Informal Fallacies

Fallacies of Distraction (or Red Herrings; fallacies of distraction occur when irrelevant points are brought into an argument which distract from the main point):

Ad hominem attack - (Latin for "to the man") this fallacy occurs when someone attacks an opponent's character, or motives for believing something, instead of disproving the argument itself.
Bulverism - condemning an argument simply because of its source (where it began, how it began, or who began it).
Tu quoque - (Latin for "You, too") dismissing someone's viewpoint on an issue because he himself is inconsistent in that very thing.
Straw Man - changing or exaggerating an opponent's position or argument to make it easier to refute.
Ipse dixit - (Latin for "He said it himself") an appeal to someone who has no special knowledge in the area being discussed. (For example, citing a celebrity's position on a political issue simply because the celebrity is popular and thus will be trusted, even though s/he has no special knowledge of the subject being discussed.)
Ad populum - (Latin for "to the people") claiming a viewpoint is correct simply because many other people agree with it. This is sometimes called "Appeal to the People" or "Bandwagon". An example is when a child appeals to his/her parents by saying, "All of my friends get to do it!"
Ad baculum - (Latin for "to the stick") this is a faulty appeal to fear. When someone uses a veiled threat (makes you fear the consequences of not doing what he wants). This is a common propaganda technique.
Ad misericordiam - a faulty appeal to pity. When someone tries to make us do something only because we pity him or something associated with him. This is also a common propaganda technique.
Ad ignorantiam - (Latin, referring to an appeal to ignorance) claiming something is true or false because there is no evidence to the contrary. This fallacy is also called "Proof by Lack of Evidence."
Chronological Snobbery - when something is attacked or defended simply because of its age. It is similar to the "Appeal to Tradition" or "Appeal to Hi Tech" forms of propaganda.  Examples of this would be claiming that some new computer is the best simply because it's the newest technology (without substantiating the claim with facts about that new technology) or claiming that something is best because it has been around for a long time.  An appeal to tradition would be a propaganda technique designed to evoke a nostalgic connection with something.
Exigency - exigency is being used when nothing more than a time limit is given as a reason for action.
Snob Appeal - when someone tries to persuade us to think their product would make us better than, or stand out from, everyone else. (Almost the opposite of ad populum, this fallacy appeals to our pride!)
Repetition - this is a propaganda or advertising technique where a message is repeated very loudly and/or often in the hope that it will soon be believed. Catchy slogans and jingles fall into this category.
Transfer - a propaganda technique in which someone tries to make us transfer our good or bad feelings about one thing to another unrelated thing.

Fallacies of Ambiguity (fallacies of ambiguity occur when the meaning of an argument is vague or unclear):

Equivocation - occurs when someone uses words with more than one meaning, and changes the meaning of the word within an argument.
Accent - occurs when the meaning of a statement is altered, simply by the way individual words are stressed in a statement.
Amphiboly (or Amphibology) - occurs when a statement is written in a vague way, such as is easily misunderstood.
Composition (or Part-to-Whole) - occurs when an assumption is made about the whole of a class, based only on its individual parts.
Division (or Whole-to-Part) - the opposite of the fallacy of composition; this fallacy occurs when an assumption is made about each part of a class, based on what is true of the whole of its class.
Contextomy - the fallacy of selectively using a quote out of context to alter its meaning.  This is often done as the basis of a Straw Man argument.
Ad pendulum - (to the bell) presenting only one side of a story or an issue.

Fallacies of Form (a fallacy of form occurs when an argument has a structural problem.):

Petitio principii - (begging the question) circular reasoning or restating the argument.
Post hoc ergo propter hoc - (after this, therefore because of this) false cause.
Either/or - oversimplifying the choices.
Complex question - loaded question, making an incriminating answer inevitable.
Apriorism - hasty generalization.

Accident -this fallacy occurs when some accidental, irrelevant factor becomes the essential point of an argument.  This is often the result of applying a general "rule of thumb" to a particular case in which the rule is inapplicable.
Weak analogy - the difference between things being compared are major and similarities are minor

Sources: The Fallacy Detective, Bluedorn,  ©2003, and Introductory Logic, Wilson & Nance, Mars Hill, ©2002.

"Histories make men wise; poets, witty; the mathematics, subtile; natural philosophy, deep; moral, grave; logic and rhetoric, able to contend."  -Sir Frances Bacon