Follow-up question of the century

In reaction to Scott McClellan's book, where he claimed that five White House officials -- including the president and vice president -- were responsible for McClellan passing incorrect information on the CIA leak case, Dana Perino said:

President Bush" has not and would not knowingly pass false information."

"Ok. Dana, if I may follow up on that: Did Dubya tell you to say that?"

Nah. That won't work. Infinite regress and it's turtles all the way down.

There were two tribes; one whose members always told the truth, one whose members always lied. There's one member of each tribe in front of you. You may ask one of them one question. What do you ask?...