Welcome to the latest diary in this series about logical argument! On Mondays, Wednesdays, & Fridays, I mention list of logic terms & describe what they mean in as plain terms as I can — hopefully resulting in a resource that will be useful for Daily Kos discussions. I encourage your comments & suggestions.
The 1st diary defined propositions & arguments...
Informal fallacies started with ambiguity...
& continued with personal attacks...
then various irrelevant appeals...
& the last one involved mistakes in generalization.
I will begin with one of the most media-misused terms in this entire family of fallacies...
(...just after I point out that a premise is a proposition that, in whatever way, is meant to lead to a conclusion in an argument. With that in mind...)
Begging The Question (Petitio Principii).
Basically this fallacy fails to advance an argument at all, instead simply restating a premise as a conclusion. Calvin Coolidge supposedly described unemployment as the result of people being out-of-work (in reality, of course, that's what unemployment means). The fallacy becomes obvious in cases where whoever commits it doesn't even bother restating it, as in the tantrum: "It IS because it IS!"
Question-begging arguments often appear in instances of circular reasoning, as in old jokes in which someone listens to sad music to forget about the depression he or she feels... from listening to sad music.
Complex Question.
In a complex question someone puts 2 premises together which may or may not belong together & tries arguing both at once. A religious apologist thus may argue for "God & values" whether or not his concept of god has anything to with the value system he assumes. One disentangles such a fallacy by dividing the question. If asked the question "Where's that ugly dog of yours?" you can answer with something like "My dog is not ugly, but he's in the yard right now."
(Also, note how that last example uses the word "ugly" as a question-begging epithet.)
Bifurcation.
Committing the "bifurcation" fallacy means denying more than 2 possibilities exist when the reality of the situation may be more complicated. Perhaps the most familiar recent example is George W. Bush declaring "You're either with us or against us", essentially dividing all of Washington — & given the scope of his rhetoric, all of the world — into "Bush Gang" & "Al Qaeda" factions. Obviously, plenty of people & political groups in the world actively opposed both, however inconvenient this fact may have been for the Bush Administration's political program.
As a more mundane example, someone who tells you "You're either the cream of the crop or a rotten apple" ignores the fact that you may be just "ripe" enough.
For that matter, that whole analogy ignores the fact that you probably don't compare to an apple anyway — but more about that later...
7:40 PM PT: Thanks again to the Rescue Rangers for my 2nd time ever in the Community Spotlight!