It may have happened to you while reading comments on a blog, watching a political commercial, or listening to a talking head on a chat show. A mental alarm goes off signaling that what you're reading, watching, or listening to is utter claptrap and twaddle.
For me, the BS alert sounded when I ran across these random observations in the "Vox Populi" column of the local newspaper:
- Learning how to swim does not guarantee you won't drown. I'm 55 years old, have never learned to swim and I haven't drowned.
- We need to pass a law that stupid people are not allowed to own pets.
- I'm aggravated with spaghetti sauce with vegetables. I love vegetables, but I don't want them in my spaghetti sauce. Where's our freedom going?
- The English language is the only language that should be spoken in the open and none other. This is the United States of America.
- Obama shouldn't go to Martha's Vineyard. Every time he does, something major happens.
In case you need a little refresher, here are 12 of the most common logical fallacies. For examples and detailed discussions, click on the highlighted terms.
- Ad Hominem
A personal attack: that is, an argument based on the perceived failings of an adversary rather than on the merits of the case.
- Ad Misericordiam
An argument that involves an irrelevant or highly exaggerated appeal to pity or sympathy.
An argument based on the assumption that the opinion of the majority is always valid: everyone believes it, so you should too.
- Begging the Question
A fallacy in which the premise of an argument presupposes the truth of its conclusion; in other words, the argument takes for granted what it's supposed to prove. Also known as a circular argument.
- Dicto Simpliciter
An argument in which a general rule is treated as universally true regardless of the circumstances: a sweeping generalization.
- False Dilemma
A fallacy of oversimplification: an argument in which only two alternatives are provided when in fact additional options are available. Sometimes called the either-or fallacy.
- Name Calling
A fallacy that relies on emotionally loaded terms to influence an audience.
- Non Sequitur
An argument in which a conclusion does not follow logically from what preceded it.
- Post Hoc
A fallacy in which one event is said to be the cause of a later event simply because it occurred earlier.
- Red Herring
An observation that draws attention away from the central issue in an argument or discussion.
- Stacking the Deck
A fallacy in which any evidence that supports an opposing argument is simply rejected, omitted, or ignored.
- Straw Man
A fallacy in which an opponent's argument is overstated or misrepresented in order to be more easily attacked or refuted.
For examples of these fallacies (and many others), follow the links at Logical Fallacies.