In logic and philosophy, a formal fallacy, deductive fallacy, logical fallacy or non sequitur (/ˌnɒn ˈsɛkwɪtər/; Latin for 'it does not follow') is a pattern...

the context in which they are made. Fallacies are commonly divided into "formal" and "informal". A formal fallacy is a flaw in the structure of a deductive...

contain fallacies. Because of their variety, fallacies are challenging to classify. They can be classified by their structure (formal fallacies) or content...

of the argument, as is the case for formal fallacies, but can also be due to their content and context. Fallacies, despite being incorrect, usually appear...

The fallacy of four terms (Latin: quaternio terminorum) is the formal fallacy that occurs when a syllogism has four (or more) terms rather than the requisite...

An ecological fallacy (also ecological inference fallacy or population fallacy) is a formal fallacy in the interpretation of statistical data that occurs...

Argument from fallacy is the formal fallacy of analyzing an argument and inferring that, since it contains a fallacy, its conclusion must be false. It...

The fallacy of the undistributed middle (Latin: non distributio medii) is a formal fallacy that is committed when the middle term in a categorical syllogism...

be confused with formal fallacy, an argument whose conclusion does not follow from its premises; instead, it is that despite its formal consistency it is...

The existential fallacy, or existential instantiation, is a formal fallacy. In the existential fallacy, one presupposes that a class has members when one...