Logical Reasoning · Flaw
PrepTest 144 · Section 3 · Question 2
Phase 1 (your first ~400 questions): read the guidance, then answer. No clock.
Step 1 · Pre-Question Guidance · read this first
- “just”
- “so”
- “must”
- “cannot”
Playground logic
Marcus's patty is that the sharpener is only a tool. His top bun is that the chewed pencils are all the kids' fault. The secret sauce he slips in is that a tool always does its job, so he never checks whether the sharpener itself is junk.
Step 2 · The kid story
The Pencil-Chewing Sharpener
Ms. Rivera's class got a shiny new pencil sharpener. Within a week, half the pencils came out chewed and crooked. Lulu wrote on her clipboard: "Sharpener = pencil monster?" Marcus laughed. "Ridiculous. A sharpener is just a tool. Tools can't be blamed. The kids are cranking it wrong." Priya set down her juice box. "Marcus, a tool can be a bad tool. What if the blade is loose? What if the gears are cheap? Even a perfect cranker gets chewed pencils from a broken sharpener." Owen tried it slowly and carefully. Chomp. Crooked pencil. Marcus stared. "Okay. Maybe tools can be guilty too." Biscuit barked, which Lulu recorded as agreement.
Step 3 · Try the model question
Some students say the new classroom pencil sharpener ruins pencils. But that is silly. A sharpener is merely an object, and objects cannot be blamed for chewed pencils. The fault must belong to the students who crank it badly.
Which one of the following identifies the weakest point in this reasoning?
Step 4 · The courtroom tale
The Case of the Wobbly Ladder
A painter fell when a store-bought ladder wobbled. The ladder company's lawyer stood up. "Your Honor, a ladder is just a tool. Tools cannot be at fault. Only clumsy painters fall." Mr. Whitfield rose, thumbs under his suspenders. "Your Honor, my learned friend forgot something. Tools can be built badly. This ladder has one leg shorter than the others. A ballet dancer would wobble on it." He set the ladder down. It rocked like a seesaw. The judge raised an eyebrow. "Counsel, 'it is just a tool' does not mean 'it is a good tool.' The defense skipped that possibility."
Step 5 · Work the real question
Open PrepTest 144, Section 3, Question 2 in your official copy from LSAC (for example in LawHub) and read it there.
Your answer
How to apply it
Find the conclusion about where blame belongs and the premise that the thing is merely a tool. Ask what the arguer assumed about the tool itself. Check whether the argument ever considered that the tool could be defective or poor at its job. Choose the answer that names that overlooked possibility. Reject answers that describe moves the argument never makes, such as inconsistency or appeals you cannot find in the text.