Before he started the judge said he didn't have to do it and Stevens replied, it's a privilege and the duty.

NPR: Sen. Stevens Will Be Back On The Witness Stand

"I believe that a pope should have a term limit or be given the privilege to resign from office, if he can't do his various duties effectively anymore due to health reasons or old age, " he said.

CNN: February 12, 2013 -- Updated 2035 GMT (0435 HKT)