Logical Fallacy
1. The Straw Man Fallacy
This fallacy occurs when your opponent over-simplifies or misrepresents your argument (i.e., setting up a "straw man") to make it easier to attack or refute. Instead of fully addressing your actual argument, speakers relying on this fallacy present a superficially similar — but ultimately not equal — version of your real stance, helping them create the illusion of easily defeating you.
Example:
John: I think we should hire someone to redesign our website.
Lola: You're saying we should throw our money away on external resources instead of building up our in-house design team? That's going to hurt our company in the long run.
2. The Bandwagon Fallacy
Just because a significant population of people believe a proposition is true, doesn't automatically make it true. Popularity alone is not enough to validate an argument, though it's often used as a standalone justification of validity. Arguments in this style don't take into account whether or not the population validating the argument is actually qualified to do so, or if contrary evidence exists. While most of us expect to see bandwagon arguments in advertising (e.g., "three out of four people think X brand toothpaste cleans teeth best"), this fallacy can easily sneak its way into everyday meetings and conversations.
Example:
The majority of people believe advertisers should spend more money on billboards, so billboards are objectively the best form of advertisement.
3. The Appeal to Authority Fallacy
While appeals to authority are by no means always fallacious, they can quickly become dangerous when you rely too heavily on the opinion of a single person — especially if that person is attempting to validate something outside of their expertise. Getting an authority figure to back your proposition can be a powerful addition to an existing argument, but it can't be the pillar your entire argument rests on. Just because someone in a position of power believes something to be true, doesn't make it true.
Example:
Despite the fact that our Q4 numbers are much lower than usual, we should push forward using the same strategy because our CEO Barbara says this is the best approach.
4. The False Dilemma Fallacy
This common fallacy misleads by presenting complex issues in terms of two inherently opposed sides. Instead of acknowledging that most (if not all) issues can be thought of on a spectrum of possibilities and stances, the false dilemma fallacy asserts that there are only two mutually exclusive outcomes. This fallacy is particularly problematic because it can lend false credence to extreme stances, ignoring opportunities for compromise or chances to re-frame the issue in a new way.
Example:
We can either agree with Barbara's plan, or just let the project fail. There is no other option.
5. The Hasty Generalization Fallacy
This fallacy occurs when someone draws expansive conclusions based on inadequate or insufficient evidence. In other words, they jump to conclusions about the validity of a proposition with some, but not enough evidence to back it up, and overlook potential counterarguments.
Example:
Two members of my team have become more engaged employees after taking public speaking classes. That proves we should have mandatory public speaking classes for the whole company to improve employee engagement.
6. The Ad Hominem Fallacy
An ad hominem fallacy occurs when you attack someone personally rather than using logic to refute their argument. Instead they’ll attack physical appearance, personal traits, or other irrelevant characteristics to criticize the other’s point of view. These attacks can also be leveled at institutions or groups.
Example:
Barbara: We should review these data sets again just to be sure they’re accurate.
Tim: I figured you would suggest that since you’re a bit slow when it comes to math.
7. The Circular Reasoning Fallacy
The circular reasoning fallacy is an argument that assumes the very thing it is trying to prove is true. Instead of offering evidence, it simply repeats the conclusion, rendering the argument logically incoherent. People may commit circular reasoning fallacy unintentionally because they are convinced of their own assumptions and take them as given. Sometimes, circular reasoning is used deliberately to mask the speaker’s lack of understanding or evidence.
Example:
Parent: “It’s time to go to bed.”
Child: “Why?”
Parent: “Because this is your bedtime.”
8. The Appeal to Ignorance Fallacy
This fallacy occurs when you argue that your conclusion must be true, because there is no evidence against it. This fallacy wrongly shifts the burden of proof away from the one making the claim.
Example:
“Since you haven't been able to prove your innocence, I must assume you're guilty.”
9. The Slippery Slope Fallacy
A slippery slope fallacy occurs when someone claims that a position or decision will lead to a series of unintended negative consequences. These negative consequences are often bad and/or increasingly outlandish. The person using the slippery slope fallacy takes these consequences as a certainty and does not analyze the logic of their own position. A slippery slope fallacy can be used as a deflection to avoid discussing the merits of a position, shifting the field of debate.
Example:
"If students are required to wear uniforms to school, they'll do less shopping at local clothing stores. With less business, the stores will close, which will hurt our local economy."
10. The Red Herring Fallacy
This fallacy consists in diverting attention from the real issue by focusing instead on an issue having only a surface relevance to the first. A red herring is known as something intended to divert attention from the real problem or matter at hand; a misleading clue.
Example:
Son: "Wow, Dad, it's really hard to make a living on my salary."
Father: "Consider yourself lucky, son. Why, when I was your age, I only made $40 a week."
11. The Selective Evidence Fallacy ‘Cherry picking’
This fallacy occurs when only evidence supporting an argument is selected and presented, while contradictory evidence is ignored. This practice harms credibility and persuasiveness by giving an impression of bias and a lack of consideration for alternative perspectives. The problem can be remedied by including an objective acknowledgement of opposing data and viewpoints.
Example:
Most fast food ads which mention percentages.