Harry Houdini (March 24, 1874 - October 31, 1926), born Erik Weisz, later spelled Ehrich Weiss, was a noted debunker of spiritualists, mediums, and psychics. He is best known as an escape artist, particularly the "water torture" trick where he would escape from inside a locked tank of water while suspended upside down.
Houdini started a tradition which has been honored by many later stage magicians and illusionists, most notably James Randi and Derren Brown. His debunking activities, where he exposed what he called "humbug" were a direct inspiration for Penn and Teller when they devised Bullshit! - although he likely didn't inspire their excessive libertarianism.