On the subject of Fallacies

Verbal fallacies

Verbal fallacies are those in which a conclusion is obtained by improper or ambiguous use of words. They are generally classified as follows.

Equivocation consists in employing the same word in two or more senses, e.g. in a syllogism, the middle term being used in one sense in the major and another in the minor premise, so that in fact there are four not three terms ("All heavy things have a great mass; this is heavy fog; therefore this fog has a great mass.")

Connotation fallacies occur when a dysphemistic word is substituted for the speaker's actual quote and used to discredit the argument. It is a form of attribution fallacy.

Amphibology is the result of ambiguity of grammatical structure, e.g. of the position of the adverb "only" in careless writers ("He only said that," in which sentence, the adverb has been intended to qualify any one of the other three words).

Fallacy of Composition "From Each to All". Arguing from some property of constituent parts, to the conclusion that the composite item has that property e.g. "all the band members (constituent parts) are highly skilled, therefore the band (composite item) is highly skilled". This can be acceptable (i.e., not a fallacy) with certain arguments such as spatial arguments e.g. "all the parts of the car are in the garage, therefore the car is in the garage"

Material fallacies

The taxonomy of material fallacies widely adopted by modern logicians and based on that of Aristotle, Organon (Sophistici elenchi), is as follows:

Fallacy of Accident (also called destroying the exception or a dicto simpliciter ad dictum secundum quid)--makes a generalization that disregards exceptions (e.g., Cutting people is a crime. Surgeons cut people. Therefore, surgeons are criminals.)

Begging the question (also called Petitio Principii, Circulus in Probando--arguing in a circle, or assuming the answer)--demonstrates a conclusion by means of premises that assume that conclusion (e.g., Paul must be telling the truth, because I have heard him say the same thing many times before. Paul may be consistent in what he says, but he may have been lying the whole time.)

Fallacy of False Cause or Non Sequitur (Latin for "it does not follow")--incorrectly assumes one thing is the cause of another (e.g., Our nation will prevail because God is great.)

• A special case of this fallacy also goes by the Latin term post hoc ergo propter hoc--the fallacy of believing that temporal succession implies a causal relation.
• Another special case is given by the Latin term cum hoc ergo propter hoc -- the fallacy of believing that happenstance implies causal relation (aka as fallacy of causation versus correlation: assumes that correlation implies causation).

Fallacy of Many Questions (Plurium Interrogationum)--groups more than one question in the form of a single question (e.g., Is it true that you no longer beat your wife? A yes or no answer will still be an admission of guilt to wife-beating.)

Argumentum as populum (Argument By Emotive Language - Appeal To The People) Using emotionally loaded words to sway the audience's sentiments instead of their minds. Many emotions can be useful: anger, spite, envy, condescension, and so on.

Example:
A person on trial for a crime of theft pleaded for mercy on the ground that he had force to steal to provide food for his starving family, instead of presenting evidence in his defense.

Argumentum ad verecundiam (Appeal To False Authority) This fallacy is committed when the debater contends that what he alleges is valid because it is supported by a person who commands respect and reverence.

For example: Famous physicist John Taylor studied Uri Geller extensively and found no evidence of trickery or fraud in his feats." Taylor was not qualified to detect trickery or fraud of the kind used by stage magicians. Taylor later admitted Geller had tricked him, but he apparently had not figured out how.

Argumentum ad judicium (Fallacy Of The General Rule) Assuming that something true in general is true in every possible case. This fallacy is committed when the debater ignores the real question and maintains that his contention is valid because people in general believe it to be so.

Example:
All chairs have four legs. Except that rocking chairs don't have any legs, and what is a one-legged "shooting stick" if it isn't a chair?

Argumentum ad bacculum (Appeal To Force) Committed when a debater ignores the real question and appeals to force rather than reason.

Example:
The traditional religious threat is that one will burn in Hell

Argumentum ad ignorantiam (Burden Of Proof) The claim that whatever has not yet been proved false must be true (or vice versa). Essentially the arguer claims that he should win by default if his opponent can't make a strong enough case. It is a case of shifting of burden of proof.

Example:
I maintain that there are ghosts, because you cannot prove that there are no ghosts.