This collection of daily Lenten meditations examines conscience and sin, defining conscience as the inner faculty applying God's law and detailing its operation before, during, and after actions. It classifies types of conscience (direct, false, scrupulous, relaxed, doubtful), analyzes the nature, sources, and gravity of sin including original and actual sin, and considers conditions that mitigate or aggravate guilt. The text treats free will, the roots and effects of the deadly vices, and the sacrifice of Christ, concluding with practical moral guidance and rules of conduct aimed at promoting spiritual progress during Lent.