About fallacy.is

fallacy.is is a reference for logical fallacies, cognitive biases, and rhetorical devices. Each entry has a short URL so a single link can replace a long explanation in a discussion.

How to use it

When a discussion runs into one of these patterns, link to the entry instead of writing a paragraph:

  • fallacy.is/straw-man
  • fallacy.is/whataboutism
  • fallacy.is/ad-hominem

Most entries also accept short aliases. fallacy.is/ah and fallacy.is/adhom both redirect to ad hominem, for example.

Who the page is written for

Most often, the person who clicks a fallacy.is link is the person whose argument was just flagged, or a bystander reading along. Entries are written with that reader in mind. The point isn't to confirm that someone "lost the thread" — it's to help anyone reading see why an argument with this shape struggles, and what a stronger version would look like.

If you've been linked here, the entries are educational, not accusatory. Read the "How to fix it" section. It's the most useful part of the page.

What belongs here

The site isn't limited to textbook fallacies. It covers the broader family of reasoning errors and persuasion techniques worth naming: classical fallacies, cognitive biases, rhetorical devices, and debate tactics. Pedants can quibble about the taxonomy. Arguments in the wild don't.

Editorial stance

Definitions are neutral. Examples can have bite. The site doesn't take sides — calling something a fallacy is a point about structure, not about who said it.

Contributing

Corrections and suggestions are welcome. If an entry is wrong or an example misfires, say so.