Attack of the 50 Ft. Woman


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October 31st, 2012 (Permalink)

Hallowe'en Headline

Giant Women's Study Short of Volunteers

Where's that 50 ft. woman when you need her?

Source: Richard Lederer, The Bride of Anguished English (2000), p. 97

October 30th, 2012 (Permalink)

A Second Puzzling List

Suppose that you find a piece of paper with the following list of sentences printed on one side:

  1. Exactly one of the statements on this list is false.
  2. Exactly two of the statements on this list are false.
  3. Exactly three of the statements on this list are false.
  4. Exactly four of the statements on…

At this point, the piece of paper has been torn across and the bottom is missing. Let's assume that the list went on in this fashion and call "n" the last sentence on the list. So, n would read:

n. Exactly n of the statements on this list are false.

Also, let's assume that each of the n sentences on this list are either true or false. Can you determine exactly how many of them are false? Which statements, if any, are true?


Resource: A Puzzling List, 9/5/2012

October 27th, 2012 (Permalink)

Blurb Watch Rises from the Grave!

Now, that the debates are over, we return to our regularly scheduled programming. The website for the new Tim Burton movie Frankenweenie includes the one-word blurb: "GLORIOUS"-RICHARD CORLISS, TIME. However, the only occurrence of the word "glorious" is at the beginning of Corliss' review:

The grownups think he’s strange, this quiet boy who may be a genius or a menace. He makes bizarre home movies about his beloved pit bull terrier, and when the creature is killed, he resolves to bring him back to life: reanimation through animation. That is the plot of Frankenweenie―and the story of the young Tim Burton in his first stint at Disney in the early 1980s. …Burton felt his imagination was being stifled by a timid hierarchy in bondage to the glorious past.

So, the word "glorious" doesn't refer to the movie, but to the past of Disney studios. It's an odd contextomy because the review is a favorable one if not quite "glorious".


October 25th, 2012 (Permalink)

Third Presidential Debate Logic Check

I didn't notice anything new that was particularly interesting in the last debate, but there were a couple of repeats of things we saw in the previous two:

  1. Both President Obama and former governor Romney dodged the following question from moderator Bob Schieffer:
    Schieffer: … I'd like to move to the next segment: red lines, Israel and Iran. Would either of you…be willing to declare that an attack on Israel is an attack on the United States, which, of course, is the same promise that we give to our close allies like Japan. And if you made such a declaration, would not that deter Iran? It certainly deterred the Soviet Union for a long, long time when we made that promise to our allies. Mr. President?

    Obama: First of all, Israel is a true friend. It is our greatest ally in the region. And if Israel is attacked, America will stand with Israel. I've made that clear throughout my presidency.

    Schieffer: So you're saying we've already made that declaration.

    Obama: I will stand with Israel if they are attacked. …

    Romney: Well, first of all, I want to underscore the same point the president made which is that if I'm President of the United States, when I'm President of the United States, we will stand with Israel. And if Israel is attacked, we have their back, not just diplomatically, not just culturally, but militarily.

    Neither candidate directly answered Schieffer's question, which was whether either was willing to declare that an attack on Israel would be tantamount to an attack on the U.S. Remember to keep your eye on the ball! Instead, each declared that they would "stand with Israel", whatever that means. Schieffer then suggested to Obama that this amounted to a declaration to treat an attack on Israel as an attack on America, but Obama neither confirmed nor denied that it would, simply repeating that he would "stand with Israel" without explaining what that means. Then, he went off into a memorized campaign speech. Romney said much the same thing.

    While not a direct answer to the question, perhaps the refusal of both candidates to answer directly can be taken as indirect denials of it. That is, at least at this point neither is willing to go so far as to commit himself to treating an attack on Israel as an attack on the U.S. Presumably, their claims to "stand with Israel" or "have their back" if attacked are meant to satisfy supporters of Israel without committing either to a particular course of action.

