The so-called "F tima prayer"--O my Jesus, forgive us our sins, save us from the fires of hell, and lead all souls to heaven, especially those in most need of thy mercy, amen--due primarily to its widespread use as a rosary decade prayer, surely ranks among the Church's most popular prayers. Despite its brevity, it is a prayer of remarkable theological depth--not to mention, daring. In the space of just twenty-nine words, it broaches some of the great...