Maggie's Farm

This fallacy site defines this fallacy as simply: "The appeal to pity takes place when an arguer tries to get people to accept a conclusion by making them feel sorry for someone."

Classic example: The boy who killed his parents pleads for mercy from the judge on the grounds of being an orphan.

Of course, pity is just one of the emotions which can be manipulated in order to attempt to overwhelm reason and to score points.

While a member of Congress from his home state of Tennessee, Davy Crockett is believed to have given a successful speech refuting an appeal to pity, regarding a Congressional appropriation of money to a widow:

"Mr. Speaker -- I have as much respect for the memory of the deceased, and as much sympathy for the sufferings of the living, if suffering there be, as any man in this House, but we must not permit our respect for the dead or our sympathy for a part of the living to lead us into an act of injustice to the balance of the living. I will not go into an argument to prove that Congress has no power to appropriate this money as an act of charity. Every member upon this floor knows it. We have the right, as individuals, to give away as much of our own money as we please in charity; but as members of Congress we have no right so to appropriate a dollar of the public money. Some eloquent appeals have been made to us upon the ground that it is a debt due the deceased. Mr. Speaker, the deceased lived long after the close of the war; he was in office to the day of his death, and I have never heard that the Government was in arrears to him. This Government can owe no debts but for services rendered, and at a stipulated price. If it is a debt, how much is it? Has it been audited, and the amount due ascertained? If it is a debt, this is not the place to present it for payment, or to have its merits examined. If it is a debt, we owe more than we can ever hope to pay, for we owe the widow of every soldier who fought in the war of 1812 precisely the same amount. There is a woman in my neighborhood, the widow of as gallant a man as ever shouldered a musket. He fell in battle. She is as good in every respect as this lady, and is as poor. She is earning her daily bread by her daily labor, and if I were to introduce a bill to appropriate five or ten thousand dollars for her benefit, I should be laughed at, and my bill would not get five votes in this House. There are thousands of widows in the country just such as the one I have spoken of; but we never hear of any of these large debts to them. Sir, this is no debt. The Government did not owe it to the deceased when he was alive; it could not contract it after he died. I do not wish to be rude, but I must be plain. Every man in this House knows it is not a debt. We cannot, without the grossest corruption, appropriate this money as the payment of a debt. We have not the semblance of authority to appropriate it as a charity. Mr. Speaker, I have said we have the right to give as much money of our own as we please. I am the poorest man on this floor. I cannot vote for this bill, but I will give one week's pay to the object, and if every member of Congress will do the same, it will amount to more than the bill asks."

That is one heck of a good argument - and an argument for the restraint of government as well. Crockett had the good sense to eliminate the tone of cold-hearted rationality with his offer at the end. More about the speech and its aftermath here.

Interesting fellow, Crockett. He was elected twice to Congress, then defeated twice, after which he said  "I told the people of my district that I would serve them as faithfully as I had done; but if not ... you may all go to hell, and I will go to Texas."

Which he did, and was killed by the Mexican Army while defending the Alamo in 1836.

Image: David Crockett (1786-1836)

Roberts at Cafe Hayek had an intriguing (at least for us who are only marginally economically  literate) piece on the limits of measurement, and the abuse of measurement, in economics. It's titled Fooling Ourselves. One quote:

...how many (other) studies can you think of where someone staked out a controversial position and convinced the skeptics based on empirical analysis? I think it can be done, but it's rare. And in today's world, most of the interesting empirical claims are being made in cases where  the data are too incomplete and the issue is so complex that we can't move to a consensus. The empirical work doesn't improve our understanding of what's going on. It masks what's going on. It gives a patina of science when in effect the numbers aren't really informing the debate.

The whole short piece is here.

Indeed, the fact that something is measurable does not render it meaningful, and not everything that is meaningful is measurable.

Economics is, of course, a "social science" and not hard science. We recently posted Data Mining and Junk Science in which we discuss some of the limits and misuses of the harder sciences.

Scientists know that all data is provisional and deserves skepticism, that most theories have a finite life span, and that capital "T" Truth is more of a metaphysical or religious concept than it is the subject of math and science.

Photo: Those of us who are my age remember these nifty tools well. To the youngsters: that is a slide rule.

Hindsight Bias, by the Great Kling at TCS.

Because we all have thousands of thoughts every day, the odds that we might have some good ones is inevitable. And, sadly, the "Law of Unintended Consequences" is always in force too: it's a law of nature, so we should never be surprised by unfortunate results.

