After warning his fellow-men "the way I pass ne'er yet was run," Dante goes on to relate what Beatrice teaches him in regard to the heavenly spheres and spiritual evolution, and how she promises to reveal to him "the truth thou lovest." _Canto III._ In the pearl-hued atmosphere of the moon, Dante beholds, "as through a glass, darkly," shadowy, nun-like forms, and is told by Beatrice to communicate with them.

Addressing the form nearest him, Dante learns she is Piccarda (sister of Forese), who was kidnapped by her husband after she had taken the veil.

Although she would fain have kept her religious vows, Piccarda proved a faithful wife, and declares she and her fellow-spirits are content to remain in their appointed sphere until called higher by the Almighty.
"She with those other spirits gently smiled; Then answer'd with such gladness, that she seem'd With love's first flame to glow: 'Brother! our will Is, in composure, settled by the power Of charity, who makes us will alone What we possess, and nought beyond desire.'" All her companions also wished to be brides of Christ, but patiently did their duty, and, knowing that "in His will is our tranquillity," they now spend all their time singing "Ave Maria." When these nun-like forms vanish, Dante gazes at Beatrice in hopes of learning more.
_Canto IV._ In reply to Dante's inquiring glance, Beatrice explains that those compelled to sin against their desire are ever held blameless in Heaven.

Then, stating: "Not seldom, brother, it hath, chanced for men To do what they had gladly left undone;" she adds that "the will that wills not, still survives unquenched," and that by will power only St.Lawrence and Mucius Scevola were enabled to brave fire.

Then she makes him see how truth alone can satisfy a mind athirst for knowledge.
_Canto V._ Beatrice asserts that the most precious gift bestowed upon mankind was freedom of will, and that "knowledge comes of learning well retain'd." She concludes that when man makes a vow he offers his will in sacrifice to God, and that for that reason no vow should be thoughtlessly made, but all should be rigidly kept.