A fallacy is a misleading argument or belief based on a falsehood. If you oppose state testing in schools, you think it is a fallacy that educational quality can be measured by standardized tests.

Fallacy comes from the Latin fallacia, for deceit. It technically means a flaw in an argument that makes it deceptive or misleading. In poetry, the "pathetic fallacy" is the false idea that things like rocks or stars have human feelings (pathos). Fallacy can also be used more generally for any false statement or idea. Some synonyms are misconception and error.

Definitions of fallacy

n a misconception resulting from incorrect reasoning

false belief
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an activity resembling science but based on fallacious assumptions
logical fallacy
a fallacy in logical argumentation
pathetic fallacy
the fallacy of attributing human feelings to inanimate objects; `the friendly sun' is an example of the pathetic fallacy
sophism, sophistication, sophistry
a deliberately invalid argument displaying ingenuity in reasoning in the hope of deceiving someone
an unintentionally invalid argument
astrology, star divination
a pseudoscience claiming divination by the positions of the planets and sun and moon
a pseudoscientific forerunner of chemistry in medieval times
hysteron proteron
the logical fallacy of using as a true premise a proposition that is yet to be proved
ignoratio elenchi
the logical fallacy of supposing that an argument proving an irrelevant point has proved the point at issue
petitio, petitio principii
the logical fallacy of assuming the conclusion in the premises; begging the question
post hoc, post hoc ergo propter hoc
the logical fallacy of believing that temporal succession implies a causal relation
Type of:
an incorrect conception

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