Logical Fallacies - How to win every argument

From Purdue Online Writing Lab

Fallacies are common errors in reasoning that will undermine the logic of your argument. Fallacies can be either illegitimate arguments or irrelevant points, and are often identified because they lack evidence that supports their claim. Avoid these common fallacies in your own arguments and watch for them in the arguments of others.

Slippery Slope: This is a conclusion based on the premise that if A happens, then eventually through a series of small steps, through B, C,..., X, Y, Z will happen, too, basically equating A and Z. So, if we don't want Z to occur, A must not be allowed to occur either. Example:

If we ban Hummers because they are bad for the environment eventually the government will ban all cars, so we should not ban Hummers.

In this example, the author is equating banning Hummers with banning all cars, which is not the same thing.

Hasty Generalization: This is a conclusion based on insufficient or biased evidence. In other words, you are rushing to a conclusion before you have all the relevant facts. Example:

Even though it's only the first day, I can tell this is going to be a boring course.

In this example, the author is basing his evaluation of the entire course on only the first day, which is notoriously boring and full of housekeeping tasks for most courses. To make a fair and reasonable evaluation the author must attend not one but several classes, and possibly even examine the textbook, talk to the professor, or talk to others who have previously finished the course in order to have sufficient evidence to base a conclusion on.

Post hoc ergo propter hoc: This is a conclusion that assumes that if 'A' occurred after 'B' then 'B' must have caused 'A.' Example:

I drank bottled water and now I am sick, so the water must have made me sick.

In this example, the author assumes that if one event chronologically follows another the first event must have caused the second. But the illness could have been caused by the burrito the night before, a flu bug that had been working on the body for days, or a chemical spill across campus. There is no reason, without more evidence, to assume the water caused the person to be sick.

Genetic Fallacy: This conclusion is based on an argument that the origins of a person, idea, institute, or theory determine its character, nature, or worth. Example:

The Volkswagen Beetle is an evil car because it was originally designed by Hitler's army.

In this example the author is equating the character of a car with the character of the people who built the car. However, the two are not inherently related.

Begging the Claim: The conclusion that the writer should prove is validated within the claim. Example:

Filthy and polluting coal should be banned.

Arguing that coal pollutes the earth and thus should be banned would be logical. But the very conclusion that should be proved, that coal causes enough pollution to warrant banning its use, is already assumed in the claim by referring to it as "filthy and polluting."

Circular Argument: This restates the argument rather than actually proving it. Example:

George Bush is a good communicator because he speaks effectively.

In this example, the conclusion that Bush is a "good communicator" and the evidence used to prove it "he speaks effectively" are basically the same idea. Specific evidence such as using everyday language, breaking down complex problems, or illustrating his points with humorous stories would be needed to prove either half of the sentence.

Either/or: This is a conclusion that oversimplifies the argument by reducing it to only two sides or choices. Example:

We can either stop using cars or destroy the earth.

In this example, the two choices are presented as the only options, yet the author ignores a range of choices in between such as developing cleaner technology, car-sharing systems for necessities and emergencies, or better community planning to discourage daily driving.

Ad hominem: This is an attack on the character of a person rather than his or her opinions or arguments. Example:

Green Peace's strategies aren't effective because they are all dirty, lazy hippies.

In this example, the author doesn't even name particular strategies Green Peace has suggested, much less evaluate those strategies on their merits. Instead, the author attacks the characters of the individuals in the group.

Ad populum/Bandwagon Appeal: This is an appeal that presents what most people, or a group of people think, in order to persuade one to think the same way. Getting on the bandwagon is one such instance of an ad populum appeal.  

Example:

If you were a true American you would support the rights of people to choose whatever vehicle they want.

In this example, the author equates being a "true American," a concept that people want to be associated with, particularly in a time of war, with allowing people to buy any vehicle they want even though there is no inherent connection between the two.

Red Herring: This is a diversionary tactic that avoids the key issues, often by avoiding opposing arguments rather than addressing them. Example:

The level of mercury in seafood may be unsafe, but what will fishers do to support their families?

In this example, the author switches the discussion away from the safety of the food and talks instead about an economic issue, the livelihood of those catching fish. While one issue may effect the other it does not mean we should ignore possible safety issues because of possible economic consequences to a few individuals.

