This is a lesson about the nature of evil and its origins. It begins by outlining the state of "original justice" enjoyed by Adam and Eve before their sin. The lesson then analyzes the fall of the angels, their rejection of God, and the subsequent sin of Adam and Eve. It explores the consequences of this sin, including the loss of supernatural grace, the introduction of suffering and death into the world, and the inclination towards sin known as concupiscence. Finally, the lesson examines the concept of redemption through Jesus Christ.