Logical Fallacies are errors--sometimes inadvertent, sometimes deliberate, that skew the logic of an argument. You might know of a few (e.g., ad hominem: attacking an opponent's character instead of his argument, or post hoc, prompter hoc: confusing correlation with causation), but these resources will introduce you to a litany of fallacies to help you avoid them in your own writing and identify them in others' arguments.
- Your Logical Fallacy is... in a nicely designed format, this site defines 24 common logical fallacies. Hover over the buttons for a quick definition, or click on them for a more thorough explanation and some examples. Includes a printable poster listing all 24.
- Fallacies (part of the Nizkor Project) is a comprehensive guide to 42 logical fallacies.