False equivalence

False equivalence is a logical fallacy which describes a situation where there is a logical and apparent equivalence, but when in fact there is none. It would be the antonym of the mathematical concept of material equivalence.

A common way for this fallacy to be perpetuated is one shared trait between two subjects is assumed to show equivalence, especially in order of magnitude, when equivalence is not necessarily the logical result. False equivalence is a common result when an anecdotal similarity is pointed out as equal, but the claim of equivalence doesn't bear because the similarity is based on oversimplification or ignorance of additional factors. The pattern of the fallacy is often as such: If A is the set of c and d, and B is the set of d and e, then since they both contain d, A and B are equal. d is not required to exist in both sets; only a passing similarity is required to cause this fallacy to be able to be used.

The following statements are examples of false equivalence:

• "They're both soft, cuddly pets. There's no difference between a cat and a dog."
• "Marijuana and alcohol are both drugs. An ounce is about the same as three bottles. If you think one should be (il)legal, you should think the same of the other."
• "We're all born naked. We're all no different from each other."

False equivalence is occasionally claimed in politics, where one political party will accuse their opponents of having performed equally wrong actions. Commentators may also accuse journalists of false equivalence in their reporting of political controversies if the stories are perceived to assign equal blame to multiple parties. It should not be confused with false balance – the media phenomenon of presenting two sides of an argument equally in disregard of the merit or evidence on a subject (a form of argument to moderation).