COMMON FALLACIES

             Traditionally, the common fallacies have been divided into three groups: fallacies of ambiguity, fallacies of presumption, and fallacies of relevance.

             Fallacies of ambiguity are linguistic fallacies in that they stem from the use of language having more than one meaning. The best way to unravel such fallacies is to clarify the language in question. Among the fallacies of ambiguity are amphibole, accent, and equivocation.

             Amphibole results from ambiguity in sentence structure, as when Macbeth draws the wrong conclusion from the witch's prophecy that "none of woman born/ Shall harm Macbeth." Accent results from ambiguity of stress or tone. Equivocation is the name given to fallacies stemming from a shift in meaning of a key term during an argument.

             Fallacies of presumption are arguments in which unfounded or unproven assumptions are smuggled in under the guise of valid argument forms. These fallacies are divided into three types: those in which the error lies in overlooking the facts, those in which the facts are evaded, and those in which they are distorted.

             Fallacies that involve overlooking the facts include sweeping generalization, hasty generalization, and bifurcation. Sweeping generalization results when a generalization is lied to a special case that properly falls outside of it. Hasty generalization Is the opposite of sweeping generalization. Here, an isolated or exceptional case is used erroneously to support a universal conclusion, as when a bad experience with a former husband is used to prove that all men are no good. Bifurcation overlooks a range of possibilities that lie between two polar alternatives. as in the assertion that something is either good or bad.

             A type of fallacy that involves evading the facts is begging the question, which occurs when the premises of an argument assume the very conclusion that the argument is supposed to prove.

             The third of presumptive fallacy distorts the facts. False analogy distorts by making the facts under discussion appear more similar to another set of facts than they really are. An example is King James I's comparison of cutting off the head of a body with removing the head of a state. False cause distorts facts by assuming that two events are causally connected when in fact they may not be, as when the Egyptians worshipped the ibis because its appearance preceded the annual Nile flooding.

             Fallacies of relevance are arguments in which the emotional appeal deceives us into believing that what is said is relevant to the conclusion being urged. Many of these fallacies involve personal attacks, including genetic fallacy, abusive ad hominem, circumstantial ad hominem, to quoque, and poisoning the well. Rather than attacking the issue itself. attacks the person or persons associated with the issue.