  2. Romney dodged another hypothetical question by rejecting its hypothesis:
    Schieffer: What if the prime minister of Israel called you on the phone and said, "Our bombers are on the way. We're going to bomb Iran." What do you―

    Romney: Bob, let's not go into hypotheticals of that nature. Our relationship with Israel, my relationship with the prime minister of Israel is such that we would not get a call saying our bombers are on the way, or their fighters are on the way. This is the kind of thing that would have been discussed and thoroughly evaluated well before that kind of―

    Schieffer: So you'd say it just wouldn't happen?

    Again Romney interrupted before Schieffer finished the question, and denied that its hypothesis is possible. Then, he went off into a memorized campaign speech.

Source: "Third Presidential Debate: Full Transcript", ABC News, 10/23/2012


October 23rd, 2012 (Permalink)

In the Mail

Bullspotting: Finding Facts in the Age of Misinformation by Loren Collins, an attorney. It couldn't be timelier, unless of course it had arrived earlier this year, but I'm sure there will still be plenty of bull to spot after the election. It's favorably blurbed by both Nicholas Capaldi, author of The Art of Deception, and Stephen Law, author of Believing B.S., both experienced bullspotters.

October 22nd, 2012 (Permalink)

Second Presidential Debate Logic Check, Part 3

Longtime friend of The Fallacy Files Vance Ricks emails:

One aspect of your most recent posting calls for a separate treatment, I think. It's this part:
Obama: Secretary Clinton has done an extraordinary job. But she works for me. I'm the president and I'm always responsible, and that's why nobody's more interested in finding out exactly what happened than I do. The day after the attack, Governor, I stood in the Rose Garden and I told the American people and the world that we are going to find out exactly what happened. That this was an act of terror and I also said that we're going to hunt down those who committed this crime. … And the suggestion that anybody in my team, whether the Secretary of State, our U.N. Ambassador, anybody on my team would play politics or mislead when we've lost four of our own, Governor, is offensive. That's not what we do. That's not what I do as president, that's not what I do as Commander in Chief. "

President Obama's by no means the first one to do this, but responding to an allegation by saying how offended you are by that allegation has to be a prime case of a fallacy of (ir)relevance, no? It bugged me when I heard him commit it during the debate, and it re-bugged me when I read your posting today, and I was moved to write to ask what you think.

Good question! I had much the same reaction to it. Feigning outrage at an accusation―or even being genuinely outraged―could function as a rhetorical distraction, or red herring, which is the most general fallacy of irrelevance. I checked several references but couldn't find any that lists a more specific fallacy that this would fall under, and perhaps that's just as well, since I don't know how common it is.

That said, I'm doubtful about labelling this particular case fallacious. Admittedly, acting outraged at an accusation doesn't supply any logically relevant information, but I wouldn't want to suggest that it's never an appropriate reaction. Rather than a logical move, it's an ethical one of rebuking someone for making an inappropriate accusation, and sometimes that's a warranted move.

Now, if Obama feigned outrage with the intention of distracting the audience from Romney's accusation, that would surely count as a red herring. However, for all we know Obama's outrage was genuine, in which case it may have been legitimate for him to express. Obviously, we can't read Obama's mind to find out which it was. Nonetheless, Romney raised an issue that deserves a hearing, and it would be a shame if Obama's expression of outrage, even if sincere, were allowed to derail it. So, I guess that I'll call this one a logical boobytrap, that is, while it may not be itself fallacious, it could mislead some into ignoring a legitimate issue.

Reader Responses (Added 10/24/2012): John S. Wilkins, an Australian philosopher and another past correspondent, emails: "Feigning outrage is a red herring/non sequitur". Alright, but was Obama feigning?

Also, Vance replies:

I think you're being very charitable to President Obama in this case, which I don't necessarily take issue with, except that I don't think that he ever actually refuted Romney's allegations. In other words: I see your point that if someone is genuinely affronted by an allegation, then it's not fallacious of them to say so. But if that's their sole response to the allegation, then it's hard for me to avoid thinking that they're using the fact of their hurt feelings as a red herring, a kind of informal fallacy.

