Prudence was getting ready for the Big Dance when her two aunts, whom she had never met, arrived from out of town. “Growing up with them made me crazy,” her mother once told her. “One lies with every breath she takes. And the other is, as they say, brutally honest.”
            “If I ask you about my dress, will you tell me the truth?” Prudence asked.
            “Oomf,” said Flora, whose mouth was full of cake.
            “What did she say?” Prudence asked her sister.
            “She said she would, of course. But you know her. Lies, lies, lies,” said Dora, smiling.
            Who’s a poor girl to believe?

         Flora obviously answered “yes.” If she always tells the truth, she would answer yes. If she always lies, she would also lie in this case and say yes. So when Dora says her sister said yes, she was telling the truth. Dora must also have been telling the truth when she called her sister a liar. Trust Dora.
            On the other hand, did Prudence really want to hear the truth?