Logical Fallacies

Inductive vs. Deductive Reasoning

Induction Reasoning from the specific to the general (starts with a specific observation/evidence then works toward a claim) Example: If x is true for John and John is a man, then x is probably true for all men.

Deduction Reasoning from the general to the specific (starts with a claim and works toward specific observations/evidence) Example: If x is true for men and John is a man, then x is true for John.

Logical Fallacy Faulty or erroneous reasoning (using either induction or deduction incorrectly). Basically, in a logical fallacy, the premises do not adequately support the claim.

Ad Hominem Latin for “to the man” – attacks the person and not the issue Example: Bill Clinton was not a good president because he had an affair with Monica Lewinsky.

Appeal to Emotions Manipulates people's emotions in order to get their attention away from an important issue Example: Public Schools, K through 12, need to have much easier exams for students because teachers don't fully realize the extent of the emotional repercussions of sorrow and depression for the many students who could score much better on easier exams.

Bandwagon Creates the impression that everybody is doing it and so should you Example: The Avengers is the number 1 movie in America. You should go see The Avengers.

False Dilemma (either/or) Limits the possible choices to avoid consideration of another choice Example: Either you use your dirty towel or our clean, disposable ones.

Appeal to Authority or Celebrity Holds that because an authority/celebrity says its true it must be true Example: Marilyn Monroe endorsing Lustre Crème Shampoo

Scare Tactic Creates fear in people as evidence to support a claim Example: This is your brain. These are drugs. This is your brain on drugs.

False Cause Wrongly assumes a cause and effect relationship Example: Utah passed a strict gun-control law, and crime there decreased. Therefore, gun-control laws decrease crime.

Hasty Generalization AKA jumping to conclusions — draws a conclusion about a population based on a small sample Example: Enron was a large, corrupt company; therefore, all large companies are corrupt.

Red Herring Presents an irrelevant topic to divert attention away from the original issue Example: “We can’t worry about the environment; we’re in the middle of a war!”

Appeal to Tradition Uses the logic that the way things used to be is better than they are now, ignoring any problems of the past Example: Our product must be good for you because it’s ancient.

Slippery Slope Argues that one decision will ultimately lead to disaster Example: “Don’t sell your hair to a wig shop.”

Begging the Question argues in circles/uses the claim to justify the warrant Example: Active euthanasia is morally acceptable. It is a decent, ethical thing to help another human being escape suffering through death.

Non Sequitur Latin for “it doesn’t follow” – argues points that have no connection to each other Example: “Never give up…keep on shopping.”