In this specific example, maybe we'll never know. Romney seized on the use or non-use of the phrase "terror attack", with now infamous consequences, and so Obama never had to directly address the allegation of bungling/coverup in Benghazi. Maybe he would have said more, and more that was relevant, if he'd been pressed. Certainly, that particular debate had a moderator who probably wouldn't have shied away from pressing him!

You're right that, other than denying that there was any attempt to mislead on the part of his administration, Obama presented no evidence against Romney's suggestion. Thus, even if he didn't commit a fallacy, he presented a very weak argument against Romney's insinuation. All it amounts to is: "Trust me, it's not true." No doubt that amounts to a "fallacy" in the colloquial sense of the term.

Update (10/25/2012): John Wilkins emails in response to my question, above:

If not, then it is still a red herring if the outrage does not imply the conclusion (the denial of the claim he is outraged about). It is not, though, an intentional red herring. If I were reconstructing the argument in a map, the outrage would need to be ignored, and that is enough to show it is rhetoric, not reasoning, and hence is liable to command assent without warrant. Motivated or not, it's a fallacy of relevance, but only if offered as an argument. If it is en passant communication, then it can be eliminated from the formalization, and treated as non-argument.

A minor technical point in explanation: "map" refers to an "argument map", which is a type of diagram designed to show logical relationships in an argument.

Note: This is not intended or claimed to be an exhaustive logical analysis of the debate. If you think that there is some fallacy or logical point that I have overlooked, please let me know.

October 20th, 2012 (Permalink)

Second Presidential Debate Logic Check, Part 2

Probably the most controversial part of the second debate between President Obama and former governor Mitt Romney came in the following exchange concerning the terrorist attack upon the United States consulate in Libya that resulted in the death of the ambassador to that country and three others:

Romney: There were many days that passed before we knew whether this was a spontaneous demonstration, or actually whether it was a terrorist attack. And there was no demonstration involved. It was a terrorist attack and it took a long time for that to be told to the American people. Whether there was some misleading, or instead whether we just didn't know what happened, you have to ask yourself why didn't we know five days later when the ambassador to the United Nations went on TV to say that this was a demonstration. How could we have not known? …[Y]ou'd hope that during that time we could call in the people who were actually eyewitnesses. We've read their accounts now about what happened. It was very clear this was not a demonstration. This was an attack by terrorists. …

Crowley: … I want to ask you something, Mr. President, and then have the governor just quickly. Your secretary of state, as I'm sure you know, has said that she takes full responsibility for the attack on the diplomatic mission in Benghazi. Does the buck stop with your secretary of state as far as what went on here?

Obama: Secretary Clinton has done an extraordinary job. But she works for me. I'm the president and I'm always responsible, and that's why nobody's more interested in finding out exactly what happened than I do. The day after the attack, Governor, I stood in the Rose Garden and I told the American people and the world that we are going to find out exactly what happened. That this was an act of terror and I also said that we're going to hunt down those who committed this crime. … And the suggestion that anybody in my team, whether the Secretary of State, our U.N. Ambassador, anybody on my team would play politics or mislead when we've lost four of our own, governor, is offensive. That's not what we do. That's not what I do as president, that's not what I do as Commander in Chief.

Crowley: Governor, if you want to quickly to this please.

Romney: I think interesting the president just said something which is that on the day after the attack he went into the Rose Garden and said that this was an act of terror.

Obama: That's what I said.

Romney: You said in the Rose Garden the day after the attack it was an act of terror. It was not a spontaneous demonstration, is that what you're saying?

Obama: Please proceed, governor.

Romney: I want to make sure we get that for the record because it took the president 14 days before he called the attack in Benghazi an act of terror.

Obama: Get the transcript.

Crowley: He did in fact, sir.

Obama: Can you say that a little louder, Candy?

Crowley: He did call it an act of terror. It did as well take two weeks or so for the whole idea there being a riot out there about this tape to come out. You are correct about that.

Romney: The administration indicated this was a reaction to a video and was a spontaneous reaction.

Crowley: It did.

Romney: It took them a long time to say this was a terrorist act by a terrorist group.