"That's my story and I'm sticking to it." Bill Clinton

The Cognitive Psychological concept of "Confirmation Bias" falls under the broader scope of my Fallacy and Logic portfolio here at Maggie's Farm.

Furthermore, it fits well into one of the main themes of Maggie's, which is to detect the insidious and fact-defying "narratives" by which we busy citizens are presented information by politicians and news organizations.

I have no doubt that we are sometimes guilty of both Confirmation Bias and Selection Bias at times - but we try to be aware of it, just as we try to be aware of the flaws of inductive reasoning. "One swallow does not make a summer", we try to remind ourselves. On the other hand, much of common sense consists of inductive "reasoning" wherein we happily greet the first swallow of summer.

This comes up today because our editor emailed me a short piece by Protein Wisdom comparing a Michael Yon Iraq report with a WaPo report. Of course, I tend to go with the Yon because he is on the ground and has no axe to grind, while I know full well that the WaPo, like the NYT, is fighting a propaganda battle and weeding out the news that will interfere with their narrative du jour.

Real life is too complex and messy for neat narratives and clean stories. That's why we love them so much. And that is why politicians and the MSM and trial lawyers, and anyone with an agenda, try to feed simple fairy tales to us.

One thing I often find myself wondering about these common biases is to what extent they are conscious manipulations, and to what extent they are automatic. With politicians, of course, one can assume that they are calculated manipulations most of the time, because those folks need the job and they need the attention.

On the other hand, I know plenty of people who just don't take in information that would conflict with their narrative about something (selection bias), and only permit into their brains information which seems to be consistent with the narrative they have adopted (confirmation bias). I have been guilty of that plenty of times, but I am more aware of it now when I am tempted.

We humans would be more rational beings if we dumped all of the fairy tales and worried about facts. Alas, "facts" can be subject to the same biases, as every scientist and attorney knows all too well.

Still, "Facts are stubborn things." - Ronald Reagan

I have been lax with our fallacy fun, but suddenly some good'uns are thrown in my face. Reductio ad absurdum is not really a logical fallacy but, at its worse, a fallacy support and, at its best, a fairly compelling logical argument, eg (from Wiki):

Father- Why did you start smoking?

Daughter - All my friends were doing it.

Father- You're saying that if all your friends jumped off a cliff, you would do that too?

Reductio can serve the purpose of truth or the purpose of fallaciousness. Example:

"If we can go into Iraq to take out a murderous dictator, then we should take out every murderous dictator on earth."

As with the Slippery Slope Fallacy, some credibility is obtained via the logical thread, but the germ of logicality is rendered trivial by the reality and the context.

Attack Machine invented the entirely reasonable and useful notion of Dilatare ad Absurdum: Expansion to Absurdity. He presents a beautiful example of expansion to absurdity in a piece on the equating of basic human needs with human rights. In his example, both reality and context support the dilatare. It begins:

LA Mayor Antonio recently gushed, “Healthcare is a basic human need, and it ought to be a basic human right.”

If healthcare is a right, then:

• Food must be a right, too. After all, you cannot be healthy if you don’t eat.
• Clothing is a right because you cannot be healthy and naked (in most parts of the world.)

Read the whole thing. I like it. It's similar to the arguments I use to crush all of my commie friends, such as "People need cars to get to work. So why can't we all get free cars and free car insurance?" Or "Legal representation is a basic human right in a free country, so why don't we all get free lawyers?"

The Traveller's Dilemma. It's a variation on the Prisoner's Dilemma, but what is interesting about these games is to play them yourself multiple times, and see what happens. We like Game Theory, but the math eludes us as this point.

But it's not just about math - it's about how illogicality can often be logical. Here's the premise:

Lucy and Pete, returning from a remote Pacific island, find that the airline has damaged the identical antiques that each had purchased. An airline manager says that he is happy to compensate them but is handicapped by being clueless about the value of these strange objects. Simply asking the travelers for the price is hopeless, he figures, for they will inflate it.

Instead he devises a more complicated scheme. He asks each of them to write down the price of the antique as any dollar integer between 2 and 100 without conferring together. If both write the same number, he will take that to be the true price, and he will pay each of them that amount. But if they write different numbers, he will assume that the lower one is the actual price and that the person writing the higher number is cheating. In that case, he will pay both of them the lower number along with a bonus and a penalty--the person who wrote the lower number will get $2 more as a reward for honesty and the one who wrote the higher number will get $2 less as a punishment. For instance, if Lucy writes 46 and Pete writes 100, Lucy will get $48 and Pete will get $44.

