" The intimate relation between obligation and likelihood is nicely illustrated by an anecdote from the Soviet era. The story goes that during his state visit to Moscow,27 Fidel Castro is shown around the capital by Leonid Brezhnev. First of all, Castro is invited for a beer, which he downs in one go, and praises heartily. ‘Yes,’ says Brezhnev, ‘it was provided by our good friends from Czechoslovakia.’ Then Castro is chauffeured around the city, and is rather taken by the limo. ‘Yes,’ says Brezhnev, ‘these cars are provided by our good friends from Czechoslovakia.’ Later on, they visit an exhibition of fine crystal, and Castro duly waxes lyrical. ‘Yes,’ says Brezhnev, ‘the crystal is provided by our good friends from Czechoslovakia.’ ‘They must be very good friends,’ says Castro. ‘Yes,’ says Brezhnev, ‘they must. "

― Guy Deutscher , The Unfolding of Language: An Evolutionary Tour of Mankind's Greatest Invention