The

fallacy A fallacy is the use of invalid or otherwise faulty reasoning in the construction of an argument that may appear to be well-reasoned if unnoticed. The term was introduced in the Western intellectual tradition by the Aristotelian '' De Sophisti ...

of converse accident is an

informal fallacy Informal fallacies are a type of incorrect argument in natural language. The source of the error is not just due to the ''form'' of the argument, as is the case for formal fallacies, but can also be due to their ''content'' and ''context''. Fallac ...

that occurs when a rule that applies only to an exceptional case is wrongly applied to all cases in general.

Example

# The Tunguska explosion happened in Siberia. #

Magnitogorsk Iron and Steel Works Magnitogorsk Iron and Steel Works (), abbreviated as MMK, is an iron and steel company located in the city of Magnitogorsk, Russia. As of 2017, it was the 30th largest steel company in the world. In 2021, the company's revenue amounted to 786 bil ...

is in Siberia. # This is a bad company to invest in because it's just going to be destroyed by a meteorite. "If we allow people with

glaucoma Glaucoma is a group of eye diseases that can lead to damage of the optic nerve. The optic nerve transmits visual information from the eye to the brain. Glaucoma may cause vision loss if left untreated. It has been called the "silent thief of ...

to use

medical marijuana Medical cannabis, medicinal cannabis or medical marijuana (MMJ) refers to Cannabis (drug), cannabis products and cannabinoid, cannabinoid molecules that are prescription drug, prescribed by physicians for their patients. The use of cannabi ...

, then everyone should be allowed to use marijuana." # People with glaucoma use

marijuana Cannabis (), commonly known as marijuana (), weed, pot, and ganja, List of slang names for cannabis, among other names, is a non-chemically uniform psychoactive drug from the ''Cannabis'' plant. Native to Central or South Asia, cannabis has ...

. # People with

should be allowed to choose what substances they use. # Therefore, all people who use marijuana should be allowed to choose what substances they use.

Related fallacies

This fallacy is similar to the

slippery slope In a slippery slope argument, a course of action is rejected because the slippery slope advocate believes it will lead to a chain reaction resulting in an undesirable end or ends. The core of the slippery slope argument is that a specific decisi ...

, where the opposition claims that if a restricted action under debate is allowed, such as allowing people with glaucoma to use medical marijuana, then the action will by stages become acceptable in general, such as eventually everyone being allowed to use marijuana. The two arguments imply there is no difference between the exception and the rule, and in fact fallacious slippery slope arguments often use the converse accident to the contrary as the basis for the argument. However, a key difference between the two is the point and position being argued. The above argument using converse accident is an argument ''for'' full legal use of marijuana given that glaucoma patients use it. The argument based on the slippery slope argues ''against'' medicinal use of marijuana because it will lead to full use. The fallacy of converse accident is a form of

hasty generalization A faulty generalization is an informal fallacy wherein a conclusion is drawn about all or many instances of a phenomenon on the basis of one or a few instances of that phenomenon. It is similar to a proof by example in mathematics. It is an examp ...

. The converse form is known as the fallacy of

accident An accident is an unintended, normally unwanted event that was not deliberately caused by humans. The term ''accident'' implies that the event may have been caused by Risk assessment, unrecognized or unaddressed risks. Many researchers, insurers ...

External links

Stephen's guide: Converse accident

References

Syllogistic fallacies {{logic-stub