What numbers will Lucy and Pete write? What number would you write?

To keep it simple, play with three people - same as The Prisoner's Dilemma. You play it over and over. Of course, they cannot discuss the strategy together.

Here's a succinct description of the Prisoner's Dilemma, from this site:

In this hypothetical situation, two accomplices to a crime are imprisoned, and they forge a pact to not betray one another and not confess to the crime. The severity of the punishment that each receives is determined not only by his or her behavior, but also by the behavior of his or her accomplice. The two prisoners are separated and cannot communicate with each other. Each is told that there are four possible outcomes:

- If one confesses to the crime and turns in the accomplice (defecting from a pact with the accomplice), his sentence will be reduced.

- If one confesses while the accomplice does not (i.e. the accomplice cooperates with the pact to not betray each other), the first can strike a deal with the police, and will be set free. But the information he provides will be used to incriminate his accomplice, who will receive the maximum sentence.

- If both prisoners confess to the crime (i.e. both defect from their pact), then each receives a reduced sentence, but neither is set free.

It's fun for two people to play this game repetitively, and see who wins over time.

My idea was to write up something about that Prisoner's Dilemma game, but then I got lured away by the topic of the Tragedy of the Commons. Game Theory ties these subjects together, and so those subjects may need to wait a bit.

My calculus is not what it used to be but, as an attorney, I still find that Game Theory has its appeal for me.

Appeal, if not too much practical utility, because Game Theory tends to assume some degree of rationality, and humans are only rational on occasion.  Indeed, one reason for hiring an attorney is to apply some degree of objective rationality to a situation. Still, I believe that formal Game Theory - as opposed to normal legal strategizing - can inform legal practice. Here's a nice summary of the book Game Theory and the Law, which has some good references at the bottom.

People are often gaming things, aren't they? There's a survival instinct to make the most of a situation to best achieve your own goals. Only conscience, character, tradition, care for others, and the desire for the respect and trust of others stand in the way of humanity's being a pure gaming, calculating, scheming, strategic machine. We consider people who operate that way all the time as sociopathic.

When I studied calculus in college, the teachers were all into game theory. Their heros were von Neumann, Morgenstern, and of course the great John Nash, who elaborated the Nash Equilibrium - and who can still be seen wandering around Princeton - about whom Sylvia Nasar wrote the fascinating book, and then Ron Howard produced the wonderful "Best Picture" Beautiful Mind.

The spiritual home of Game Theory is the RAND Corporation, where very smart people work on interesting economic, military, and policy problems. I was interested to find that they have a graduate program. That would be one cool place to hang out for a while, in Santa Monica.

OK, this is already long enough and, as usual with my occasional rambles, I arrived both nowhere and somewhere. I will do the Tragedy of the Commons - more accurately termed The Tragedy of the Unregulated Commons (since, historically, all commoners (those with the right of commons) were of necessity highly regulated either by tradition or by law) - sometime soon. And eventually work my way back into the Prisoner's Dilemma.

I have been truant with our Fallacies for a while, but I figure I do them as much for myself as for our readers.

By posing, or implying, a false dilemma, you put the other guy off balance for a moment. Like most fallacies, it works because we, in the Western World, tend to give the other guy the benefit of the doubt and to assume his logical integrity. Wrong! He just might be working an agenda.

Always watch out for "either A or B" arguments. Examples:

1. A classic: "If the glove don't fit, you must acquit." Why? Aren't there other considerations? What if they weren't the same gloves? What if they shrunk from the blood? What if he didn't care whether they were a nice fit or not?  He got the jury going, though - and the rhyme helped.

2. "You believe in choice? What are you, some sort of baby-killer?" You see how false dilemmas give the illusion of a sharply-divided reality. What can you say? "No, wait - I never killed a baby..." and you are on the defensive right away.

3. A famous Christian one: "Either Christ was the son of God, or he was a con-man or a loony." I worship Him, but not because of this false dilemma.

4. "If you're not part of the solution, you're part of the problem." This false dilemma tugs at one's guilt a little, until you see the trick that is being pulled. After all, what if there is nothing meaningful I can do about it? Or what if I don't care? Or what if I think it's a minor problem? Or what if managing my own life is all I can handle? Or what if saving the world just isn't my bag?

Image: The late, great defence lawyer Johnny Cochran.

It was clear to me that the point Michael Crichton made in his speech we linked was that linear thinking does not accurately describe the world, or predict events.

