# Fallacy of accident

 Part of the series on Key articles General logic Bad logic v - t - e
Not to be confused with overgeneralization or fallacy of accent.
 “”No rule is so general, which admits not some exception. —Robert Burton, The Anatomy of Melancholy

Fallacy of accident is a logical fallacy that occurs when a general rule (a rule of thumb or a "soft" generalization) is taken to be universal (an unconditionally true statement).

The fallacy is an imprecision fallacy and an informal fallacy.

## Alternate names

• a dicto simpliciter ad dictum secundum quid
• sweeping generalization
• misuse of a principle
• ignoring qualifications

## Form

P1: Bs are normally Cs.
P2: A (an abnormal example) is a B.
C1: A is C.

## Examples

 “”Water boils at a temperature of 212° Fahrenheit; therefore boiling water will be hot enough to cook an egg hard in five minutes: but if we argue thus at an altitude of 5,000 feet, we shall be disappointed; for the height, through the difference in the pressure of the air, qualifies the truth of our general principle. —H. W. B. Joseph
• "Birds can [normally] fly" is a general rule, and doesn't imply that all birds (such as emus or penguins) can fly. To take this general rule and apply it to all birds would be committing a sweeping generalization.