The first thing which kindles ardour in learning is the greatness of the teacher. What is greater than the Mother of God? What more glorious than she whom Glory Itself chose? What more chaste than she who bore a body without contact with another body? For why should I speak of her other virtues? She was a virgin not only in body but also in mind, who stained the sincerity of its disposition by no guile, who was humble in heart, grave in speech, prudent in mind, sparing of words, studious in reading, resting her hope not on uncertain riches, but on the prayer of the poor, intent on work, modest in discourse; accustom to seek not man but God as the judge of her thoughts, to injure no one, to have goodwill towards all, to rise up before her elders, not to envy her equals, to avoid boastfulness, to follow reason, to love virtue.
When did she pain her parents even by a look? When did she disagree with her neighbours? When did she despise the lowly? When did she avoid the needy? Being accustom only to go to such gatherings of men as mercy would not blush at nor modesty pass by, there was nothing gloomy in her eyes, nothing forward in her words, nothing unseemly in her acts, there was not a silly movement, nor unrestrained step, nor was her voice petulant, that the very appearance of her outward being might be the image of her soul, the representation of what is approved. For a well-ordered house ought to be recognized on the very threshold, and should show at the very first entrance that no darkness is hidden within, as our soul hindered by no restraints of the body may shine abroad like a lamp placed within.
Source: Excerpt from St. Ambrose, De Virginibus; Book II, chapter 2