More Logical Fallacies & Rhetorical Tricks

“In the End, we will remember not the words of our enemies, but the silence of our friends.” - Martin Luther King, Jr.

While I enjoyed my previous two blogs based upon the lecture series, Way with Words, what I really wanted to write about (so I don’t forget) is the list of rhetorical devices that the lecturer presents.

Here are common tricks made in persuasive arguments:

Asserting the Consequent
If X implies Y, then it is NOT necessarily true that Y implies X.
This can be very subtle and easy to miss. Suppose we agree that, “Witches must be burned.” By Asserting the Consequent one can justify burning anyone by saying “Since she was burnable, she must have been a witch.”

Denying the Antecedent
If X implies Y, then it is NOT necessarily true that NOT X implies NOT Y.
Example: We agree that if you play by rules you will succeed. However this does not mean that if you don’t play by the rules, you won’t succeed. It is possible to cheat and win.

Post Hoc Ergo Propter Hoc
“It follows therefore it was caused” Politicians love this one. “Since I was elected four years ago, the crime rate has fallen, smog has gone away, and people are happier.” The politician may have done NOTHING about crime, smog or happiness. He was just lucky that these things improved while he was in office.

Petitio Principii (Begging the Question)
This trick causes your opponent to lose the debate with a seemingly innocent question. Take abortion for example. One could ask, “Wouldn’t you agree that people have a right to control what happens inside their own body?” If you say yes, the debate is over. On the flip side, anti-abortion advocates try to counter with “Wouldn’t you agree that killing is wrong?” This counter-rhetoric is less effective because you can be anti-murder but, by refusing to recognize a fetus as life, make the question moot.
Petitio Principii is also used when a politician makes an agreeable/popular statement that is meaningless. “I am opposed to wasteful spending”. (Is anyone in favor of wasteful spending?) The thing to ask the speaker is, “what do you consider wasteful”? Is volcano research wasteful? Is Military spending wasteful? NASA and space exploration? You might not agree with his/her interpretation of wasteful once the details are discovered.

Attacking the Messenger: ad Hominem
I discussed this a few weeks ago in Insults & Logical Fallacies
A popular modern variant of the ad Hominem attack is comparing the opponent to Hitler. (In the 19th century Napoleon was the villain of choice). According to Godwin’s Law, any debate on the Internet will eventually include a comparison to Hitler. A bylaw of Godwin says the first person to mention Hitler loses the debate. Ironically, I'll mention Hitler at the end of this blog posting (but I hope in a valid context).

Tu Quoque (the hypocrite fallacy)
Another variant of ad Hominem when the speaker is made to look like a hypocrite. We see this today used against Al Gore – “He can’t be serious about global warming, just look at the carbon footprint of his huge house!”

Red Herring (Ignoratio Elenchi – Irrelevant Thesis)
I'll shift your attention away from this one by mentioning that I covered it in my posting Insults & Logical Fallacies as the Strawman Attack.

Appeal to Popularity (Ad Populum) also called the Bandwagon effect
Very common in advertising – “Everybody loves Jiff!” (Implied, You will too!) Note that parents rarely fall for this, “But mom, everyone is doing it!”

Hasty Generalization
News media does this all the time by turning events into trends. By saying “The President’s falling popularity rating hit X% today…” one implies the rating will continue to fall. It is more honest to say the rate “fell” or “has fallen” to X% without predicting where it might go next. Lookout for “ing” participles in news copy, “the worsening economy”, “the rising deficit”, etc.

Sweeping Generalization
When you say, “Everyone agrees with life, liberty and the pursuit of happiness” you are making a broad categorical claim without merit. Just one counter example makes the statement false. It is more honest to say “Most everyone agrees…” or “Nearly everyone agrees …” (but even with this you are now using Ad Populum to sway opinion).

Hyperbole
Exaggerating your claim (often falsely) for effect. “This is the best weight loss diet ever!” “This is the worst recession in American history.”

Appeal to Ignorance
This is attempt by sway opinion by saying your point has NOT been disproved. “No one has proved that aliens don’t exist”

Plurium Interrogationum (Badgering the Witness)
When a debater attacks with a long list of questions, Isn’t is true that X and Y and Z and ..., this is a form of badgering your way to victory. Can the defender be expected to remember each question and will he/she be allowed sufficient time to respond to each? Afterwards an accuser might claim, I asked 20 damaging questions but my opponent had answers for only three.

Apophasis and Paralipsis
Making your point by claiming you are NOT saying it.
“Since I’m not a mudslinger, I won’t tell you about my opponent’s drinking problem.” “We haven’t the time (or it’s not relevant) to discuss rumors that my opponent is a wife-beater.”

Passive Voice
The passive voice can be used to avoid disclosing information. “Mistakes were made” is a nice example that avoids saying WHO made the mistake.

Bottom Line
When Plato and other philosophers wrote about government, they were very fearful of democracies. “The People” can be easily led by effective public speakers into voting for the noose that hangs them. Hitler (via amazing speeches) was democratically elected in Germany and, via legal means, transformed his role into dictator. Today Hugo Chavez in Venezuela is doing the same thing with legal changes to the constitution allowing him to be President for Life.
The cure for this is teaching “The People” the tricks of rhetoric so they won’t be fooled by silver-tongued politicians.