Our five senses are dulled by inordinate pleasure. Penance makes them keen, gives them back their vitality, and more. Penance clears the eye of conscience and reason. It helps us to think clearly, judge sanely. It strengthens the action of our will. And penance also tones us the quality of emotion; it is the lack of self-denial and self-discipline that explains the mediocrity of so much devotional art, so much pious writing, so much sentimental prayer, so many religious lives.