In the 1970’s, the psychic Uri Geller was a fixture on the TV chat shows. He was famous for bending spoons with nothing more, he said, than the power of his mind. But when Geller appeared on “The Tonight Show” in 1973, things didn’t go so well. Carson spoiled Geller’s act by consulting with a magician named The Amazing Randi. After that, Randi became Geller’s lifelong nemesis, and one of the world’s most famous skeptics. Now, a new documentary about Randi tells the story of how he unmasked multiple deceivers, from mentalists to televangelists. It’s called “An Honest Liar.” We speak to the subject himself.