Fallacies

A logical fallacy is an argument form that is logically weak yet often disproportionately persuasive.

Fallacies List

Fallacies of Distraction
- Red Herring (Non-Sequitur, Irrelevant Reason, Irrelevant Conclusion, Whataboutism)
  - Bringing up irrelevant consideration or changing the subject. Example:
    - “A criminal can fall on a steak knife and sue the person whose house they broke into. That’s why the justice system should be eye-for-an-eye.”
    - “I understand that you in the media want to know how I’ll respond to the allegations of corruption. But the important thing to focus on right now is the economy.”
- Improper Appeal to Emotion
  - Persuading by evoking emotion that is inappropriate for the situation, out of proportion, or irrelevant to the conclusion
    - Pity: “How can you give me a bad grade on the test? My mom is in a coma.”
    - Fear: “There’s an invasion of illegal aliens poisoning the blood of our country!”
Fallacies of Illicit Presumption
- Begging the Question (Circular Reasoning)
  - Assuming that which needs to be proven
  - The conclusion is already assumed in the premises or is a premise reworded
  - Rely on A to prove B & vice versa
  - Assuming the truth of a crucial premise that is in dispute & needs a subargument
  - To prove one thing, appeal to something at least as hard to prove
  - Argument relies on already believing conclusion or dismissing objection
  - Example: “Capital punishment is just because murderers should be put to death.”
- Equivocation (Fallacy of Ambiguity)
  - The meaning of a word shifts over the course of an argument
  - Example: “Logic teaches you how to make arguments. Getting in arguments with your spouse can lead to divorce. So if you want a happy marriage, stay away from logic.”
Fallacies of Weak Induction
- Hasty Generalization (Anecdotal Evidence)
  - Making an inference from a sample that is too small or unrepresentative
  - Example: “My girlfriend cheated on me. Therefore, girls are evil.”
- Faulty Analogy (False Analogy, Weak Analogy, Questionable Analogy)
  - Analogical argument where analogues not really similar in ways relevant to conclusion
  - Example: “Prince was short just like Kevin Hart, so he must have been funny too.”
Genetic Fallacies
- Improper Appeal to Authority
  - Argument from authority other than consensus of relevant experts in descriptive domain
  - Example: “That has to be true because Simon says so.”
- Appeal to Popularity (Ad Populum, Bandwagon Fallacy, Fallacy of Numbers)
  - A claim is purported to be true because many people (non-experts) believe it.
  - Example: “Most people agree on this, so it must be true.”
Genetic Fallacies 2
- Appeal to Tradition
  - A claim is purported to be true because it is part of a certain tradition.
  - Examples:
    - “We know we can believe this because it has long been a teaching of the Church.”
    - “It’s the American way.”
- Naturalistic Fallacy (Is-Ought Fallacy, Appeal to Nature)
  - Argument with normative conclusion but all descriptive premises, including claiming that something is good/bad because it’s natural/unnatural
  - Examples:
    - “People have many different views on morality. Therefore, all their views are equally right.”
    - “Cloning is unnatural. Therefore, it’s immoral.”
    - “This vitamin is all-natural, so it must be good for you.”
Genetic Ad Hominem Fallacies
- Ad Hominem (Against the Person, Abusive Fallacy, Personal Attack)
  - Aiming to discredit someone’s argument based on an irrelevant personal attack
  - Example: “Your argument is weak because you’re ugly!”
- Circumstantial Fallacy (Circumstantial Ad Hominem, Guilt by Association)
  - Dismissing someone’s argument based on their circumstances or identity
  - Example: “Of course you would argue for low taxes as a rich person – you just want to keep hoarding money.”
Causal Fallacies
- Post Hoc (Post hoc, ergo propter hoc: “After this, therefore because of this”)
  - Concluding that A causes B just because A is followed by B.
  - Example: “My friend got vaccinated and then died 2 years later. The vaccine must have killed him.”
- Cum Hoc (“With this, therefore b/c of this”; Correlation Implies Causation Fallacy)
  - Concluding that A causes B just because A and B are correlated.
  - Example: “People with gray hair are more likely to need hearing aids. Therefore, gray hair causes hearing loss.”
Fallacies of Exaggeration
- Slippery Slope Fallacy
  - Claiming that something will cause chain reaction without good reason for believing this
  - Example: “If we get rid of affirmative action, then before you know it we’ll be going back to segregation, and eventually we’ll have slavery again.”
- False Dilemma (False Dichotomy, Black-or-White, Either-Or, Excluded Middle)
  - Claiming there are some limited # of alternatives (usually 2) when there are really more
  - Example: “If you’re not with us, then you’re against us.”
Formal (Deductive) Fallacies
- Affirming the Consequent (Mixed up Modus Ponens)
  - If p, then q. q. Therefore p.
  - Example: “If you are in State College, then you are in PA. You are in PA. Therefore, you are in State College.”
- Denying the Antecedent (Mixed up Modus Tollens)
  - If p, then q. Not p. Therefore, not q.
  - Example: “If you are in State College, then you are in PA. You’re not in State College. Therefore, you’re not in PA.”
Dialectical Fallacies
- Appeal to Ignorance (Ad Ignorantium; Arg. from Absence of Evidence, Shifting the Burden of Proof)
  - Claiming that something is true merely because of lack of evidence that it’s false
  - Examples:
    - “You can’t prove unicorns don’t exist. Therefore, they must exist.”
    - “It’s a mystery that we can never know for sure. So we’ll just assume my view is right.”
- Strawman Fallacy (Straw Person)
  - Misrepresenting someone’s argument in order to refute it more easily
  - Example:
    - Initial Argument: “Pancakes are good to get for breakfast because they’re tasty and cheap.”
    - Response: “So you’re saying you hate waffles?”