Penn Jillette is an American magician, comedian, and author, and is half of "Penn and Teller." Jillette began his career as a juggler, graduating from Ringling Brothers and Barnum & Bailey Clown College, and in 1981 he teamed up with his friend Teller for a famous off-Broadway show. Since 2003, Penn and Teller have hosted the popular television show "Penn & Teller: Bullshit!" in which they debunk popular misconceptions or pseudo-scientific beliefs. Jillette is an outspoken advocate of atheism and libertarianism, and is the author of the novel "Sock."