The state of Virginity is undoubtedly commended in holy Scripture, both by our Lord and St. Paul, but learned men have differed in their opinions as to the original customs and rules observed by virgins in the earliest ages. Some suppose that from the very beginning it was the custom for them to make a solemn profession of the virgin life, and to live together in common. Others consider that their vows were private, and they lived sometimes together, sometimes in the homes of their parents. Others, again, believing that there was no more than a simple purpose on the part of the virgins signified by the veil, and the simplicity of their dress, attribute the first commencements of community life to St. Ambrose himself.
It would appear, then, that from the days of the apostles there were some who devoted themselves to God in a life of chastity, and that later on the promise or vow was made in the presence of others the bishop, clergy, and friends. These virgins lived at home with their parents, while the times of persecution endured, making it practically impossible for them to live elsewhere. Common life among them would seem to have commenced in the East, and St. Athanasius, when, seeking refuge from the Arians, he came to Rome, introduced the custom to the Western Church.
St. Ambrose worked vigorously in this direction, not only in his own diocese, but in neighbouring provinces, and even in Africa. Early in his episcopate he addressed his flock on the subject, and at the request of his sister, Marcellina, gathered up his teaching in the following three books.
In the first book he treats of the dignity of Virginity, and states his reason for writing. As he commences his addresses on the anniversary of the martyrdom of St. Agnes, he takes her story as the subject of the earlier part of the treatise, and shows how, among the Jews, and even among the heathen, the grace of virginity was shadowed forth, and eventually proclaimed by the corning of our Lord. He then warns parents, especially widows, not to prevent their daughters from hearing addresses on this subject, and touches on the number of those who came even from great distances to receive the veil at Milan.
In the second book, speaking of the character and manner of life of virgins, he does this, as he says, by adducing examples and instances, preferably to laying down a code of rules. He speaks of Thecla, patron saint of Milan, a disciple of St. Paul, and of other virgins.
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.