In the third book he goes through a summary of the address given by Pope Liberius, when Marcellina received the veil at his hands, before a large congregation. Some cautions are introduced by St. Ambrose against excessive austerity, and instead of some outward acts, prayer and the practice of interior virtues are recommended. The subject of certain virgins who had committed suicide rather than lose their chastity is dwelt upon in answer to a question of Marcellina.