Deliver Us From Fallacious Arguments

Thou Shalt Not Commit Logical Fallacies

Philosophy is not a discipline familiar to many orthodontists, so it comes as no surprise to find fallacious logic infecting most of our professional discussions. A fallacy is simply reasoning that has been judged as logically incorrect, and leads to an argument being recognized as unsound.

In the desire to persuade colleagues, the usage of fallacies as rhetorical tools is exceedingly common since sound reasoning is often abandoned in favor generating consensus. While the effective use of a particular fallacy by an individual can sometimes be considered clever, that person’s reasoning must at the same time be recognized as unsound, and thus their claim, propped up by a flimsy argument, should be deemed as unfounded and generally dismissed.

If we value the truth that emerges from the competition of ideas in free and transparent discourse, we must sharpen our critical faculties to be able to recognize faulty logic when it arises. 

Below is a short list of logical fallacies I see frequently used in orthodontic discussions along with their definitions and some common examples:

Red Herring Fallacies

A red herring fallacy is an error in logic whereby an irrelevant argument is made to deliberately divert attention away from the subject of an argument with the aim of redirecting to another issue to which the person doing the redirecting can better respond.

• Ad hominem – Attacking the person making the argument, rather than the argument itself, when the attack on the person is completely irrelevant to the argument the person is making.
  • Abusive – a subtype of ad hominem that verbally abuses the opponent rather than arguing about the originally proposed argument
    Example: General insulting language rather than constructive debate
  • Circumstantial – Suggesting that the person who is making the argument is biased or predisposed to take a particular stance, and therefore, the argument is necessarily invalid
    Example: Claiming that KOLs are inherently biased so their claims are less valid
  • Guilt By Association – when the source is viewed negatively because of its association with another person or group who is already viewed negatively.
    Example: Assuming all people trained in particular treatment philosophy are bad
  • Tu Quoque (“you too”) – the argument states that a certain position is false or wrong or should be disregarded because its proponent fails to act consistently in accordance with that position
  • Tone Policing – an attempt to detract from the validity of a statement by attacking the tone or manner in which it was presented rather than the message itself.
    Example: I find that offensive!
    -> Claiming offense is not making a point, it simply tells the audience that you are ruled by your emotions and don’t know how to correctly reason.
  • Ad Fidentia – Attacking the person’s confidence in their claim rather than the argument or the evidence.
    Example: Are you sure?
• Appeal to Authority – where an claim is sheltered from criticism because of the position or authority of the person asserting it.
  Example: Blindly accepting assertions of prominent orthodontics or academics
  -> Never be afraid to challenge authority
• Appeal to Accomplishment – where an assertion is deemed true or false based on the accomplishments or claimed accomplishments of the proposer
  Example: When an assertions are prefaced by boasts like “I have been doing _____ for X number of years…”
  -> No one cares, get to your point.
• Appeal to Emotion (fear, flattery, pity, ridicule, spite, wishful thinking) – where an argument is made due to the manipulation of emotions, rather than the use of valid reasoning.
  Example: Robots are going to take your job live in fear
• Appeal to Novelty – where a proposal is claimed to be superior or better solely because it is new or modern
  Example: This new 3D printer/resin is more accurate than previous generations
• Appeal to Tradition – a conclusion supported solely because it has long been held to be true and is common practice
  Example: Rapid expansion produces a better orthopedic effect
  -> Dogma is useless
• Appeal to Common Belief – when the claim that most or many people in general or of a particular group accept a belief as true is presented as evidence for the claim.
  Example: Everyone knows braces are better than Invisalign
• Straw Man Fallacy – Substituting a person’s actual position or argument with a distorted, exaggerated, or misrepresented version of the position of the argument.
• Subjectivist Fallacy – Claiming something is true for one person, but not for someone else when, in fact, it is true for everyone as demonstrated by empirical evidence.
  Example: My patients won’t wear their aligners. 
• Selective Attention – Focusing attention on certain aspects of the argument while completely ignoring or missing other parts that are difficult to prove.
• Appeal to Self-Evident Truth – A claim that a proposition is self-evidently true, so needs no further supporting evidence.
  Example: It’s obvious that _____
  -> If self-evidence is actually the basis for the claim, it is arbitrary and the opposite is equally true.

