right but I still don't see why E is wrong or how it is a mistaken reversal.

[Jeremy Press]

Hi kmaragh,

Part of the problem with understanding how answer choice E relates to the stimulus is in being clear on whether, in any given condition, we're talking about a person that has lied TO someone else [active verb] or a person that has been lied to BY someone else [passive verb]. I'm going to use those underlined terms to diagram both the last sentence of the stimulus and answer choice E.

The last sentence of the stimulus says, "[A]nyone who has been lied to has also lied to someone or other." "Anyone" indicates a sufficient condition, so this sentence diagrams as:

Been lied to BY someone else Lied TO someone else.

Answer choice E states, "Whoever lies to anyone is lied to by someone," which roughly diagrams as:

Lied TO someone else Been lied to BY someone else

Thus, answer choice E is the Mistaken Reversal of the last sentence of the stimulus.

I hope this helps!

Jeremy