Saint Bernard enumerates several progressive manifestations of pride, a ladder we climb down to perdition, "curiosity, levity of mind, foolish and misplaced joy, boasting, singularity, arrogance, presumption, the refusal to recognize one's errors, the dissimulation of one's sins in confession, rebellion, unbridled liberty, the habit of sin even to the contempt of God." He then explains how to overcome these vices in order to achieve virtue, salvation and eternal happiness. St. Alphonsus writes: "a single bad book will be sufficient to cause the destruction of a monastery." Pope Pius XII wrote...