# Post hoc ergo propter hoc

(Difference between revisions)

Literally, "after this, therefore because of this".

This logical fallacy represents a mistaken assertion of causality. Two events, which may have no significant causal connection, are erroneously considered to represent a cause and its effect. Correlation does not equal causation.

## Examples

• I took 2 pills
• Therefore, those pills cured my headache

Those pills might be responsible, but that causality can't be determined from this argument alone. This sort of confusion about cause and effect is demonstrated by the placebo effect and is a common basis for folk remedies and many basic religious beliefs.

Another example:

• I prayed that I would find my lost keys
• I found them behind the couch
• Therefore, prayer helped me find my keys

There's no evidence that demonstrates a direct causal relationship between prayer and finding lost keys. Plenty of people have found their keys without prayer and many keys remain lost despite prayer. Yet, for those individuals who willingly accept arguments based on this fallacy, each occurrence represents another data point supporting the idea that prayer produces results.

A third example, popularized by the Church of the Flying Spaghetti Monster:

• Between 1820 and 2000, the global mean temperature has increased
• During this same time period, the pirate population has decreased from 45,000 to 17
• Therefore, pirates prevent global warming.

Obviously, the link between pirates and global temps is specious at best.

 v · d Logical fallacies
 v · d Formal fallacies
 Propositional logic Affirming a disjunct · Affirming the consequent · Argument from fallacy · False dilemma 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 Genetic Fallacies Genetic fallacy · Chronological snobbery · Association fallacy · Appeal to tradition · Texas sharpshooter fallacy