Type of fallacy

Definition

Ad hominem

An ad hominem argument attacks the messenger, not the message itself.

Argument from authority

This type of argument relies on the identity of an authority rather than the components of the argument itself.

Argument from adverse consequences

Saying that because the implications of a statement being true would create negative results, it must not be true.

Appeal to ignorance

If something is not known to be false, it must be true.

Special pleading

Stating a universal principle, then insisting that it doesn't apply to your assertions for some reason.

Begging the question/ assuming the answer

This occurs when a statement has an unproven premise. It is also called "circular reasoning" or "circular logic".

Observational selection

Looking at only positive evidence while ignoring the negative.

Statistics of small numbers

Using small numbers in order to report large percentage increases

Misunderstanding of the nature of statistics

Ignorance about central statistical assumptions and the definition of metrics.

Inconsistency

Being inconsistent in any form, especially as in holding double standards.

Non sequitur

Latin for "it does not follow."

Post hoc, ergo propter hoc

Basing an effect on a cause only on the basis of chronology.

Excluded middle, or false dichotomy

portraying an issue or argument as having only two options and no spectrum in between.

Short-term vs. long-term

Assuming a current trend has remained constant throughout its history and will continue to do so in the future, even though no evidence suggests such an extrapolation is justified.

Slippery slope, related to excluded middle

Saying something is wrong because it is next to or loosely related to something wrong.

Confusion of correlation and causation

Just because two phenomena happen simultaneously does not mean that one causes the other.

Straw man

Misrepresenting a position to make it easier to criticize.

Suppressed evidence and half-truths

Drawing an unwarranted conclusion from premises that are at least in part correct.

Weasel words

The usage of euphemisms and vague, non-specific references.