Indeed it does not. Linear thinking is the domain of dangerous oversimplification and distortion - if not superstitious and magical thinking - most of the time. And especially when organisms are involved.

I am referring to linear thinking of the type that A leads to B. As an example that Crichton might have used, I recently read a medical piece about the illusion that germs cause disease. We know they don't -germs tend to be a necessary but not sufficient cause for infection. It requires the alignment of many stars to get a lung infection with pneumococcus, a germ which is everywhere. Thus the "fallacy of the single cause."

We love simplicity so we don't blow up our brains' hard drives, but simplicity (linearity) renders us vulnerable to all sorts of irrationality, such as the temptations of the fallacy of the single cause, cum hoc ergo propter hoc, and, everyone's favorite,  post hoc ergo propter hoc thinking.

The Global Warming fans are especially prone to the Texas Sharpshooter Fallacy, probably because they know nothing about statistics and graph-creation - leaving them also subject to the ipse dixit fallacy. The Cherry Picking fallacy is another one prefered by those who are more agenda-driven than fact-driven. All of this is boob bait, like that Polar Bear photo.

As we quoted Edward Murrow last week, "Anyone who isn't confused really doesn't understand the situation."

Update: Working on those links that don't work - a bug in the system.

From Stumbling and Mumbling:

Given a choice between £44,000 for sure and a 50-50 chance of either £3,000 or £250,000, which would you choose?

Risk and risk aversion can be "logically illogical." Read the piece. This is the reason Captain Kirk was the Captain, not Mr. Spock, even though Mr. Spock had a higher IQ.

How many of these did you get wrong?

An excellent and amusing video (10 or so quick and worthwhile minutes) of Peter Donnelly discussing common statistical errors. (h/t, Junk Science)

It's about time for another fun fallacy.

This one goes back to the astonishing Aristotle, and hence to the Roman Petitio Principii.

That is, pleading, or begging for the premise to be accepted.

What is fun about this fallacy is that the statements may be fully logical, but erroneous because they are circular: if you accept the premise, then the conclusion logically follows. As in: My premise is A=B, so I will create another assertion which implies, or is built on, or derives from, the notion that A=B.

The classic example of this form of logic abuse is "When did you stop beating your wife?" The premise contains the accusatory conclusion.

Also known as "circular arguments," such arguments can seem persuasive if you don't step back and examine the often-hidden premise. They are technically "informal fallacies," because the error is not within the "form" of the argument: the form can be fine while the basis is flawed.

Example: God created the earth and its creatures five thousand years ago. Well, that hidden premise is that every word of the Bible is scientifically and chronologically true according to modern thinking. If you accept the premise, then I suppose you must accept the conclusion.

Example: Massachusetts politicians alarmed by rapid erosion of Cape Cod: Blame Bush's global warming. Hidden premise/assumption: man-made warming is raising sea levels and washing Cape Cod out to sea. Of course, there is no evidence for that mechanism - Cape Cod was disappearing in Thoreau's time, and he commented on it. The wise will buy Monomoy Island real estate, which is where the sand is being deposited. Hey - it's the next Nantucket.

Example: All of the money from our healthy economy is going into the pockets of wealthy corporate thieves. The notion, or premise, that wealth consists of a finite number of dollars is a famous fallacious assumption of the economically illiterate. If that premise were true, the socialists would have an argument. But the premise is wrong: wealth is created, almost miraculously, out of work, investment, creativity, and risk. There is no end to it.

Another famous example which contains this fallacy, from the late, lamented Johnny Cochran:  "If the glove don't fit, you must acquit." How many assumptions are built into that assertion, besides the stated one? Enough for an acquittal by a jury which couldn't see his tricks, or refused to. The assumptions of the premise were, of course, that a murderer would only wear gloves that fit well, that blood-soaked gloves would not shrink, etc etc - but, most of all, the assumption that the jury would welcome any excuse to acquit. They took the bait and swallowed the hook, too.

Always examine the premise or assumption of an argument before taking on the logical flow. They are commonly hidden, or implied by tricksters so that it all seems to make sense if the premise is accepted. That is Rule #1.

This is the final piece of our mini-series on The Risk of Inaction, and Type 1 and Type 2 errors. With a final word about luck.

Last week we talked about the Null Hypothesis (Part 1), and Type 1 and Type 2 errors using the example of appendicitis, and we talked about the often-reciprocal relationship between Type 1 and Type 2 errors - when you reduce one, the other rises (Part 2).