Straw Man: This move oversimplifies an opponent's viewpoint and then attacks that hollow argument.

People who don't support the proposed state minimum wage increase hate the poor.

In this example, the author attributes the worst possible motive to an opponent's position. In reality, however, the opposition probably has more complex and sympathetic arguments to support their point. By not addressing those arguments, the author is not treating the opposition with respect or refuting their position.

Moral Equivalence: This fallacy compares minor misdeeds with major atrocities, suggesting that both are equally immoral.

That parking attendant who gave me a ticket is as bad as Hitler.

In this example, the author is comparing the relatively harmless actions of a person doing their job with the horrific actions of Hitler. This comparison is unfair and inaccurate.

Momentum, a convenient sporting myth

Suresh Menon in The Hindu

So Australia has the “momentum” going into the final Test match in Dharamsala.

At least, their skipper Steve Smith thinks so. Had Virat Kohli said that India have the momentum, he would have been right too. The reason is quite simple. “Momentum” does not exist, so you can pour into the word any meaning you want. Sportsmen do it all the time. It is as uplifting as the thought: “I am due a big score” or “the rivals are due a defeat”. Sport does not work that way, but there is consolation in thinking that it does.

“Momentum” is one of our most comforting sporting myths, the favourite of television pundits and newspaper columnists as well as team coaches everywhere. It reaffirms what we love to believe about sport: that winning is a habit, set to continue if unchecked; that confidence is everything, and players carry it from one victory to the next; and above all, that randomness, which is a more fundamental explanation, is anathema. It is at once the loser’s solace and the winner’s excuse. Few streaks transcend random processes. Of course streaks occur — that is the nature of sport. But that is no guide to future  performance.

Momentum, momentum, who’s got the momentum? is a popular sport-within-a-sport. It is a concept that borders on the verge of meaning, and sounds better than “I have a feeling about this.”

A study in the 1980s by Thomas Gilovich and Amos Tversky raised the question of “hot hands” or streaks in the NBA. They studied the Philadelphia 76ers and found no evidence of momentum. Immediate past success had no bearing on future attempts, just as a coin might fall heads or tails regardless of what the previous toss might have been.
That and later studies — including the probability of the winner of the fourth set winning the fifth too in tennis — confirmed what a coin-tossing logician might have suspected: that momentum, like the unicorn, does not exist.

Statistics and mythology are strange bedfellows, wrote the late Stephen Jay Gould, evolutionary biologist and baseball fan. One can lead to the other over the course of an entire series or even through a single over in cricket.

Gould has also explained the attraction of patterns, and how we are hard-wired to see patterns in randomness. In many cases, patterns can be discerned in retrospect anyway, but only in retrospect. “Momentum” is usually recognised after the event, and seems to be borne of convenience rather than logic.

The momentum in the current series was with India before the matches began. Then they lost the first Test in Pune, and the momentum swung to Australia for the Bengaluru Test which then India won, grabbing the momentum again.

The third Test was drawn, so the momentum is either with Australia for plucking a draw from the jaws of defeat or with India for pushing Australia to the edge. Such simplistic analyses have kept pundits in business and given “momentum” a respectability and false importance in competitive sport. There is something romantic too in the idea, and many find that irresistible.

Momentum is such a vital component of sport that it has assumed the contours of a tangible object. Fans can reach out and touch it. Teams have it, they carry it, they ride it, they take great comfort from it and work hard to ensure that the opposition does not steal it from them. They carry it from venue to venue like they might their bats and boots and helmets.

To be fair to Steve Smith, what he actually said was “If there’s anything called momentum, it’s with us at the moment,” giving us a glimpse into a measured skepticism. If it exists, then we have it.

Does Peter Handscomb have momentum on his side, after a match-saving half-century in Ranchi? By the same token, does Ravindra Jadeja, after a half-century and nine wickets in the same match? Is team momentum the sum total of all the individual momentums? Will Ravi Ashwin, in that case, begin the final Test with a negative momentum having been less than at his best on the final day in Ranchi? How long before someone decides that momentum is temporary, but skill is permanent?