Two aspects of this exchange have caused controversy: first, whether President Obama in fact referred to the attack as "an act of terror" the day after; and, second, whether Crowley should have interjected herself into the debate by agreeing that he had.

  1. Did Obama actually call the attack "an act of terror" the day after? Not exactly, though this is not as simple a question as you might think. The only such reference in his Rose Garden remarks was the following sentence: "No acts of terror will ever shake the resolve of this great nation, alter that character, or eclipse the light of the values that we stand for." This sentence does not refer directly to the Benghazi attack as "an act of terror"; rather, it's a claim about acts of terror in general, and what effects such acts won't have.

    However, a principle of communication is that what one says should be relevant to the topic of conversation. If the attack on the consulate were not an act of terror, the sentence would be irrelevant. Therefore, if Obama was abiding by the rules of communication, the attack must have been an act of terror after all. Thus, while Obama never directly referred to the attack as "an act of terror", he did suggest that it was one by talking about such acts in general while discussing it.

  2. Was moderator Candy Crowley wrong to take Obama's side on the above question? Crowley violated the rules of the debate as agreed upon by the two campaigns and the Commission on Presidential Debates (CPD) by intervening on one side, though it appears that she never agreed to abide by those rules. However, given the complexity of the question that she opined on, as discussed above, it was a mistake for her to get involved. She should have left the fact-checking to after-the-fact, rather than announcing that Obama had said something that he had at best suggested. At this point, it would seem that the only thing the CPD can do to punish Crowley, and deter future moderators from ignoring the rules, is to never invite her to moderate another debate.



October 18th, 2012 (Permalink)

Second Presidential Debate Logic Check

During the second presidential debate, the following exchange occurred between President Obama, moderator Candy Crowley, and former governor Mitt Romney:

Obama: Look, the cost of lowering rates for everybody across the board, 20 percent. Along with what he [Romney] also wants to do in terms of eliminating the estate tax, along with what he wants to do in terms of corporate changes in the tax code, it costs about $5 trillion. Governor Romney then also wants to spend $2 trillion on additional military programs…. That's $7 trillion. He also wants to continue the Bush tax cuts for the wealthiest Americans. That's another trillion dollars: that's $8 trillion. Now, what he says is he's going to make sure that this doesn't add to the deficit and he's going to cut middle class taxes. But when he's asked, how are you going to do it, which deductions, which loopholes are you going to close? He can't tell you. … We haven't heard from the governor any specifics beyond Big Bird and eliminating funding for Planned Parenthood in terms of how he pays for that. Now, Governor Romney was a very successful investor. If somebody came to you, Governor, with a plan that said, here, I want to spend $7 or $8 trillion, and then we're going to pay for it, but we can't tell you until maybe after the election how we're going to do it, you wouldn't take such a sketchy deal and neither should you, the American people, because the math doesn't add up. …

Crowley: …Governor, before we get into a vast array of who says, what study says what, if it shouldn't add up, if somehow when you get in there there isn't enough tax revenue coming in, if somehow the numbers don't add up, would you be willing to look again at a 20 percent….

Romney: Well, of course they add up. I was someone who ran businesses for 25 years, and balanced the budget. I ran the Olympics and balanced the budget. I ran the state of Massachusetts as a governor, to the extent any governor does, and balanced the budget all four years. When we're talking about math that doesn't add up, how about $4 trillion of deficits over the last four years, $5 trillion? That's math that doesn't add up. We have a president talking about someone's plan in a way that's completely foreign to what my real plan is. And then we have his own record, which is we have four consecutive years where he said when he was running for office, he would cut the deficit in half. Instead he's doubled it. We've gone from $10 trillion of national debt, to $16 trillion of national debt. If the president were reelected, we'd go to almost $20 trillion of national debt. This puts us on a road to Greece. I know what it takes to balance budgets. I've done it my entire life.

Obama advances a common criticism of Romney's plan, namely, that it is mathematically impossible to lower tax rates on all taxpayers while reducing deductions for high income people so that the percentage of taxes paid by the wealthy remains the same. Some doubt whether there are enough deductions to do this, and Romney has not specified which ones he would reduce.

