ARCANA FALLACIORUM · MMXXVI
the deck of bad thinking

Arcana
Fallaciorum· a seventy-eight-card divination of the errors we make in argument ·

Cut the deck. Let a card surface. Hold it against the last sentence you believed without checking — and see what shifts.

❦   ✦   ❦   ✦   ❦
· XIII ·
Post Hoc
post hoc, ergo propter hocafter · therefore · because
· V ·
The Straw Man
argumentum fictitiuman argument made of straw
· THE FOOL ·  0  · ad hominem ·
Ad Hominem
argumentum ad hominemagainst the person, never the claim
· II ·
False Dichotomy
dilemma falsuma world of two doors
· IX ·
Slippery Slope
lubricus gradusthe greased step
◦ THE CARD IN THE EAST ◦

Ad Hominem· The Finger and The Crown ·

"A crown is offered, and because the one who extends it has mud upon the hand, the offering is refused. The mud and the crown are separate objects. The querent confuses them at their peril."

The hand in the foreground is clean; the one who holds it is not. The querent has turned away from the claim and toward the speaker — they are now arguing about a person instead of a proposition. The truth of the statement is untouched by the character of the one who said it. This is the oldest error, and the one the deck draws most often.

Name the claim out loud, then name the attack. Separate them on the page. Ask whether the attack would have any force if the speaker were a stranger. If not, return to the claim and evaluate it as if no one had said it.

The Seventy-Eight · cards of the deck

Six suits of fallacies, arranged from the obvious to the insidious. Choose a suit, then a card. Read it against your most recent certainty.

RELEVANCE cups · ♡
PRESUMPTION swords · ♤
AMBIGUITY pentacles · ✧
CAUSAL wands · ♧
EMOTIONAL chalices · ✠
FORMAL keys · ⚷
· I ·
The Straw Man
argumentum fictitium
· II ·
False Dichotomy
dilemma falsum
· III ·
Begging the Question
petitio principii
· IV ·
Appeal to Authority
ad verecundiam
· V ·
Ad Populum
ad populum
· VI ·
No True Scotsman
ad nauseam definitionis
· VII ·
The Gambler
ludicri erratum
· VIII ·
Post Hoc
post hoc, ergo propter hoc
· IX ·
Slippery Slope
lubricus gradus
· X ·
The Red Herring
ignoratio elenchi
· XI ·
The Gish Gallop
argumentum ad multitudinem
· XII ·
Moving the Goalposts
meta anteponenda

THE FIVE MARKS OF THE CARD

  1. A claim has been made. Identify it.
  2. A response has been made. Name what it targeted.
  3. If the response and the claim do not touch, a card is in play.
  4. Consult the deck. Read the upright meaning against the response.
  5. Apply the reversed meaning as your counter — quietly, without declaring the card.

Never name the card at the table. The deck is for the reader, not the dealer.

THE THREE OMENS

  1. "Of course they would say that —" ad hominem approaches.
  2. "If we allow X, next will be Y, and eventually Z —" the slope is already greased.
  3. "So you're saying —" a straw man is being built while you watch.

When two of the three appear in the same exchange, shuffle the deck in your mind and draw a card. The exchange is no longer about the subject.