Logical Fallacies

Logical fallacies are errors in reasoning. If you become familiar with them, you can identify logical fallacies in others' arguments. You can also avoid using logical fallacies in your own writing . . . or if you're very clever, use them to your advantage to convince others of something.

Post hoc fallacy: Just because Event A happened before Event B, you assume that Event A caused Event B.

Non sequitur fallacy: This is an even more illogical connection of cause/effect, in which Event A clearly has nothing to do with Event B. The evidence offered does not support the conclusion that is reached.

Ad hominem argument:You attack the person instead of the person's argument or point of view on a subject.

Appeal to questionable or faulty authority: citing an authority who may not have expertise on the subject or using phrasing like "Sources close to . . . " or "Experts claim. . . ."

Begging the question: Asking the reader to assume that something is true without proving it first--especially flawed if that "something" is controversial.

False analogy: You assume that because two things share some characteristics, they are alike in all respects.

Either/Or Fallacy: You assume that taking a certain viewpoint or course of action will result in one of two diametrically opposed outcomes (no other outcomes possible).

Red herring argument: You intentionally digress from the real issue being discussed, introducing a side issue that has nothing to do with the real issue under discussion--in an attempt to remove attention from the real issue.

Sweeping or hasty generalization: You've reached a conclusion based on only a little evidence that might be relevant but is not typical.

Card stacking: If someone says, "The cards were stacked against me," the speaker is saying he/she was never given a fair chance. This is a complicated one--one side may distort evidence or facts presented, suppress evidence, oversimplify or even suppress facts, etc.

There are many, many different types of logical fallacies. These are just a few.


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