Logical Reasoning · Principle

PrepTest 141 · Section 2 · Question 6

Phase 1 (your first ~400 questions): read the guidance, then answer. No clock.

Step 1 · Pre-Question Guidance · read this first

Question type

Principle (justify)

The one idea it tests

The arguer admits a weakness but says it doesn't matter, because the thing does well at what its own kind is supposed to do.

The basic logic

Find the conclusion (a criticism is wrong) and the evidence (it does its kind's main job well). The principle is the general rule that links them: a thing should be judged by how well it succeeds at its own kind's purpose.

Tiny words that decide it

“but”
“what matters”
“even if”

Playground logic

Frankie's paper airplane doesn't look like a real plane. Sharon calls that a failure. Frankie's patty: it flies far, and flying is what matters for a paper airplane. The principle: judge a thing by its own kind's goal.

Step 2 · The kid story

The Ugliest Plane in the Sky

Frankie and Sharon are debating again. Frankie folded a paper airplane that looks like a squashed sandwich. Sharon laughs. 'That doesn't look anything like a real airplane. Total failure.' Frankie shrugs. 'Sure, it doesn't look real. In some contests that would matter. But this is a paper airplane contest, and it just flew all the way across the gym.' Kevin, eating pineapple pizza, says, 'It went past the basketball hoop!' Priya nods. 'A paper airplane's job is to fly. If it does that job well, it is a good paper airplane, no matter what it looks like.' Sharon crosses her arms, then quietly starts folding her own sandwich plane. Lulu writes: judge it by the job its kind is supposed to do.

Step 3 · Try the model question

Frankie: Sharon says my paper airplane is a failure because it looks nothing like a real airplane. True, it does not look real. But it flew across the whole gym, and for a paper airplane, flying far is what counts. So Sharon's criticism misses the mark.

Which principle, if valid, would most help to support Frankie's argument?

Step 4 · The courtroom tale

The Lumpy Lifeboat

A ship owner sued a boatbuilder. 'Your Honor, this lifeboat is lumpy and ugly. It looks nothing like a proper yacht.' The boatbuilder's lawyer, Ms. Tran, stood up. 'Certainly it is not a yacht. But it is a lifeboat. It floats in any storm and holds twenty people. For a lifeboat, that is the whole point.' Judge Abernathy considered. 'So your position is that a thing should be judged by whether it succeeds at what its own kind is for?' 'Exactly, Your Honor.' 'Then the lumps are irrelevant. Nobody needs a pretty lifeboat. They need one that floats.' The ship owner withdrew his complaint.

Step 5 · Work the real question

Open PrepTest 141, Section 2, Question 6 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

Identify the criticism being rejected and the weakness the arguer admits. Then find the reason the arguer says the weakness doesn't matter: the thing succeeds at the main goal of its own category. Pick the principle that says success is measured by meeting that category's goal. Make sure the principle covers the gap between the evidence and the conclusion. Avoid principles that support the critic, add new standards, or bring in popularity or other outside measures.