The Daily Parker

Politics, Weather, Photography, and the Dog

The man's talking about logic at a time like this

Yes I am.

In this first post of a new series, I'm going to explain in brief the most common logical fallacies that we hear (and sometimes use) all the time.

Fallacies come in a few basic flavors: irrelevance, formality, ambiguity, and materiality. I'll begin with irrelevance, since blogs traditionally start there.

Argumentum ad hominem

An "argument to the person" focuses on the opponent as a person, rather than the opponent's argument. The President excels at these: think about all the nicknames he uses to taunt people he doesn't like.

Other statements he makes about his opponents, like "low-energy" or "a total lightweight," are also arguments to the person. He isn't providing evidence one way or another about the matter in question; he merely provides evidence about his opinions of his opponents, which is irrelevant.

Argumentum ad populum

An "argument to the people" uses a group's opinion as evidence, rather than the opinions of qualified people. When the President says "everybody agrees" or "nobody knew" something, he doesn't provide evidence that anyone can use; he only provides evidence that, in his opinion, an undefined group of people believe something.

Advertisers do this all the time. Think of "4 out of 5 dentists agree" (who are the dentists? were more than 5 polled?) or "biggest box-office for its opening weekend" (many people bought tickets, but did they like the movie?).

Parents may hear this one, too: "Aw, mom! Peter gets to stay up until ten, so why can't I?" (The child provides evidence only that her sibling can stay up until 10, not that her doing the same would benefit either her or her parents.)

That's it for today. I'll post two or three of these daily until I run out. (There are quite a few.)

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