"The subtle experimenter lost his subtlety when he shifted from doing science to proselytizing for God. Rigor slipped to Chautauqua logic and he perpetrated such howlers as the notion that Heisenberg's uncertainty principle somehow extends beyond the dimensions of the atom into the human world and confirms free will. Bohr heard Compton's Free Will lecture when he visited the United States in the early 1930s and scoffed. "Bohr spoke highly of Compton as a physicist and a man," a friend of the Danish laureate remembers, "but he felt that Compton's philosophy was too primitive: 'Compton would like to say that for God there is no uncertainty principle. That is nonsense. In physics we do not talk about God but about what we can know. If we are to speak of God we must do so in an entirely different manner."