(By the way, Here's a site that discusses in detail how Type 1 and Type 2 errors work, in the judicial system.)

And I mentioned that it seems to be human nature to focus on the risks of action more than on the risks of inaction. It's as if we have a bias for the Null Hypothesis, and a wishful neglect of False Negative errors. "Don't worry about it." "If it ain't broke, don't fix it." Or, in the words of Mark Twain, "I have known a great many troubles, but most of them never happened." Oftentimes, that is true. Not always. Inaction is just a special sort of action.

Today, a few more examples from regular life.

1. I have heard Bob Brinker say this many times: If you own a stock, but would not buy that stock today at its current price, sell it (unless tax considerations trump that logic). Traders and professional investors think as much about selling or shorting as they do about buying, but my experience is that the regular retail investor puts much more thought into buying than selling.

Thus the amateur tends to think of the risk as being front-loaded - it feels as if the risk lies in the buying. (There is a huge literature on the psychology of perceived risk.)

However, the truth is that the risk of buying and of selling are comparable. Somehow, owning the stock psychologically comes to feel like a new Null Hypothesis, and the default position. That is illogical, Captain.

2. One of the wisdom themes that I hand out to my grandkids is this: Life is just a conveyor belt of opportunity, but they only pass by once. Jobs, friends, fun - everything. You usually get only one chance - well, sometimes more if you're lucky - before the thing or the moment passes you by. But we often let them pass by, for fear of error, or for excessive bias towards the Null Hypothesis (eg "there is nothing here"). Thus life gradually fills up with the regrets of lost chances.

When I was young, I was timid with charming girls. I'd gin up some courage to say "Hey" to one, and end up with pain and humiliation (False Positive, Type 1 error). I said "Hey" to another, and ended up with a year of grief and confusion (False Positive, again, in the end). Eventually, I said "Hey" to one, and it worked out just fine, to this day. But you always wonder - how many False Negatives did I overlook, for fear of the unpleasant False Positives?

Risk-aversion can be a blessing, but also a paralyzing curse. The most relevant example below.

3.  Invading Afghanistan and Iraq, to bring the fight to "them." Man, those were some tough decisions: I wouldn't want the job of making them, (but I have no problem second-guessing them after the fact, from my armchair). The evidence for the Null Hypothesis - "There is nothing of concern here" was adequately disproven by evidence. Bill Clinton was paralyzed by fear of Type 1 errors, although he had little reason for that. In the process, he ignored the risk of inaction - which was extremely serious.

Recently in the news, Bill Clinton complained that he had no chances to deal with terrorism - no opportunities to be a hero. Wrong. Truth is, he was too worried about False Positives, and doing something in error. But what about the False negatives concern on the other side of the debate?

As Anchoress reminds us, he had plenty of opportunities to deal with terrorism, but wimped out, while blaming history for not giving him chances to do something. Didn't WTC 1, and the Cole, and Somalia happen while he was Pres? He had opportunities, but declined to engage them, like someone who is so fearful of buying stocks that they end up ten years behind.

Mitchell at Democracy Project points this out with great clarity. What are the risks of NOT taking the fight to the jihadists? Well, the risk would be, probably, getting more of the same from an emboldened Jihad. When we focus too much on error and risk, we can miss taking account of Opportunity Cost: there is a life price paid for every missed opportunity, as all grown-ups know - to their chagrin.

Decisions that involve life and death are tough. But fear of error can cause many missed opportunities to do what might be best. Yes, there is risk. Always. However, chosing not to act can be as consequential a decision, in life, as chosing to act.

As I see it, the people who take Opportunity Costs and False Negatives into account when making their choices are often called "lucky."

I knew a Beagle named Lucky. Got hit by a car but survived, grew old, and died.

The null hypothesis is not a logical fallacy. We are discussing it as a base for further discussions of fallacies in future posts on the subject of the risks of action vs. inaction and Type 1 and Type 2 errors.

Outside of the world of statistics, the "null hypothesis" has become equated with the "nil hypothesis," which means, basically, nothing. That is to say, that nothing occurred that was not by chance or accident, or maybe by undiscovered or undiscussed causes. Thus it is a handy tool to use as a starting point for an honest discussion, debate, or argument.

The null hypothesis is what many logical arguments ultimately argue about, or around, whether it is made explicit or not (it is a basic assumption of thinking in Western Civilization). When a null hypothesis is not assumed, a case for something is often termed "biased." (As we will discuss in a future post, "bias" is often a very useful and reality-oriented posture, and is the reason we do not look for Bluebirds in Brooklyn.)

