Logical Reasoning

PT111 · S3 · Q11 Teacher to a student: You agree

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Teacher to a student: You agree that it is bad to break promises.

Conclusion (So)

You should not tell me that Jeanne is home sick, if you know that she is well.

Evidence

Sure, you promised Jeanne you would tell me she is home sick, and sure, you agree that it's bad to break promises.

Well, when we speak to each other we all make an implicit promise to tell the truth. When we lie, we are breaking that promise.

Evaluate

The teacher is saying,

It should strike us as weird that the teacher feels so settled on the final choice. The way he has framed it, it seems like the student is stuck between a rock and hard place:

- either she lies to the teacher (breaking the implicit promise to tell the truth) - or she breaks the promise to Jeanne

Either way she's doomed to break a promise. So why is the teacher sure that the final decision is, ? Couldn't the final decision be the reverse?

Since the backdrop to this conclusion is Weighing Tradeoffs, we might expect an answer choice to tell us how the author ends up arriving at his decision.

Goal

He must be assuming that .

He is definitely assuming in some way that the resolution to this conundrum somehow leans in favor of telling him the truth, so we'll anticipate a correct answer to name an assumption that is making the teacher think it's more important that the student not break a promise with him than it is to not break a promise with Jeanne.

11.

Which one of the following is an assumption on which the teacher's argument depends?

  1. Most people always tell the

    Too Specific: most

    "Most" is wrong 99% of the time we see it on Necessary Assumption, because most means "more than 50%" and that distinction between being 51% and 49% is usually not a meaningful one. Would this argument be different, whether 51% of people always tell the truth or only 49% of people always tell the truth? Nope, same either way, so the author doesn't need to assume it's at least 51%. The author isn't talking about what most people do do. The conclusion is about what the student should do. The teacher may be arguing that the student should do X, even if most people don't do X. I might recommend to people that they meditate, get plenty of sleep, and get daily exercise, even though I know most people (including me) don't pull off doing those three things.

    2% picked this

  2. It is sometimes better to

    Irrelevant Comparison

    The first half of this comparison doesn't match any part of the conversation. The student has to choose between keeping a promise with Jeanne and breaking a promise to Jeanne (we were never even told that Jeanne was a friend, so that concept is out of scope). This answer makes it sound like the choice is between acting in Jeanne's interests and keeping a promise to Jeanne. But as far as we know (and as far as Jeanne's opinion on the matter goes), keeping the promise to Jeanne would be acting in Jeanne's interest. We could fix this answer by saying something that better matches the choice, like, It is sometimes better to keep a promise with your teacher than to keep a promise with your friend.

    7% picked this

  3. Breaking a promise leads to

    Too Strong

    Too Strong: Leads to Out of Scope: Worse Consequences Weakens The author is never discussing consequences of lying, other than the superficial one of breaking an implicit promise. She doesn't guarantee that breaking promises always leads to worse outcomes than lying does. The author isn't comparing the consequences of a breaking a promise to those of telling a lie. In fact, the author is saying that telling a lie is breaking a promise, so it would be nonsense to say that one had worse consequences than the other. Finally, this answer tips the scales of the Weighing Tradeoffs, but it does so in the opposite direction of the author. This answer makes it seem like "it would be worse to break the promise to Jeanne, so I should keep that promise and tell the teacher that she is home sick."

    4% picked this

  4. Correct

    Some implicit promises are worse

    Why this is right

    This correctly expresses the tilted scales of how the author was Weighing Tradeoffs. The student can either break her explicit promise to Jeanne (by not telling her teacher the phony 'home sick' alibi). Or the student can break the implicit promise she makes to tell the truth, (by telling her teacher the phony "home sick" alibi). The teacher is saying, "You should tell me the truth (thereby breaking the promise you made with Jeanne)." So he must be thinking that, in this case, it's more important for the student to keep the implicit promise to tell the truth than to keep the explicit promise to lie about Jeanne's alibi. If we negated this, we'd get, "Implicit promises are never worse to break than explicit promises." That would badly weaken the argument, because it would either imply that the explicit promise is more important, thus the student should keep her explicit promise to Jeanne, or imply that the explicit promise is equally important, thus the student is stuck in a no-win impasse, because she can't help but break a promise, and they're both equally important to keep.

    Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.

    70% picked this

  5. One should never break a

    Too Strong: Never

    The teacher is literally counseling the student to break a promise (he's saying, "I know you promised Jeanne you'd say X, but don't say X".) So he's definitely not assuming one should never break a promise. He's trying to tell the student how to choose which promise to keep and which to break.

    16% picked this

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