Recently, when I inadvertently ended up reading a little dust-up between a couple of science fiction writers — boy, science fiction writers do like to argue, don’t they? — I went searching for a list of all the common logical fallacies and stumbled upon this (click to go to the site for a larger image):
It’s from yourlogicalfallacyis.com, which offers a great primer on the most common logical pitfalls that befall people when they argue. Most people can’t help but use one or two — strawmen and appeal to authority, probably being the most common — but some folks manage to cover at least a dozen. In fact, I’d say one of the immutable truths of arguing on the Internet is that the longer it goes on, the more of these fallacies will eventually be covered.