ACCESS // OPEN

01MIND ARCHIVE // OPEN ACCESS

SPIN.OPEN.DOUBT.

One spin opens a file from psychology, philosophy, logic, or society. Read it with suspicion.

01204 case files02ES + EN034 fronts
02

IDEA ROTOR

CURATED RANDOM
FILE SELECTED: Denying the Antecedent, 2 min.
FRONTS / 04

Fronts

LOCAL
ARCHIVE

00 / 204

Local archive

This browser remembers what you opened and saved.

0 / 204 opened
Nothing leaves this browser.

FILE SELECTED // FILE 00

Logic & science2 MINBrief fileEstablished evidence

Denying the Antecedent

Closing one route does not prove the destination is unreachable.

01 / SUMMARY

In short

The invalid form is: if A, then B; not A; therefore not B. A can be sufficient for B without being the only way to obtain B.

03 / SCENE

In the wild

If I take the train, I reach downtown. I did not take the train. I might still have arrived by bicycle.

04 / LIMIT

The limit

Confusing a sufficient condition with a necessary one erases genuine alternatives.

FINAL NOTE

What remains

Before denying B, ask whether routes other than A were available.

Source trail

Editorial review: 2026-08-06

Open another thread