It is convenient to believe that either one team or the other has the momentum going into the final Test. Yet it is equally possible that those who swing the match with their performance might be players who haven’t been a great success in the series so far.

Someone like fast bowler Pat Cummins, or Virat Kohli himself. A whole grocery list of attributes then becomes more important than momentum: motivation, attitude, desperation, and imponderables that cannot be easily packaged and labeled.

Whichever team wins, momentum will have nothing to do with it. But that will not stop the next captain from telling us that the momentum is with his side. It might seem like blasphemy to disagree with him, so deeply is the concept grouted into our sporting consciousness.

Lucky Dip

by Girish Menon

Shiv is in a bind

Got no more options

Throws the ball to the leggie

Abdul save me from my plight

What should I do skip?

Flight or darts?

The game will be lost

In a jiff or in time

Do what you please

Take a risk if you wish

Take the field that you want

Save me from my fate

I will be deposed

My record exposed

Personally divorced

Abdul, take the risk

You don't have to worry

It is my flutter

Just get me a winner

Abdul flights the ball

Six runs to win

Twelve balls to play

Three wickets left

The ball slips from his grip

Dips and hits a divot on the pitch

Shoots along the mud

Hits the batter on his foot

The ump raises his finger

The crowd is happy

The experts begin to rave

At the great bowling change

I still have some hope

My record intact

My family safe

The match is won soon after

The experts sing my praise

The cup is saved

I will remain captain again

  

Many wins follow

Folks call me the greatest

Skipper and tactician

That ever played

But if it was not for Abdul

And the divot on the pitch

Daily I’d be walking to Tesco

To buy a lucky dip.

Cricket and Causes - It's not about selection or tactics, silly

Understanding causes is incredibly difficult. It is much easier to assume that easily discernible surface issues are the primary explanations for victory and defeat

Ed Smith

May 1, 2013

	Mike Atherton copped criticism during Australia's dominance in the 1990s: "It is not easy to be bold, consistent or whatever else is deemed topical, when you are losing matches" Paul McGregor / © ESPNcricinfo Ltd  Enlarge
Related Links Ed Smith : What can colonoscopies teach us about cricket? Players/Officials: Mike Atherton | Michael Clarke Teams: Australia | England

If you want to understand sport, you have to understand causes. More accurately, you have to understand how difficult it is to be sure about which causes really influence events, and which are merely irrelevant side issues.

Coaching is about understanding causes: what causes players to perform better? Journalism is about causes: which factors led one team to beat the other? Fans, too, reflect obsessively about causes: what might make the difference for us next season? Sport, like history, is about causes.

And yet understanding causes is incredibly difficult. Causal threads must be observed and disentangled, then weighed and judged. It is much easier simply to assume that easily discernible surface issues - such as selection and short-term tactics - are the primary explanations for why teams win and lose.

That is why the books that have most influenced my thinking about sport address the question of causes rather than sport itself. If I had to name one book that anyone with a serious interest in sport should read, it would be Nassim Taleb's Fooled by Randomness. It scarcely mentions sport, and Taleb actively dislikes organised games. But Fooled by Randomness explores the dangers of sloppy assumptions about causality. It attacks lazy guesses about one thing "leading" to another. It makes the reader re-examine his own flawed reasoning.

Taleb recalls watching the financial markets on Bloomberg TV in December 2003. When Saddam Hussein was captured, the price of US treasury bills went up. The caption on TV explained that this price movement was "due to the capture of Saddam Hussein". Half an hour later, the price of US treasury bills went down. The TV caption explained that this was "due to the capture of Saddam Hussein".

The same "cause" had been invoked to "explain" two opposite effects, which is, obviously, logically impossible.

The next time you absorb sports punditry, keep in mind that story about Bloomberg TV and the price of Treasury bills. You will learn that a golfer misses a crucial putt "because he lost concentration", and then misses the next putt because he was "trying too hard". You will learn that a team loses one match "because they didn't stick to the game plan", then loses the next "because they were unable to think on their feet".

A manager messes up one match "because he was too loyal to his favourite players", then fails in the next "because he unnecessarily alienated the core of the team". And, my favourite: there is always the player who "benefits from utter single-mindedness" one week, and then "suffers from a damaging lack of perspective" the next.