After Obama's remarks, Crowley tries to ask a hypothetical question, but Romney interrupts her so that it isn't completely clear what she meant. Presumably, she intended to ask whether, if the reductions of deductions weren't equal to the loss of tax revenue for the top taxpayers, Romney would ease off the tax cuts.

However, Romney dodged Crowley's hypothetical question by rejecting the hypothesis, that is, insisting that the numbers will "add up". This is a version what Nigel Warburton calls the "no hypotheticals move", which he describes as follows:

…[S]ome people in positions of authority have devised a way of avoiding commitment to particular courses of action. Whenever they are asked a question about what they would do in some hypothetical situation they respond that that is irrelevant and that they needn't answer questions about what might happen: they have to deal with the real world, not an imaginary one.

In this case, Romney dodges the question by denying that the hypothesis is possible. He goes on to list his experience at balancing budgets, then turns the attack back against Obama's unbalanced budgets. Perhaps he's right about being able to pay for the tax cuts with reduced deductions, and if we knew exactly how he plans to do that maybe we would see it, but without the details we just have to take his word for it.



October 13th, 2012 (Permalink)

Vice Presidential Debate Logic Check

One job of the moderator of a political debate is to supply the specific propositions that the debaters are then to either attack or defend. Consider, for instance, the first question asked by moderator Martha Raddatz in the recent Vice Presidential debate:

Raddatz: … One month ago tonight, on the anniversary of 9/11, Ambassador Chris Stevens and three other brave Americans were killed in a terrorist attack in Benghazi. The State Department has now made clear there were no protesters there. It was a pre-planned assault by heavily armed men. Wasn't this a massive intelligence failure, Vice President Biden?

Raddatz has set up the first issue for Vice President Biden and Congressman Paul Ryan to debate: Was the terrorist attack in Benghazi the result of a massive intelligence failure? Now, this is a yes/no question, but neither candidate is expected to simply answer "yes" or "no". Rather, it is their job to argue for or against the proposition that the terrorist attack was the result of a massive intelligence failure. Because the attack took place while Biden was vice president, his job is to argue either that the attack was not the result of an intelligence failure, or that it was but that it does not reflect badly upon the Obama administration. Ryan, in his turn, would be expected to argue that the attack was indeed the result of an intelligence failure, and that the Obama administration is to blame for that failure.

Keeping that in mind, here is Biden's complete answer to the question:

Vice President Joe Biden: What it was, it was a tragedy, Martha. Chris Stevens was one of our best. We lost three other brave Americans. And I can make absolutely two commitments to you and all of the American people tonight: One, we will find and bring to justice the men who did this. And secondly, we will get to the bottom of it, and wherever the facts lead us, wherever they lead us, we will make clear to the American public, because whatever mistakes were made will not be made again. When you're looking at a president, Martha, it seems to me that you should take a look at his most important responsibility. That's carrying forward the national security of the country. And the best way to do that is take a look at how he's handled the issues of the day. On Iraq, the president said he would end the war. Governor Romney said that was a tragic mistake; we should have left 30,000 troops there. With regard to Afghanistan, he said he will end the war in 2014. Governor Romney said we should not set a date, number one, and number two, with regard to 2014, it depends. When it came to Osama bin Laden, the president, the first day in office, I was sitting with him in the Oval Office. He called in the CIA and signed an order saying, my highest priority is to get bin Laden. Prior to the election, prior to him being sworn in, Governor Romney was asked a question about how he would proceed. He said, I wouldn't move heaven and earth to get bin Laden. He didn't understand it was more than about taking a murderer off the battlefield; it was about restoring America's heart and letting terrorists around the world know if you do harm to America, we will track you to the gates of hell, if need be. And lastly, the president of the United States has led with a steady hand and clear vision. Governor Romney, the opposite. The last thing we need now is another war.

