FAQ: Logical fallacies and how to beat them

Tony Koutsoumbos
The Argument Clinic
6 min readOct 23, 2015

Question #1: What are logical fallacies?

Fundamental flaws in the logic used to reach a specific conclusion. It is important to distinguish them from factual inaccuracies, as your facts and figures can be spot on, but still lead to a false conclusion if there is a flaw in your logic.

Here is a glossary of the most common logical fallacies — it should be noted, there are hundreds more — grouped into categories to reflect where they often crop up.

They can’t be wrong…

  1. Appeal to numbers: because a majority of people think it’s the right think to do, we should do it.
  2. Appeal to nature: if God had wanted us to fly, He would have given us wings, which is why we shouldn’t mess with nature.
  3. Appeal to tradition: this is the way we’ve always done it, so it must still be the right way today.

It’s no coincidence…

  1. Fallacy of simultaneous events: two things happened at the same time, so they must have a common cause.
  2. Fallacy of consecutive events: two things happened one after the other, so the second must have been caused by the first.

Something must be done…

  1. Circular arguments: The conclusion you are trying to prove is proof of the evidence you are using to prove it — e.g: “help me, I’m limping. Why are you limping? Because I have a sprained ankle. How do you know you have a sprained ankle? Because I’m limping.”
  2. Jumping the gun (aka non-sequitur): Jumping to a conclusion without stopping to consider what your evidence really proves — e.g: Two police officers have been killed in the last week, therefore we should arm all police officers.
  3. Slippery slope: Predicting extreme consequences from a single decision without explaining how you even reached that conclusion — e.g: see below.
  4. Appeal to emotion: Using an emotional response as a justification for action, the problem being that once the emotion wears off (like when the disturbing images you saw on TV disappear), so does the rationale for taking action even if nothing has changed. Although that’s by far the only problem with acting on an appeal to emotion — what if that emotion is rooted in prejudice or acting on it makes things even worse?

Trust me…

  1. Appeal to authority: I’m right because an expert agrees with me — works like a charm until you run into another expert who doesn’t agree with you. Also, even experts can be wrong or have ulterior motives, which is why we need to see their evidence too.
  2. Attack on the person: The opposite of appeal to authority, where an argument is written off because of a judgement made about the speaker’s character, whether they can prove they’re right or not — e.g: see below.
  3. Straw man (aka the scarecrow): The simple act of deliberately twisting someone’s words to make their argument easier to beat. Can you guess why it’s called the Straw Man?

Question #2: Are logical fallacies ever deliberately used as a tactic to beat an opponent in a debate and if so, how can they be countered?

Countering them is simply a matter of explaining why they are fallacies and how they could easily be proven false if taken to their logical conclusion. A great book to read that is dedicated purely to this subject is ‘How to Win Every Argumentby Madsen Pirie, the President of the Adam Smith Institute.

If you want to see an example of a logical fallacy in action, you need only pick up virtually any newspaper or watch any of the following TV discussion programmes: Question Time, Sunday Morning Live, Loose Women, The Wright Stuff, or my all time favourite — Prime Minister’s Question Time. Here are a couple of the fallacies you are most likely to hear.

Fallacy: Attack on the person
Many people will remember the Daily Mail’s scandalous attack on former Labour leader, Ed Miliband’s, late father, Ralph, in 2013 in an article titled: ‘The Man who Hated Britain.’ The purpose of the article, as exemplified by its ending, was to convince readers that Ed would make a bad Prime Minister because of his father’s political views.

Counter:
If your argument is that Ed Miliband would make a bad PM because his father held views you consider to be extreme, then tell me — if his father was a decorated war hero with a knighthood, would you automatically assume he would be a good PM? Furthermore, if a parent’s opinions are the most important indicator of their children’s future performance, is it safe to assume that because my father liked popular music, I am destined to become a talented musician?”

Fallacy: the slippery slope

The result is confusion. Marriage is abolished, redefined and recreated, being different and unequal for different categories. The idea of marriage as a covenant is diminished. The family in its normal sense, predating the state and as our base community of society, as we have already heard, is weakened.”

Counter:
If I understand your argument correctly, you are saying that if the law is changed to allow two people of the same sex to marry each other, then no one will understand what it means to be married any more and people who choose to start families will be deterred from doing so or suffer a reduced quality of life — even though you can’t tell me why. Since this fortunately didn’t happen the last time it was predicted as an objection to mixed race marriage, could you talk me through the process of how you expect it to happen this time?”

Question #3: Is an incomplete argument the same thing as a logical fallacy?

Yes it is. A fallacy just means that something has gone wrong with the process of linking your evidence to your conclusion. One of the many things that can go wrong is simply that the process is incomplete. The jumping the gun and slippery slope fallacies are prime examples of this. In reality, the main problem with virtually every fallacy is that something is missing that could have made the statement true if it had been included. This is why it is important to highlight that each time a logical fallacy is exposed, it doesn’t mean the person making the argument is wrong. There could well be extreme consequences of a single decision, two consecutive events could well have a direct link, but so far they have failed to prove it.

Question #4: How do you keep calm under pressure, during a debate, so you can think clearly about the arguments you are trying to analyse?

In short, by giving yourself as little to think about as possible and knowing what to look for when analysing an argument. I can only speak from personal experience here, but my nerves only get the better of me when I feel like I don’t know what I’m meant to do or I’m grasping at straws under tight time constraints. As a result, I feel most uncomfortable during fluid social situations, such as a networking event, because I don’t have a captive audience, or a case to make, and I have no allotted time to speak.

The first step to becoming comfortable analysing arguments during a debate is to watch them on television, or read opinion pieces in the press, and have a list of the logical fallacies listed above in front of you. Over time, you will learn to spot them without even thinking about it and you will also learn under what circumstances different fallacies are most likely to occur. The easier this becomes for you, the more natural it will feel, and the more natural it feels, the more calm you will be when it counts.

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Tony Koutsoumbos
The Argument Clinic

Tony is the founder of the Great Debaters Club, a social enterprise that teaches adults how to debate.