An inmate in the mental institution was writing himself a letter. When the patient was asked by the psychiatrist what he was doing, he calmly replied, “Writing a letter.” The psychiatrist was pleased and asked the patient, “To whom are you writing?” Again the patient calmly replied. “To myself, of course!” The doctor then inquired, “What are you writing about?” To that, the patient replied, “I don’t know; I haven’t received the letter yet.”
This dilemma is termed a Double Bond in Zen Buddhism. No matter what question the doctor asks, he gets into deeper difficulties and he traps himself.