Despite the power of his physical presence - or perhaps, because of it - Peter Morrone preferred writing to oratory. This is not surprising. The man, after all, was a hermit, and although the word didn't exist back then, it's safe to say that the monk with the body of an athlete and the heart of a rebel was an introvert. When he had something to say, more often than not, he wrote a letter.
-Jon M. Sweeney, The Pope Who Quit: A True Medieval Tale of Mystery, Death, and Salvation
Editor's Note: Timing is everything. Sweeney's book on the tale of Pope Celestine V, who resigned the papacy in 1294, was published in 2012. On the last day of February of 2013, Pope Benedict XVI became only the second Pope in history to voluntarily resign. All you history mavens will remember that Pope Gregory XII resigned for political reasons in 1415 to end the Western Schism.