Day 25 of 168 · Week 5
Day 25 / 168 Week 5 of 28 Phase 2: Logical Reasoning Deep Dive

Flaw IV: Equivocation, Part–Whole, Ad Hominem & Appeals

🕑 ~75 min · Archetype A — LR Deep Dive

Recap: Flaw, Part 4 — Equivocation, Part-Whole, Ad Hominem

Two more Flaw clusters before Week 5 moves to the assumption family: arguments that shift a term's meaning, arguments that confuse a part's properties with the whole's (or vice versa), and arguments that attack the arguer instead of the argument.

1. Equivocation

A key term is used in two different senses across the argument — same word, different meaning, and the argument depends on nobody noticing the shift.

2. Part-Whole Flaws

Assuming what's true of the parts is true of the whole (composition) or what's true of the whole is true of each part (division) — neither is guaranteed in general.

3. Ad Hominem and Appeals

Attacking the source of a claim instead of the claim's content, or appealing to popularity/tradition/authority as if that alone settled the matter.

Practice items on this page are curriculum-authored in LSAT style; they are not official LSAC questions. Real drilling happens on LawHub — see the assignment below.

Q1. Argument: "This engine is powerful, and this chassis is lightweight, so this car must be fast." Which flaw is most clearly present?

A. Ad hominem
B. Composition — assuming a whole (the car) has a property because its parts individually have related properties
C. Equivocation
D. Sampling flaw
Correct answer: B. Each part having a favorable property doesn't guarantee the assembled whole has the resulting property — other factors (aerodynamics, weight distribution) matter too.

LawHub drill-tier LR section, untimed. Scan for Flaw stems only.

Tomorrow closes out the Flaw sequence: numeric flaws, absence-of-evidence arguments, false choice, and circular reasoning.