Vatican City » Pope John Paul II whipped himself with a belt, even on vacation, and slept on the floor as acts of penitence and to bring him closer to Christian perfection, according to a new book by the Polish prelate spearheading his sainthood case.

The book Why He's a Saint also includes previously unpublished speeches and documents written by John Paul, including a 1989 signed memo in which he said he would resign if he became incapacitated. The book also reported for the first time that John Paul forgave his would-be assassin on the way to the hospital moments after he was shot on May 13, 1981, in St. Peter's Square. It also reported that he initially thought his attacker was a member of the Italian terrorist organization the Red Brigades.

The book, released Tuesday, was written by Monsignor Slawomir Oder, the main promoter for John Paul's canonization.