Informal - non structural flaws.
1. Argument from Ignorance- true b/c not proven false.
2. Ad Hominem- attack the opponent
3. Begs the question- conclusion of the argument as a premise.
4. Equivocation- use of a term with more than one meaning.
5. False dilemma (false dichotomy, fallacy of bifurcation, black-or-white fallacy) - two alternative statements as the only possible options.
6. Fallacy of many questions- presupposes something not accepted by all the people involved.
7. Inflation of conflict - Experts of a field disagree on a certain point, so scholars know nothing, and legitimacy of their entire field is in question.
8. Ignoratio elenchi -(irrelevant conclusion) argument may be valid, but does not address the issue.
9. Mind projection fallacy- one considers the way one sees the world as the way the world really is.
10. Moralistic fallacy- inferring factual conclusions from purely evaluative premises. Inferring "is" from "ought." Inverse of naturalistic fallacy.
11.Moving the goalposts (raising the bar) - evidence to a specific claim dismissed and other (often greater) evidence demanded.
12. Onus probandi- burden of proof is on the person who makes the claim not the person who denies (or questions the claim).
13. Post hoc ergo propter hoc Latin for "after this, therefore because of this" (faulty cause/effect, coincidental correlation, correlation without causation) - X happened, then Y happened; therefore X caused Y.
14. Psychologist's fallacy - an observer presupposes the objectivity of his own perspective when analyzing a behavioral event.
15. Red herring - a speaker attempts to distract an audience by deviating from the topic at hand by introducing a separate argument the speaker believes is easier to speak to.
16. Reification (hypostatization) - a fallacy of ambiguity, when an abstraction (abstract belief or hypothetical construct) is treated as if it were a concrete, real event or physical entity. In other words, it is the error of treating as a "real thing" something that is not a real thing, but merely an idea.
17. Retrospective determinism - the argument that because some event has occurred, its occurrence must have been inevitable beforehand.
18. Shotgun argumentation - the arguer offers such a large number of arguments for their position that the opponent can't possibly respond to all of them. (See "Argument by verbosity" and "Gish Gallop", above.)
19. Special pleading - where a proponent of a position attempts to cite something as an exemption to a generally accepted rule or principle without justification.
20. Wrong direction - cause and effect are reversed.