This fallacy occurs when it is inferred that an often-irrelevant shared quality (or qualities) shows that two things are equivalent, often in terms of their degree or magnitude. One way to formalize this fallacy is as follows:
Premise 1: A is X (to degree D) because it has qualities A, B, and C.
Premise 2: B has quality C.
Conclusion: A and B are equivalent, so B is X (to degree D).
This reasoning is defective because it does not follow that because two things have qualities in common that they are equivalent. To use an extreme example, while it is true that both Adolph Hitler and Donald Trump were elected officials, this does not entail that they are equivalent. It also does not follow that they are not equivalent.
What this reasoning lacks is an adequate comparison of A and B to determine if they are similar enough to warrant the inference that they are equivalent. If a strong enough Argument by Analogy can be made, then the claim of equivalence would be supported one and the fallacy would be avoided. The logical defense against a false accusation you have made a false equivalence is to present just such a strong argument.
While people often make use of this fallacy for nefarious reasons, people also fall into it in good faith. Sometimes the fallacy is even the result of good intention. For example, credible American news sources often try to include both sides of an issue. This is laudable when both sides are worthy of serious consideration and roughly on par. But when one side is quite evidently not even close in credibility, including both sides can lend credence to a view that has not earned it.
This fallacy can be self-inflicted but is most often used in bad faith. In such cases the person using the fallacy is aware that they are making a False Equivalence but are hoping the target audience will not be critical enough to notice it. This fallacy is most effective when the target of the false equivalence is something the target audience has strong feelings about.
This fallacy can be employed to try to downplay the severity of something. For example, someone might compare a major oil spill to having a bit of oil leaking from a car. The fallacy can also be used to try to persuade the target audience that something minor is extreme. For example, someone might compare a run of the mill political proposal to the evils of the Nazis.
Defense: The defense against this fallacy is to assess the comparison being drawn to determine if it supports the alleged equivalence. See also False Analogy.
“I don’t get why people think my having a pet tiger is a bad idea. It is a pet that I must take care of, just as I would take care of a cat or a dog.”
“The Republicans are proposing that we build more prisons. Need I remind you that under Stalin the Soviet Union built more prisons?”
“A military pilot who bombs a target that results in civilian deaths is just like a criminal who sets off a bomb in a church or school. Both are murders who should be executed.”
“The theory that the earth is hollow is a theory just like the theory of evolution. So, the hollow earth theory should be taught in public schools.”
“Both those politicians are big liars. Smith exaggerated about the number of jobs he created. Brown said he never committed sexual assault, but six people have come forward with credible accusations. It doesn’t matter who you vote for, a liar is going to win.”
Originally appeared on A Philosopher’s Blog Read More