Conditional fallacy

A conditional fallacy may or may not be a logical fallacy, conditional on whether or not one of its premises is accepted.

Cogito ergo sum Logic and rhetoric

Key articles

Logical fallacy Syllogism Argument

General logic

Argumento Authenticity of divine revelation Bait-and-switch Ham Hightail One-way hash argument سفسطه‌ی حد وسط

Bad logic

Association fallacy Danth's Law Intuition pump Non sequitur Toupee fallacy گزاره‌ی صاحب‌نظر v - t - e

Conditional fallacies are almost always informal fallacies. However, if comparing multiple systems of logic (which would imply different valid and invalid logical structures, and thus different formal fallacies) then it may be possible for a formal fallacy to be conditional.

Form

An informal conditional fallacy follows the form:

P1: X is Y.

P2: Being Y causes something to be true / to be false / etc.

C: X is true / false / etc.

Examples

Non-fallacious

This is not always fallacious. For example, a good (rational) conditional argument:

P1: Global warming is agreed to exist by over 95% of climatologists, making it the scientific consensus.

P2: The scientific consensus is probably true.

C: Global warming probably exists.

Fallacious

The problem only occurs when Y is something stupid. For example, a bad (fallacious) argument from authority:

P1: Creationism is agreed to be true by at least 250 people.

P2: Some of those 250 people are scientists, and scientists are normally right.

C: Creationism is probably true.

Subfallacies

See the main article on this topic: Logical fallacy § Conditional

See also

• Fallacious argument style