A basic principle of reasoning―of "critical thinking", if you will―is to keep your eye on the ball. All of those fallacies that fall under the broad category of "red herrings" involve irrelevancies that may cause you to lose track of an argument, and thus not realize that either no evidence has been given to support a conclusion, or that the evidence given supports a different conclusion than that the arguer set out to defend.

I included all of Biden's answer, above, because it's necessary to see that nowhere does he answer Raddatz' question, nor even address it directly. Recall that the question was whether there was an intelligence failure involved in the terrorist attack: keep your eye on the ball! The closest that the vice president comes to addressing this is in his claim that "whatever mistakes were made will not be made again", which admits that mistakes may have been made, but not whether they were intelligence failures. In fact, only Biden's first few sentences have even indirect bearing on Raddatz' question, after which he goes off on a general speech about foreign policy for the rest of his answer. The only relationship most of Biden's speech has to the question is that both involve foreign policy, but the answer is long enough that many viewers of the debate on television, or listeners on radio―and perhaps even those who read the transcript, above!―will have forgotten what the question was by the time Biden finishes.

I point this out not because this is an unusual example, but because it's a typical case of "the politician's answer", as Nigel Warburton has called it:

A kind of irrelevance which is often encountered when politicians are interviewed…. It is a rhetorical technique…by which they avoid giving direct answers to questions which they don't really want to answer in public. Instead of giving a direct answer to a direct question, the politician delivers a short…speech on a related topic. The trick is to make the speech internally coherent; thus the politician seems to give a confident and plausible performance in response to what should be probing questions. This diversionary tactic allows him…to avoid giving an honest response to a potentially damaging question and also provides air time for a short party political broadcast.

That could almost be a description of Biden's answer!

Another job of the moderator should be to at least make an effort to keep the debaters on topic, and should this prove impossible, to remind the audience of what the question was so that it is obvious when one has been ducked. Raddatz made no attempt to keep Biden on topic, nor to point out his failure to do so, but perhaps she had forgotten her own question!

Moreover, when Raddatz turned to Ryan to respond to Biden, she missed a perfect opportunity to ask the question again. Ryan also fails to address the original question (I won't quote his response at length; see the transcript if you're interested), and misses the opportunity to criticize his opponents for an intelligence failure leading to the attack, but perhaps by then everyone had forgotten the question.

Unfortunately, Raddatz' performance as moderator did not improve much as the debate wore on, though she did do a better job later in pressing Ryan to answer a question about keeping troops in Afghanistan. Hopefully, future debate moderators will be better able to keep the debate on topic, as well as stop the debaters from constantly interrupting each other.


Fallacy: Red Herring


October 9th, 2012 (Permalink)


The Internet Blowhard’s Favorite Phrase

Why do people love to say that correlation does not imply causation?

It may be no big news that Slate sometimes runs misleading headlines, presumably as a bait and switch tactic to trick people into reading the article. Usually it turns out that the article isn't about what the headline claims, but something more modest and less interesting. For instance, a recent article was headlined "The Worst Nobel Prize", with the subheadline "Who is the least deserving Nobel laureate of all time?" However, if the headline fools you into reading the article, you find out that it limits itself to Nobel Prizes in the sciences, excluding by definition such Peace Prize recipients as Yasser Arafat and Rigoberta Menchú Tum.

In the case of the headline above, the obvious answer to the question asked by the subheadline is: "Because it's true". The article itself eventually admits this: "No, correlation does not imply causation…." However, after a handful of supposed examples of the phrase being misused, author Daniel Engber asks: "So how did a stats-class admonition become so misused and so widespread?" Do people occasionally misuse the phrase "correlation does not imply causation"? Of course, but a few examples doesn't show that such misuse is common.

Engber proceeds to give statistical evidence that use of the phrase has increased in the past sixty years. This is good news! It's evidence that not all of the effort made by scientists, statisticians, and logicians to educate the public has been in vain. Of course, it's likely that as the catchphrase has gained wider currency it's also misused more often, but Engber gives no evidence that the bad has outweighed the good from this change.