The point, of course, is that causes are being manipulated to fit outcomes. They weren't causes at all, merely things that happened before the defeat. The ancient Romans had an ironic phrase for this terrible logic - post hoc, ergo propter hoc, "after this, therefore because of this".

It is hard to imagine a stronger contender for adopting false causes than the failure of English cricket teams to win the Ashes between 1987 and 2005. This dismal sequence was, apparently, "caused" by the following factors: structure of county cricket, unshaven stubbles worn by some England captains, sticking with a failing core of senior players for too long, introducing too many new players, being insufficiently hard-working and professional, being insufficiently joyful and amateur, having too many counties, being too English, not being English enough. And so on.

Pretty much anything that existed within English cricket, at some point or other, was used to explain England's lack of success in the Ashes. An English cricketer in the 1990s only had to brush his teeth to be told that they didn't do it like that in Australia.

Above all, English cricket failed because it was not like Australian cricket. If only England teams would copy Australian teams by (in no particular order): swearing/caring/sledging/bonding/singing/ drinking/attacking/being mates/taking risks/backing themselves/fronting up/digging in/manning up/playing for the badge/never saying die… if England teams simply did all that, then, frankly, playing Shane Warne's flipper and Glenn McGrath's metronomic seam-up would be a doddle.

	When your best is not quite good enough, the two levers under your control - selection and tactics - begin to look very inadequate. In other words, they are not really "causes" of defeat at all. They are simply things that happened along the way

Imagine the logical gymnastics required when England started winning Ashes series again. All the previous causes of defeat had now to be converted into explanations for victory. If England's Ashes success continues, it can only be a matter of time until we have the ultimate "Bloomberg moment", when an article is written arguing that Australia routinely loses the Ashes because they have too few state sides and must urgently copy England's first-class structure of 18 counties.

True, some things within English cricket have changed in reality as well as perception: players are now centrally contracted to the England team, for example, rather than to their counties. But not as much has changed as is often claimed. Revolution - "chumps to champs" - is a snappier narrative than gradual evolution.

But the real fun lies elsewhere. It has now become fashionable to scour Australian cricket looking for "causes" of their decline. A few years ago, the personality of Michael Clarke became the focal point for critics of the culture within Australian cricket. When Clarke came good, it was time to look elsewhere for "causes" of muted Australian performances. Ex-players attacked selection as confused, even insulting. Australia, they argued, had to pick more young players, and yet had to pick more players with hard-earned experience; they had to stick with a consistent team while also, inevitably, abandoning obvious mistakes. Sound familiar?

Mike Atherton, the former England captain who received his fair share of criticism during the era of Australian dominance, remarked wryly this week: "It is not quite so easy to be bold, to be consistent or whatever else is deemed topical, when you are losing matches."

The two central variables in sport, the main levers controlled by the management, are selection and tactics. Imagine, for a moment, that you are in charge of the lesser of two teams. You pick what you think is your best XI. And you lose, despite the team playing at or near its potential. If you stick with the same team, are you not merely sleepwalking towards another defeat? And yet if you change it, what has led you to change your mind about the team that you thought was the best XI last week and which, after all, did not really under-perform? Difficult one, isn't it, picking a team that is less good than the opposition?

Now tactics. Imagine you devise what you consider to be your optimal tactical approach. You execute the plan reasonably well. And you lose. Do you change tactics, with the same logic that led you to change the team, or stick with the old tactics that led to defeat?

Very simply, when your best is not quite good enough, the two levers under your control - selection and tactics - begin to look very inadequate. In other words, they are not really "causes" of defeat at all. They are simply things that happened along the way.

It is the same with national economics. Governments and central banks control the familiar levers of interest rates, money supply and taxation. They are endlessly criticised for their handling of all three. But what if the actual economy, the thing itself, is simply not very robust? A rabbit cannot always be conjured magically from a hat.

I would not have explored all this if I wasn't surprised at how often it is forgotten or overlooked in the analysis of sport at every level, from the pub to the board room, and from the commentary box to the armchair. We have long accepted that understanding historical causes is profoundly subtle and intellectually demanding. Exactly the same applies to understanding causes in sport.