# Affirming the consequent

Affirming the consequent, sometimes also called asserting the consequent or the converse error, is a type of logical fallacy where a premise is asserted as true simply because a conclusion implied by the premise is true. This is a fallacy because it assumes that the conclusion could only have been reached in one particular way.

For example:

1. If an animal is a rat, then it has four legs
2. My dog Lassie has four legs
3. Therefore, Lassie is a rat

• A implies B
• B
• Therefore, A

## Further Examples

• Creationism example 1
1. If the universe was created by God, then there would be order and natural laws observed in the universe
2. We see examples of order and natural laws in the universe
3. Therefore, the universe was created by God

This argument assumes that a deity is the one and only explanation for order in the universe. And even if we do assume that a deity is the only explanation, it doesn't automatically mean that it must be the Christian deity. The Flying Spaghetti Monster is a good counter-example that satirically exposes the underlying fallacy of this argument.

• Creationism example 2
1. If the Biblical flood story is true, then there was a boat built with the dimensions described in the Bible
2. We found a boat with these dimensions
3. Therefore, the Biblical flood story is true.

To see why this is a fallacy, consider the same logic applied to the story of Cinderella and the existence of Cinderella's castle in Disneyland.

 v · d Logical fallacies
 v · d Formal fallacies
 Propositional logic Affirming a disjunct · Affirming the consequent · Argument from fallacy · False dilemma · Denying the antecedent Quantificational logic Existential fallacy · Illicit conversion · Proof by example · Quantifier shift Syllogistic Affirmative conclusion from a negative premise · Exclusive premises · Necessity · Four-term fallacy · Illicit major · Illicit minor · Undistributed middle

 v · d Faulty generalisations
 General Begging the question · Gambler's fallacy · Slippery slope · Equivocation · argumentum verbosium Distribution fallacies Fallacy of composition · Fallacy of division Data mining Cherry picking · Accident fallacy · Spotlight fallacy · Hasty generalization · Special pleading Causation fallacies Post hoc ergo propter hoc · Retrospective determinism · Suppressed correlative · Wrong direction Ontological fallacies Fallacy of reification · Pathetic fallacy · Loki's Wager
 v · d False relevance
 Appeals Appeal to authority · Appeal to consequences · Appeal to emotion · Appeal to motive · Appeal to novelty · Appeal to tradition · Appeal to pity · Appeal to popularity · Appeal to poverty · Appeal to spite · Appeal to wealth · Sentimental fallacy · Argumentum ad baculum Ad hominem Ad hominem abusive · Reductio ad Hitlerum · Judgmental language · Straw man · Tu quoque · Poisoning the well Genetic Fallacies Genetic fallacy · Association fallacy · Appeal to tradition · Texas sharpshooter fallacy