In law, the null hypothesis is the presumption of innocence. In science, it is the presumption that there is no connection between two phenomena. (Scientists and social scientists often complain that it is difficult to publish papers which support null hypotheses.) Hypotheses other than null hypotheses are often termed "alternative hypotheses."  In general, it is easier to destroy an hypothesis than to prove one: proof is usually too much to ask for.

Let's take one incendiary example:

Null hypothesis: Blacks are not economically discriminated against, and there is nothing of interest here to debate or discuss.

Fact: Black households have lower incomes than white households.

Hypothesis #1: Employers pay blacks less money, or blacks get lower-paying jobs because of their color.

Fact: Black households with intact marriages have essentially the same average family incomes as whites, but blacks have very high rates of unmarried families.

Logical conclusion: An extraneous factor, such as marital status, may be determining the data, not skin color. The null hypothesis is supported by these facts.

A liability example:

Null hypothesis: Jim is innocent of liability or neglect.

Fact: Jim had no proper fence around his pool, and the neighbor's beloved Shitsu wandered over, fell in, and drowned, so the neighbor wants $100,000. for pain and suffering.

Hypothesis: Jim is guilty of not properly fencing his pool.

Fact: Hurricane Jose knocked down his pool fence a week ago.

Logical conclusion: Facts support the null hypothesis. Jim is innocent of negligence because of an accident of nature.

A vegetable example:

Null hypothesis: What you eat has no relationship with colon cancer.

Fact: People who eat lots of broccoli have lower rates of colon cancer.

Hypothesis #2: Broccoli helps prevent colon cancer.

Fact: People who eat broccoli tend to eat lots of other veggies too.

Hypothesis #3: Eating lots of veggies helps reduce colon cancer rates.

Fact: Volume of dietary roughage (cellulose) probably correlates with reduced rates of colon cancer.

Logical conclusion: The null hypothesis is probably wrong. There is some relationship, although causality is not demonstrated (that would be a cum hoc ergo propter hoc fallacy - a favorite fallacy of litigators). You might reduce your risk of colon cancer a bit by eating plenty of daily veggies and salads. (Still, your genes - or your GI doctor -  may determine the outcome, eventually.)

We wll build on this null hypothesis subject in the next Fallacy posting, which will highlight Type l and Type ll  errors.

More on the subject of the very important Null Hypothesis here. (I enjoy giving myself this elementary refresher - hope you like it too. Next installment probably on Thursday.)

Wierd conspiracy theories could not exist without this handy fallacy, but it is one for which juries are often total suckers.

Argumetium ad ignorantium -  "argument from ignorance", or "argument from incredulity", does not mean argument from stupidity - it means argument from a proposition which cannot be proven as fact, or from a proposition which cannot readily be disproven due to "ignorance" - eg lack of data.

The lack of certain evidence for, or against, something does not make it either untrue, or believeable. Nor does the lack of certain evidence for something make an alternative theory more likely to be true.

"It's hard to believe that a couple of terrorists knocked down the Trade Center, so it seems that Bush and the Israelis must have blown up the World Trade Center towers, and faked the TV images with the cooperation of TV news, so Bush could go into Iraq to get free oil to reward his rich friends. It's a huge conspiracy for the benefit of the Illuminati."

Prove that is wrong. It is amazingly easy to make propositions which are simple lies, or absurd, but difficult to prove wrong. Thus you raise doubt, which can appeal to the paranoid part of people.

Here's another: "Abe Lincoln greatly enjoyed his male friends and colleagues, so he probably was gay."  Prove that isn't true.

"The authors of the Second Amendment could not have intended that Americans should be killing eachother by having guns to protect their homes, so we should ban guns."  Well, name me one of those guy's families which had no guns in their homes, but it's a bit late to do a poll now, so you can assert anything you want, based on your bias.  I'd bet every one of the Founders had many guns in their home.

Or, "Would my client, an experienced driver, forget to put n his parking brake? Impossible. My client deliberately declined to put on his parking brake, because he was afraid that the brake might fail on his '57 convertible Chevy, so he put it safely in "park" before it unfortunately, and tragically, but innocently, rolled down over all of those nice families at the beach."

Try to prove I am wrong on that. Doubt? He's a nice guy - your next-door neighbor -  not a murderer or a manslaughterer. He just likes antique Chevys, like we all do.