from CityJournal:
Throughout his professional life, Houdini had no illusions about his talent. He always assured onlookers that no matter how miraculous his tricks appeared to be, they were actually earthbound, consisting of muscular contortions, lock-picking skills, inventive gimmicks, and misdirection. He did his best to expose charlatans who claimed that their magic came from occult sources. One of his colorful posters is succinct:DO SPIRITS RETURN? HOUDINI SAYS NO—AND PROVES IT.