Speaking of correlations―or, more accurately, the lack thereof―Engber seems to think that the spread of the phrase has something to do with the internet, yet according to the charts he gives its use has grown fairly steadily―except for dips in the '80s and '00s―starting around 1950, long before the internet. However, despite what Engber suggests, lack of correlation doesn't imply lack of causation, either (see the "Q&A" in the Resources, below). It's still possible that the internet has causally contributed to the spread of the phrase and, if so, more power to the internet!

What Engber doesn't consider is why people seem to feel the need to repeat this catchphrase. One answer is that we are inundated by media reports of statistical studies that make causal claims when all that has been found are correlations (see the Resources, below, for a few examples). The fault is seldom with the studies themselves, and the scientists involved are usually careful not to make unjustified claims of causation. Rather, it is science journalists who choose to report correlations as causal relations. If Engber is so bothered by the phrase, perhaps he should turn his wrath on his fellow reporters and not on those who repeatedly correct them.



October 4th, 2012 (Permalink)

Presidential Debate Logic Check


Resource: Update (6/3/2004), 6/3/2004

Note: This is not intended or claimed to be an exhaustive logical analysis of the debate. If you think that there is some fallacy or logical point that I have overlooked, please let me know.

October 3rd, 2012 (Permalink)

Pre-Debate Warm-Up

It's getting close to that scary time again. No, I don't mean Halloween; I mean the time before the election when the presidential candidates debate. The first debate is tonight, but I probably won't have anything to say about it until tomorrow at the earliest. One reason is that I prefer to read the debate transcript rather than watch it on television. It's easier to concentrate on the logical aspects without the distractions of the candidates' appearances and other visual and auditory irrelevancies.

Rob Garver writes with a question about the debates:

We are faced with a series of high-profile presidential debates in the next few weeks. Everybody knows the most common logical fallacies that politicians employ: the Straw Man, the Slippery Slope, etc. But when the Fallacist watches politicians talk, what are some of the more subtle logical fallacies he commonly notices?

I think that full-fledged logical fallacies are less likely to occur than what I call logical boobytraps, which are uses of language with the potential of misleading the audience: vagueness, over-generality, loaded words, and doublespeak. The politicians of today seem to avoid making explicit arguments as much as possible. Specifically, one thing to look for is whether the candidates give direct answers to questions, or instead go off on scripted talking points. When they address an issue, do they give specifics or use "glittering generalities"? Beware of the "politician's answer" to a question, that is, an answer that doesn't answer the question but dodges it.

Another point: don't neglect the questions asked by the moderator, reporters, or occasional members of the audience. Reporters seem to think that asking loaded questions constitutes "tough" questioning, but this actually encourages the candidate to dodge the question since there's no way of directly answering it without admitting something that the politician doesn't want to admit.

I've done weblog entries on the presidential debates since 2004 (see the table below), and one way to logically prepare for the debates would be to review those entries.

Weblog Entries on Debate Fallacies
2004 2007 2008 2011 2012
10/3 6/4 10/3 10/13 1/19
10/4 6/8 10/9 10/22
10/5 7/25 10/16 11/26
10/9 9/27
10/13 10/22


Solution to a Second Puzzling List: Only the next-to-last sentence―that is, sentence n minus 1―is true. Thus, n-1 sentences are false.

This puzzle is a generalization of the previous puzzling list (see the Resource, above): as we saw in the previous puzzle, at most one of the sentences can be true, since each sentence is inconsistent with every other sentence on the list. But what if all of the sentences are false? In that case, exactly n sentences on the list would be false. However, that's just what the last sentence on the list says, which would make it true. So, exactly one of the sentences on the list is true.

If exactly one sentence on the list is true, then exactly n-1 sentences are false. However, the next-to-last sentence on the list says that exactly n-1 sentences on the list are false. Therefore, sentence n-1 is the only true sentence on the list.

Notice that, since we didn't specify what number n is, this holds true for any finite list of similar sentences: for any such list, the next-to-last sentence will be true and all of the other sentences false. How about that!

Source: Martin Gardner, Knotted Doughnuts and Other Mathematical Entertainments (1986). The puzzle was suggested by one on page 70.

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