Dante enters the Earthly Paradise — the Garden of Eden, recovered. The forest is dense and alive, its canopy so perfect it filters the air to a green-gold warmth. It is unlike any earthly forest: no storm comes here, no weather disturbs it; the leaves and branches move only from within, stirred by a sweet, mild breeze that follows its own constant law. Dante is enchanted — this is the primeval forest, the original home, the world as it was before the Fall. His slow, rapt walk through it is one of the most sensually beautiful passages in the poem.
He comes to a stream — small, dark as shadow — that he cannot cross. On the other bank, a woman gathers flowers and sings; she turns to look at him. She is Matelda (whose exact historical identity is debated — perhaps the Countess Matilda of Tuscany). She smiles at him — the smile of a woman in love; Dante compares her to Persephone before Hades stole her from the meadow of flowers. He asks why she is here and why the stream exists.
Matelda explains: the Garden is moved by a celestial wind that blows from the Primum Mobile, which does not reach below but circulates in the forest at the summit. The seeds it carries fall to earth and produce the botanical diversity of the world below. The stream has two branches: Lethe, which erases the memory of sin, and Eunoe, which restores the memory of every good deed done. To drink Lethe is to lose the burden of guilt; to drink Eunoe is to be restored in one's best self. She says that perhaps the ancient poets who wrote of the Golden Age and of Parnassus and the Elysian fields had a dim, distorted memory of this very place — Paradise as the archetype behind every myth of a happy land.