Informal Fallacies

Arguments that are fallacious because the argument’s stated premises fail to adequately support its conclusions.

• Argument from Ignorance – Assuming a fact based primarily on lack of evidence to the contrary. Usually best described as “the absence of evidence is not evidence of absence.”
  Example: It remains to be seen if “plastic” can do the same things as braces.
• Argument from Hearsay – using anecdotal evidence, which is generally considered as weak evidence, to support a claim
  Example: In my experience non-extraction cases are less stable
• Argument from Moderation – assuming that the compromise between two positions is always correct.
  Example: Extreme moderation
  -> Striking a position straight down the middle on all issues is less than worthless. Growth comes from competition not compromise.
• Cherry Picking – When only select evidence is presented in order to persuade the audience to accept a position, and evidence that would go against the position is withheld.  The stronger the withheld evidence, the more fallacious the argument.
  Example: This one study proves my point. We do not need to look at further studies.
  -> Evidenced based practice is about the repeatability of conclusions and common threads across the body of literature not just one study.
• Circular Reasoning – when the reasoner begins with what he or she is trying to end up with; sometimes called assuming the conclusion
  Example: We finished with a broad smile because these braces are known for broadening the smile
• Identity Fallacy – When one’s argument is evaluated based on their physical or social identity, i.e., their social class, generation, ethnic group, gender or sexual orientation, profession, occupation or subgroup when the strength of the argument is independent of identity.
  Example: Unless you have been practicing a lot time you can’t say that something is stable.
  -> This is simply a refusal to hear evidence
• Shifting the Burden of Proof – I need not prove my claim, you must prove my claim as false
  Example: Prove me wrong.
  -> People cannot be called upon to prove a negative. The onus is always on the person making the claim.
• Anonymous Authority – When an unspecified source is used as evidence for the claim.
  Example: Phrases such as “It has been said…”, “I heard that…”, “Studies show…”
  -> If you fail to specify a source of the authority, we can’t verify the source or the credibility of the argument. This usually indicates that they are making up facts.
• False Authority – using an expert of dubious credentials or using only one opinion to sell a product or idea
  Example: Someone fraudulently representing their business acumen, despite a failed business, as authority to make a claim
• Hasty Generalization – Drawing a conclusion based on a small sample size, rather than looking at statistics that are much more in line with the typical or average situation.
  Example: My 10 cases using this custom attachment prove that you should use this instead of the optimized attachment that is based on thousands of specifically data-mined cases.
• Moralistic Fallacy – When the conclusion expresses what is, based only on what one believes ought to be, or what isn’t is based on what one believes ought not to be.
  Example: People ought not be able to order at-home aligners through the mail. 
  -> Just because you believe something ought to be true doesn’t mean that it is.
• If-By-Whiskey –A response to a question that is contingent on the questioner’s opinions and makes use of words with strong connotations.  This fallacy appears to support both sides of an issue — a tactic common in politics.
  Example: If by Invisalign treatment you mean getting a patient to be perfectly compliant with their aligners, of course you’ll get a result. But, if by Invisalign you mean submitting an unreviewed ClinCheck direct from the technician, you definitely shouldn’t short change your patients with an inferior treatment.
• Moving the Goalposts – argument in which evidence presented in response to a specific claim is dismissed and some other (often greater) evidence is demanded
• Special Pleading –Applying standards, principles, and/or rules to other people or circumstances, while making oneself or certain circumstances exempt from the same critical criteria, without providing adequate justification.
• Unfalsifiability/Untestability – Confidently asserting that a theory or hypothesis is true or false even though the theory or hypothesis cannot possibly be contradicted by an observation or the outcome of any physical experiment.
  -> Making claims that cannot be disproven is how you leave the realm of rational discourse. There needs to be a way to test the claim.