Day 23 of 168 · Week 4
Day 23 / 168 Week 4 of 28 Phase 2: Logical Reasoning Deep Dive

Flaw III: Conditional Flaws, Mistaken Reversal & Negation

🕑 ~75 min · Archetype A — LR Deep Dive

Recap: Flaw, Part 3 — Conditional Flaws

The third Flaw cluster ties directly back to Days 4 and 8: arguments that commit a mistaken reversal or mistaken negation of a conditional statement.

1. Recognizing the Shape

A conditional premise ("if p, then q"), followed by a conclusion drawn from the wrong direction (from q, concluding p — reversal) or from the negation of the wrong side (from not-p, concluding not-q — negation).

2. Answer-Choice Phrasing

"Treats a necessary condition as sufficient," "confuses a condition for its converse," "mistakenly infers the antecedent from the consequent" — all describe the same two errors from Day 4 in different words.

3. Why This Cluster Is High-Yield

Because conditional logic recurs throughout the test, conditional Flaw questions are some of the most mechanically gradable — once you can diagram accurately, these become close to automatic.

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: "All licensed electricians passed the certification exam. Maria passed the certification exam. So Maria is a licensed electrician." What's the flaw?

A. Causal flaw
B. Mistaken reversal — treats passing the exam (necessary) as if it were sufficient for being licensed
C. Sampling flaw
D. No flaw; the argument is valid
Correct answer: B. Passing the exam is necessary (all licensed electricians passed it) but the argument treats it as sufficient to prove licensure — a classic mistaken reversal.

LawHub drill-tier LR section, untimed. Scan for Flaw stems involving conditional-sounding stimuli.

Saturday: Week 4 synthesis, contrasting the whole Describe family — Main Point, Role, Method, and all three Flaw clusters — against each other.