A Collection of Strange Beliefs, Amusing Deceptions, and Dangerous Delusions

Topical Indexes

Other Writings

Other Resources

From Abracadabra to Zombies - 765 entries | View All

The Skeptic's Dictionary features definitions, arguments, and essays on hundreds of strange beliefs, amusing deceptions, and dangerous delusions. It also features dozens of entries on logical fallacies, cognitive biases, perception, science, and philosophy.


Sample the Skeptic's Dictionary

detoxification therapies

A detoxification therapy claims to remove toxic substances from the body. Toxic substances may be natural or synthetic, and occur in a wide variety of strengths. Plants, for example, produce toxins that ward off or kill pests. Synthetic insecticides also kill pests. Most foods have toxins occurring in small amounts that are not likely to be harmful to most people. Many toxic substances occur naturally in foods, e.g., arsenic, but in doses so small as not to be worthy of concern. (There is no way to know that a particular dose of a toxic substance could never harm anyone.) Some toxins, like botulinum or the venom of an inland taipan or box jellyfish, are deadly. Botulinum toxin, produced by the bacterium Clostridium botulinum, is the most dangerous toxin to humans. Oddly,botulinum toxin can also heal, demonstrating an important point: not all dangerous toxins are always dangerous to your health.The dose makes the poison.>>more

sample Mysteries and Science (for kids 9 and up)


In a nutshell: A zombie is a mythical creature who is one of the walking dead. Zombies are not friendly and they don't like civilization.

zombie is a character in stories and movies who is shown as a dead person brought back to life—though not to a full and independent life—by witchcraft or sorcery. In some stories, zombies are monsters who like to eat human flesh. Zombies are usually shown as sleepwalking slaves of whoever brings them back to life. Zombies like to destroy things. They don't like civilization. If you ever meet a zombie on the road—which you won't unless one jumps off a movie screen!—and she says "Hi. I'm a zombie and I'm here to help," don't believe her.>>more

a blast from the past

A Short History of Psi Research

"The concrete evidence for most of the 'psychic' phenomena under discussion is good enough to hang a man 20 times over." --William James

"Many brilliant men have investigated the paranormal but they have yet to find a single person who can, without trickery, send or receive even a three-letter word under test conditions." --Milbourne Christopher

Interest in the scientific study of psychical phenomena—as they were called in the 19th century—began with a movement known as spiritism or spiritualism in upstate New York in 1848 with the Fox Sisters: Kate, Margaretta, and Leah. Kate (age 12) and Margaretta (15) claimed to hear strange rapping noises in their bedroom. They convinced a few folks that they were getting messages from spirits. Soon they hit the road, managed by big sister Leah, who was in her mid-30s. They went on tour performing séances, which became the rage in both the U.S. and Europe.>>more

Upcoming Skeptical Events

See Lanyrd.com


twitterfollow SD on Twitter

Books by R. T. Carroll

cover The Critical Thinker's Dictionary

The Skeptic's Dictionary


Print versions available in Dutch, Russian, Japanese, and Korean.

Unnatural Virtue podcast archive

Skepticality logo
Click here to listen to Skepticality


Caring for Carcinoid Foundation

This page was designed by Cristian Popa.